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Radiation and Medical Oncology Perspectives on Oligometastatic Disease Treatment
Radiation and Medical Oncology Perspectives on Oligometastatic Disease Treatment
The treatment of metastatic solid tumors has been based historically on systemic therapies, with the goal of delaying progression and extend life as long as possible, with tolerable treatment-related adverse events. Some exceptions were made for local treatment with surgery or radiotherapy (RT), often for patients with a single metastasis. A 1939 report describes a patient with renal adenocarcinoma and a solitary lung metastasis who underwent RT to the lung lesion after nephrectomy and subsequently partial lobectomy after the metastatic lesion progressed. The authors argued that if a metastasis appears solitary and accessible, it is plausible to remove it in addition to the primary growth.1
In 1995 Hellman and Weichselbaum proposed oligometastatic disease (OMD). They reasoned that malignancy exists along a spectrum from localized disease to widely disseminated disease, with OMD existing in between with a still-restricted tumor metastatic capacity. Appropriately selected patients with OMD may be candidates for prolonged disease-free survival or cure with the addition of local therapy to systemic therapy.2
The EORTC 4004 phase 2 randomized control trial (RCT) analyzed radiofrequency ablation (RFA) for colorectal liver metastases with systemic therapy vs systemic therapy alone for patients with ≤ 9 liver lesions.3 Systemic therapyconsisted of 5-FU/leucovorin/oxaliplatin, with bevacizumab added to the regimen 3.5 years into the study, per updated standard- of-care. This trial was the first to demonstrate the benefit of aggressive local treatment vs system treatment alone for OMD with a progression-free survival (PFS) benefit (16.8 vs 9.9 months; hazard ratio [HR], 0.63; P = .03) and overall survival (OS) benefit (45.3 vs 40.5 months; HR, 0.74; P = .02) with the addition of local treatment with RFA.
Since the presentations of the SABR-COMET phase 2 RCT and another study by Gomez et al at the American Society for Radiation Oncology (ASTRO) 2018 annual meeting, the paradigm for offering local RT for OMD has rapidly evolved. Both studies found PFS and OS benefits of RT for patients with OMD.4,5 Additional RCTs have since demonstrated that for properly selected patients with OMD, aggressive local RT improved PFS and OS.6-9 These small studies have led to larger RCTs to better understand who benefits from local consolidative treatment, particularly RT.10,11
There is a large degree of heterogeneity in how oncologists define and approach OMD treatment. The 2020 European Society for Radiotherapy and Oncology (ESTRO) and ASTRO consensus guidelines defined the OMD state as 1 to 5 metastatic lesions for which all metastatic sites are safely treatable.12 The purpose of this study was to evaluate perceptions and practice patterns among radiation oncologists and medical oncologists regarding the use of local RT for OMD across the Veterans Health Administration (VHA).
Methods
A 12-question survey was developed by the VHA Palliative Radiotherapy Task Force using the ESTRO-ASTRO consensus guidelines to define OMD. The survey was emailed to the VHA radiation oncology and medical oncology listservs on August 1, 2023. These listservs consist of physicians in these specialties either directly employed by the VHA or serve in its facilities as contractors. The original response closure date was August 11, 2023, but it was extended to August 18, 2023, to increase responses. No incentives were offered to respondents. Two email reminders were sent to the medical oncology listserv and 3 to the radiation oncology listserv. Descriptive statistics and X2 tests were used for data analysis. The impact of specialty and presence of an on-site department of radiation oncology were reviewed. This project was approved by the VHA National Oncology Program and National Radiation Oncology Program.
Results
The survey was sent to 125 radiation oncologists and 515 medical oncologists and 106 were completed for a 16.6% response rate. There were 59 (55.7%) radiation oncologist responses and 47 (44.3%) medical oncologist responses. Most (96.2%) respondents were board-certified, and 84 (79.2%) were affiliated with an academic center. Not every respondent answered every question (Table).
All respondents (n = 105) indicated there is a potential benefit of high-dose RT for appropriately selected cases. Ninety-four oncologists (88.7%) believed that RT for OMD contributes to cure (88.1% of radiation oncologists, 89.4% of medical oncologists; P = .84) for appropriately selected cases. Some respondents who did not believe RT for OMD contributes to cure added comments about other perceived benefits, such as local disease control for palliation, delaying systemic therapy with its associated toxicities, and prolongation of disease-free survival or OS. A higher percentage of respondents with academic affiliations believed high-dose RT contributes to cure, although this difference did not reach statistical significance (Figure 1).
Fifty-five respondents (51.9%; 55.2% radiation oncologists vs 50.0% medical oncologists; P = .60) responded that local RT for OMD treatment should not be limited by primary tumor type. Of respondents who responded that OMD treatment should be limited based on the type of primary tumor, many provided comments that argued there was a benefit for non-small cell lung cancer (NSCLC), prostate adenocarcinoma (PCa), and colorectal cancer.
The definition of how many metastatic lesions qualify as OMD varied. A total of 48.6% of respondents defined OMD as ≤ 3 lesions and 42.9% answered ≤ 5 lesions. A majority of radiation oncologists (55.2%) classified ≤ 5 lesions as OMD, whereas a majority of medical oncologists (66.0%) considered ≤ 3 lesions as OMD (P = .006) (Figure 2).
Thirty-six medical oncologists (76.6%) report having an on-site department of radiation oncology (Figure 3). This subgroup was more likely to consider local RT potentially curative compared with their medical oncology peers without on-site radiation oncology (94.4% vs 72.7%; P = .04).
Case Management
The 3 clinical cases demonstrated the heterogeneity of management approaches for OMD. The first described a man aged 65 years with PCa and 2 asymptomatic pelvic bone metastases. Ninety-three respondents (90.3%) recommended RT at the primary site and 74.8% recommended RT to both the primary site and metastatic foci. Sixty-three respondents (67.7%) recommended a STAMPEDE-compatible dose, and 30 (32.3%) recommended a definitive dose.
The second clinical case was a 60-year-old man with a cT1N2M1 NSCLC, with a solitary metastatic focus to the left iliac wing. Fifty-eight respondents (54.7%) recommended upfront systemic chemotherapy and the option of local therapy to the chest and metastatic focus after initial chemotherapy; 28 respondents (26.4%) recommended upfront chemoradiation to the chest and definitive radiation to the left iliac wing metastasis.
The third clinical case described a male aged 70 years with a history of a treated base of tongue squamous cell carcinoma, with a solitary metastatic focus within the right lung. Respondents could pick multiple treatment options and 85 (81.7%) favored upfront definitive local therapy with surgery or stereotactic body radiotherapy (SBRT), rather than upfront chemotherapy, with future consideration for local treatment. About half of respondents (51.8%) recommended SBRT and 41.2% would let the patient decide between surgery or SBRT. Additionally, 39.6% included in their patient counselling that the treatment may be for curative intent.
Discussion
The use of local treatment to increased PFS, OS, or even cure treatment for OMD has become more accepted since the 2018 ASTRO meeting.4,5 Palma et al analyzed a controlled primary malignancy of any histology and ≤ 5 metastatic lesions, with all lesions amenable to SBRT.4 With a median follow-up of 51 months when comparing the standard-of-care (SOC) arm and the SBRT arm, the 5-year PFS was not reached and the 5-year OS rates were 17.7% and 42.3% (P = .006), respectively. In the SBRT arm, about 1 in 5 patients survived > 5 years without a recurrence or disease progression, vs 0 patients in the control arm. There was a 29% rate of grade 2 or higher toxicity in the SBRT arm, including 3 deaths that were likely due to treatment. Subsequent trials, such as the phase 3 SABR-COMET-3 (1-3 metastases), phase 3 SABR-COMET-10 (4-10 metastases), and phase 1 ARREST (> 10 metastases) trials, have been specifically designed to minimize treatment-related toxicities.13-15
Gomez et al analyzed patients at 3 sites with a controlled NSCLC primary tumor and ≤ 3 metastases.5 At a follow-up of 38.8 months, the PFS was 4.4 months in the SOC arm vs 14.2 months in the RT and/or surgery local treatment arm (P = .02). There was also an OS benefit of 17.0 vs 41.2 months (P = .02), respectively.
Several RCTs soon followed that demonstrated improved PFS and OS with local radiotherapy for OMD; however, total metastatic ablation of the foci is necessary to attain these PFS and OS benefits.6-9 Still, an oncologic benefit has yet to be proven. The randomized NRGBR002 study phase 2/3 trial for oligometastatic breast cancer included patients with ≤ 4 extracranial metastases and controlled primary disease to metastasis-directed therapy (SBRT and/ or surgical resection) and systemic therapy vs systemic therapy alone.10 The study did not demonstrate improved PFS or OS at 3 years. However, for most breast cancers, especially with the rapid advancements in systemic therapy that have been achieved, longer follow-up may be necessary to detect a significant difference.
The prospective single-arm phase 2 SABR-5 trial retrospectively demonstrated important lessons about the timing of SBRT and systemic therapy.11 This study included patients with ≤ 5 metastases of any histology, and they received SBRT to all lesions. SABR-5 retrospectively compared patients who received upfront systemic therapy followed by SBRT vs another cohort that first received SBRT and did not receive systemic therapy until there was disease progression. Patients with oligo-progression were excluded, as it demonstrated systemic drug resistance. At a median follow-up time of 34 months, delayed systemic treatment was associated with shorter PFS (23 vs 34 months, respectively; P = .001), but not worse 3-year OS (80% vs 85%, respectively; P = .66). In addition, the delayed systemic treatment arm demonstrated a reduced risk of grade 2 or higher SBRT-related toxicity (odds ratio, 0.35; P < .001).
Similarly, the STOMP phase 2 trial analyzed the role of metastasis-directed therapy (MDT) in delaying initiation of androgen deprivation therapy (ADT) in a randomized phase 2 trial.16 This study included patients with asymptomatic PCa with a biochemical recurrence after primary treatment, 1 to 3 extracranial metastatic lesions, and serum testosterone levels > 50 ng/mL. Sixty-two patients were randomized 1:1 to either MDT (SBRT or surgery) of all lesions or surveillance. The 5-year ADT-free survival was 34% for MDT vs 8% for surveillance (P = .06).
VHA Radiation Oncology
The VHA has 138 departments of medical oncology, but only 41 departments of radiation oncology. Compared with medical oncologists without an on-site radiation oncology department, those with on-site departments were more likely to believe that local RT was potentially curative (94.4% vs 72.7%, respectively; P = .04). This finding suggests that a cancer center that includes both specialties has closer collaboration, which results in greater inclination to embrace local RT for OMD, as it has demonstrated PFS and OS benefits.
The radiation and medical oncologists surveyed had statistically significant differences in response by specialty regarding the maximal number of lesions still believed to constitute OMD. Most radiation oncologists classified ≤ 5 lesions as OMD, whereas most medical oncologists classified ≤ 3 lesions as OMD. This difference is not unexpected. There is no universally agreed-upon definition of OMD, and criteria differ across studies.
While the SABR-COMET trial did include ≤ 5 metastatic lesions, it was a phase 2 RCT, making subgroup analysis difficult. Ongoing phase 3 trials that are more specific in the number of metastases, comparing 1 to 3 vs 4 to 10 metastases (SABR-COMET-3 and SABR-COMET-10, respectively).13,14 There is even an ongoing phase 1 trial (ARREST) studying the potential benefits of treating (“restraining”) > 10 metastases, if dosimetrically feasible.15 Within the VHA, VA STARPORT is investigating MDT for recurrent or de novo hormone-sensitive metastatic PCa.17 The ongoing HALT phase 2/3 trial focuses on patients with actionable mutations to help determine management of oligo-progression in mutation-positive NSCLC.18
There was no significant difference by specialty in who responded that offering local RT for OMD treatment should not be limited by histology (55.2% of radiation oncologists and 50.0% of medical oncologists; P = .60). Oncologists could make the argument that some histologies (eg, pancreatic adenocarcinomas) have such poor prognoses that local RT would not meaningfully affect oncologic outcomes, while potentially adding toxicity, whereas others could point to improved systemic therapy regimens and the low toxicity rates with careful hypofractionation regimens. Of note, the 41-patient phase 2 EXTEND trial for pancreatic ductal adenocarcinoma suggested an oncologic benefit to MDT, with far better PFS and no grade ≥ 3 toxicities related to MDT.19 About half of respondents for each specialty believed the primary histology should affect the decision. Further clarification may emerge from phase 3 trials.
Of note, a 2023 study of 44 radiation and medical oncologists at 2 Harvard Medical School-affiliated hospitals found that for synchronous OMD, 50.0% of medical oncologists and 5.3% (P < .01) of radiation oncologists recommended systemic treatment, suggesting a greater divergence in approach than found in this study.20
Limitations
The response rate of 17.0% raised a potential for selection bias, but this rate is expected for a nonincentivized medical survey. A study by the American Board of Internal Medicine with 11 surveys and 6 weekly email contacts only generated a 23.7% response rate, while another study among physicians demonstrated a 4.5% response rate for email-based contact and 11.8% for mail-based contact.21,22 We could have asked participants questions regarding demographics and geography to ensure the survey represented a diverse sample of the medical community, although additional questions would likely suppress the response rate. Additional data collection about respondents may elucidate the rationale for differences in their responses, especially between the specialties. In a planned subsequent survey in several years, the question on the number of lesions that qualifies as OMD may be amended to reflect the context and dosimetry for the maximal number of metastases constituting OMD; the joint ESTRO-ASTRO consensus defined OMD as 1 to 5 metastatic lesions, but in which all metastatic sites must be safely treatable.12 Also, fewer example cases could be included to simplify the survey and boost response rates. A future survey may ask about the timing of SBRT and systemic therapy, and whether SBRT can safely delay systemic therapy.
Conclusions
Survey results demonstrated significant confidence among both radiation oncologists and medical oncologists that local RT for OMD improves outcomes, which is encouraging and a reflection of the recent evidence-based paradigm shift in viewing metastatic disease as a spectrum. However, there is a difference between radiation oncologists and medical oncologists in how they define OMD, and preferred treatment of the sample cases presented revealed nuanced differences by specialty. Close collaboration with radiation oncologists influences the belief of medical oncologists in the beneficial role of RT for OMD. As more phase 3 data for OMD local treatments emerge, additional investigation is needed on how beliefs and practice patterns evolve among radiation and medical oncologists.
- Barney JD, Churchill EJ. Adenocarcinoma of the kidney with metastasis to the lung. J Urology. 1939.
- Hellman S, Weichselbaum RR. Oligometastases. J Clin Oncol. 1995;13(1):8-10. doi:10.1200/JCO.1995.13.1.8
- Ruers T, Punt C, Van Coevorden F, et al. Radiofrequency ablation combined with systemic treatment versus systemic treatment alone in patients with non-resectable colorectal liver metastases: a randomized EORTC Intergroup phase II study (EORTC 4004). Ann Oncol. 2012;23(10):2619-2626. doi:10.1093/annonc/mds053
- Palma DA, Olson R, Harrow S, et al. Stereotactic ablative radiotherapy for the comprehensive treatment of oligometastatic cancers: long-term results of the SABR-COMET phase II randomized trial. J Clin Oncol. 2020;38(25):2830- 2838. doi:10.1200/JCO.20.00818
- Gomez DR, Tang C, Zhang J, et al. Local consolidative therapy vs. maintenance therapy or observation for patients with oligometastatic non-small-cell lung cancer: long-term results of a multi-institutional, phase II, randomized study. J Clin Oncol. 2019;37(18):1558-1565. doi:10.1200/JCO.19.00201
- Iyengar P, Wardak Z, Gerber DE, et al. Consolidative radiotherapy for limited metastatic non-small-cell lung cancer: a phase 2 randomized clinical trial. JAMA Oncol. 2018;4(1):e173501. doi:10.1001/jamaoncol.2017.3501
- Phillips R, Shi WY, Deek M, et al. Outcomes of observation vs stereotactic ablative radiation for oligometastatic prostate cancer: the ORIOLE phase 2 randomized clinical trial. JAMA Oncol. 2020;6(5):650-659. doi:10.1001/jamaoncol.2020.0147
- Wang XS, Bai YF, Verma V, et al. Randomized trial of first-line tyrosine kinase inhibitor with or without radiotherapy for synchronous oligometastatic EGFR-mutated NSCLC. J Natl Cancer Inst 2023;115(6):742-748. doi:10.1093/jnci/djac015
- Tang C, Sherry AD, Haymaker C, et al. Addition of metastasis- directed therapy to intermittent hormone therapy for oligometastatic prostate cancer (EXTEND): a multicenter, randomized phase II trial. Am Soc Radiat Oncol Annu Meet. 2023;9(6):825-834. doi:10.1001/jamaoncol.2023.0161
- Chmura SJ, Winter KA, Woodward WA, et al. NRG-BR002: a phase IIR/III trial of standard of care systemic therapy with or without stereotactic body radiotherapy (SBRT) and/or surgical resection (SR) for newly oligometastatic breast cancer (NCT02364557). J Clin Oncol. 2022;40:1007. doi:10.1200/JCO.2022.40.16_suppl.1007
- Baker S, Lechner L, Liu M, et al. Upfront versus delayed systemic therapy in patients with oligometastatic cancer treated with SABR in the phase 2 SABR-5 trial. Int J Radiat Oncol Biol Phys. 2024;118(5):1497-1506. doi:10.1016/j.ijrobp.2023.11.007
- Lievens Y, Guckenberger M, Gomez D, et al. Defining oligometastatic disease from a radiation oncology perspective: an ESTRO-ASTRO consensus document. Radiother Oncol. 2020;148:157-166. doi:10.1016/j.radonc.2020.04.003
- Olson R, Mathews L, Liu M, et al. Stereotactic ablative radiotherapy for the comprehensive treatment of 1-3 oligometastatic tumors (SABR-COMET-3): study protocol for a randomized phase III trial. BMC Cancer. 2020;20(1):380. doi:10.1186/s12885-020-06876-4
- Palma DA, Olson R, Harrow S, et al. Stereotactic ablative radiotherapy for the comprehensive treatment of 4-10 oligometastatic tumors (SABR-COMET-10): study protocol for a randomized phase III trial. BMC Cancer. 2019;19(1):816. doi:10.1186/s12885-019-5977-6
- Bauman GS, Corkum MT, Fakir H, et al. Ablative radiation therapy to restrain everything safely treatable (ARREST): study protocol for a phase I trial treating polymetastatic cancer with stereotactic radiotherapy. BMC Cancer. 2021;21(1):405. doi:10.1186/s12885-021-08136-5
- Ost P, Reynders D, Decaestecker K, et al. Surveillance or metastasis-directed therapy for oligometastatic prostate cancer recurrence (STOMP): five-year results of a randomized phase II trial. J Clin Oncol. 2020;38:suppl.
- Solanki AA, Campbell D, Carlson K, et al. Veterans Affairs seamless phase II/III randomized trial of standard systemic therapy with or without PET-directed local therapy for oligometastatic prostate cancer (VA STARPORT). J Clin Oncol. 2024;42:16.
- McDonald F, Guckenberger M, Popat S. EP08.03-005 HALT – Targeted therapy with or without dose-intensified radiotherapy in oligo-progressive disease in oncogene addicted lung tumours. J Thor Oncol. 2022;17:S492.
- Ludmir EB, Sherry AD, Fellman BM, et al. Addition of metastasis- directed therapy to systemic therapy for oligometastatic pancreatic ductal adenocarcinoma (EXTEND): a multicenter, randomized phase II trial. J Clin Oncol. 2024;42(32):3795-3805. doi:10.1200/JCO.24.00081
- Cho HL, Balboni T, Christ SB, et al. Is oligometastatic cancer curable? A survey of oncologist perspectives, decision making, and communication. Adv Radiat Oncol. 2023;8(5):101221. doi:10.1016/j.adro.2023.101221
- Barnhart BJ, Reddy SG, Arnold GK. Remind me again: physician response to web surveys: the effect of email reminders across 11 opinion survey efforts at the American Board of Internal Medicine from 2017 to 2019. Eval Health Prof. 2021;44(3):245-259. doi:10.1177/01632787211019445
- Murphy CC, Lee SJC, Geiger AM, et al. A randomized trial of mail and email recruitment strategies for a physician survey on clinical trial accrual. BMC Med Res Methodol. 2020;20(1):123. doi:10.1186/s12874-020-01014-x
The treatment of metastatic solid tumors has been based historically on systemic therapies, with the goal of delaying progression and extend life as long as possible, with tolerable treatment-related adverse events. Some exceptions were made for local treatment with surgery or radiotherapy (RT), often for patients with a single metastasis. A 1939 report describes a patient with renal adenocarcinoma and a solitary lung metastasis who underwent RT to the lung lesion after nephrectomy and subsequently partial lobectomy after the metastatic lesion progressed. The authors argued that if a metastasis appears solitary and accessible, it is plausible to remove it in addition to the primary growth.1
In 1995 Hellman and Weichselbaum proposed oligometastatic disease (OMD). They reasoned that malignancy exists along a spectrum from localized disease to widely disseminated disease, with OMD existing in between with a still-restricted tumor metastatic capacity. Appropriately selected patients with OMD may be candidates for prolonged disease-free survival or cure with the addition of local therapy to systemic therapy.2
The EORTC 4004 phase 2 randomized control trial (RCT) analyzed radiofrequency ablation (RFA) for colorectal liver metastases with systemic therapy vs systemic therapy alone for patients with ≤ 9 liver lesions.3 Systemic therapyconsisted of 5-FU/leucovorin/oxaliplatin, with bevacizumab added to the regimen 3.5 years into the study, per updated standard- of-care. This trial was the first to demonstrate the benefit of aggressive local treatment vs system treatment alone for OMD with a progression-free survival (PFS) benefit (16.8 vs 9.9 months; hazard ratio [HR], 0.63; P = .03) and overall survival (OS) benefit (45.3 vs 40.5 months; HR, 0.74; P = .02) with the addition of local treatment with RFA.
Since the presentations of the SABR-COMET phase 2 RCT and another study by Gomez et al at the American Society for Radiation Oncology (ASTRO) 2018 annual meeting, the paradigm for offering local RT for OMD has rapidly evolved. Both studies found PFS and OS benefits of RT for patients with OMD.4,5 Additional RCTs have since demonstrated that for properly selected patients with OMD, aggressive local RT improved PFS and OS.6-9 These small studies have led to larger RCTs to better understand who benefits from local consolidative treatment, particularly RT.10,11
There is a large degree of heterogeneity in how oncologists define and approach OMD treatment. The 2020 European Society for Radiotherapy and Oncology (ESTRO) and ASTRO consensus guidelines defined the OMD state as 1 to 5 metastatic lesions for which all metastatic sites are safely treatable.12 The purpose of this study was to evaluate perceptions and practice patterns among radiation oncologists and medical oncologists regarding the use of local RT for OMD across the Veterans Health Administration (VHA).
Methods
A 12-question survey was developed by the VHA Palliative Radiotherapy Task Force using the ESTRO-ASTRO consensus guidelines to define OMD. The survey was emailed to the VHA radiation oncology and medical oncology listservs on August 1, 2023. These listservs consist of physicians in these specialties either directly employed by the VHA or serve in its facilities as contractors. The original response closure date was August 11, 2023, but it was extended to August 18, 2023, to increase responses. No incentives were offered to respondents. Two email reminders were sent to the medical oncology listserv and 3 to the radiation oncology listserv. Descriptive statistics and X2 tests were used for data analysis. The impact of specialty and presence of an on-site department of radiation oncology were reviewed. This project was approved by the VHA National Oncology Program and National Radiation Oncology Program.
Results
The survey was sent to 125 radiation oncologists and 515 medical oncologists and 106 were completed for a 16.6% response rate. There were 59 (55.7%) radiation oncologist responses and 47 (44.3%) medical oncologist responses. Most (96.2%) respondents were board-certified, and 84 (79.2%) were affiliated with an academic center. Not every respondent answered every question (Table).
All respondents (n = 105) indicated there is a potential benefit of high-dose RT for appropriately selected cases. Ninety-four oncologists (88.7%) believed that RT for OMD contributes to cure (88.1% of radiation oncologists, 89.4% of medical oncologists; P = .84) for appropriately selected cases. Some respondents who did not believe RT for OMD contributes to cure added comments about other perceived benefits, such as local disease control for palliation, delaying systemic therapy with its associated toxicities, and prolongation of disease-free survival or OS. A higher percentage of respondents with academic affiliations believed high-dose RT contributes to cure, although this difference did not reach statistical significance (Figure 1).
Fifty-five respondents (51.9%; 55.2% radiation oncologists vs 50.0% medical oncologists; P = .60) responded that local RT for OMD treatment should not be limited by primary tumor type. Of respondents who responded that OMD treatment should be limited based on the type of primary tumor, many provided comments that argued there was a benefit for non-small cell lung cancer (NSCLC), prostate adenocarcinoma (PCa), and colorectal cancer.
The definition of how many metastatic lesions qualify as OMD varied. A total of 48.6% of respondents defined OMD as ≤ 3 lesions and 42.9% answered ≤ 5 lesions. A majority of radiation oncologists (55.2%) classified ≤ 5 lesions as OMD, whereas a majority of medical oncologists (66.0%) considered ≤ 3 lesions as OMD (P = .006) (Figure 2).
Thirty-six medical oncologists (76.6%) report having an on-site department of radiation oncology (Figure 3). This subgroup was more likely to consider local RT potentially curative compared with their medical oncology peers without on-site radiation oncology (94.4% vs 72.7%; P = .04).
Case Management
The 3 clinical cases demonstrated the heterogeneity of management approaches for OMD. The first described a man aged 65 years with PCa and 2 asymptomatic pelvic bone metastases. Ninety-three respondents (90.3%) recommended RT at the primary site and 74.8% recommended RT to both the primary site and metastatic foci. Sixty-three respondents (67.7%) recommended a STAMPEDE-compatible dose, and 30 (32.3%) recommended a definitive dose.
The second clinical case was a 60-year-old man with a cT1N2M1 NSCLC, with a solitary metastatic focus to the left iliac wing. Fifty-eight respondents (54.7%) recommended upfront systemic chemotherapy and the option of local therapy to the chest and metastatic focus after initial chemotherapy; 28 respondents (26.4%) recommended upfront chemoradiation to the chest and definitive radiation to the left iliac wing metastasis.
The third clinical case described a male aged 70 years with a history of a treated base of tongue squamous cell carcinoma, with a solitary metastatic focus within the right lung. Respondents could pick multiple treatment options and 85 (81.7%) favored upfront definitive local therapy with surgery or stereotactic body radiotherapy (SBRT), rather than upfront chemotherapy, with future consideration for local treatment. About half of respondents (51.8%) recommended SBRT and 41.2% would let the patient decide between surgery or SBRT. Additionally, 39.6% included in their patient counselling that the treatment may be for curative intent.
Discussion
The use of local treatment to increased PFS, OS, or even cure treatment for OMD has become more accepted since the 2018 ASTRO meeting.4,5 Palma et al analyzed a controlled primary malignancy of any histology and ≤ 5 metastatic lesions, with all lesions amenable to SBRT.4 With a median follow-up of 51 months when comparing the standard-of-care (SOC) arm and the SBRT arm, the 5-year PFS was not reached and the 5-year OS rates were 17.7% and 42.3% (P = .006), respectively. In the SBRT arm, about 1 in 5 patients survived > 5 years without a recurrence or disease progression, vs 0 patients in the control arm. There was a 29% rate of grade 2 or higher toxicity in the SBRT arm, including 3 deaths that were likely due to treatment. Subsequent trials, such as the phase 3 SABR-COMET-3 (1-3 metastases), phase 3 SABR-COMET-10 (4-10 metastases), and phase 1 ARREST (> 10 metastases) trials, have been specifically designed to minimize treatment-related toxicities.13-15
Gomez et al analyzed patients at 3 sites with a controlled NSCLC primary tumor and ≤ 3 metastases.5 At a follow-up of 38.8 months, the PFS was 4.4 months in the SOC arm vs 14.2 months in the RT and/or surgery local treatment arm (P = .02). There was also an OS benefit of 17.0 vs 41.2 months (P = .02), respectively.
Several RCTs soon followed that demonstrated improved PFS and OS with local radiotherapy for OMD; however, total metastatic ablation of the foci is necessary to attain these PFS and OS benefits.6-9 Still, an oncologic benefit has yet to be proven. The randomized NRGBR002 study phase 2/3 trial for oligometastatic breast cancer included patients with ≤ 4 extracranial metastases and controlled primary disease to metastasis-directed therapy (SBRT and/ or surgical resection) and systemic therapy vs systemic therapy alone.10 The study did not demonstrate improved PFS or OS at 3 years. However, for most breast cancers, especially with the rapid advancements in systemic therapy that have been achieved, longer follow-up may be necessary to detect a significant difference.
The prospective single-arm phase 2 SABR-5 trial retrospectively demonstrated important lessons about the timing of SBRT and systemic therapy.11 This study included patients with ≤ 5 metastases of any histology, and they received SBRT to all lesions. SABR-5 retrospectively compared patients who received upfront systemic therapy followed by SBRT vs another cohort that first received SBRT and did not receive systemic therapy until there was disease progression. Patients with oligo-progression were excluded, as it demonstrated systemic drug resistance. At a median follow-up time of 34 months, delayed systemic treatment was associated with shorter PFS (23 vs 34 months, respectively; P = .001), but not worse 3-year OS (80% vs 85%, respectively; P = .66). In addition, the delayed systemic treatment arm demonstrated a reduced risk of grade 2 or higher SBRT-related toxicity (odds ratio, 0.35; P < .001).
Similarly, the STOMP phase 2 trial analyzed the role of metastasis-directed therapy (MDT) in delaying initiation of androgen deprivation therapy (ADT) in a randomized phase 2 trial.16 This study included patients with asymptomatic PCa with a biochemical recurrence after primary treatment, 1 to 3 extracranial metastatic lesions, and serum testosterone levels > 50 ng/mL. Sixty-two patients were randomized 1:1 to either MDT (SBRT or surgery) of all lesions or surveillance. The 5-year ADT-free survival was 34% for MDT vs 8% for surveillance (P = .06).
VHA Radiation Oncology
The VHA has 138 departments of medical oncology, but only 41 departments of radiation oncology. Compared with medical oncologists without an on-site radiation oncology department, those with on-site departments were more likely to believe that local RT was potentially curative (94.4% vs 72.7%, respectively; P = .04). This finding suggests that a cancer center that includes both specialties has closer collaboration, which results in greater inclination to embrace local RT for OMD, as it has demonstrated PFS and OS benefits.
The radiation and medical oncologists surveyed had statistically significant differences in response by specialty regarding the maximal number of lesions still believed to constitute OMD. Most radiation oncologists classified ≤ 5 lesions as OMD, whereas most medical oncologists classified ≤ 3 lesions as OMD. This difference is not unexpected. There is no universally agreed-upon definition of OMD, and criteria differ across studies.
While the SABR-COMET trial did include ≤ 5 metastatic lesions, it was a phase 2 RCT, making subgroup analysis difficult. Ongoing phase 3 trials that are more specific in the number of metastases, comparing 1 to 3 vs 4 to 10 metastases (SABR-COMET-3 and SABR-COMET-10, respectively).13,14 There is even an ongoing phase 1 trial (ARREST) studying the potential benefits of treating (“restraining”) > 10 metastases, if dosimetrically feasible.15 Within the VHA, VA STARPORT is investigating MDT for recurrent or de novo hormone-sensitive metastatic PCa.17 The ongoing HALT phase 2/3 trial focuses on patients with actionable mutations to help determine management of oligo-progression in mutation-positive NSCLC.18
There was no significant difference by specialty in who responded that offering local RT for OMD treatment should not be limited by histology (55.2% of radiation oncologists and 50.0% of medical oncologists; P = .60). Oncologists could make the argument that some histologies (eg, pancreatic adenocarcinomas) have such poor prognoses that local RT would not meaningfully affect oncologic outcomes, while potentially adding toxicity, whereas others could point to improved systemic therapy regimens and the low toxicity rates with careful hypofractionation regimens. Of note, the 41-patient phase 2 EXTEND trial for pancreatic ductal adenocarcinoma suggested an oncologic benefit to MDT, with far better PFS and no grade ≥ 3 toxicities related to MDT.19 About half of respondents for each specialty believed the primary histology should affect the decision. Further clarification may emerge from phase 3 trials.
Of note, a 2023 study of 44 radiation and medical oncologists at 2 Harvard Medical School-affiliated hospitals found that for synchronous OMD, 50.0% of medical oncologists and 5.3% (P < .01) of radiation oncologists recommended systemic treatment, suggesting a greater divergence in approach than found in this study.20
Limitations
The response rate of 17.0% raised a potential for selection bias, but this rate is expected for a nonincentivized medical survey. A study by the American Board of Internal Medicine with 11 surveys and 6 weekly email contacts only generated a 23.7% response rate, while another study among physicians demonstrated a 4.5% response rate for email-based contact and 11.8% for mail-based contact.21,22 We could have asked participants questions regarding demographics and geography to ensure the survey represented a diverse sample of the medical community, although additional questions would likely suppress the response rate. Additional data collection about respondents may elucidate the rationale for differences in their responses, especially between the specialties. In a planned subsequent survey in several years, the question on the number of lesions that qualifies as OMD may be amended to reflect the context and dosimetry for the maximal number of metastases constituting OMD; the joint ESTRO-ASTRO consensus defined OMD as 1 to 5 metastatic lesions, but in which all metastatic sites must be safely treatable.12 Also, fewer example cases could be included to simplify the survey and boost response rates. A future survey may ask about the timing of SBRT and systemic therapy, and whether SBRT can safely delay systemic therapy.
Conclusions
Survey results demonstrated significant confidence among both radiation oncologists and medical oncologists that local RT for OMD improves outcomes, which is encouraging and a reflection of the recent evidence-based paradigm shift in viewing metastatic disease as a spectrum. However, there is a difference between radiation oncologists and medical oncologists in how they define OMD, and preferred treatment of the sample cases presented revealed nuanced differences by specialty. Close collaboration with radiation oncologists influences the belief of medical oncologists in the beneficial role of RT for OMD. As more phase 3 data for OMD local treatments emerge, additional investigation is needed on how beliefs and practice patterns evolve among radiation and medical oncologists.
The treatment of metastatic solid tumors has been based historically on systemic therapies, with the goal of delaying progression and extend life as long as possible, with tolerable treatment-related adverse events. Some exceptions were made for local treatment with surgery or radiotherapy (RT), often for patients with a single metastasis. A 1939 report describes a patient with renal adenocarcinoma and a solitary lung metastasis who underwent RT to the lung lesion after nephrectomy and subsequently partial lobectomy after the metastatic lesion progressed. The authors argued that if a metastasis appears solitary and accessible, it is plausible to remove it in addition to the primary growth.1
In 1995 Hellman and Weichselbaum proposed oligometastatic disease (OMD). They reasoned that malignancy exists along a spectrum from localized disease to widely disseminated disease, with OMD existing in between with a still-restricted tumor metastatic capacity. Appropriately selected patients with OMD may be candidates for prolonged disease-free survival or cure with the addition of local therapy to systemic therapy.2
The EORTC 4004 phase 2 randomized control trial (RCT) analyzed radiofrequency ablation (RFA) for colorectal liver metastases with systemic therapy vs systemic therapy alone for patients with ≤ 9 liver lesions.3 Systemic therapyconsisted of 5-FU/leucovorin/oxaliplatin, with bevacizumab added to the regimen 3.5 years into the study, per updated standard- of-care. This trial was the first to demonstrate the benefit of aggressive local treatment vs system treatment alone for OMD with a progression-free survival (PFS) benefit (16.8 vs 9.9 months; hazard ratio [HR], 0.63; P = .03) and overall survival (OS) benefit (45.3 vs 40.5 months; HR, 0.74; P = .02) with the addition of local treatment with RFA.
Since the presentations of the SABR-COMET phase 2 RCT and another study by Gomez et al at the American Society for Radiation Oncology (ASTRO) 2018 annual meeting, the paradigm for offering local RT for OMD has rapidly evolved. Both studies found PFS and OS benefits of RT for patients with OMD.4,5 Additional RCTs have since demonstrated that for properly selected patients with OMD, aggressive local RT improved PFS and OS.6-9 These small studies have led to larger RCTs to better understand who benefits from local consolidative treatment, particularly RT.10,11
There is a large degree of heterogeneity in how oncologists define and approach OMD treatment. The 2020 European Society for Radiotherapy and Oncology (ESTRO) and ASTRO consensus guidelines defined the OMD state as 1 to 5 metastatic lesions for which all metastatic sites are safely treatable.12 The purpose of this study was to evaluate perceptions and practice patterns among radiation oncologists and medical oncologists regarding the use of local RT for OMD across the Veterans Health Administration (VHA).
Methods
A 12-question survey was developed by the VHA Palliative Radiotherapy Task Force using the ESTRO-ASTRO consensus guidelines to define OMD. The survey was emailed to the VHA radiation oncology and medical oncology listservs on August 1, 2023. These listservs consist of physicians in these specialties either directly employed by the VHA or serve in its facilities as contractors. The original response closure date was August 11, 2023, but it was extended to August 18, 2023, to increase responses. No incentives were offered to respondents. Two email reminders were sent to the medical oncology listserv and 3 to the radiation oncology listserv. Descriptive statistics and X2 tests were used for data analysis. The impact of specialty and presence of an on-site department of radiation oncology were reviewed. This project was approved by the VHA National Oncology Program and National Radiation Oncology Program.
Results
The survey was sent to 125 radiation oncologists and 515 medical oncologists and 106 were completed for a 16.6% response rate. There were 59 (55.7%) radiation oncologist responses and 47 (44.3%) medical oncologist responses. Most (96.2%) respondents were board-certified, and 84 (79.2%) were affiliated with an academic center. Not every respondent answered every question (Table).
All respondents (n = 105) indicated there is a potential benefit of high-dose RT for appropriately selected cases. Ninety-four oncologists (88.7%) believed that RT for OMD contributes to cure (88.1% of radiation oncologists, 89.4% of medical oncologists; P = .84) for appropriately selected cases. Some respondents who did not believe RT for OMD contributes to cure added comments about other perceived benefits, such as local disease control for palliation, delaying systemic therapy with its associated toxicities, and prolongation of disease-free survival or OS. A higher percentage of respondents with academic affiliations believed high-dose RT contributes to cure, although this difference did not reach statistical significance (Figure 1).
Fifty-five respondents (51.9%; 55.2% radiation oncologists vs 50.0% medical oncologists; P = .60) responded that local RT for OMD treatment should not be limited by primary tumor type. Of respondents who responded that OMD treatment should be limited based on the type of primary tumor, many provided comments that argued there was a benefit for non-small cell lung cancer (NSCLC), prostate adenocarcinoma (PCa), and colorectal cancer.
The definition of how many metastatic lesions qualify as OMD varied. A total of 48.6% of respondents defined OMD as ≤ 3 lesions and 42.9% answered ≤ 5 lesions. A majority of radiation oncologists (55.2%) classified ≤ 5 lesions as OMD, whereas a majority of medical oncologists (66.0%) considered ≤ 3 lesions as OMD (P = .006) (Figure 2).
Thirty-six medical oncologists (76.6%) report having an on-site department of radiation oncology (Figure 3). This subgroup was more likely to consider local RT potentially curative compared with their medical oncology peers without on-site radiation oncology (94.4% vs 72.7%; P = .04).
Case Management
The 3 clinical cases demonstrated the heterogeneity of management approaches for OMD. The first described a man aged 65 years with PCa and 2 asymptomatic pelvic bone metastases. Ninety-three respondents (90.3%) recommended RT at the primary site and 74.8% recommended RT to both the primary site and metastatic foci. Sixty-three respondents (67.7%) recommended a STAMPEDE-compatible dose, and 30 (32.3%) recommended a definitive dose.
The second clinical case was a 60-year-old man with a cT1N2M1 NSCLC, with a solitary metastatic focus to the left iliac wing. Fifty-eight respondents (54.7%) recommended upfront systemic chemotherapy and the option of local therapy to the chest and metastatic focus after initial chemotherapy; 28 respondents (26.4%) recommended upfront chemoradiation to the chest and definitive radiation to the left iliac wing metastasis.
The third clinical case described a male aged 70 years with a history of a treated base of tongue squamous cell carcinoma, with a solitary metastatic focus within the right lung. Respondents could pick multiple treatment options and 85 (81.7%) favored upfront definitive local therapy with surgery or stereotactic body radiotherapy (SBRT), rather than upfront chemotherapy, with future consideration for local treatment. About half of respondents (51.8%) recommended SBRT and 41.2% would let the patient decide between surgery or SBRT. Additionally, 39.6% included in their patient counselling that the treatment may be for curative intent.
Discussion
The use of local treatment to increased PFS, OS, or even cure treatment for OMD has become more accepted since the 2018 ASTRO meeting.4,5 Palma et al analyzed a controlled primary malignancy of any histology and ≤ 5 metastatic lesions, with all lesions amenable to SBRT.4 With a median follow-up of 51 months when comparing the standard-of-care (SOC) arm and the SBRT arm, the 5-year PFS was not reached and the 5-year OS rates were 17.7% and 42.3% (P = .006), respectively. In the SBRT arm, about 1 in 5 patients survived > 5 years without a recurrence or disease progression, vs 0 patients in the control arm. There was a 29% rate of grade 2 or higher toxicity in the SBRT arm, including 3 deaths that were likely due to treatment. Subsequent trials, such as the phase 3 SABR-COMET-3 (1-3 metastases), phase 3 SABR-COMET-10 (4-10 metastases), and phase 1 ARREST (> 10 metastases) trials, have been specifically designed to minimize treatment-related toxicities.13-15
Gomez et al analyzed patients at 3 sites with a controlled NSCLC primary tumor and ≤ 3 metastases.5 At a follow-up of 38.8 months, the PFS was 4.4 months in the SOC arm vs 14.2 months in the RT and/or surgery local treatment arm (P = .02). There was also an OS benefit of 17.0 vs 41.2 months (P = .02), respectively.
Several RCTs soon followed that demonstrated improved PFS and OS with local radiotherapy for OMD; however, total metastatic ablation of the foci is necessary to attain these PFS and OS benefits.6-9 Still, an oncologic benefit has yet to be proven. The randomized NRGBR002 study phase 2/3 trial for oligometastatic breast cancer included patients with ≤ 4 extracranial metastases and controlled primary disease to metastasis-directed therapy (SBRT and/ or surgical resection) and systemic therapy vs systemic therapy alone.10 The study did not demonstrate improved PFS or OS at 3 years. However, for most breast cancers, especially with the rapid advancements in systemic therapy that have been achieved, longer follow-up may be necessary to detect a significant difference.
The prospective single-arm phase 2 SABR-5 trial retrospectively demonstrated important lessons about the timing of SBRT and systemic therapy.11 This study included patients with ≤ 5 metastases of any histology, and they received SBRT to all lesions. SABR-5 retrospectively compared patients who received upfront systemic therapy followed by SBRT vs another cohort that first received SBRT and did not receive systemic therapy until there was disease progression. Patients with oligo-progression were excluded, as it demonstrated systemic drug resistance. At a median follow-up time of 34 months, delayed systemic treatment was associated with shorter PFS (23 vs 34 months, respectively; P = .001), but not worse 3-year OS (80% vs 85%, respectively; P = .66). In addition, the delayed systemic treatment arm demonstrated a reduced risk of grade 2 or higher SBRT-related toxicity (odds ratio, 0.35; P < .001).
Similarly, the STOMP phase 2 trial analyzed the role of metastasis-directed therapy (MDT) in delaying initiation of androgen deprivation therapy (ADT) in a randomized phase 2 trial.16 This study included patients with asymptomatic PCa with a biochemical recurrence after primary treatment, 1 to 3 extracranial metastatic lesions, and serum testosterone levels > 50 ng/mL. Sixty-two patients were randomized 1:1 to either MDT (SBRT or surgery) of all lesions or surveillance. The 5-year ADT-free survival was 34% for MDT vs 8% for surveillance (P = .06).
VHA Radiation Oncology
The VHA has 138 departments of medical oncology, but only 41 departments of radiation oncology. Compared with medical oncologists without an on-site radiation oncology department, those with on-site departments were more likely to believe that local RT was potentially curative (94.4% vs 72.7%, respectively; P = .04). This finding suggests that a cancer center that includes both specialties has closer collaboration, which results in greater inclination to embrace local RT for OMD, as it has demonstrated PFS and OS benefits.
The radiation and medical oncologists surveyed had statistically significant differences in response by specialty regarding the maximal number of lesions still believed to constitute OMD. Most radiation oncologists classified ≤ 5 lesions as OMD, whereas most medical oncologists classified ≤ 3 lesions as OMD. This difference is not unexpected. There is no universally agreed-upon definition of OMD, and criteria differ across studies.
While the SABR-COMET trial did include ≤ 5 metastatic lesions, it was a phase 2 RCT, making subgroup analysis difficult. Ongoing phase 3 trials that are more specific in the number of metastases, comparing 1 to 3 vs 4 to 10 metastases (SABR-COMET-3 and SABR-COMET-10, respectively).13,14 There is even an ongoing phase 1 trial (ARREST) studying the potential benefits of treating (“restraining”) > 10 metastases, if dosimetrically feasible.15 Within the VHA, VA STARPORT is investigating MDT for recurrent or de novo hormone-sensitive metastatic PCa.17 The ongoing HALT phase 2/3 trial focuses on patients with actionable mutations to help determine management of oligo-progression in mutation-positive NSCLC.18
There was no significant difference by specialty in who responded that offering local RT for OMD treatment should not be limited by histology (55.2% of radiation oncologists and 50.0% of medical oncologists; P = .60). Oncologists could make the argument that some histologies (eg, pancreatic adenocarcinomas) have such poor prognoses that local RT would not meaningfully affect oncologic outcomes, while potentially adding toxicity, whereas others could point to improved systemic therapy regimens and the low toxicity rates with careful hypofractionation regimens. Of note, the 41-patient phase 2 EXTEND trial for pancreatic ductal adenocarcinoma suggested an oncologic benefit to MDT, with far better PFS and no grade ≥ 3 toxicities related to MDT.19 About half of respondents for each specialty believed the primary histology should affect the decision. Further clarification may emerge from phase 3 trials.
Of note, a 2023 study of 44 radiation and medical oncologists at 2 Harvard Medical School-affiliated hospitals found that for synchronous OMD, 50.0% of medical oncologists and 5.3% (P < .01) of radiation oncologists recommended systemic treatment, suggesting a greater divergence in approach than found in this study.20
Limitations
The response rate of 17.0% raised a potential for selection bias, but this rate is expected for a nonincentivized medical survey. A study by the American Board of Internal Medicine with 11 surveys and 6 weekly email contacts only generated a 23.7% response rate, while another study among physicians demonstrated a 4.5% response rate for email-based contact and 11.8% for mail-based contact.21,22 We could have asked participants questions regarding demographics and geography to ensure the survey represented a diverse sample of the medical community, although additional questions would likely suppress the response rate. Additional data collection about respondents may elucidate the rationale for differences in their responses, especially between the specialties. In a planned subsequent survey in several years, the question on the number of lesions that qualifies as OMD may be amended to reflect the context and dosimetry for the maximal number of metastases constituting OMD; the joint ESTRO-ASTRO consensus defined OMD as 1 to 5 metastatic lesions, but in which all metastatic sites must be safely treatable.12 Also, fewer example cases could be included to simplify the survey and boost response rates. A future survey may ask about the timing of SBRT and systemic therapy, and whether SBRT can safely delay systemic therapy.
Conclusions
Survey results demonstrated significant confidence among both radiation oncologists and medical oncologists that local RT for OMD improves outcomes, which is encouraging and a reflection of the recent evidence-based paradigm shift in viewing metastatic disease as a spectrum. However, there is a difference between radiation oncologists and medical oncologists in how they define OMD, and preferred treatment of the sample cases presented revealed nuanced differences by specialty. Close collaboration with radiation oncologists influences the belief of medical oncologists in the beneficial role of RT for OMD. As more phase 3 data for OMD local treatments emerge, additional investigation is needed on how beliefs and practice patterns evolve among radiation and medical oncologists.
- Barney JD, Churchill EJ. Adenocarcinoma of the kidney with metastasis to the lung. J Urology. 1939.
- Hellman S, Weichselbaum RR. Oligometastases. J Clin Oncol. 1995;13(1):8-10. doi:10.1200/JCO.1995.13.1.8
- Ruers T, Punt C, Van Coevorden F, et al. Radiofrequency ablation combined with systemic treatment versus systemic treatment alone in patients with non-resectable colorectal liver metastases: a randomized EORTC Intergroup phase II study (EORTC 4004). Ann Oncol. 2012;23(10):2619-2626. doi:10.1093/annonc/mds053
- Palma DA, Olson R, Harrow S, et al. Stereotactic ablative radiotherapy for the comprehensive treatment of oligometastatic cancers: long-term results of the SABR-COMET phase II randomized trial. J Clin Oncol. 2020;38(25):2830- 2838. doi:10.1200/JCO.20.00818
- Gomez DR, Tang C, Zhang J, et al. Local consolidative therapy vs. maintenance therapy or observation for patients with oligometastatic non-small-cell lung cancer: long-term results of a multi-institutional, phase II, randomized study. J Clin Oncol. 2019;37(18):1558-1565. doi:10.1200/JCO.19.00201
- Iyengar P, Wardak Z, Gerber DE, et al. Consolidative radiotherapy for limited metastatic non-small-cell lung cancer: a phase 2 randomized clinical trial. JAMA Oncol. 2018;4(1):e173501. doi:10.1001/jamaoncol.2017.3501
- Phillips R, Shi WY, Deek M, et al. Outcomes of observation vs stereotactic ablative radiation for oligometastatic prostate cancer: the ORIOLE phase 2 randomized clinical trial. JAMA Oncol. 2020;6(5):650-659. doi:10.1001/jamaoncol.2020.0147
- Wang XS, Bai YF, Verma V, et al. Randomized trial of first-line tyrosine kinase inhibitor with or without radiotherapy for synchronous oligometastatic EGFR-mutated NSCLC. J Natl Cancer Inst 2023;115(6):742-748. doi:10.1093/jnci/djac015
- Tang C, Sherry AD, Haymaker C, et al. Addition of metastasis- directed therapy to intermittent hormone therapy for oligometastatic prostate cancer (EXTEND): a multicenter, randomized phase II trial. Am Soc Radiat Oncol Annu Meet. 2023;9(6):825-834. doi:10.1001/jamaoncol.2023.0161
- Chmura SJ, Winter KA, Woodward WA, et al. NRG-BR002: a phase IIR/III trial of standard of care systemic therapy with or without stereotactic body radiotherapy (SBRT) and/or surgical resection (SR) for newly oligometastatic breast cancer (NCT02364557). J Clin Oncol. 2022;40:1007. doi:10.1200/JCO.2022.40.16_suppl.1007
- Baker S, Lechner L, Liu M, et al. Upfront versus delayed systemic therapy in patients with oligometastatic cancer treated with SABR in the phase 2 SABR-5 trial. Int J Radiat Oncol Biol Phys. 2024;118(5):1497-1506. doi:10.1016/j.ijrobp.2023.11.007
- Lievens Y, Guckenberger M, Gomez D, et al. Defining oligometastatic disease from a radiation oncology perspective: an ESTRO-ASTRO consensus document. Radiother Oncol. 2020;148:157-166. doi:10.1016/j.radonc.2020.04.003
- Olson R, Mathews L, Liu M, et al. Stereotactic ablative radiotherapy for the comprehensive treatment of 1-3 oligometastatic tumors (SABR-COMET-3): study protocol for a randomized phase III trial. BMC Cancer. 2020;20(1):380. doi:10.1186/s12885-020-06876-4
- Palma DA, Olson R, Harrow S, et al. Stereotactic ablative radiotherapy for the comprehensive treatment of 4-10 oligometastatic tumors (SABR-COMET-10): study protocol for a randomized phase III trial. BMC Cancer. 2019;19(1):816. doi:10.1186/s12885-019-5977-6
- Bauman GS, Corkum MT, Fakir H, et al. Ablative radiation therapy to restrain everything safely treatable (ARREST): study protocol for a phase I trial treating polymetastatic cancer with stereotactic radiotherapy. BMC Cancer. 2021;21(1):405. doi:10.1186/s12885-021-08136-5
- Ost P, Reynders D, Decaestecker K, et al. Surveillance or metastasis-directed therapy for oligometastatic prostate cancer recurrence (STOMP): five-year results of a randomized phase II trial. J Clin Oncol. 2020;38:suppl.
- Solanki AA, Campbell D, Carlson K, et al. Veterans Affairs seamless phase II/III randomized trial of standard systemic therapy with or without PET-directed local therapy for oligometastatic prostate cancer (VA STARPORT). J Clin Oncol. 2024;42:16.
- McDonald F, Guckenberger M, Popat S. EP08.03-005 HALT – Targeted therapy with or without dose-intensified radiotherapy in oligo-progressive disease in oncogene addicted lung tumours. J Thor Oncol. 2022;17:S492.
- Ludmir EB, Sherry AD, Fellman BM, et al. Addition of metastasis- directed therapy to systemic therapy for oligometastatic pancreatic ductal adenocarcinoma (EXTEND): a multicenter, randomized phase II trial. J Clin Oncol. 2024;42(32):3795-3805. doi:10.1200/JCO.24.00081
- Cho HL, Balboni T, Christ SB, et al. Is oligometastatic cancer curable? A survey of oncologist perspectives, decision making, and communication. Adv Radiat Oncol. 2023;8(5):101221. doi:10.1016/j.adro.2023.101221
- Barnhart BJ, Reddy SG, Arnold GK. Remind me again: physician response to web surveys: the effect of email reminders across 11 opinion survey efforts at the American Board of Internal Medicine from 2017 to 2019. Eval Health Prof. 2021;44(3):245-259. doi:10.1177/01632787211019445
- Murphy CC, Lee SJC, Geiger AM, et al. A randomized trial of mail and email recruitment strategies for a physician survey on clinical trial accrual. BMC Med Res Methodol. 2020;20(1):123. doi:10.1186/s12874-020-01014-x
- Barney JD, Churchill EJ. Adenocarcinoma of the kidney with metastasis to the lung. J Urology. 1939.
- Hellman S, Weichselbaum RR. Oligometastases. J Clin Oncol. 1995;13(1):8-10. doi:10.1200/JCO.1995.13.1.8
- Ruers T, Punt C, Van Coevorden F, et al. Radiofrequency ablation combined with systemic treatment versus systemic treatment alone in patients with non-resectable colorectal liver metastases: a randomized EORTC Intergroup phase II study (EORTC 4004). Ann Oncol. 2012;23(10):2619-2626. doi:10.1093/annonc/mds053
- Palma DA, Olson R, Harrow S, et al. Stereotactic ablative radiotherapy for the comprehensive treatment of oligometastatic cancers: long-term results of the SABR-COMET phase II randomized trial. J Clin Oncol. 2020;38(25):2830- 2838. doi:10.1200/JCO.20.00818
- Gomez DR, Tang C, Zhang J, et al. Local consolidative therapy vs. maintenance therapy or observation for patients with oligometastatic non-small-cell lung cancer: long-term results of a multi-institutional, phase II, randomized study. J Clin Oncol. 2019;37(18):1558-1565. doi:10.1200/JCO.19.00201
- Iyengar P, Wardak Z, Gerber DE, et al. Consolidative radiotherapy for limited metastatic non-small-cell lung cancer: a phase 2 randomized clinical trial. JAMA Oncol. 2018;4(1):e173501. doi:10.1001/jamaoncol.2017.3501
- Phillips R, Shi WY, Deek M, et al. Outcomes of observation vs stereotactic ablative radiation for oligometastatic prostate cancer: the ORIOLE phase 2 randomized clinical trial. JAMA Oncol. 2020;6(5):650-659. doi:10.1001/jamaoncol.2020.0147
- Wang XS, Bai YF, Verma V, et al. Randomized trial of first-line tyrosine kinase inhibitor with or without radiotherapy for synchronous oligometastatic EGFR-mutated NSCLC. J Natl Cancer Inst 2023;115(6):742-748. doi:10.1093/jnci/djac015
- Tang C, Sherry AD, Haymaker C, et al. Addition of metastasis- directed therapy to intermittent hormone therapy for oligometastatic prostate cancer (EXTEND): a multicenter, randomized phase II trial. Am Soc Radiat Oncol Annu Meet. 2023;9(6):825-834. doi:10.1001/jamaoncol.2023.0161
- Chmura SJ, Winter KA, Woodward WA, et al. NRG-BR002: a phase IIR/III trial of standard of care systemic therapy with or without stereotactic body radiotherapy (SBRT) and/or surgical resection (SR) for newly oligometastatic breast cancer (NCT02364557). J Clin Oncol. 2022;40:1007. doi:10.1200/JCO.2022.40.16_suppl.1007
- Baker S, Lechner L, Liu M, et al. Upfront versus delayed systemic therapy in patients with oligometastatic cancer treated with SABR in the phase 2 SABR-5 trial. Int J Radiat Oncol Biol Phys. 2024;118(5):1497-1506. doi:10.1016/j.ijrobp.2023.11.007
- Lievens Y, Guckenberger M, Gomez D, et al. Defining oligometastatic disease from a radiation oncology perspective: an ESTRO-ASTRO consensus document. Radiother Oncol. 2020;148:157-166. doi:10.1016/j.radonc.2020.04.003
- Olson R, Mathews L, Liu M, et al. Stereotactic ablative radiotherapy for the comprehensive treatment of 1-3 oligometastatic tumors (SABR-COMET-3): study protocol for a randomized phase III trial. BMC Cancer. 2020;20(1):380. doi:10.1186/s12885-020-06876-4
- Palma DA, Olson R, Harrow S, et al. Stereotactic ablative radiotherapy for the comprehensive treatment of 4-10 oligometastatic tumors (SABR-COMET-10): study protocol for a randomized phase III trial. BMC Cancer. 2019;19(1):816. doi:10.1186/s12885-019-5977-6
- Bauman GS, Corkum MT, Fakir H, et al. Ablative radiation therapy to restrain everything safely treatable (ARREST): study protocol for a phase I trial treating polymetastatic cancer with stereotactic radiotherapy. BMC Cancer. 2021;21(1):405. doi:10.1186/s12885-021-08136-5
- Ost P, Reynders D, Decaestecker K, et al. Surveillance or metastasis-directed therapy for oligometastatic prostate cancer recurrence (STOMP): five-year results of a randomized phase II trial. J Clin Oncol. 2020;38:suppl.
- Solanki AA, Campbell D, Carlson K, et al. Veterans Affairs seamless phase II/III randomized trial of standard systemic therapy with or without PET-directed local therapy for oligometastatic prostate cancer (VA STARPORT). J Clin Oncol. 2024;42:16.
- McDonald F, Guckenberger M, Popat S. EP08.03-005 HALT – Targeted therapy with or without dose-intensified radiotherapy in oligo-progressive disease in oncogene addicted lung tumours. J Thor Oncol. 2022;17:S492.
- Ludmir EB, Sherry AD, Fellman BM, et al. Addition of metastasis- directed therapy to systemic therapy for oligometastatic pancreatic ductal adenocarcinoma (EXTEND): a multicenter, randomized phase II trial. J Clin Oncol. 2024;42(32):3795-3805. doi:10.1200/JCO.24.00081
- Cho HL, Balboni T, Christ SB, et al. Is oligometastatic cancer curable? A survey of oncologist perspectives, decision making, and communication. Adv Radiat Oncol. 2023;8(5):101221. doi:10.1016/j.adro.2023.101221
- Barnhart BJ, Reddy SG, Arnold GK. Remind me again: physician response to web surveys: the effect of email reminders across 11 opinion survey efforts at the American Board of Internal Medicine from 2017 to 2019. Eval Health Prof. 2021;44(3):245-259. doi:10.1177/01632787211019445
- Murphy CC, Lee SJC, Geiger AM, et al. A randomized trial of mail and email recruitment strategies for a physician survey on clinical trial accrual. BMC Med Res Methodol. 2020;20(1):123. doi:10.1186/s12874-020-01014-x
Radiation and Medical Oncology Perspectives on Oligometastatic Disease Treatment
Radiation and Medical Oncology Perspectives on Oligometastatic Disease Treatment
Radiotherapeutic Care of Patients With Stage IV Lung Cancer with Thoracic Symptoms in the Veterans Health Administration (FULL)
Lung cancer is the leading cause of cancer mortality both in the US and worldwide.1 Many patients diagnosed with lung cancer present with advanced disease with thoracic symptoms such as cough, hemoptysis, dyspnea, and chest pain.2-4 Palliative radiotherapy is routinely used in patients with locally advanced and metastatic lung cancer with the goal of relieving these symptoms and improving quality of life. Guidelines published by the American Society for Radiation Oncology (ASTRO) in 2011, and updated in 2018, provide recommendations on palliation of lung cancer with external beam radiotherapy (EBRT) and clarify the roles of concurrent chemotherapy and endobronchial brachytherapy (EBB) for palliation.5,6
After prostate cancer, lung cancer is the second most frequently diagnosed cancer in the Veterans Health Administration (VHA).7 The VHA consists of 172 medical centers and is the largest integrated health care system in the US. At the time of this study, 40 of these centers had onsite radiation facilities. The VHA Palliative Radiation Taskforce has conducted a series of surveys to evaluate use of palliative radiotherapy in the VHA, determine VHA practice concordance with ASTRO and American College of Radiology (ACR) guidelines, and direct educational efforts towards addressing gaps in knowledge. These efforts are directed at ensuring best practices throughout this large and heterogeneous healthcare system. In 2016 a survey was conducted to evaluate concordance of VHA radiation oncologist (RO) practice with the 2011 ASTRO guidelines on palliative thoracic radiotherapy for non-small cell lung cancer (NSCLC).
Methods
A survey instrument was generated by VHA National Palliative Radiotherapy Taskforce members. It was reviewed and approved for use by the VHA Patient Care Services office. In May of 2016, the online survey was sent to the 88 VHA ROs practicing at the 40 sites with onsite radiation facilities. The survey aimed to determine patterns of practice for palliation of thoracic symptoms secondary to lung cancer.
Demographic information obtained included years in practice, employment status, academic appointment, board certification, and familiarity with ASTRO lung cancer guidelines. Two clinical scenarios were presented to glean opinions on dose/fractionation schemes preferred, use of concurrent chemotherapy, and use of EBB and/or yttrium aluminum garnet (YAG) laser technology. Survey questions also assessed use of EBRT for palliation of hemoptysis, chest wall pain, and/or stridor as well as use of stereotactic body radiotherapy (SBRT) for palliation.
Survey results were assessed for concordance with published ASTRO guidelines. χ2 tests were run to test for associations between demographic factors such as academic appointment, years of practice, full time vs part time employment, and familiarity with ASTRO palliative lung cancer guidelines, with use of EBRT for palliation, dose and fractionation preference, use of concurrent chemotherapy, and strategy for management of endobronchial lesions.
Results
Of the 88 physicians surveyed, 54 responded for a response rate of 61%. Respondents represented 37 of the 40 (93%) VHA radiation oncology departments (Table 1). Among respondents, most were board certified (96%), held academic appointments (91%), and were full-time employees (85%). Forty-four percent of respondents were in practice for > 20 years, 19% for 11 to 20 years, 20% for 6 to 10 years, and 17% for < 6 years. A majority reported familiarity with the ASTRO guidelines (64%), while just 11% reported no familiarity with the guidelines.
When asked about use of SBRT for palliation of hemoptysis, stridor, and/or chest pain, the majority (87%) preferred conventional EBRT. Of the 13% who reported use of SBRT, most (11%) performed it onsite, with 2% of respondents referring offsite to non-VHA centers for the service. When asked about use of EBB for palliation, only 2% reported use of that procedure at their facilities, while 26% reported referral to non-VHA facilities for EBB. The remaining 72% of respondents favor use of conventional EBRT.
Respondents were presented with a case of a male patient aged 70 years who smoked and had widely metastatic NSCLC, a life expectancy of about 3 months, and 10/10 chest wall pain from direct tumor invasion. All respondents recommended palliative radiotherapy. The preferred fractionation was 20 Gray (Gy) in 5 fractions, which was recommended by 69% of respondents. The remainder recommended 30 Gy in 10 fractions (22%) or a single fraction of 10 Gy (9%). No respondent recommended the longer fractionation options of 60 Gy in 30 fractions, 45 Gy in 15 fractions, or 40 Gy in 20 fractions. The majority (98%) did not recommend concurrent chemotherapy.
When the above case was modified for an endobronchial lesion requiring palliation with associated lung collapse, rather than chest wall invasion, 20 respondents (38%) reported they would refer for EBB, and 20 respondents reported they would refer for YAG laser. As > 1 answer could be selected for this question, there were 12 respondents who selected both EBB and YAG laser; 8 selected only EBB, and 8 selected only YAG laser. Many respondents added comments about treating with EBRT, which had not been presented as an answer choice. Nearly half of respondents (49%) were amenable to referral for the use of EBB or YAG laser for lung reexpansion prior to radiotherapy. Three respondents mentioned referral for an endobronchial stent prior to palliative radiotherapy to address this question.
χ2 tests were used to evaluate for significant associations between demographic factors, such as number of years in practice, academic appointment, full-time vs part-time status, and familiarity with ASTRO guidelines with clinical management choices (Table 2). The χ2 analysis revealed that these demographic factors were not significantly associated with familiarity with ASTRO guidelines, offering SBRT for palliation, EBRT fractionation scheme preferred, use of concurrent chemotherapy, or use of EBB or YAG laser.
Discussion
This survey was conducted to evaluate concordance of management of metastatic lung cancer in the VHA with ASTRO guidelines. The relationship between respondents’ familiarity with the guidelines and responses also was evaluated to determine the impact such guidelines have on decision-making. The ASTRO guidelines for palliative thoracic radiation make recommendations regarding 3 issues: (1) radiation doses and fractionations for palliation; (2) the role of EBB; and (3) the use of concurrent chemotherapy.5,6
Radiation Dose and Fractionation for Palliation
A variety of dose/fractionation schemes are considered appropriate in the ASTRO guideline statement, including more prolonged courses such as 30 Gy/10 fractions as well as more hypofractionated regimens (ie, 20 Gy/5 fractions, 17 Gy/2 fractions, and a single fraction of 10 Gy). Higher dose regimens, such as 30 Gy/10 fractions, have been associated with prolonged survival, as well as increased toxicities such as radiation esophagitis.8 Therefore, the guidelines support use of 30 Gy/10 fractions for patients with good performance status while encouraging use of more hypofractionated regimens for patients with poor performance status. In considering more hypofractionated regimens, one must consider the possibility of adverse effects that can be associated with higher dose per fraction. For instance, 17 Gy/2 fractions has been associated with myelopathy; therefore it should be used with caution and careful treatment planning.9
For the survey case example (a male aged 70 years with a 3-month life expectancy who required palliation for chest wall pain), all respondents selected hypofractionated regimens; with no respondent selected the more prolonged fractionations of 60 Gy/30 fractions, 45 Gy/15 fractions, or 40 Gy/20 fractions. These more prolonged fractionations are not endorsed by the guidelines in general, and particularly not for a patient with poor life expectancy. All responses for this case selected by survey respondents are considered appropriate per the consensus guideline statement.
Role of Concurrent Chemotherapy
The ASTRO guidelines do not support use of concurrent chemotherapy for palliation of stage IV NSCLC.5,6 The 2018 updated guidelines established a role for concurrent chemotherapy for patients with stage III NSCLC with good performance status and life expectancy of > 3 months. This updated recommendation is based on data from 2 randomized trials demonstrating improvement in overall survival with the addition of chemotherapy for patients with stage III NSCLC undergoing palliative radiotherapy.10-12
These newer studies are in contrast to an older randomized study by Ball and colleagues that demonstrated greater toxicity from concurrent chemotherapy, with no improvement in outcomes such as palliation of symptoms, overall survival, or progression free survival.13 In contrast to the newer studies that included only patients with stage III NSCLC, about half of the patients in the Ball and colleagues study had known metastatic disease.10-13 Of note, staging for metastatic disease was not carried out routinely, so it is possible that a greater proportion of patients had metastatic disease that would have been seen on imaging. In concordance with the guidelines, 98% of the survey respondents did not recommend concurrent chemotherapy for palliation of intrathoracic symptom; only 1 respondent recommended use of chemotherapy for palliation.
Role of Endobronchial Brachytherapy
EBB involves implantation of radioactive sources for treatment of endobronchial lesions causing obstructive symptoms.14 Given the lack of randomized data that demonstrate a benefit of EBB over EBRT, the ASTRO guidelines do not endorse routine use of EBB for initial palliative management.15,16 The ASTRO guidelines reference a Cochrane Review of 13 trials that concluded that EBRT alone is superior to EBB alone for initial palliation of symptoms from endobronchial NSCLC.17
Of respondents surveyed, only 1 facility offered onsite EBB. The majority of respondents (72%) preferred the use of conventional EBRT techniques, while 26% refer to non-VHA centers for EBB. Lack of incorporation of EBB into routine VHA practice likely is a reflection of the unclear role of this technology based on the available literature and ASTRO guidelines. In the setting of a right lower lung collapse, more respondents (49%) would consider use of EBB or YAG laser technology for lung reexpansion prior to EBRT.
The ASTRO guidelines recommend that initial EBB in conjunction with EBRT be considered based on randomized data demonstrating significant improvement in lung reexpansion and in patient reported dyspnea with addition of EBB to EBRT over EBRT alone.18 However, the guidelines do not mandate the use of EBB in this situation. It is possible that targeted education regarding the role of EBB would improve knowledge of the potential benefit in the setting of lung collapse and increase the percentage of VHA ROs who would recommend this procedure.
Limitations
The study is limited by lack of generalizability of these findings to all ROs in the country. It is also possible that physician responses do not represent practice patterns with complete accuracy. The use of EBB varied among practitioners. Further study of this technology is necessary to clarify its role in the management of endobronchial obstructive symptoms and to determine whether efforts should be made to increase access to EBB within the VHA.
Conclusions
Most of the ROs who responded to our survey were cognizant and compliant with current ASTRO guidelines on management of lung cancer. Furthermore, familiarity with ASTRO guidelines and management choices were not associated with the respondents’ years in practice, academic appointment, full-time vs part-time status, or familiarity with ASTRO guidelines. This study is a nationwide survey of ROs in the VHA system that reflects the radiation-related care received by veterans with metastatic lung cancer. Responses were obtained from 93% of the 40 radiation oncology centers, so it is likely that the survey accurately represents the decision-making process at the majority of centers. It is possible that those who did not respond to the survey do not treat thoracic cases.
1. Torre LA, Bray F, Siegel RL, Ferlay J, Lortet-Tieulent J, Jemal A. Global cancer statistics, 2012. CA Cancer J Clin. 2015 65(2):87-108.
2. Kocher F, Hilbe W, Seeber A, et al. Longitudinal analysis of 2293 NSCLC patients: a comprehensive study from the TYROL registry. Lung Cancer. 2015;87(2):193-200.
3. Chute CG, Greenberg ER, Baron J, Korson R, Baker J, Yates J. Presenting conditions of 1539 population-based lung cancer patients by cell type and stage in New Hampshire and Vermont. Cancer. 1985;56(8):2107-2111.
4. Hyde L, Hyde Cl. Clinical manifestations of lung cancer. Chest. 1974;65(3):299-306.
5. Rodrigues G, Videtic GM, Sur R, et al. Palliative thoracic radiotherapy in lung cancer: An American Society for Radiation Oncology evidence-based clinical practice guideline. Pract Radiat Oncol. 2011;1(2):60-71.
6. Moeller B, Balagamwala EH, Chen A, et al. Palliative thoracic radiation therapy for non-small cell lung cancer: 2018 Update of an American Society for Radiation Oncology (ASTRO) Evidence-Based Guideline. Pract Radiat Oncol. 2018;8(4):245-250.
7. Zullig LL, Jackson GL, Dorn RA, et al. Cancer incidence among patients of the United States Veterans Affairs (VA) healthcare system. Mil Med. 2012;177(6):693-701.
8. Fairchild A, Harris K, Barnes E, et al. Palliative thoracic radiotherapy for lung cancer: a systematic review. J Clin Oncol. 2008;26(24):4001-4011.
9. A Medical Research Council (MRC) randomised trial of palliative radiotherapy with two fractions or a single fraction in patients with inoperable non-small-cell lung cancer (NSCLC) and poor performance status. Medical Research Council Lung Cancer Working Party. Br J Cancer. 1992;65(6):934-941.
10. Nawrocki S, Krzakowski M, Wasilewska-Tesluk E, et al. Concurrent chemotherapy and short course radiotherapy in patients with stage IIIA to IIIB non-small cell lung cancer not eligible for radical treatment: results of a randomized phase II study. J Thorac Oncol. 2010;5(8):1255-1262.
11. Strøm HH, Bremnes RM, Sundstrøm SH, Helbekkmo N, Fløtten O, Aasebø U. Concurrent palliative chemoradiation leads to survival and quality of life benefits in poor prognosis stage III non-small-cell lung cancer: a randomised trial by the Norwegian Lung Cancer Study Group. Br J Cancer. 2013;109(6):1467-1475.
12. Strøm HH, Bremnes RM, Sundstrøm SH, Helbekkmo N, Aasebø U. Poor prognosis patients with inoperable locally advanced NSCLC and large tumors benefit from palliative chemoradiotherapy: a subset analysis from a randomized clinical phase III trial. J Thorac Oncol. 2014;9(6):825-833.
13. Ball D, Smith J, Bishop J, et al. A phase III study of radiotherapy with and without continuous-infusion fluorouracil as palliation for non-small-cell lung cancer. Br J Cancer. 1997;75(5):690-697.
14. Stewart A, Parashar B, Patel M, et al. American Brachytherapy Society consensus guidelines for thoracic brachytherapy for lung cancer. Brachytherapy. 2016;15(1):1-11.
15. Sur R, Ahmed SN, Donde B, Morar R, Mohamed G, Sur M, Pacella JA, Van der Merwe E, Feldman C. Brachytherapy boost vs teletherapy boost in palliation of symptomatic, locally advanced non-small cell lung cancer: preliminary analysis of a randomized prospective study. J Brachytherapy Int. 2001;17(4):309-315.
16. Sur R, Donde B, Mohuiddin M, et al. Randomized prospective study on the role of high dose rate intraluminal brachytherapy (HDRILBT) in palliation of symptoms in advanced non-small cell lung cancer (NSCLC) treated with radiation alone. Int J Radiat Oncol Biol Phys. 2004;60(1):S205.
17. Ung YC, Yu E, Falkson C, et al. The role of high-dose-rate brachytherapy in the palliation of symptoms in patients with non-small cell lung cancer: a systematic review. Brachytherapy. 2006;5:189-202.
18. Langendijk H, de Jong J, Tjwa M, et al. External irradiation versus external irradiation plus endobronchial brachytherapy in inoperable non-small cell lung cancer: a prospective randomized study. Radiother Oncol. 2001;58(3):257-268.
Lung cancer is the leading cause of cancer mortality both in the US and worldwide.1 Many patients diagnosed with lung cancer present with advanced disease with thoracic symptoms such as cough, hemoptysis, dyspnea, and chest pain.2-4 Palliative radiotherapy is routinely used in patients with locally advanced and metastatic lung cancer with the goal of relieving these symptoms and improving quality of life. Guidelines published by the American Society for Radiation Oncology (ASTRO) in 2011, and updated in 2018, provide recommendations on palliation of lung cancer with external beam radiotherapy (EBRT) and clarify the roles of concurrent chemotherapy and endobronchial brachytherapy (EBB) for palliation.5,6
After prostate cancer, lung cancer is the second most frequently diagnosed cancer in the Veterans Health Administration (VHA).7 The VHA consists of 172 medical centers and is the largest integrated health care system in the US. At the time of this study, 40 of these centers had onsite radiation facilities. The VHA Palliative Radiation Taskforce has conducted a series of surveys to evaluate use of palliative radiotherapy in the VHA, determine VHA practice concordance with ASTRO and American College of Radiology (ACR) guidelines, and direct educational efforts towards addressing gaps in knowledge. These efforts are directed at ensuring best practices throughout this large and heterogeneous healthcare system. In 2016 a survey was conducted to evaluate concordance of VHA radiation oncologist (RO) practice with the 2011 ASTRO guidelines on palliative thoracic radiotherapy for non-small cell lung cancer (NSCLC).
Methods
A survey instrument was generated by VHA National Palliative Radiotherapy Taskforce members. It was reviewed and approved for use by the VHA Patient Care Services office. In May of 2016, the online survey was sent to the 88 VHA ROs practicing at the 40 sites with onsite radiation facilities. The survey aimed to determine patterns of practice for palliation of thoracic symptoms secondary to lung cancer.
Demographic information obtained included years in practice, employment status, academic appointment, board certification, and familiarity with ASTRO lung cancer guidelines. Two clinical scenarios were presented to glean opinions on dose/fractionation schemes preferred, use of concurrent chemotherapy, and use of EBB and/or yttrium aluminum garnet (YAG) laser technology. Survey questions also assessed use of EBRT for palliation of hemoptysis, chest wall pain, and/or stridor as well as use of stereotactic body radiotherapy (SBRT) for palliation.
Survey results were assessed for concordance with published ASTRO guidelines. χ2 tests were run to test for associations between demographic factors such as academic appointment, years of practice, full time vs part time employment, and familiarity with ASTRO palliative lung cancer guidelines, with use of EBRT for palliation, dose and fractionation preference, use of concurrent chemotherapy, and strategy for management of endobronchial lesions.
Results
Of the 88 physicians surveyed, 54 responded for a response rate of 61%. Respondents represented 37 of the 40 (93%) VHA radiation oncology departments (Table 1). Among respondents, most were board certified (96%), held academic appointments (91%), and were full-time employees (85%). Forty-four percent of respondents were in practice for > 20 years, 19% for 11 to 20 years, 20% for 6 to 10 years, and 17% for < 6 years. A majority reported familiarity with the ASTRO guidelines (64%), while just 11% reported no familiarity with the guidelines.
When asked about use of SBRT for palliation of hemoptysis, stridor, and/or chest pain, the majority (87%) preferred conventional EBRT. Of the 13% who reported use of SBRT, most (11%) performed it onsite, with 2% of respondents referring offsite to non-VHA centers for the service. When asked about use of EBB for palliation, only 2% reported use of that procedure at their facilities, while 26% reported referral to non-VHA facilities for EBB. The remaining 72% of respondents favor use of conventional EBRT.
Respondents were presented with a case of a male patient aged 70 years who smoked and had widely metastatic NSCLC, a life expectancy of about 3 months, and 10/10 chest wall pain from direct tumor invasion. All respondents recommended palliative radiotherapy. The preferred fractionation was 20 Gray (Gy) in 5 fractions, which was recommended by 69% of respondents. The remainder recommended 30 Gy in 10 fractions (22%) or a single fraction of 10 Gy (9%). No respondent recommended the longer fractionation options of 60 Gy in 30 fractions, 45 Gy in 15 fractions, or 40 Gy in 20 fractions. The majority (98%) did not recommend concurrent chemotherapy.
When the above case was modified for an endobronchial lesion requiring palliation with associated lung collapse, rather than chest wall invasion, 20 respondents (38%) reported they would refer for EBB, and 20 respondents reported they would refer for YAG laser. As > 1 answer could be selected for this question, there were 12 respondents who selected both EBB and YAG laser; 8 selected only EBB, and 8 selected only YAG laser. Many respondents added comments about treating with EBRT, which had not been presented as an answer choice. Nearly half of respondents (49%) were amenable to referral for the use of EBB or YAG laser for lung reexpansion prior to radiotherapy. Three respondents mentioned referral for an endobronchial stent prior to palliative radiotherapy to address this question.
χ2 tests were used to evaluate for significant associations between demographic factors, such as number of years in practice, academic appointment, full-time vs part-time status, and familiarity with ASTRO guidelines with clinical management choices (Table 2). The χ2 analysis revealed that these demographic factors were not significantly associated with familiarity with ASTRO guidelines, offering SBRT for palliation, EBRT fractionation scheme preferred, use of concurrent chemotherapy, or use of EBB or YAG laser.
Discussion
This survey was conducted to evaluate concordance of management of metastatic lung cancer in the VHA with ASTRO guidelines. The relationship between respondents’ familiarity with the guidelines and responses also was evaluated to determine the impact such guidelines have on decision-making. The ASTRO guidelines for palliative thoracic radiation make recommendations regarding 3 issues: (1) radiation doses and fractionations for palliation; (2) the role of EBB; and (3) the use of concurrent chemotherapy.5,6
Radiation Dose and Fractionation for Palliation
A variety of dose/fractionation schemes are considered appropriate in the ASTRO guideline statement, including more prolonged courses such as 30 Gy/10 fractions as well as more hypofractionated regimens (ie, 20 Gy/5 fractions, 17 Gy/2 fractions, and a single fraction of 10 Gy). Higher dose regimens, such as 30 Gy/10 fractions, have been associated with prolonged survival, as well as increased toxicities such as radiation esophagitis.8 Therefore, the guidelines support use of 30 Gy/10 fractions for patients with good performance status while encouraging use of more hypofractionated regimens for patients with poor performance status. In considering more hypofractionated regimens, one must consider the possibility of adverse effects that can be associated with higher dose per fraction. For instance, 17 Gy/2 fractions has been associated with myelopathy; therefore it should be used with caution and careful treatment planning.9
For the survey case example (a male aged 70 years with a 3-month life expectancy who required palliation for chest wall pain), all respondents selected hypofractionated regimens; with no respondent selected the more prolonged fractionations of 60 Gy/30 fractions, 45 Gy/15 fractions, or 40 Gy/20 fractions. These more prolonged fractionations are not endorsed by the guidelines in general, and particularly not for a patient with poor life expectancy. All responses for this case selected by survey respondents are considered appropriate per the consensus guideline statement.
Role of Concurrent Chemotherapy
The ASTRO guidelines do not support use of concurrent chemotherapy for palliation of stage IV NSCLC.5,6 The 2018 updated guidelines established a role for concurrent chemotherapy for patients with stage III NSCLC with good performance status and life expectancy of > 3 months. This updated recommendation is based on data from 2 randomized trials demonstrating improvement in overall survival with the addition of chemotherapy for patients with stage III NSCLC undergoing palliative radiotherapy.10-12
These newer studies are in contrast to an older randomized study by Ball and colleagues that demonstrated greater toxicity from concurrent chemotherapy, with no improvement in outcomes such as palliation of symptoms, overall survival, or progression free survival.13 In contrast to the newer studies that included only patients with stage III NSCLC, about half of the patients in the Ball and colleagues study had known metastatic disease.10-13 Of note, staging for metastatic disease was not carried out routinely, so it is possible that a greater proportion of patients had metastatic disease that would have been seen on imaging. In concordance with the guidelines, 98% of the survey respondents did not recommend concurrent chemotherapy for palliation of intrathoracic symptom; only 1 respondent recommended use of chemotherapy for palliation.
Role of Endobronchial Brachytherapy
EBB involves implantation of radioactive sources for treatment of endobronchial lesions causing obstructive symptoms.14 Given the lack of randomized data that demonstrate a benefit of EBB over EBRT, the ASTRO guidelines do not endorse routine use of EBB for initial palliative management.15,16 The ASTRO guidelines reference a Cochrane Review of 13 trials that concluded that EBRT alone is superior to EBB alone for initial palliation of symptoms from endobronchial NSCLC.17
Of respondents surveyed, only 1 facility offered onsite EBB. The majority of respondents (72%) preferred the use of conventional EBRT techniques, while 26% refer to non-VHA centers for EBB. Lack of incorporation of EBB into routine VHA practice likely is a reflection of the unclear role of this technology based on the available literature and ASTRO guidelines. In the setting of a right lower lung collapse, more respondents (49%) would consider use of EBB or YAG laser technology for lung reexpansion prior to EBRT.
The ASTRO guidelines recommend that initial EBB in conjunction with EBRT be considered based on randomized data demonstrating significant improvement in lung reexpansion and in patient reported dyspnea with addition of EBB to EBRT over EBRT alone.18 However, the guidelines do not mandate the use of EBB in this situation. It is possible that targeted education regarding the role of EBB would improve knowledge of the potential benefit in the setting of lung collapse and increase the percentage of VHA ROs who would recommend this procedure.
Limitations
The study is limited by lack of generalizability of these findings to all ROs in the country. It is also possible that physician responses do not represent practice patterns with complete accuracy. The use of EBB varied among practitioners. Further study of this technology is necessary to clarify its role in the management of endobronchial obstructive symptoms and to determine whether efforts should be made to increase access to EBB within the VHA.
Conclusions
Most of the ROs who responded to our survey were cognizant and compliant with current ASTRO guidelines on management of lung cancer. Furthermore, familiarity with ASTRO guidelines and management choices were not associated with the respondents’ years in practice, academic appointment, full-time vs part-time status, or familiarity with ASTRO guidelines. This study is a nationwide survey of ROs in the VHA system that reflects the radiation-related care received by veterans with metastatic lung cancer. Responses were obtained from 93% of the 40 radiation oncology centers, so it is likely that the survey accurately represents the decision-making process at the majority of centers. It is possible that those who did not respond to the survey do not treat thoracic cases.
Lung cancer is the leading cause of cancer mortality both in the US and worldwide.1 Many patients diagnosed with lung cancer present with advanced disease with thoracic symptoms such as cough, hemoptysis, dyspnea, and chest pain.2-4 Palliative radiotherapy is routinely used in patients with locally advanced and metastatic lung cancer with the goal of relieving these symptoms and improving quality of life. Guidelines published by the American Society for Radiation Oncology (ASTRO) in 2011, and updated in 2018, provide recommendations on palliation of lung cancer with external beam radiotherapy (EBRT) and clarify the roles of concurrent chemotherapy and endobronchial brachytherapy (EBB) for palliation.5,6
After prostate cancer, lung cancer is the second most frequently diagnosed cancer in the Veterans Health Administration (VHA).7 The VHA consists of 172 medical centers and is the largest integrated health care system in the US. At the time of this study, 40 of these centers had onsite radiation facilities. The VHA Palliative Radiation Taskforce has conducted a series of surveys to evaluate use of palliative radiotherapy in the VHA, determine VHA practice concordance with ASTRO and American College of Radiology (ACR) guidelines, and direct educational efforts towards addressing gaps in knowledge. These efforts are directed at ensuring best practices throughout this large and heterogeneous healthcare system. In 2016 a survey was conducted to evaluate concordance of VHA radiation oncologist (RO) practice with the 2011 ASTRO guidelines on palliative thoracic radiotherapy for non-small cell lung cancer (NSCLC).
Methods
A survey instrument was generated by VHA National Palliative Radiotherapy Taskforce members. It was reviewed and approved for use by the VHA Patient Care Services office. In May of 2016, the online survey was sent to the 88 VHA ROs practicing at the 40 sites with onsite radiation facilities. The survey aimed to determine patterns of practice for palliation of thoracic symptoms secondary to lung cancer.
Demographic information obtained included years in practice, employment status, academic appointment, board certification, and familiarity with ASTRO lung cancer guidelines. Two clinical scenarios were presented to glean opinions on dose/fractionation schemes preferred, use of concurrent chemotherapy, and use of EBB and/or yttrium aluminum garnet (YAG) laser technology. Survey questions also assessed use of EBRT for palliation of hemoptysis, chest wall pain, and/or stridor as well as use of stereotactic body radiotherapy (SBRT) for palliation.
Survey results were assessed for concordance with published ASTRO guidelines. χ2 tests were run to test for associations between demographic factors such as academic appointment, years of practice, full time vs part time employment, and familiarity with ASTRO palliative lung cancer guidelines, with use of EBRT for palliation, dose and fractionation preference, use of concurrent chemotherapy, and strategy for management of endobronchial lesions.
Results
Of the 88 physicians surveyed, 54 responded for a response rate of 61%. Respondents represented 37 of the 40 (93%) VHA radiation oncology departments (Table 1). Among respondents, most were board certified (96%), held academic appointments (91%), and were full-time employees (85%). Forty-four percent of respondents were in practice for > 20 years, 19% for 11 to 20 years, 20% for 6 to 10 years, and 17% for < 6 years. A majority reported familiarity with the ASTRO guidelines (64%), while just 11% reported no familiarity with the guidelines.
When asked about use of SBRT for palliation of hemoptysis, stridor, and/or chest pain, the majority (87%) preferred conventional EBRT. Of the 13% who reported use of SBRT, most (11%) performed it onsite, with 2% of respondents referring offsite to non-VHA centers for the service. When asked about use of EBB for palliation, only 2% reported use of that procedure at their facilities, while 26% reported referral to non-VHA facilities for EBB. The remaining 72% of respondents favor use of conventional EBRT.
Respondents were presented with a case of a male patient aged 70 years who smoked and had widely metastatic NSCLC, a life expectancy of about 3 months, and 10/10 chest wall pain from direct tumor invasion. All respondents recommended palliative radiotherapy. The preferred fractionation was 20 Gray (Gy) in 5 fractions, which was recommended by 69% of respondents. The remainder recommended 30 Gy in 10 fractions (22%) or a single fraction of 10 Gy (9%). No respondent recommended the longer fractionation options of 60 Gy in 30 fractions, 45 Gy in 15 fractions, or 40 Gy in 20 fractions. The majority (98%) did not recommend concurrent chemotherapy.
When the above case was modified for an endobronchial lesion requiring palliation with associated lung collapse, rather than chest wall invasion, 20 respondents (38%) reported they would refer for EBB, and 20 respondents reported they would refer for YAG laser. As > 1 answer could be selected for this question, there were 12 respondents who selected both EBB and YAG laser; 8 selected only EBB, and 8 selected only YAG laser. Many respondents added comments about treating with EBRT, which had not been presented as an answer choice. Nearly half of respondents (49%) were amenable to referral for the use of EBB or YAG laser for lung reexpansion prior to radiotherapy. Three respondents mentioned referral for an endobronchial stent prior to palliative radiotherapy to address this question.
χ2 tests were used to evaluate for significant associations between demographic factors, such as number of years in practice, academic appointment, full-time vs part-time status, and familiarity with ASTRO guidelines with clinical management choices (Table 2). The χ2 analysis revealed that these demographic factors were not significantly associated with familiarity with ASTRO guidelines, offering SBRT for palliation, EBRT fractionation scheme preferred, use of concurrent chemotherapy, or use of EBB or YAG laser.
Discussion
This survey was conducted to evaluate concordance of management of metastatic lung cancer in the VHA with ASTRO guidelines. The relationship between respondents’ familiarity with the guidelines and responses also was evaluated to determine the impact such guidelines have on decision-making. The ASTRO guidelines for palliative thoracic radiation make recommendations regarding 3 issues: (1) radiation doses and fractionations for palliation; (2) the role of EBB; and (3) the use of concurrent chemotherapy.5,6
Radiation Dose and Fractionation for Palliation
A variety of dose/fractionation schemes are considered appropriate in the ASTRO guideline statement, including more prolonged courses such as 30 Gy/10 fractions as well as more hypofractionated regimens (ie, 20 Gy/5 fractions, 17 Gy/2 fractions, and a single fraction of 10 Gy). Higher dose regimens, such as 30 Gy/10 fractions, have been associated with prolonged survival, as well as increased toxicities such as radiation esophagitis.8 Therefore, the guidelines support use of 30 Gy/10 fractions for patients with good performance status while encouraging use of more hypofractionated regimens for patients with poor performance status. In considering more hypofractionated regimens, one must consider the possibility of adverse effects that can be associated with higher dose per fraction. For instance, 17 Gy/2 fractions has been associated with myelopathy; therefore it should be used with caution and careful treatment planning.9
For the survey case example (a male aged 70 years with a 3-month life expectancy who required palliation for chest wall pain), all respondents selected hypofractionated regimens; with no respondent selected the more prolonged fractionations of 60 Gy/30 fractions, 45 Gy/15 fractions, or 40 Gy/20 fractions. These more prolonged fractionations are not endorsed by the guidelines in general, and particularly not for a patient with poor life expectancy. All responses for this case selected by survey respondents are considered appropriate per the consensus guideline statement.
Role of Concurrent Chemotherapy
The ASTRO guidelines do not support use of concurrent chemotherapy for palliation of stage IV NSCLC.5,6 The 2018 updated guidelines established a role for concurrent chemotherapy for patients with stage III NSCLC with good performance status and life expectancy of > 3 months. This updated recommendation is based on data from 2 randomized trials demonstrating improvement in overall survival with the addition of chemotherapy for patients with stage III NSCLC undergoing palliative radiotherapy.10-12
These newer studies are in contrast to an older randomized study by Ball and colleagues that demonstrated greater toxicity from concurrent chemotherapy, with no improvement in outcomes such as palliation of symptoms, overall survival, or progression free survival.13 In contrast to the newer studies that included only patients with stage III NSCLC, about half of the patients in the Ball and colleagues study had known metastatic disease.10-13 Of note, staging for metastatic disease was not carried out routinely, so it is possible that a greater proportion of patients had metastatic disease that would have been seen on imaging. In concordance with the guidelines, 98% of the survey respondents did not recommend concurrent chemotherapy for palliation of intrathoracic symptom; only 1 respondent recommended use of chemotherapy for palliation.
Role of Endobronchial Brachytherapy
EBB involves implantation of radioactive sources for treatment of endobronchial lesions causing obstructive symptoms.14 Given the lack of randomized data that demonstrate a benefit of EBB over EBRT, the ASTRO guidelines do not endorse routine use of EBB for initial palliative management.15,16 The ASTRO guidelines reference a Cochrane Review of 13 trials that concluded that EBRT alone is superior to EBB alone for initial palliation of symptoms from endobronchial NSCLC.17
Of respondents surveyed, only 1 facility offered onsite EBB. The majority of respondents (72%) preferred the use of conventional EBRT techniques, while 26% refer to non-VHA centers for EBB. Lack of incorporation of EBB into routine VHA practice likely is a reflection of the unclear role of this technology based on the available literature and ASTRO guidelines. In the setting of a right lower lung collapse, more respondents (49%) would consider use of EBB or YAG laser technology for lung reexpansion prior to EBRT.
The ASTRO guidelines recommend that initial EBB in conjunction with EBRT be considered based on randomized data demonstrating significant improvement in lung reexpansion and in patient reported dyspnea with addition of EBB to EBRT over EBRT alone.18 However, the guidelines do not mandate the use of EBB in this situation. It is possible that targeted education regarding the role of EBB would improve knowledge of the potential benefit in the setting of lung collapse and increase the percentage of VHA ROs who would recommend this procedure.
Limitations
The study is limited by lack of generalizability of these findings to all ROs in the country. It is also possible that physician responses do not represent practice patterns with complete accuracy. The use of EBB varied among practitioners. Further study of this technology is necessary to clarify its role in the management of endobronchial obstructive symptoms and to determine whether efforts should be made to increase access to EBB within the VHA.
Conclusions
Most of the ROs who responded to our survey were cognizant and compliant with current ASTRO guidelines on management of lung cancer. Furthermore, familiarity with ASTRO guidelines and management choices were not associated with the respondents’ years in practice, academic appointment, full-time vs part-time status, or familiarity with ASTRO guidelines. This study is a nationwide survey of ROs in the VHA system that reflects the radiation-related care received by veterans with metastatic lung cancer. Responses were obtained from 93% of the 40 radiation oncology centers, so it is likely that the survey accurately represents the decision-making process at the majority of centers. It is possible that those who did not respond to the survey do not treat thoracic cases.
1. Torre LA, Bray F, Siegel RL, Ferlay J, Lortet-Tieulent J, Jemal A. Global cancer statistics, 2012. CA Cancer J Clin. 2015 65(2):87-108.
2. Kocher F, Hilbe W, Seeber A, et al. Longitudinal analysis of 2293 NSCLC patients: a comprehensive study from the TYROL registry. Lung Cancer. 2015;87(2):193-200.
3. Chute CG, Greenberg ER, Baron J, Korson R, Baker J, Yates J. Presenting conditions of 1539 population-based lung cancer patients by cell type and stage in New Hampshire and Vermont. Cancer. 1985;56(8):2107-2111.
4. Hyde L, Hyde Cl. Clinical manifestations of lung cancer. Chest. 1974;65(3):299-306.
5. Rodrigues G, Videtic GM, Sur R, et al. Palliative thoracic radiotherapy in lung cancer: An American Society for Radiation Oncology evidence-based clinical practice guideline. Pract Radiat Oncol. 2011;1(2):60-71.
6. Moeller B, Balagamwala EH, Chen A, et al. Palliative thoracic radiation therapy for non-small cell lung cancer: 2018 Update of an American Society for Radiation Oncology (ASTRO) Evidence-Based Guideline. Pract Radiat Oncol. 2018;8(4):245-250.
7. Zullig LL, Jackson GL, Dorn RA, et al. Cancer incidence among patients of the United States Veterans Affairs (VA) healthcare system. Mil Med. 2012;177(6):693-701.
8. Fairchild A, Harris K, Barnes E, et al. Palliative thoracic radiotherapy for lung cancer: a systematic review. J Clin Oncol. 2008;26(24):4001-4011.
9. A Medical Research Council (MRC) randomised trial of palliative radiotherapy with two fractions or a single fraction in patients with inoperable non-small-cell lung cancer (NSCLC) and poor performance status. Medical Research Council Lung Cancer Working Party. Br J Cancer. 1992;65(6):934-941.
10. Nawrocki S, Krzakowski M, Wasilewska-Tesluk E, et al. Concurrent chemotherapy and short course radiotherapy in patients with stage IIIA to IIIB non-small cell lung cancer not eligible for radical treatment: results of a randomized phase II study. J Thorac Oncol. 2010;5(8):1255-1262.
11. Strøm HH, Bremnes RM, Sundstrøm SH, Helbekkmo N, Fløtten O, Aasebø U. Concurrent palliative chemoradiation leads to survival and quality of life benefits in poor prognosis stage III non-small-cell lung cancer: a randomised trial by the Norwegian Lung Cancer Study Group. Br J Cancer. 2013;109(6):1467-1475.
12. Strøm HH, Bremnes RM, Sundstrøm SH, Helbekkmo N, Aasebø U. Poor prognosis patients with inoperable locally advanced NSCLC and large tumors benefit from palliative chemoradiotherapy: a subset analysis from a randomized clinical phase III trial. J Thorac Oncol. 2014;9(6):825-833.
13. Ball D, Smith J, Bishop J, et al. A phase III study of radiotherapy with and without continuous-infusion fluorouracil as palliation for non-small-cell lung cancer. Br J Cancer. 1997;75(5):690-697.
14. Stewart A, Parashar B, Patel M, et al. American Brachytherapy Society consensus guidelines for thoracic brachytherapy for lung cancer. Brachytherapy. 2016;15(1):1-11.
15. Sur R, Ahmed SN, Donde B, Morar R, Mohamed G, Sur M, Pacella JA, Van der Merwe E, Feldman C. Brachytherapy boost vs teletherapy boost in palliation of symptomatic, locally advanced non-small cell lung cancer: preliminary analysis of a randomized prospective study. J Brachytherapy Int. 2001;17(4):309-315.
16. Sur R, Donde B, Mohuiddin M, et al. Randomized prospective study on the role of high dose rate intraluminal brachytherapy (HDRILBT) in palliation of symptoms in advanced non-small cell lung cancer (NSCLC) treated with radiation alone. Int J Radiat Oncol Biol Phys. 2004;60(1):S205.
17. Ung YC, Yu E, Falkson C, et al. The role of high-dose-rate brachytherapy in the palliation of symptoms in patients with non-small cell lung cancer: a systematic review. Brachytherapy. 2006;5:189-202.
18. Langendijk H, de Jong J, Tjwa M, et al. External irradiation versus external irradiation plus endobronchial brachytherapy in inoperable non-small cell lung cancer: a prospective randomized study. Radiother Oncol. 2001;58(3):257-268.
1. Torre LA, Bray F, Siegel RL, Ferlay J, Lortet-Tieulent J, Jemal A. Global cancer statistics, 2012. CA Cancer J Clin. 2015 65(2):87-108.
2. Kocher F, Hilbe W, Seeber A, et al. Longitudinal analysis of 2293 NSCLC patients: a comprehensive study from the TYROL registry. Lung Cancer. 2015;87(2):193-200.
3. Chute CG, Greenberg ER, Baron J, Korson R, Baker J, Yates J. Presenting conditions of 1539 population-based lung cancer patients by cell type and stage in New Hampshire and Vermont. Cancer. 1985;56(8):2107-2111.
4. Hyde L, Hyde Cl. Clinical manifestations of lung cancer. Chest. 1974;65(3):299-306.
5. Rodrigues G, Videtic GM, Sur R, et al. Palliative thoracic radiotherapy in lung cancer: An American Society for Radiation Oncology evidence-based clinical practice guideline. Pract Radiat Oncol. 2011;1(2):60-71.
6. Moeller B, Balagamwala EH, Chen A, et al. Palliative thoracic radiation therapy for non-small cell lung cancer: 2018 Update of an American Society for Radiation Oncology (ASTRO) Evidence-Based Guideline. Pract Radiat Oncol. 2018;8(4):245-250.
7. Zullig LL, Jackson GL, Dorn RA, et al. Cancer incidence among patients of the United States Veterans Affairs (VA) healthcare system. Mil Med. 2012;177(6):693-701.
8. Fairchild A, Harris K, Barnes E, et al. Palliative thoracic radiotherapy for lung cancer: a systematic review. J Clin Oncol. 2008;26(24):4001-4011.
9. A Medical Research Council (MRC) randomised trial of palliative radiotherapy with two fractions or a single fraction in patients with inoperable non-small-cell lung cancer (NSCLC) and poor performance status. Medical Research Council Lung Cancer Working Party. Br J Cancer. 1992;65(6):934-941.
10. Nawrocki S, Krzakowski M, Wasilewska-Tesluk E, et al. Concurrent chemotherapy and short course radiotherapy in patients with stage IIIA to IIIB non-small cell lung cancer not eligible for radical treatment: results of a randomized phase II study. J Thorac Oncol. 2010;5(8):1255-1262.
11. Strøm HH, Bremnes RM, Sundstrøm SH, Helbekkmo N, Fløtten O, Aasebø U. Concurrent palliative chemoradiation leads to survival and quality of life benefits in poor prognosis stage III non-small-cell lung cancer: a randomised trial by the Norwegian Lung Cancer Study Group. Br J Cancer. 2013;109(6):1467-1475.
12. Strøm HH, Bremnes RM, Sundstrøm SH, Helbekkmo N, Aasebø U. Poor prognosis patients with inoperable locally advanced NSCLC and large tumors benefit from palliative chemoradiotherapy: a subset analysis from a randomized clinical phase III trial. J Thorac Oncol. 2014;9(6):825-833.
13. Ball D, Smith J, Bishop J, et al. A phase III study of radiotherapy with and without continuous-infusion fluorouracil as palliation for non-small-cell lung cancer. Br J Cancer. 1997;75(5):690-697.
14. Stewart A, Parashar B, Patel M, et al. American Brachytherapy Society consensus guidelines for thoracic brachytherapy for lung cancer. Brachytherapy. 2016;15(1):1-11.
15. Sur R, Ahmed SN, Donde B, Morar R, Mohamed G, Sur M, Pacella JA, Van der Merwe E, Feldman C. Brachytherapy boost vs teletherapy boost in palliation of symptomatic, locally advanced non-small cell lung cancer: preliminary analysis of a randomized prospective study. J Brachytherapy Int. 2001;17(4):309-315.
16. Sur R, Donde B, Mohuiddin M, et al. Randomized prospective study on the role of high dose rate intraluminal brachytherapy (HDRILBT) in palliation of symptoms in advanced non-small cell lung cancer (NSCLC) treated with radiation alone. Int J Radiat Oncol Biol Phys. 2004;60(1):S205.
17. Ung YC, Yu E, Falkson C, et al. The role of high-dose-rate brachytherapy in the palliation of symptoms in patients with non-small cell lung cancer: a systematic review. Brachytherapy. 2006;5:189-202.
18. Langendijk H, de Jong J, Tjwa M, et al. External irradiation versus external irradiation plus endobronchial brachytherapy in inoperable non-small cell lung cancer: a prospective randomized study. Radiother Oncol. 2001;58(3):257-268.