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Purpose: Traditional radiation therapy for prostate cancer is given over 39 – 42 daily fractions. There have been increasing efforts to decrease the treatment time by using hypofractionated radiotherapy. The purpose of this retrospective study is to evaluate the acute toxicities (RTOG definition) in prostate cancer patients when using hypofractionated radiotherapy.

Methods: 42 patients were treated with 25 daily fractions from 2014 – 2015. Patient, tumor, and dosimetric factors (rectal and bladder min dose, max dose, mean dose, median dose, volume, V31, V50, as well as PTV max, min, mean, and median doses) were analyzed to find associations between acute (< 90 days) GU and GI toxicities.

Results: The median age was 68 with a median follow-up of 18 months. There were 2 low, 12 intermediate, and 18 high risk patients (NCCN criteria). Dose fractionations schemas used were 267 cGy (n = 6), 270 cGy (n = 14); 275 cGy (n = 17), and some high risk patients received a simultaneous integrated boost (SIB) of 300 cGy (n = 5) to a smaller volume of the prostate. 13 patients received pelvic irradiation via SIB at 200 cGy per fraction. 10 patients received no androgen deprivation therapy (ADT), 15 received short term ADT (≤ 6 months), and 17 received long term ADT (> 6 months). Grade 0 acute GU toxicity occurred in 12 patients (29%), grade 1 in 7 (17%), grade 2 in 22 (52%), and grade 3 in 1 (2%). Grade 0 acute GI toxicity occurred in 30 patients (71%), grade 1 in 5 (12%), grade 2 in 7 (17), and no grade 3 toxicity. There were no grade 4 or 5 toxicities. On univariate analysis, factors positively associated with acute GU toxicity were AUA score (P = .02) and PTV max dose (P = .04); acute GI were pelvic radiation (P = .04) and rectal min dose (P = .02). These factors were not significant on multivariate analysis.

Conclusion: Volumetric Arc Therapy based hypofractionated radiotherapy was well tolerated and is an acceptable treatment for prostate cancer patients. Larger and adequately powered studies are needed to validate these findings.

Purpose: Traditional radiation therapy for prostate cancer is given over 39 – 42 daily fractions. There have been increasing efforts to decrease the treatment time by using hypofractionated radiotherapy. The purpose of this retrospective study is to evaluate the acute toxicities (RTOG definition) in prostate cancer patients when using hypofractionated radiotherapy.

Methods: 42 patients were treated with 25 daily fractions from 2014 – 2015. Patient, tumor, and dosimetric factors (rectal and bladder min dose, max dose, mean dose, median dose, volume, V31, V50, as well as PTV max, min, mean, and median doses) were analyzed to find associations between acute (< 90 days) GU and GI toxicities.

Results: The median age was 68 with a median follow-up of 18 months. There were 2 low, 12 intermediate, and 18 high risk patients (NCCN criteria). Dose fractionations schemas used were 267 cGy (n = 6), 270 cGy (n = 14); 275 cGy (n = 17), and some high risk patients received a simultaneous integrated boost (SIB) of 300 cGy (n = 5) to a smaller volume of the prostate. 13 patients received pelvic irradiation via SIB at 200 cGy per fraction. 10 patients received no androgen deprivation therapy (ADT), 15 received short term ADT (≤ 6 months), and 17 received long term ADT (> 6 months). Grade 0 acute GU toxicity occurred in 12 patients (29%), grade 1 in 7 (17%), grade 2 in 22 (52%), and grade 3 in 1 (2%). Grade 0 acute GI toxicity occurred in 30 patients (71%), grade 1 in 5 (12%), grade 2 in 7 (17), and no grade 3 toxicity. There were no grade 4 or 5 toxicities. On univariate analysis, factors positively associated with acute GU toxicity were AUA score (P = .02) and PTV max dose (P = .04); acute GI were pelvic radiation (P = .04) and rectal min dose (P = .02). These factors were not significant on multivariate analysis.

Conclusion: Volumetric Arc Therapy based hypofractionated radiotherapy was well tolerated and is an acceptable treatment for prostate cancer patients. Larger and adequately powered studies are needed to validate these findings.

Purpose: Traditional radiation therapy for prostate cancer is given over 39 – 42 daily fractions. There have been increasing efforts to decrease the treatment time by using hypofractionated radiotherapy. The purpose of this retrospective study is to evaluate the acute toxicities (RTOG definition) in prostate cancer patients when using hypofractionated radiotherapy.

Methods: 42 patients were treated with 25 daily fractions from 2014 – 2015. Patient, tumor, and dosimetric factors (rectal and bladder min dose, max dose, mean dose, median dose, volume, V31, V50, as well as PTV max, min, mean, and median doses) were analyzed to find associations between acute (< 90 days) GU and GI toxicities.

Results: The median age was 68 with a median follow-up of 18 months. There were 2 low, 12 intermediate, and 18 high risk patients (NCCN criteria). Dose fractionations schemas used were 267 cGy (n = 6), 270 cGy (n = 14); 275 cGy (n = 17), and some high risk patients received a simultaneous integrated boost (SIB) of 300 cGy (n = 5) to a smaller volume of the prostate. 13 patients received pelvic irradiation via SIB at 200 cGy per fraction. 10 patients received no androgen deprivation therapy (ADT), 15 received short term ADT (≤ 6 months), and 17 received long term ADT (> 6 months). Grade 0 acute GU toxicity occurred in 12 patients (29%), grade 1 in 7 (17%), grade 2 in 22 (52%), and grade 3 in 1 (2%). Grade 0 acute GI toxicity occurred in 30 patients (71%), grade 1 in 5 (12%), grade 2 in 7 (17), and no grade 3 toxicity. There were no grade 4 or 5 toxicities. On univariate analysis, factors positively associated with acute GU toxicity were AUA score (P = .02) and PTV max dose (P = .04); acute GI were pelvic radiation (P = .04) and rectal min dose (P = .02). These factors were not significant on multivariate analysis.

Conclusion: Volumetric Arc Therapy based hypofractionated radiotherapy was well tolerated and is an acceptable treatment for prostate cancer patients. Larger and adequately powered studies are needed to validate these findings.