Safety of accelerated hypofractionated whole pelvis radiation therapy prior to high dose rate brachytherapy or stereotactic body radiation therapy prostate boost

Abstract

Background To evaluate acute and late genitourinary and gastrointestinal toxicities and patient reported urinary and sexual function following accelerated, hypofractionated external beam radiotherapy to the prostate, seminal vesicles and pelvic lymph nodes and high dose rate (HDR) brachytherapy or stereotactic body radiation therapy (SBRT) prostate boost. Methods Patients at a single institution with NCCN intermediate- and high-risk localized prostate cancer with logistical barriers to completing five weeks of whole pelvic radiotherapy (WPRT) were retrospectively reviewed for toxicity following accelerated, hypofractionated WPRT (41.25 Gy in 15 fractions of 2.75 Gy). Patients also received prostate boost radiotherapy with either HDR brachytherapy (1 fraction of 15 Gy) or SBRT (19 Gy in 2 fractions of 9.5 Gy). The duration of androgen deprivation therapy was at the discretion of the treating radiation oncologist. Toxicity was evaluated by NCI CTCAE v 5.0. Results Between 2015 and 2017, 22 patients with a median age of 71 years completed accelerated, hypofractionated WPRT. Median follow-up from the end of radiotherapy was 32 months (range 2–57). 5%, 73%, and 23% of patients had clinical T1, T2, and T3 disease, respectively. 86% of tumors were Gleason grade 7 and 14% were Gleason grade 9. 68% and 32% of patients had NCCN intermediate- and high-risk disease, respectively. 91% and 9% of patients received HDR brachytherapy and SBRT prostate boost following WPRT, respectively. Crude rates of grade 2 or higher GI and GU toxicities were 23% and 23%, respectively. 3 patients (14%) had late or persistent grade 2 toxicities of urinary frequency and 1 patient (5%) had late or persistent GI toxicity of diarrhea. No patient experienced grade 3 or higher toxicity at any time. No difference in patient-reported urinary or sexual function was noted at 12 months. Conclusions Accelerated, hypofractionated whole pelvis radiotherapy was associated with acceptable GU and GI toxicities and should be further validated for those at risk for harboring occult nodal disease.

Postoperative Hypofractionated Intensity-Modulated Radiotherapy With Concurrent Chemotherapy in Cervical Cancer

“…The safety of using hypofractionation exceeding 2 Gy per fraction in the pelvic area has been extensively evaluated in prostate cancer . Phuong et al reported acceptable toxic effects without any that were grade 3 or higher when using whole pelvis RT with 41.25 Gy at 15 fractions. Similarly, Moll et al evaluated GI tract and GU toxic effects following hypofractionated whole pelvis RT with 46 Gy at 2.3 Gy per fraction compared with conventional fractionated RT.…”

“…However, evidence regarding bowel tolerance in hypofractionation regimens is limited. The safety of using hypofractionation exceeding 2 Gy per fraction in the pelvic area has been extensively evaluated in prostate cancer . Phuong et al reported acceptable toxic effects without any that were grade 3 or higher when using whole pelvis RT with 41.25 Gy at 15 fractions.…”

Assessing the toxicity after moderately hypofractionated prostate and whole pelvis radiotherapy compared to conventional fractionation

“…We were able to identify 3 publications covering the topic of WPRT hypofractionation. The first one is a small retrospective study with only 22 patients, applying WPRT with 2.75 Gy in 15 fractions and a HDR-brachytherapy or stereotactic boost to the prostate, showing acceptable GI and GU toxicity [ 29 ]. The other 2 are also mentioned in a recently published meta-analysis [ 19 ], covering the topic of moderate hypofractionation for prostate cancer.…”