Accelerated hypofractioned postoperative radiotherapy for prostate cancer: a prospective phase I/II study.

ABSTRACT

AIMS: To present the initial findings of a single institution, phase I/II study investigating hypofractionated radiotherapy in patients undergoing post-prostatectomy treatment. MATERIALS AND METHODS: Patients requiring postoperative radiotherapy were prospectively enrolled. Dose was prescribed to the prostate bed with 51 Gy in 17 daily fractions. Androgen deprivation was optional. Acute and late gastrointestinal/genitourinary toxicity were assessed using the National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0 and quality of life was assessed using the Expanded Prostate Cancer Index Composite evaluation tool. Prostate-specific antigen (PSA) was evaluated at every follow-up. RESULTS: Thirty patients were enrolled between 2009 and 2011. The median age was 65 years and most had Gleason 7 disease (86%) with pT2c or pT3a (82%). Positive margins were documented in 67% of the patients. The median pre-treatment PSA was 0.12 ng/ml. The median follow-up was 24 months. Overall toxicity was low, with >80% of patients having ≤ grade 1 acute toxicity in both genitourinary and gastrointestinal realms. Similarly, only two patients (6%) experienced grade 2/3 late gastrointestinal/genitourinary toxicity. Quality of life scores were also indicative of a well-tolerated treatment. PSA failure was seen in five patients (17%). CONCLUSIONS: We present a hypofractionated schedule of postoperative prostate radiotherapy that is both well tolerated in terms of both toxicity and quality of life measures. Initial PSA control is encouraging. Further evaluation with a longer follow-up and a larger cohort is warranted.