Stereotactic body radiotherapy for prostate cancer: A preliminary report

Abstract

We report the results of a retrospective study of stereotactic body radiotherapy (SBRT) using a Cyberknife for prostate cancer. In all 29 patients were treated with hypofractionated SBRT using a Cyberknife at median 36 Gy in five fractions. All the patients were treated with a radical aim. Prostate-specific antigen (PSA) was evaluated at baseline and after radiotherapy. Acute (≤3 months) and late (>3 months) urinary and rectal toxicities were recorded according to the CTCAE version 4.0. The median duration of follow up was 41 months. PSA values decreased in a time-dependent way. The median PSA nadir was 0.329 ng/mL, achieved after a median of 23 months' follow up. Two patients had a PSA failure according to the definition of nadir + 2 ng/mL. Eight patients (28%) had a benign PSA bounce at median 9 months after radiotherapy. CTCAE Grade 2 and 3 late urinary toxicities were reported in 3 and 3%, respectively. One patient had exacerbated urinary symptoms and received an operation. There were no severe late rectal toxicities. The preliminary findings of our study suggest SBRT is feasible for prostate cancer treatment. Further studies with more patients and longer follow-up duration are required.