Biochemical outcome of prostate cancer patients treated with hypofractionated external radiation and a single high-dose-rate brachytherapy boost

INTRODUCTION Treating localized high-risk prostate cancer with a combination of external beam radiation therapy (EBRT) and high-dose-rate brachytherapy (HDR-BT) is a common approach. Moderately hypofractionated EBRT and a single HDR-BT boost simplifies the treatment. We aim to present our five-year results. METHODS In this study, 355 patients treated with moderately hypofractionated EBRT (42 Gy in 14 fractions) and a single HDR-BT boost (14.5 Gy) at & Ouml;rebro University Hospital between 2008 and 2018 were included. They were followed with regular PSA tests. RESULTS The median age of the cohort was 70 years (range: 51-81) and the median follow-up duration was 56 months (range: 6-150). Among them, 45% were classified as very high-risk, 38% as high-risk and 17% as intermediate-risk. Adjuvant androgen deprivation therapy (ADT) with a median duration of 24 months was given to 75% of the patient cohort. The estimated 5-year failure free survival rates were 79% (whole cohort), 66% (very high-risk), 90% (high-risk) and 85% (intermediate-risk), respectively. Initial PSA > 10 ng/mL, Gleason score 9-10 and tumor stage T3 were significantly associated with biochemical failure (BF). A PSA bounce occurred in 53 (15%) cases and was inversely associated with BF (p = 0.001) for patients receiving ADT. CONCLUSIONS Moderately hypofractionated EBRT and a single HDR-BT boost seems to be an effective treatment against intermediate- and high-risk localized prostate cancer. Treatment escalation strategies should be investigated for very high-risk patients where the risk of recurrence remains high. (c) 2024 The Authors. Published by Elsevier Inc. on behalf of American Brachytherapy Society. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/)