Is hemi-gland focal LDR brachytherapy as effective as whole-gland treatment for unilateral prostate cancer?

PURPOSE: The Hemi-Ablative Prostate Brachytherapy (HAPpy) trial evaluated hemi-gland (HG) low-dose-rate prostate brachytherapy (LDR-PB) as a focal approach to control unilateral localized prostate cancer and reduce treatment-related toxicity at 2-years postimplant. Herewith we present further outcomes with a minimum of 5 years post-implant follow-up. METHODS AND MATERIALS: Outcomes of 30 HG implants and 362 whole-gland (WG) brachytherapy controls were monitored with IPSS, urinary Quality-of-Life (QoLU), GI component of EORTC-PR25 (QoLB), and IIEF-5 instruments, and PSA values. The median (range) follow-up for HG and WG cases was 72 (60-96) months and 84 (24-144) months respectively. RESULTS: The IPSS was significantly reduced in HG relative to WG patients and trends indicating improved bowel QoL and erectile function were observed. The mean of change in PSA from baseline to last follow-up was -5.6 and -6.5 in HG and WG respectively (p = 0.1). The mean time to nadir was 4.2 and 4.8 years in HG and WG respectively (p = 0.06). Over time PSA in HG patients mirrored the sustained decline observed in WG cases but levels were higher by an average 0.5 ng/ml over WG controls (p < 0.001). Treatment failure occurred in 2 (6.7%) HG patients and in 20 (5.5%) WG cases. Five-year relapse-free survival was 97% in both groups (p = 0.7). CONCLUSIONS: At 5 years postimplant HG LDR-PB was as effective as WG treatment for control of unilateral localized prostate cancer with moderate improvement in treatment-related symptoms. Importantly, PSA is a valuable marker to assess disease control in this form of focal therapy. (c) 2022 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.