Introduction: Localised prostate cancer recurrence after radiotherapy is commonly managed with systemic therapy or watchful waiting due to significant complications and side-effects following salvage prostatectomy. Focal Ablative Salvage Therapy (FAST) using high intensity focussed ultrasound (HIFU) or cryotherapy might be an optimal approach to delay metastases and time to systemic therapy. Methods: The HEAT and ICE registries included 292 patients undergoing FAST (June 2008-Feb 2022) (HIFU n=232, cryotherapy n=60). Primary outcome was metastases free survival. Secondary outcomes were 1) overall survival (OS), 2) ADT free survival (AFS) where ADT was prescribed due to biochemical recurrence (BCR, PSA nadir+2ng/ml), 3) retreatment free survival (RFS), and 4) composite Failure Free Survival (FFS) where a failure event was BCR, retreatment of any form, ADT, metastases or prostate cancer death was reported. 6-year Kaplan-Meier estimates (95% CI) and adverse events classified using Clavien-Dindo (CD) are reported. Results: 276 (HIFU n=216, cryotherapy n=60) recorded follow-up outcomes at the time of analysis. 242, 25 and 9 previously had external radiotherapy, brachytherapy or combination, respectively. Patients underwent mpMRI and systematic +/- targeted biopsy, with PET imaging (choline or PSMA). Median (IQR) PSA at time of recurrence was 5.5ng/ml (3-8); stage T2 in 66%, T3a 13% and T3b 8%. Median (IQR) follow up time was 30 months (14-52). 141/276 had reported composite treatment failure, 82 patients received at least 1 form of retreatment (25 focal ablation, 1 whole gland ablation, 2 salvage prostatectomy, 1 salvage radiotherapy, 51 ADT), 8 had metastases and 22 died. Metastases-free survival was 94% (86-97%) with median (IQR) 21 (13-44) months metastases (Figure 1). OS was 86% (76-92%), AFS 61% (47-72%), RFS 40% (29-52%), and composite FFS 21% (13-30%). Median (IQR) time from FAST to retreatment, ADT prescription and OS was 18 (12-33), 20 (13-39), and 53 (38-84) months, respectively. 24 had an adverse event with 4 CD grade >/=3 events: 3 (1%) had fistula and 1 (0.4%) a urethral stricture. Conclusions: With a low rate of adverse events, FAST confers good metastases-free survival in this high risk cohort with the majority avoiding ADT due to biochemical recurrence. SOURCE OF Funding: n/a
