Magnetic resonance imaging-ultrasound fusion guided focal cryoablation for men with intermediate-risk prostate cancer

Abstract

IntroductionFocal therapy (FT) is a form of ablative treatment offered to men with localized, organ-confined prostate cancer (CaP). Pelvic multiparametric magnetic resonance imaging (mpMRI) and mpMRI/transrectal ultrasound fusion (MRI-US) guidance enable the precise delivery of FT with limited ablation of adjacent benign tissue or vital genitourinary structures. This article presents our findings on using MRI-US to perform FT as a primary treatment for men with intermediate-risk CaP. MethodsThirty-six men underwent MRI-US fusion-guided FT cryoablation at a single center from 2018 to 2023 as a primary treatment for intermediate-risk CaP. Following FT, quarterly prostate-specific antigen (PSA) testing and a 6 to 9 month mpMRI and combined MRI-US targeted and systematic biopsy were performed. Oncological outcomes were determined using several endpoints containing biochemical recurrence, imaging failure, and pathological failure. Functional outcomes were measured using reported erectile dysfunction/potency rates, urinary incontinence rates, and the American Urologic Association Symptom Score (AUA-SS) and Sexual Health Inventory for Men (SHIM) indices. ResultsMedian follow-up was 29.1 months, most (75%) of whom had grade group 2 CaP. Out of the 36 men, 32 (88.9%) completed the combined MRI-targeted and systematic biopsy follow-up after treatment. The study had no major complications, but 12 (33.3%) patients experienced Clavien-Dindo grade II or lower complications. For oncological outcomes, 6 (16.7%) men had biochemical recurrence, 9 (25%) showed imaging failure, and 8 (22.2%) met the criteria for positive biopsy- out-of-field vs. in-field. 88.2% of previously potent patients remained potent postoperatively at 12 months. All patients were continent at 12 months. There were no statistically significant changes in the AUA-SS and SHIM scores postoperatively. ConclusionMRI-US-guided cryoablation to target lesions in intermediate-risk CaP appears to be a safe treatment option, with functional outcomes indicating minimal short and intermediate-term morbidity and acceptable oncological outcomes. However, despite close monitoring and follow-up, there is still a limitation in accurately predicting/detecting pathological failure after FT. The long-term durability of FT for intermediate-risk, organ-confined CaP remains uncertain.