Natural History of Patients Undergoing Transperineal Fusion Biopsies to Transperineal Fusion Cryoablation: 5-Year...

Introduction: Randomized trials comparing radical treatments with surveillance for prostate cancer (PCa) have shown marginal survival benefit with significant detriment in quality of life. MR fusion cryoablation (MRFC) has emerged as a promising approach. We evaluated outcomes of men diagnosed with transperineal fusion biopsies (TPFBx) and treated with MRFC providing intermediate oncological and functional outcomes. Methods: Clinical trial NCT02381990 is a longitudinal registry designed to evaluate outcomes of MRFC for PCa. In this multi-institutional study, we evaluated men with clinically significant PCa (CSPCa) determined by TPFBx, managed with MRFC (<40% of the prostate) in an office setting under local anesthesia. Disease progression (DP), considered a natural history event, was defined as conversion to whole gland treatment, or androgen deprivation or development of metastasis. Univariate and Cox proportional hazards models along with competing risk (CRA) were used against DP. Secondary and functional outcomes are also reported to provide a comprehensive understanding of the therapeutic impact of MRFC. Results: In total, 632 patients met CSPCa criteria managed with MRFC. Median procedure time and pain score were 52 minutes and 2/10, respectively. The 5-year DP rate was 10%. Prostate-specific antigen density was the only independent predictor. Urinary outcomes improved in 3 months and held overtime. Sexual function was affected modestly. A 1-year TPFBx was performed in 439/632 (69%) with PCa and CSPCa found in 144 and 54. IN-field CSPCa and OUT-field CSPCa were present in 19 and 43, respectively. Eight had CSPCa in both fields. Significant reduction in cancer burden at the 1-year biopsy was observed as both IN-field and OUT-field lesions showed a median tumor size under 5 mm. Overall, a second MRFC was conducted in 106/632 men; 17 and 89 were for IN-field and OUT-field tumors, respectively. Conclusions: Office-based MRFC affects the natural progression of PCa while causing minimal impact on functional outcomes. Comprehensive evaluations through randomized controlled trials are necessary to further validate these findings and confirm their effectiveness.