MR-guided Transrectal Focal Laser Ablation for Localized Low- and Intermediate Risk Prostate Cancer: Initial Outcomes Using an Integrated Laser Ablation System.

Purpose: To investigate the feasibility and safety of MRI-guided focal laser ablation (FLA) in localized, International Society of Urological Pathology (ISUP) grade 1-3, prostate cancer (PCa) using an integrated system.

Methods: Ten consecutive males (mean age: 66±7 years) with low-to-intermediate risk PCa were prospectively included (April 2022-May 2023) and treated with MRI-guided FLA using an integrated system for laser energy control and MR thermometry monitoring. Primary endpoints were technical success, procedure-related adverse events (AEs) following SIR (Society of Interventional Radiology) classification, and 12-months local tumor progression-free survival (LTPFS), defined as no evident residual/ recurrent disease on follow-up imaging or histopathology at the treatment site. Secondary endpoints included MRI-derived percentual volumetric tumor coverage, prostate-specific antigen (PSA), sexual and urinary function response measured by the International Prostate Symptom Score index and Sexual Health Inventory for Men (SHIM) questionnaires.

Results: Technical success was achieved in 10/10 (100%) patients (ISUP grade 1 (n=1), 2 (n=8) and 3 (n=1)). Three AEs were observed: urinary tract infection (n=2; SIR grade B) and acute urinary retention (n=1; SIR grade D). Cumulative 12-month LTPFS was 80% (8/10 patients). Median tumor coverage was 100% (IQR: 95-100%). Compared to baseline, the mean PSA level decreased, but did not reach statistical significance (6.6 vs. 4.4 ng/mL; p=0.06), and mean urinary (8.6 vs. 7.3; p=0.60) and sexual function (11.3 vs. 10.5; p=1.00) scores were non-significantly altered at 12 months follow-up.

Conclusion: MRI-guided FLA in patients with low-to-intermediate risk PCa using an integrated system was feasible and safe and indicates promising short-term oncological and functional outcomes.