Objective: To understand oncologic outcomes of focal cryoablation for prostate cancer and efficacy MRI and PSA to predict residual disease and recurrence.
Methods: We retrospectively analyzed patients who underwent focal cryotherapy at a single institution. Inclusion criteria included clinically localized biopsy-proven cancer that was clearly visible on MRI or ultrasound. The primary outcomes were failure-free survival (FFS) defined as no transition to radical, whole-gland or systemic therapy and biochemical recurrence (Phoenix PSA nadir +2 increases), and secondary outcomes included changes in the Gleason grade group (GG) and MRI findings.
Results: 75 patients completed post cryotherapy biopsy with a median follow-up of 1.89 [IQR 1.19-2.77] years. Failure free survival was met by 96.2% of patients at 2 year follow up and of those who did not meet this outcome, 3 had metastasis, 1 had a salvage prostatectomy and 5 underwent radiation. On the treated side of the prostate, 7 (9.5%) of patients had residual ≥GG2 disease compared to 7 (9.5%) patients on the untreated side. Out of the 12 patients who had residual ≥GG2 disease at follow up biopsy (either on treated or untreated side of the prostate), 11 (91.7%) had PI-RADS 1-3 on follow up MRI. Using a multivariate cox proportional hazards model, Phoenix criteria for recurrence (PSA nadir +2) was not predictive for FFS.
Conclusions: Focal cryotherapy is effective for treating focal lesions of prostate cancer, but patients require continued surveillance. MRI and PSA are not reflective of residual disease on follow up biopsy.
Keywords: Cryosurgery; Magnetic resonance imaging; Prostate ancer.
Published by Elsevier Inc.