Purpose: We report the largest data set to date to our knowledge regarding outcomes for primary whole gland prostate cryoablation.
Materials and methods: The COLD (Cryo On-Line Data) Registry consists of case report forms obtaining pretreatment and posttreatment information for patients undergoing whole gland prostate cryoablation. A total of 1,198 patients were stratified into low, intermediate and high risk groups. Biochemical success was defined according to the traditional American Society for Therapeutic Radiology and Oncology definition (3 increases) and the newer (Phoenix) definition (nadir +2). Biopsy was performed at physician discretion but most commonly for cause if a patient had an increasing or suspicious prostate specific antigen.
Results: Average patient age was 69.8 +/- 7.5 years. Pretreatment prostate specific antigen was 9.6 +/- 8.6 ng/ml and median Gleason sum was 7 (range 4 to 10). Patients were followed for 24.4 +/- 25.9 months with 136 having minimum 5-year data. The 5-year biochemical disease-free status for the entire population was 77.1% +/- 2.1% (American Society for Therapeutic Radiology and Oncology) and 72.9% +/- 2.1% (Phoenix). Five-year American Society for Therapeutic Radiology and Oncology biochemical disease-free status was 84.7% +/- 4.5%, 73.4% +/- 4.3% and 75.3% +/- 3.7% for the low, moderate and high risk groups, respectively. Using the Phoenix definition the biochemical disease-free status was 91.1% +/- 2.9%, 78.5% +/- 3.6% and 62.2% +/- 4.9%, respectively. As predicted based on intentional preservation of some prostatic tissue, 72.5 +/- 1.8% had a detectable prostate specific antigen 0.2 ng/ml or greater at 5 years. Biopsy after cryotherapy was positive during empiric without cause biopsy in 30 of 207 patients (14.5%), and the highly selected group biopsied based on suspicion of treatment failure due to abnormal or increasing prostate specific antigen had positive results in 38.0% (49 of 129). The rectal fistula rate was 0.4% and incontinence was 4.8% with 2.9% of patients using pads. Intercourse was reported by 25.2% but only 8.8% without pharmaceutical or device assistance.
Conclusions: Whole gland cryoablation, practiced in a spectrum of academic and community users, maintains efficacy and morbidity similar to that of single center reports.