Proactive rectal warming during total-gland prostate cryoablation.

ABSTRACT

PURPOSE: Proactive rectal warming (PRW), as a modification of prostate cryoablation, was assessed in terms of rectal complications and therapeutic outcomes. MATERIALS AND METHODS: A cohort of 166 patients cumulatively treated between September, 2009 and November, 2012 qualified for study, each undergoing total-gland cryoablation (TGC) for prostate cancer. The initial 100 patients accrued submitted to TGC alone. PRW was administered to the final 66 patients. Preemptive warming is achieved by inserting a cryoprobe midline through perineal skin into anterior rectal wall under ultrasound guidance. The activated probe generates warmth as the ice ball encroaches on rectum. Prospective, post-ablative grading of rectal pain was measured at weeks 1, 2, 4, 8, 12, and 24 by using the Common Terminology Criteria for Adverse Events. Recurrent prostate cancer was gauged by Phoenix criterion (nadir+2 ng/ml). The Mann-Whitney U test and Chi-square test were used to compare clinical characteristics of therapeutic subsets. The Cox proportional hazard model was applied for comparison of cancer recurrence risk by group. RESULTS: Rectal pain (all grades) was experienced by patients treated with (62%) and without (74%) PRW. Although such pain typically resolved with time, it was milder (general lineal model, p=0.023) and less prolonged (median 0.75 vs 1.5 months; log-rank test, p=0.002) in patients receiving PRW than in controls. Of note, PRW did not heighten cancer recurrence risk (hazard ratio=1.3 [95% CI, 0.3-5.0]). CONCLUSIONS: PRW helps to protect the rectum from freeze injury during prostate cryoablation, significantly reducing post-ablative rectal pain without compromising therapeutic outcomes.