Transurethral Vapor Ablation in Patients with Intermediate-Risk Localized Prostate Cancer

Abstract

Purpose: We report results of a prospective, multicenter, single-arm study of transurethral vapor ablation (TUVA) of prostate tissue in patients with unilateral, intermediate risk localized prostate cancer. Materials and Methods: Men ≥45 years of age with biopsy confirmed unilateral Gleason Grade Group 2 (GGG2) adenocarcinoma of the prostate, prostate volume 20-80 cc, and PSA ≤15 ng/mL were enrolled. Cystoscopy and transrectal ultrasound (TRUS) guidance were used to deliver ~103°C water vapor to prostate zones for unilateral hemi-gland ablation including destruction of cancers suspected by mpMRI and confirmed by biopsy. The primary outcome was device-related serious adverse events (SAEs). At 7 days and 6 months post-procedure, ablation extent was assessed by mpMRI; MRI/TRUS fusion biopsies were completed at 6 months. Quality of life (QOL) was assessed with validated questionnaires. Results: At baseline 8/15 subjects had positive biopsy cores of GGG1 cancer on the targeted treatment side. All subjects successfully underwent a single hemi-gland TUVA procedure. No SAEs occurred. Grade 2 procedure-related AEs included transient urinary retention (n=4) and erectile (n=1) or ejaculatory dysfunction (n=1). At 7 days, mpMRI revealed complete ablation of 14/17 (82%) lesions visible. At 6 months, biopsies showed no Gleason pattern ≥ 4 or ≥ GGG2 cancer on the treated side of prostates in 13/15 (87%) subjects. Ten of 15 (66.7%) subjects had no evidence of cancer; 2/5 biopsy positive subjects had one core each of 3+4 disease, and 3/5 had one core each of 3+3 disease, all ≤5% involvement. Median prostate size was reduced 40.7% and PSA by 58%. Extensive QOL assessments showed on average no appreciable negative effects of treatment. Conclusions: Initial evidence suggests TUVA is safe in men with intermediate-risk prostate cancer. Preliminary results demonstrate the absence of ≥ GGG2 disease on the treated side in 87% of men and a favorable QOL profile.