'Mohs surgery of the prostate': the utility of in situ frozen section analysis during robotic prostatectomy

What's known on the subject? and What does the study add? Interim result of this study had shown promising efficacy, with response rate of 14.7% and median PFS of 7.4 months, and good tolerability in previously-treated Japanese metastatic RCC patients. The final result of the study adds: The median overall survival in Japanese metastatic RCC patients was 25.3 months, which is longer than that in the Treatment Approaches in Renal Cancer Global Evaluation Trial (TARGET). The response rate elevated from 14.7% to 19.4% because of 6 late responders achieved after 9.2 months or longer of SD period. Neither unknown adverse events nor cumulative toxicity was observed in the long-term use of sorafenib. OBJECTIVE center dot To evaluate a novel technique to lower positive surgical margin rates while preserving as much of the neurovascular bundles as possible during nerve-sparing robotic prostatectomy. MATERIALS AND METHODS center dot In situ intraoperative frozen section (IFS) was performed during robotic-assisted laparoscopic prostatectomy (RALP) when there was macroscopic concern for a positive margin or residual prostate tissue. center dot When IFS was positive, additional sections were taken from the same area until the IFS was negative, similar to the procedure of Mohs micrographic surgery. center dot Positive surgical margin and biochemical recurrence rates were compared between the patients who underwent IFS and those who did not. RESULTS center dot Of 970 patients consecutively undergoing RALP at a single institution, IFS was performed on 177 (18%). center dot Eleven patients (6%) had IFS positive for carcinoma, whereas another 25 (14%) had benign prostatic tissue in the IFS specimen. center dot IFS and non-IFS patients had similar pathological and nerve-sparing characteristics. center dot The IFS group had significantly lower rates of positive surgical margins, 7% vs 18% (P = 0.001) but similar rates of biochemical recurrence (5%) at a median follow-up of 11 months. CONCLUSIONS center dot In situ IFS is an effective way of reducing positive margins during RALP. center dot Twenty percent of patients who underwent IFS, representing 4% of the overall RALP population, had either malignant or benign prostate tissue removed from their prostatic fossa. center dot Although a reduction of biochemical recurrence was not demonstrated, the follow-up is short and a difference may become apparent as the data mature.