Utility of intraoperative frozen section analysis of surgical margins in region of neurovascular bundles at radical prostatectomy.

OBJECTIVES: To report our experience with intraoperative frozen section (IFS) analysis in patients who are potential candidates for nerve-sparing surgery. Potency can be maintained in select patients who undergo radical prostatectomy using a nerve-sparing approach. However, extracapsular disease extension in the area of the neurovascular bundles may compromise adequate surgical margins in some patients undergoing such surgery.
METHODS: We reviewed the pathologic results from 101 patients who underwent either unilateral or bilateral nerve-sparing radical prostatectomy in whom IFS analysis was performed. The clinical disease stage was T1 in 20 patients and T2 in 81 patients. The mean serum prostate-specific antigen level before surgery was 7.2 ng/mL. Of the 101 patients, 62, 28, and 11 had a biopsy Gleason score of 2 to 6, 7, and 8 to 10, respectively. IFS analysis was performed on the surgical margin thought to be at risk of tumor involvement as determined by the results of systematic prostate biopsy, transrectal ultrasonography, or intraoperative inspection. If the frozen section was positive, additional tissue, including the neurovascular bundle, was subsequently removed to establish clear surgical margins. IFS results were compared with those on the final, permanent tissue section, as well as with the status of the additionally resected tissue.
RESULTS: The IFS results were identical to those obtained on the final, permanent section in 92 (91%) of the 101 cases. The IFS results showed positive margins in 15 (15%) of 101 patients. Of these cases, 11 demonstrated positive margins on the final permanent sections. Of the 86 patients with negative frozen section diagnosis, 5 had positive surgical margins on permanent sections at the site of the IFS. The positive and negative predictive value for the IFS technique was 73% and 94%, respectively. Of the 15 patients with positive IFS, 12 (80%) had no evidence of tumor in the additionally resected tissue. Prostate-specific antigen recurrence was noted in 7% of the study population. The risk of recurrence in patients with either positive or negative IFS findings was similar.
CONCLUSIONS: IFS at the time of radical prostatectomy can reliably predict the final surgical margin status in most carefully selected high-risk patients when there are concerns about the margin status.