Systematic biopsies and digital rectal examination to identify the nerve-sparing side for radical prostatectomy without risk of positive margin in patients with clinical stage T2, N0 prostatic carcinoma.
Systematic biopsies and digital rectal examination were used to identify the nerve-sparing side for radical prostatectomy without risk of positive margin in patients with clinical Stage T2, N0 prostatic carcinoma. We studied specimens from 73 consecutive radical prostatectomies by the 3 mm step-section technique for clinical Stage T2a, T2b (n = 57), and T2c (n = 16) tumors to see whether digital rectal examination or the use of 6 systematic biopsies could identify the side where nerve-sparing could be used without risk of positive margin. In 39 of the 57 (68%) patients with clinical Stage T2a, T2b 3 contralateral biopsies were negative. Only in these 39 patients was unilateral nerve-sparing done on the biopsy-negative side. None of these 39 specimens had a positive margin at this nerve-sparing side. The other 18 (32%) of the 57 patients with clinical T2a, T2b tumors had positive biopsies on the contralateral side of the palpable tumor; no nerve-sparing was done in this group. Of the 18 specimens, only 5 (28%) had full capsular penetration on the contralateral side in the area of the nerve bundle and thus the potential risk of positive margins if contralateral nerve-sparing would have been done. That could mean that 13 patients of these 18 (23% of the whole group of the 57 patients with T2a, T2b lesions) were unnecessarily excluded from the unilateral contralateral nerve-sparing. We conclude that unilateral contralateral nerve-sparing can be done safely in patients with T2a, T2b lesions without risk of positive margins when three biopsies on the contralateral side are negative. We calculate that by such strict selection criteria for unilateral contralateral nerve-sparing technique only one of five patients with clinical unilateral tumors will be excluded unnecessarily from the nerve-sparing technique.