Objective: To analyse the distance between the ipsilateral neurovascular bundles (NVBs) and foci of prostate cancer (N-T distance) in specimens removed by radical prostatectomy (RP) and identify the predictor for N-T distance for preserving the ipsilateral NVB, as an accurate understanding of the anatomical relationship between prostate cancer foci and the NVB is necessary for establishing the indications for the appropriate use of nerve-sparing (NS) modifications of RP.
Patients and methods: The study included 245 patients with prostate cancer who had RP through the perineal or retropubic approach between June 2000 and November 2006. The analysis focused on 302 foci of prostate cancer (192 cases), which involved at least the posterolateral region of the prostate. The N-T distance was separately measured in the apex, middle and base of the prostate, and was correlated with the maximum diameter and Gleason score of the foci, and the preoperative prostate-specific antigen (PSA) level.
Results: The mean N-T distance was 2.98, 2.95 and 3.03 mm in the apex (216 foci), middle (195 foci) and base (80 foci), respectively. In the apex, the N-T distance was related to both tumour size and preoperative PSA value (P < 0.001 and P < 0.05, respectively). In the base, tumour size was related to the N-T distance (P < 0.01), but the preoperative PSA level was not related to the N-T distance. In the middle, the association of tumour size with N-T distance was of borderline significance (P = 0.07). Irrespective of tumour location, the Gleason score did not contribute to the N-T distance.
Conclusions: These findings show the basic information necessary when making a decision to perform NS-RP in patients with localized prostate cancer. The application of N-T distance could provide a better strategy for determining indications that warrant the use of NS RP than with the conventional tactile feedback approach.