Use of MR imaging to determine preservation of the neurovascular bundles at robotic-assisted laparoscopic prostatectomy

Abstract

Purpose: To determine whether findings at preoperative endorectal coil magnetic resonance (MR) imaging influence the decision to preserve neurovascular bundles and the extent of surgical margins in robotic-assisted laparoscopic prostatectomy (RALP).

Materials and methods: This study was approved by the investigational review board and was compliant with the HIPAA; the requirement to obtain informed consent was waived. The authors prospectively evaluated 104 consecutive men with biopsy-proved prostate cancer who underwent preoperative endorectal coil MR imaging of the prostate and subsequent RALP. MR imaging was performed at 1.5 T between January 2004 and April 2008 and included T2-weighted imaging (n = 104), diffusion-weighted imaging (n = 88), dynamic contrast-enhanced imaging (n = 51), and MR spectroscopy (n = 91). One surgeon determined the planned preoperative extent of resection bilaterally on the basis of clinical information and then again after review of the final MR imaging report. The differences in the surgical plan before and after review of the MR imaging report were determined and compared with the actual surgical and pathologic results by using logistic regression analysis. Continuous and ranked variables underwent Pearson and Spearman analysis.

Results: After review of MR imaging results, the initial surgical plan was changed in 28 of the 104 patients (27%); the surgical plan was changed to a nerve-sparing technique in 17 of the 28 patients (61%) and to a non-nerve-sparing technique in 11 (39%). Seven of the 104 patients (6.7%) had positive surgical margins. In patients whose surgical plan was changed to a nerve-sparing technique, there were no positive margins on the side of the prostate with a change in treatment plan.

Conclusion: Preoperative prostate MR imaging data changed the decision to use a nerve-sparing technique during RALP in 27% of patients in this series.