Invasion of the neurovascular bundle by prostate cancer: evaluation with MR imaging

Preservation of the neurovascular bundle (NVB) and potency without compromising tumor control are current objectives of radical retropubic prostatectomy as treatment for prostate cancer, but preoperative determination of whether cancer has invaded the NVB can be difficult. The use of conventional body-coil magnetic resonance (MR) imaging to make this preoperative determination was evaluated in 50 patients with biopsy-proved cancer. All patients underwent radical retropubic prostatectomy after MR imaging. MR imaging, surgical, and pathologic data were correlated relative to tumor location and volume, Gleason grade, presence of capsular penetration, and depth of NVB invasion. The sensitivity of MR imaging for invasion was 68%, specificity was 59%, and overall accuracy was 64%. Results of this study indicate that MR imaging can help identify the NVB and predict invasion of the NVB by tumor, but the usefulness of the technique is limited by the lack of spatial resolution associated with use of the whole-body coil.