Prostate MRI prior to radical prostatectomy: effects on nerve sparing and pathological margin status

Abstract

Objectives

The aim of this study was to assess the positive surgical margin (PSM) and nerve sparing (NS) rates in patients who underwent prostate MRI (pMRI) prior to radical prostatectomy (RP) and compare them with matched, nonimaged control RP patients.

Methods

We identified 204 men who underwent preoperative pelvic MRI (pelMRI), of whom 176 (86.3%) underwent pMRIs, within 60 days of RP, and compared them (1:1) with a nonim-aged control group matched by surgeon, age, race, body mass index (BMI), prostate-specific antigen (PSA), pathological Gleason score, prostate specimen weight, and RP year.

Results

The rates of nonfocal extracapsular extension (nfECE) on RP pathology in the MRI and control groups were similar. PSM rates were lower in the MRI group (13.7% vs 19.3%; P=0.14), but the difference did not meet statistical significance; this was also the case in patients with nfECE on RP pathology (27.7% vs 39.5%; P=0.3). NS rates were similar between groups. In the MRI group, 54 (26.5%) patients had an MRI suspicious for nfECE; their PSM rate (20.4%) was higher than that of patients with an MRI not suspicious for nfECE (11.3%; P=0.11), but the difference lacked statistical significance; the former group had significantly lower rates of NS. Limitations of the study include sample power and nonuniform heeding of MRI results by each surgeon.

Conclusion

MRI did not significantly decrease the rates of PSM, including in the subset of patients with nfECE on final pathology. Even wider resection may be necessary in patients with MRIs suggesting locally-advanced disease. Studies with greater power are needed.

Keywords:

• MRI
• positive surgical margins
• nerve sparing
• extracapsular extension
• radical prostatectomy

Supplementary materials

Table S1 Patients’ characteristics by surgery type: robotic-assisted laparoscopic vs open retropubic radical prostatectomy

Table S2 Pathological and surgical outcomes by surgery type: robotic-assisted laparoscopic vs open retropubic radical prostatectomy

Acknowledgments

We acknowledge Dr. Alan W. Partin, Dr. Misop Han, and Ms. Elizabeth Humphreys from The James Buchanan Brady Urological Institute and Department of Urology at The Johns Hopkins University School of Medicine, Baltimore, MD, USA, for assistance with this study. The abstract of this paper was presented as a poster at the 31st Annual Meeting of the Engineering and Urology Society on May 7, 2016, in San Diego, CA, USA. The abstract was published in the Journal of Endourology.

This study was supported by NIH SPORE grant P50CA58236. It was performed at The James Buchanan Brady Urological Institute and Department of Urology and Department of Radiology and Radiological Sciences at The Johns Hopkins University School of Medicine, Baltimore, MD, USA.

Disclosure

The authors report no conflicts of interest in this work.