Presentation Authors: Amir Lebastchi*, Samuel Gold, Michael Ahdoot, Jonathan Bloom, Sherif Mehralivand, Patrick Gomella, Thomas Sanford, Graham Hale, Vladimir Valera Romero, Mark Ball, Peter Choyke, Brad Wood, Maria Merino, Bethesda, MD, Minhaj Siddiqui, Baltimore, MD, Baris Turkbey, Peter Pinto, Bethesda, MD
Introduction: Prostate multiparametric magnetic resonance imaging (mpMRI) can precisely depict prostate cancer (PCa) location and adverse pathologic features. Surgeons can utilize this information to maximize sparing of the neurovascular bundles (NVBs) during radical prostatectomy (RP) while avoiding a positive surgical margin (PSM). The objective of this study was to see if mpMRI can identify men likely to benefit with wide resection versus nerve-sparing at RP.
Methods: A prospectively maintained database was queried for robotic-assisted RPs (RARPs) with preoperative mpMRI between 2007-2017. Imaging margin risk factors (iMRF) were defined on mpMRI as frank extraprostatic extension (EPE), possible EPE, and capsular irregularity (capsular bulge, lesion-capsule contact, or lesion adjacency to the neurovascular bundles). Effect of surgical adjustments to nerve-sparing technique (full sparing vs wide resection (partial or no nerve-sparing) on PSM were examined in patients with iMRF versus those with no iMRF.
Results: A total of 1041 prostate lesion sides from 532 patients were included for analysis. iMRF were seen in 30.1% (313/1041) prostate sides. iMRF effectively identified men at risk for PSM with a 16.9% PSM (53/313) in men with iMRF versus 3.7% PSM (27/728) in men without iMRF (p < 0.00001). Adjustment of surgical technique from nerve-sparing to wide resection decreased the rate of PSM in the iMRF men from 29.0% PSM (20/69) with nerve-sparing versus 13.5% PSM (33/244) with wide resection (p=0.002). By contrast, adjustment of surgical technique in the no iMRF group had no impact on the PSM rate within that group (p=0.4). MRI-guided surgical adjustments based on preoperative iMRF decreased risk for PSM by 68% and 15% in pT3 and pT2 cases, respectively. On multivariable analysis controlling for PSA and surgical approach, iMRF remained significantly associated with PSM (OR 1.78, [95% CI 1.01-3.16], p = 0.047).
Conclusions: Preoperative mpMRI of the prostate effectively identifies men at high risk for PSM and may guide selection of men most likely to benefit with wide resection of the prostate to decrease PSM rates.
Source of Funding: This research was supported by the Intramural Research Program of the NIH, National Cancer Institute, Center for Cancer Research.