An updated approach to incremental nerve sparing for robot-assisted radical prostatectomy

Area of Science:

• Urology
• Oncology
• Radiology

Background:

• Robot-assisted radical prostatectomy (RARP) outcomes depend on precise surgical techniques.
• Multiparametric magnetic resonance imaging (mpMRI) aids in preoperative cancer assessment.
• Nerve sparing (NS) dissection is crucial for preserving erectile function during RARP.

Purpose of the Study:

• To update and refine an algorithm for incremental nerve sparing (NS) during RARP.
• To utilize a multiparametric MRI (mpMRI)-based nomogram for predicting extracapsular extension (ECE).
• To correlate ECE risk categories with specific NS dissection grades.

Main Methods:

• Applied a validated mpMRI-based nomogram to predict ECE in 561 patients undergoing RARP.
• Used PSA, biopsy Gleason grade, tumor involvement, and mpMRI findings.
• Employed a classification tree to define ECE risk thresholds and guide NS grading (Grade 1-4).

Main Results:

• Identified four risk categories for ECE: low (≤10%), intermediate (10-21%), high (21-73%), and very-high (>73%).
• ECE rates were 3.3%, 16%, 61.6%, and 90% in these respective risk groups.
• Focal ECE varied significantly across risk groups, from 41.7% in low-risk to 0% in very-high-risk.

Conclusions:

• Recommended Grade 1 NS (intrafascial) for low-risk ECE.
• Suggested Grades 2-3 NS (inter-fascial) for intermediate and high-risk ECE.
• Advocated Grade 4 NS (extrafascial) for very-high-risk ECE, improving upon previous algorithms.