Creation of a Novel, Race-Adjusted, and Risk-Adapted Scoring System to Predict Positive Surgical Margins and Prolonged Operative Time During Robotic Radical Prostatectomy.

Objectives: To compare racial differences and pelvis dimensions between Caucasians and African Americans (AAs) and to develop a risk calculator and scoring system to predict the risk of prolonged operative time and presence of positive surgical margins (PSM) based on these dimensions. Materials and Methods: A retrospective review of 88 consecutive patients undergoing robot-assisted laparoscopic prostatectomy with a preoperative prostate MRI conducted. Data extraction included demographic, perioperative, and postoperative oncologic outcomes. Prostate-specific antigen (PSA) was obtained within 3 months postsurgery. Wilcoxon rank sum and Fisher's exact tests were used to compare continuous and categorical data, respectively. Single and multivariable regression analysis were used to determine contribution of each factor to the composite outcomes. A risk score was created based on this analysis for predicting the composite outcome. Results: We identified 88 consecutive patients with localized prostate cancer that underwent a preoperative prostate MRI. No statistically significant differences were found with respect to age, body mass index, or any postoperative outcome. PSA was lower at diagnosis (6.49 vs 9.72, p = 0.006) and operative times were shorter in Caucasians. Rates of PSM (13 vs 14, p = 0.35), biochemical recurrence (4 vs 2, p = 0.69), and complications did not vary between the groups. Caucasians had wider/shallower pelvis dimensions. Based on these variables, we found that the log (odds of OR time >3 hours or PSM) = -5.333 + 1.158 (if AA) +0.105 × PSA +0.076 × F -0.035 × G with an area under the receiver operating characteristic curve = 0.73. Using the predefined variables, patients can be risk stratified for PSM or prolonged operative times. Conclusions: Several pelvis dimensions were found to be shorter/narrower in AAs and were associated with longer operative times. The presented risk calculator and stratification system may be used to predict prolonged operative time or having PSM.