Analysis of MRI radiomic pelvimetry and correlation with margin status after robotic prostatectomy

To evaluate the use of preoperative magnetic resonance imaging (MRI) as a predictor of positive margins after radical prostatectomy (RP). This is important as such patients may benefit from postoperative radiotherapy. With the advent of preoperative MRI, we posited that pelvimetry could predict positive margins after RP in patients with less-than ideal pelvic dimensions undergoing robotic-assisted laparoscopic surgery.

After IRB approval, data from patients undergoing RP at our center between 1/1/2018 and 12/31/2019 (n = 314) who had undergone prior prostate MRI imaging (n = 102) were analyzed. All RPs were performed using robotic-assisted laparoscopic technique. Data from the cancer center data warehouse were retrieved, to include postoperative T-stage, gland size, responsible surgeon, PSA, patient body mass index, and surgical margin status. These data were analyzed with corresponding pelvimetry data from 91 preoperative scans with complete data and imaging.

On multivariable analysis, pathologic T-stage (p = 0.004), anteroposterior pelvic outlet (p = 0.015) and pelvic depth (length of the pubic symphysis; p = 0.019) were all statistically correlated with positive surgical margins.

With the widespread use of MRI in the initial staging of prostate cancer, automated radiomic analysis could augment the critical data already being accumulated in terms of seminal vesical involvement, extracapsular extension, and suspicious lymph nodes as risk factors for postoperative salvage radiation. Such automated data could help screen patients preoperatively for robotic RP.