Presentation Authors: Florian Alexander Schmid*, Marian Severin Wettstein, Thomas M. Kessler, Andreas Boss, Daniel Eberli, Zurich, Switzerland
Introduction: While radical prostatectomy (RP) renders good cancer control, urinary incontinence (UI) remains a major morbidity issue and significantly influences the postoperative quality of life. With the possibility of predicting the chances of UI, urologists receive an important tool in their prognostic armamentarium, which will influence consulting and treatment strategies. The aim of the study was to use data from routine preoperative MRI to estimate the risk of incontinence after RP.
Methods: We analyzed patients who underwent robot-assisted RP for localized prostate cancer at our institution between July 2015 and April 2017. Preoperatively, all patients received a multiparametric MRI of the prostate (3 Tesla Siemens Magnetom). Prospectively collected questionnaires regarding UI were evaluated one year postoperatively (ICIQ-Score). "Tissue 4D" software from Siemens on "Syngo Multimodality Workplace" was used to measure the contrast media (CM) kinetics (median initial area under the curve for the first 60 seconds after injection of CM [median iAUC]). With this technique, we were able to visualize the preoperative perfusion quality of the pelvic floor (levator ani muscle) in comparison to the surrounding pelvic muscle structures (reference). Outcomes were dichotomized into groups "continent" (ICIQ-score = 0-5) and "incontinent" (ICIQ-score > 5). In each patient, we determined the ratio between the median iAUC of the levator ani muscle to the median iAUC of the surrounding pelvic muscle structures. The resulting perfusion ratios among the group of continent patients were then compared to the ratios of the incontinent patients.
Results: In total 42 patients were included in this study (n=22 in "continent", n=20 in "incontinent" group). The groups did not differ with regard to clinically relevant characteristics (age, PSA, Gleason-Score and nerve sparing). The perfusion ratio from the continent group was significantly higher than the one from the incontinent group (1.61 vs. 1.15, respectively; difference in perfusion ratios = 0.45; 95% confidence interval (CI): 0.09 - 0.81, p = 0.015). A further analysis of excellent outcomes (ICIQ = 0) vs. poor outcomes (ICIQ > 10) of 10 patients in each group, the perfusion ratio of excellent outcomes was also significantly higher (1.48 vs. 0.94, respectively; difference in perfusion ratios = 0.53; 95% CI: 0.04 - 1.03, p = 0.036).
Conclusions: Our data demonstrate a promising new strategy to assess the perfusion of pelvic muscle structures with CM kinetics to predict continence after RP. This may facilitate preoperative patient consulting and decision making.