SRS255 - Impact of patient-specific 3D Prostate models during robotic assisted radical prostatectomy (RARP) on positive surgical margins

Abstract Purpose The use of 3D models during robotic-assisted radical prostatectomy (RARP) is associated with a reduction of positive surgical margins (PSMs), a trend that is limited in statistical significance. Whether these effects are specifically induced by either 3D printed or virtual models is unclear. We aim to compare the PSM rate of two prospective intervention arms with respect to a retrospective control cohort. Methods 97 patients were prospectively recruited at Guy’s Hospital (London) and assigned to a 3D printed (N = 43) or a virtual (N = 54) cohort (REC: 23/LO/0492). We compared intervention groups with a retrospective cohort (N = 35). Participants were men eligible for RARP treatment with T2-T3a prostate cancer lesions of >3 + 4 Gleason score located near neurovascular bundles. Results PSMs were 22.9%, 20.9% and 18.5% for control, printed, and virtual cohorts, respectively. In T2 cancer staging cases, we observed higher PSMs in control cohort 26.9%) versus 7.4% (printed) and 11.1% (virtual) in intervention groups. When combining printed and virtual cohorts, PSMs were 25% (control) versus 13.6% (3D models). A Barnard exact test confirmed 3D models will lower the chance of PSMs (P = 0.029), whereas the odds ratio of PSMs for those cases using 3D models were 0.29 times that of those who have received standard of care (c.i.: 91.5%). Conclusions A two-parallel-arm feasibility study confirmed 3D models used on T2 cases have an effect on oncological outcomes. In future work, we will extend our study investigating the potential benefits of 3D models for maintaining continence and potency.