Evaluation of Interactive Virtual Reality as a Preoperative Aid in Localizing Renal Tumors.

INTRODUCTION A detailed understanding of renal tumor anatomy is required to perform partial nephrectomy. We evaluated the utility of a computed tomography (CT) based, interactive virtual reality (iVR) display to assist surgeons' understanding of the precise location of the renal tumor. METHODS CT scans and iVR models of 11 patients with a mean R.E.N.A.L. nephrometry score of 6.9 were evaluated. Seven faculty urologists and 6 urology residents reviewed CT scans and positioned each tumor onto a digital 3D model of the same kidney, albeit without the tumor present. A week later, participants repeated the session using both iVR models and CT scans. For both time points, the overlap between the surgeon-inserted tumor and the actual tumor location was calculated. Participants answered a 1-10 Likert scale survey to gauge their understanding of renal and tumor anatomy based on CT alone vs. CT+iVR. RESULTS Median tumor overlap for the entire cohort was 28% after CT review and 42% after CT+iVR (p=0.05); among faculty urologists, for CT+iVR vs. CT alone, percent overlap improved (47% vs. 33%, p=0.033) and the incidence of 0% overlap decreased (19% to 4%, p=0.024), respectively. Among residents, there was no significant difference for either percent overlap or 0% overlap for CT vs. CT+iVR. The percent overlap for the two tumors with high R.E.N.A.L. nephrometry scores (i.e. 10) increased from 51% to 67% after using CT+iVR (p=0.039). The combination of CT+iVR was an independent predictor of improved overlap versus CT alone (OR 2.22, 95% CI 1.04-4.78, p=0.039). Faculty surgeons' survey responses showed an improved understanding of the tumor location and shape with the addition of iVR (p<0.05). CONCLUSIONS The addition of patient-specific iVR models to standard CT imaging improved the ability of faculty urologists to accurately configure the location of a renal tumor, and improved their understanding of tumor anatomy.