Rapid Communication Physical Models of Renal Malignancies Using Standard Cross-sectional Imaging and 3-Dimensional Printers: A Pilot Study Jonathan L. Silberstein, Michael M. Maddox, Phillip Dorsey, Allison Feibus, Raju Thomas, and Benjamin R. Lee OBJECTIVE To construct high-fidelity, patient customized, physical, 3-dimensional (3D) models of renal units with enhancing renal lesions identified on cross-sectional imaging, which may aid patients, trainees, and clinicians in their comprehension, characterization, localization, and extirpation of suspicious renal masses. METHODS Specialized software was used to import patient’s diagnostic computerized tomography cross- sectional imaging into 3D printers and create physical 3D models of renal units with enhancing in situ lesions. Patients and trainees had the opportunity to manipulate the indi- vidualized model before surgical resection. Sterolithography additive manufacturing, a technique in which an ultraviolet laser is used to cure a photosensitive resin in sequential horizontally oriented layers, was used to build the models (Medical Modeling Inc., Golden, CO). Normal renal parenchyma was printed with a clear translucent resin, and red translucent resin delineated suspicious lesions. Renal vasculature and the proximal collecting system were printed in some models. RESULTS We constructed 5 physical models of renal units with suspected malignancies before surgery. All patients successfully underwent partial nephrectomy (4 robotic and 1 open). Average ischemia time was 21 minutes, nephrometry score was 6.8, and all margins were negative. Anecdotally, patients, their families, and trainees consistently stated that the models enhanced their comprehension of the renal tumor in relation to surrounding normal renal parenchyma and hilar structures and improved understanding of the goals of the surgery. CONCLUSION Preoperative physical 3D models using available printing techniques can be constructed and may potentially influence both patients’ and trainees’ understanding of renal malignancies. UROLOGY 84: 268e273, 2014. Ó 2014 Elsevier Inc. P hysical 3-dimensional (3D) anatomic models based on cross-sectional imaging can be con- structed using 3D printers and have been used for complex maxillofacial reconstruction. 1 There are also reports of physical models constructed from 3D printers for use in forensics, orthopedics, and rare complex in- terventions. 2-5 To date, there are no peer-reviewed man- uscripts on the use of such physical models constructed to aid in the understanding and subsequent extirpation of in situ genitourinary solid organ malignancies. High-fidelity physical 3D models of renal malignancies with surrounding normal parenchyma can be constructed from patients’ routine preoperative imaging studies, using standard cross-sectional computed tomography (CT) im- aging integrated with 3D printers and sterolithographic additive manufacturing. We have constructed several of these models to aid both patient and trainee’s conceptual- ization and understanding of individual tumors before sur- gical extirpation; herein, we report our preliminary findings. METHODS Five patients with enhancing renal lesions found on standard cross-sectional CT imaging had 3D physical models of their complete renal unit with in situ lesion printed using 3D printing technique before intended partial nephrectomy. All patients, trainees, and surgeons inspected and palpated models before sur- gery and filled out a questionnaire to assess their understanding. Kidney models were created with the assistance of a third party private company (Medical Modeling Inc., Golden, CO) using a clear translucent resin with the in situ tumor in a red hue (Fig. 1A). For 2 patients, the major renal Financial Disclosure: The authors declare that they have no relevant financial interests. From the Department of Urology, Tulane University School of Medicine, New Orleans, LA Reprint requests: Jonathan L. Silberstein, M.D., Department of Urology, Tulane University School of Medicine, 1430 Tulane Avenue, SL-42, New Orleans, LA 70112-2632. E-mail: jsilbers@tulane.edu Submitted: March 11, 2014, accepted (with revisions): March 31, 2014 268 ª 2014 Elsevier Inc. All Rights Reserved http://dx.doi.org/10.1016/j.urology.2014.03.042 0090-4295/14