Three-dimensional Virtual Imaging to Improve the Accuracy of Standard CT-based Nephrometric Scores: a Prospective Multicentric Observational Study

STUDY DESIGN:prospective multicentric observationalSAMPLE SIZE OF THE STUDY:The estimated number of patients to enroll in the multicenter study is at least 270 patients (statistically calculated referring to the results of a monocentric analysis including 101 patients with the same design, already performed by the Coordinator Center).NUMBER OF CENTERS INVOLVED:Considering a total number of patients enrolled of at least 270, number of Centers to be involved: 5.STUDY PROCEDURES:3D virtual model renderingCT-scan images sent in DICOM format to MEDICS (Turin, Italy) after anonymization.Dedicated online platform available to upload the anonymized CT images, after registration.CT imaging processing by bioengineers and 3DVM building within 72 hours3D-PDF download from the same online platformNephrometric score assessmentAll CT-scans and their 3DVMsevaluation in order to assess surgical complexity, as classified by the PADUA nephrometry score and its relative PADUA risk category.For each Center:assessment of the PADUA score on the basis of the CT-scans (2D-NS) by one urologist;assessment of the PADUA score on the basis of the 3DVMs (3D-NS) by another urologist.Surgical intervention and pathological assessmentDedicated expert surgeon for each Center performing NSS to all patients with the same surgical technique.Dedicated uro-pathologist for each Center performing the histopathological evaluations of the specimens.

Inclusion Criteria:four-phase (unenhanced, corticomedullary, nephrographic and urographic phases) contrast enhanced CT-scanExclusion Criteria:evidence of anatomical abnormalities, like horse-shoe shaped or ectopic kidney.preoperative imaging inadequate to perform a 3DVM (such as those with a CT-scan with >3 mm acquisition interval of the slices, or suboptimal difference of enhancement among the enhanced phases) or older than 3 months.