To evaluate accuracy of MRI in detecting renal tumor pseudocapsule (PC) invasion and to propose a classification based on imaging of PC status in patients with renal cell carcinoma.
From January 2017 to June 2018, 58 consecutive patients with localized renal cell carcinoma were prospectively enrolled. MRI was performed preoperatively and PC was classified, according to its features, as follows: MRI-Cap 0 (absence of PC), MRI-Cap 1 (presence of a clearly identifiable PC), MRI-Cap 2 (focally interrupted PC), and MRI-Cap 3 (clearly interrupted and infiltrated PC). A 3D image reconstruction showing MRI-Cap score was provided to both surgeon and pathologist to obtain complete preoperative evaluation and to compare imaging and pathology reports. All patients underwent laparoscopic partial nephrectomy. In surgical specimens, PC was classified according to the renal tumor capsule invasion scoring system (i-Cap).
A concordance between MRI-Cap and i-Cap was found in 50/58 (86%) cases. ρ coefficient for each MRI-cap and iCap categories was: MRI-Cap 0: 0.89 (p < 0.0001), MRI-Cap1: 0.75 (p < 0.0001), MRI-Cap 2: 0.76 (p < 0.0001), and MRI-Cap3: 0.87 (p < 0.0001). Sensitivity, specificity, positive predictive value, negative predictive value, and AUC were: MRI-Cap 0: Se 97.87% Spec 83.3%, PPV 95.8%, NPV 90.9%, and AUC 90.9; MRI-Cap 1: Se 77% Spec 95.5%, PPV 83.3%, NPV 93.5%, and AUC 0.86; MRI-Cap 2- iCap 2: Se 88% Spec 90%, PPV 79%, NPV 95%, and AUC 0.89; MRI-Cap 3: Se 94% Spec 95%, PPV 88%, NPV 97%, and AUC 0.94.
MRI-Cap classification is accurate in evaluating renal tumor PC features. PC features can provide an imaging-guided landmark to figure out where a minimal margin could be preferable during nephron-sparing surgery.
World journal of urology. 2019 Apr 25 [Epub ahead of print]
Rocco Papalia, Valeria Panebianco, Riccardo Mastroianni, Maurizio Del Monte, Emanuela Altobelli, Eliodoro Faiella, Francesco Rosario Grasso, Mariangela Bellangino, Giuseppe Simone, Massimo Ciccozzi, Silvia Angeletti, Giulia D'ovidio, Carlo Catalano, Michele Gallucci, Roberto Mario Scarpa, Giovanni Muto
Department of Urology, Campus Bio-medico University of Rome, Via Alvaro del Portillo 200, 00128, Rome, Italy. ., Department of Radiological Sciences, Sapienza University of Rome, Rome, Italy., Department of Urology, Campus Bio-medico University of Rome, Via Alvaro del Portillo 200, 00128, Rome, Italy., Department of Diagnostic and Interventional Radiology, Campus Bio-medico University of Rome, Rome, Italy., Department of Urology, Ospedale Sant'Andrea, Sapienza University of Rome, Rome, Italy., Department of Urology, "Regina Elena" National Cancer Institute, Rome, Italy., Unit of Medical Statistics and Molecular Epidemiology, Campus Bio-medico University of Rome, Rome, Italy., Unit of Clinical Laboratory Science, Campus Bio-Medico University of Rome, Rome, Italy., Department of Urology, Sapienza University of Rome, Rome, Italy., Department of Urology, Humanitas "Gardenigo" University, Turin, Italy.