Use of MRI in Differentiation of Papillary Renal Cell Carcinoma Subtypes: Qualitative and Quantitative Analysis.

OBJECTIVE: The purpose of this study was to determine whether qualitative and quantitative MRI feature analysis is useful for differentiating type 1 from type 2 papillary renal cell carcinoma (PRCC). MATERIALS AND METHODS: This retrospective study included 21 type 1 and 17 type 2 PRCCs evaluated with preoperative MRI. Two radiologists independently evaluated various qualitative features, including signal intensity, heterogeneity, and margin. For the quantitative analysis, a radiology fellow and a medical student independently drew 3D volumes of interest over the entire tumor on T2-weighted HASTE images, apparent diffusion coefficient parametric maps, and nephrographic phase contrast-enhanced MR images to derive first-order texture metrics. Qualitative and quantitative features were compared between the groups. RESULTS: For both readers, qualitative features with greater frequency in type 2 PRCC included heterogeneous enhancement, indistinct margin, and T2 heterogeneity (all, p < 0.035). Indistinct margins and heterogeneous enhancement were independent predictors (AUC, 0.822). Quantitative analysis revealed that apparent diffusion coefficient, HASTE, and contrast-enhanced entropy were greater in type 2 PRCC (p < 0.05; AUC, 0.682-0.716). A combined quantitative and qualitative model had an AUC of 0.859. Qualitative features within the model had interreader concordance of 84-95%, and the quantitative data had intraclass coefficients of 0.873-0.961. CONCLUSION: Qualitative and quantitative features can help discriminate between type 1 and type 2 PRCC. Quantitative analysis may capture useful information that complements the qualitative appearance while benefiting from high interobserver agreement.

Outcomes of robotic-assisted laparoscopic upper urinary tract reconstruction: 250 consecutive patients.

OBJECTIVE: To evaluate the long-term outcomes of robotic-assisted laparoscopic (RAL) upper urinary tract (UUT) reconstruction performed at a tertiary referral centre. MATERIALS AND METHODS: Data from 250 consecutive patients undergoing RAL UUT reconstruction, including pyeloplasty with or without stone extraction, ureterolysis, uretero-ureterostomy, ureterocalicostomy, ureteropyelostomy, ureteric reimplantation and buccal mucosa graft ureteroplasty, were collected at a tertiary referral centre between March 2003 and December 2013. The primary outcomes were symptomatic and radiographic improvement of obstruction and complication rate. The mean follow-up was 17.1 months. RESULTS: Radiographic and symptomatic success rates ranged from 85% to 100% for each procedure, with a 98% radiographic success rate and 97% symptomatic success rate for the entire series. There were a total of 34 complications, none greater than Clavien grade 3. CONCLUSION: Robotic-assisted laparoscopic UUT can be performed with few complications, with durable long-term success, and is a reasonable alternative to the open procedure in experienced robotic surgeons.