Scientific Publications Database

Article Title: Can MRI be used to diagnose histologic grade in T1a (< 4cm) clear cell renal cell carcinomas?
Authors: Moran, Kevin; Abreu-Gomez, Jorge; Krishna, Satheesh; Flood, Trevor A.; Walker, Daniel; McInnes, Matthew D. F.; Schieda, Nicola
Journal: ABDOMINAL RADIOLOGY Volume 44 Issue 8
Date of Publication:2019
Abstract:
ObjectiveTo assess whether MRI can differentiate low-grade from high-grade T1a cc-RCC.Materials and methodsWith IRB approval, 49 consecutive solid <4cm cc-RCC (low grade [Grade 1 or 2] N=38, high grade [Grade 3] N=11) with pre-operative MRI before nephrectomy were identified between 2013 and 2018. Tumor size, apparent diffusion coefficient (ADC) histogram analysis, enhancement wash-in and wash-out rates, and chemical shift signal intensity index (SI index) were assessed by a blinded radiologist. Subjectively, two blinded Radiologists also assessed for (1) microscopic fat, (2) homogeneity (5-point Likert scale), and (3) ADC signal (relative to renal cortex); discrepancies were resolved by consensus. Outcomes were studied using Chi square, multivariate analysis, logistic regression modeling, and ROC. Inter-observer agreement was assessed using Cohen's kappa.ResultsTumor size was 247 (13-39)mm with no association to grade (p=0.45). Among quantitative features studied, corticomedullary phase wash-in index (p=0.015), SI index (p=0.137), and tenth-centile ADC (p=0.049) were higher in low-grade tumors. 36.8% (14/38) low-grade tumors versus zero high-grade tumors demonstrated microscopic fat (p=0.015; Kappa=0.67). Microscopic fat was specific for low-grade disease (100.0% [71.5-100.0]) with low sensitivity (36.8% [21.8-54.6]). Other subjective features did not differ between groups (p>0.05). A logistic regression model combining microscopic fat+wash-in index+tenth-centile-ADC yielded area under ROC curve 0.98 (Confidence Intervals 0.94-1.0) with sensitivity/specificity 87.5%/100%.Conclusion p id=Par The combination of microscopic fat, higher corticomedullary phase wash-in and higher tenth-centile ADC is highly accurate for diagnosis of low-grade disease among T1a clear cell RCC.