CT-Derived Extracellular Volume Fraction Enables Noninvasive Risk Stratification of Small Clear Cell Renal Cell...

Area of Science:

• Radiology
• Oncology
• Medical Imaging

Background:

• Clear cell renal cell carcinoma (ccRCC) grading is crucial for treatment planning.
• Accurate preoperative differentiation of ccRCC grades is challenging.
• Novel imaging biomarkers are needed for risk stratification.

Purpose of the Study:

• To determine if extracellular volume fraction (ECV) measured by contrast-enhanced computed tomography (CT) differs between low-grade and high-grade ccRCC.
• To assess the diagnostic value of CT-derived ECV for identifying high-grade ccRCC.

Main Methods:

• Retrospective analysis of 115 treatment-naïve patients with ccRCC ≤4 cm.
• Classification of tumors into low-grade (ISUP grades 1-2) and high-grade (ISUP grades 3-4).
• Independent measurement of CT-derived ECV by two radiologists, with statistical analysis including ROC and multivariable logistic regression.

Main Results:

• High-grade ccRCC exhibited significantly lower ECV values compared to low-grade ccRCC (P = 0.002).
• CT-derived ECV demonstrated modest-to-moderate diagnostic performance for high-grade ccRCC (AUC = 0.69).
• Higher ECV was associated with a lower likelihood of high-grade ccRCC after multivariable adjustment (OR = 0.36, P = 0.028).

Conclusions:

• CT-derived ECV is associated with pathological grade in small ccRCC.
• ECV is a reproducible biomarker that can complement preoperative risk stratification.
• External validation is recommended to confirm these findings.