Quantitative Analysis With Time-Dependent Diffusion MRI for Assessing WHO/ISUP Tumor Grade in Clear Cell Renal Cell...

Area of Science:

• Radiology
• Oncology
• Medical Imaging

Background:

• Clear cell renal cell carcinoma (ccRCC) grading is crucial for treatment decisions.
• Accurate noninvasive grading of ccRCC remains a clinical challenge.

Purpose of the Study:

• To evaluate the feasibility of time-dependent diffusion-weighted imaging (td-dMRI) for assessing the pathological World Health Organization/International Society of Urological Pathology (WHO/ISUP) grade of ccRCC.
• To identify td-dMRI parameters that can differentiate between low- and high-grade ccRCC.

Main Methods:

• 138 patients with surgically confirmed ccRCC underwent preoperative td-dMRI.
• Microstructural parameters (cell diameter, intracellular volume fraction, cellularity, extracellular diffusivities) were quantified using a two-compartment model.
• Correlation between td-dMRI parameters and pathological nuclear fraction was assessed.

Main Results:

• Low-grade ccRCC showed lower cellularity and intracellular volume fraction, and higher diameter and extracellular diffusivities compared to high-grade tumors.
• Intracellular volume fraction demonstrated the highest diagnostic performance (AUC=0.943) for differentiating tumor grades, followed by cellularity (AUC=0.931).
• Pathological nuclear fraction moderately correlated with intracellular volume fraction (r=0.65).

Conclusions:

• TD-dMRI parameters show potential for noninvasively assessing WHO/ISUP grades in ccRCC.
• TD-dMRI may serve as a promising biomarker for characterizing ccRCC, aiding in clinical decision-making.