Discriminating rectal cancer grades using restriction spectrum imaging.

Area of Science:

• Radiology
• Oncology
• Medical Imaging

Background:

• Rectal cancer grading is crucial for treatment planning.
• Tumor cellularity, an indicator of aggressiveness, can be assessed using diffusion MRI.
• Novel diffusion MRI models aim to improve accuracy in cancer characterization.

Purpose of the Study:

• To evaluate the efficacy of the Restriction Spectrum Imaging (RSI) model in grading rectal tumors.
• To compare the performance of RSI against traditional ADC and DKI models for rectal cancer grading.

Main Methods:

• Fifty-eight rectal cancer patients with biopsy-confirmed grades were included.
• Diffusion-weighted imaging (DWI) data were acquired using a 3T MRI scanner.
• A three-compartment RSI model was applied and compared with ADC and DKI models using ROC analysis.

Main Results:

• The restricted compartment (C1) volume fraction from RSI significantly correlated with rectal cancer grades.
• RSI demonstrated a significant difference between low-grade (G1+G2) and high-grade (G3) tumors (P < 0.001).
• The AUC for C1 in differentiating low-grade from high-grade tumors was 0.753, with 72.0% sensitivity and 70.0% specificity.

Conclusions:

• The three-compartment RSI model is effective in discriminating low and high grades of rectal cancer.
• RSI shows superior performance compared to traditional ADC and DKI models for rectal cancer grading.
• RSI has the potential to serve as a valuable tool for assessing rectal cancer aggressiveness.