¹⁸F-FDG PET/CT-derived parameters for differentiating colorectal carcinoma from adenoma

The aim of this study is to evaluate the ability of ¹⁸F-FDG PET/CT-derived parameters to differentiate between colorectal cancer and adenoma.

One-hundred and twenty-five patients with colorectal cancers and 57 with colorectal adenomas were retrospectively analyzed. Parameters assessed on ¹⁸F-FDG PET/CT included maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG). Mann-Whitney U-test was used to compare parameters between groups, and receiver-operating characteristic (ROC) curve analysis was performed to assess their discriminatory performance.

Colorectal carcinomas demonstrated significantly higher SUVmax (P = 0.003), SUVmean (P = 0.005), MTV (P < 0.001) and TLG (P< 0.001). The AUCs for differentiating colorectal carcinomas and adenomas were 0.657, 0.649, 0.979, and 0.987, for SUVmax, SUVmean, MTV, and TLG, respectively. The optimal cut-off value for MTV and TLG was 3.5 and 22.6, respectively, yielding a high sensitivity and specificity (96.5% and 92.5% for MTV, 96.5% and 95.5% for TLG). The optimal cut-off value for SUVmax and SUVmean was 8.8 and 4.4, respectively, yielding a sensitivity of 88.6% for SUVmax and 95.6% for SUVmean, and a low specificity of 42.5% for SUVmax, and 32.5% for SUVmean.

Of the ¹⁸F-FDG PET/CT parameters investigated, MTV and TLG showed high accuracy in distinguishing colorectal carcinoma from adenomas, and were significantly higher in colorectal carcinomas than in adenomas.