The value of 18F-FDG PET/MRI in prediction of microvascular invasion in hepatocellular carcinoma

Rationale and Objectives: Investigating the association between maximum standardized uptake value (SUVmax), peritumoral and intratumoral apparent diffusion coefficient (ADC) values and whether these parameters are useful in predicting the preoperative microvascular invasion (MVI) of hepatocellular carcinoma (HCC).Materials and methods: Forty-four patients [8 women and 36 men, median age of 62 (21-76)] with single HCCs (>= 2 cm) who underwent preoperative 18F-FDG PET/MRI were retrospectively evaluated. The peritumoral and intratumoral ADC values were evaluated on diffusion-weighted images using Image J an open software and the intratumoral SUVmax values were measured on fusion 18F-FDG PET/MRI images. Univariate and multivariate logistic regression analyses were performed to determine the most influential factor predicting MVI. Interobserver agreement was checked using the intraclass correlation coefficient (ICC).Results: Univariate analysis showed that the histologic grade, tumor size, maximum peritumoral ADC (PT(band )ADC(max)), mean peritumoral ADC (PTband ADC(mean)), mean intratumoral ADC (IT ADC(mean)), and maximum SUV (SUVmax) correlated with MVI (p < 0.05). On multivariate analysis, the SUVmax was the only independent risk factor for the MVI of HCC [OR, 1.68; 95% CI (1.04-2.70); p = 0.032)]. An AUC value of 0.896, 95% CI, 0.786-1.0) had a sensitivity of 75% and specificity of 97% using the best cut-off SUVmax 5.85 to differentiate MVI-positive HCCs from MVI-negative. The PPV, NPV, and accuracy were 92.3%, 87%, and 89%, respectively. The ICC values were 0.95-0.99, a nearly perfect level of agreement.Conclusion: 18F-FDG PET/MRI is a useful noninvasive imaging tool for predicting the MVI of HCC.