Prediction of Microvascular Invasion and Recurrence Using Preoperative 18F-FDG PET/CT Metabolic Parameters in Hepatocellular Carcinoma

Background: Microvascular invasion (MVI) is very important in the evaluation of hepatocellular carcinoma (HCC),but diagnosis is determined by postoperative pathology; thus, preoperative non-invasive methods will play an active role. The purpose of this study was to assess the performance of metabolic parameters of preoperative 18 F-fluorodeoxyglucose positron emission tomography/computerized tomography ( 18 F-FDG PET/CT) in the prediction of MVI and postoperative recurrence in primary hepatocellular carcinoma. Methods: : We retrospectively collected 72 patients with HCC who have performed 18 F-FDG PET/CT scan before partial hepatectomy between 2016 and 2019. We used both normal liver tissue and inferior vena cava as the reference background, and combined with clinicopathological features, 18 F-FDG PET/CT metabolic and volumetric indices to predict MVI and postoperative recurrence of primary HCC before surgery. Results: : Twenty-one of the 72 patients recurred, in recurrent cases showed higher maximum standard uptake value (SUV max ), TNR (ratio of tumor SUV max to mean SUV [SUV mean ] of the background tissue), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) than nonrecurrence cases( p <0.001). All 18 F-FDG PET metabolic and volumetric indices for predicting postoperative HCC recurrence were significant on receiver-operating-characteristic (ROC) curve analyses ( p <0.05). TNR IVC , TNR NL , MTV, TLG IVC , and TLG NL were significant factors for predicting MVI in HCC (p<0.05). On multivariate analyses, MVI, SUV max , TNR IVC , TNR NL , MTV, TLG IVC , and TLG NL (p<0.05) are independent risk factors for predicting postoperative HCC recurrence. TNR IVC is the most relevant PET/CT parameter for predicting MVI in HCC, and MTV is the most valuable for predicting postoperative HCC recurrence. Moreover, the PET/CT parameters are more accurate for prognosis with inferior vena cava as a reference background than with normal liver tissue. Conclusion: 18 F-FDG PET/CT metabolic and volumetric indices are effective predictors, and could non-invasively provide more comprehensive predictive information on MVI and postoperative recurrence of primary HCC before surgery.