Total Lesion Glycolysis on F-18-FDG PET/CT Is a Better Prognostic Factor Than Tumor Dose on Y-90 PET/CT in Patients With Hepatocellular Carcinoma Treated With Y-90 Transarterial Radioembolization

Purpose This study aimed to evaluate the prognostic value of metabolic parameters on F-18-FDG PET/CT and tumor dose (TD) on posttreatment Y-90 PET/CT in patients with hepatocellular carcinoma (HCC) who underwent Y-90 transarterial radioembolization (TARE). Patients and Methods Forty-seven HCC patients treated with Y-90 TARE were retrospectively enrolled between January 2013 and October 2018. F-18-FDG PET/CT was performed before treatment. Maximum tumor SUV-to-mean normal liver SUV ratio (TLR), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were measured for each patient. Voxel dosimetry was performed on Y-90 PET/CT images to measure TD. The prognostic significance of metabolic parameters on F-18-FDG PET/CT, TD on Y-90 PET/CT, and clinical factors for overall survival (OS) was evaluated. In addition, TD on Y-90 PET/CT was analyzed in relation to the administered dose of Y-90-labeled microspheres and metabolic parameters on F-18-FDG PET/CT. Results The median patient age was 57 years, and 37 patients (78.7%) were men. During the follow-up period, 25 patients (53.2%) died. In univariable analysis, Barcelona Clinic Liver Cancer stage C, Child-Pugh score, TD on Y-90 PET/CT, TLR, MTV, and TLG were significant prognostic factors affecting OS (P < 0.05). In multivariable analysis, Barcelona Clinic Liver Cancer stage C and high TLG on F-18-FDG PET/CT were independent prognostic factors for OS (P < 0.05). The 1-year OS rates were 72.9% in patients with low TLG and 33.3% in patients with high TLG (P < 0.05). We also found that TD on Y-90 PET/CT was not correlated with the administered dose of Y-90-labeled microspheres, but negatively correlated with TLG on pretreatment F-18-FDG PET/CT (P < 0.05). Conclusions TLG, a parameter incorporating both the degree of F-18-FDG uptake and amount of metabolically active tumor volume on pretreatment F-18-FDG PET/CT, is a better prognostic factor than TD on Y-90 PET/CT for predicting OS in HCC patients treated with Y-90 TARE.