Prognostic Value of Pretreatment Metabolic Tumor Volume and Total Lesion Glycolysis Using 18F-FDG PET/CT in Patients With Metastatic Renal Cell Carcinoma Treated With Anti–Vascular Endothelial Growth Factor–Targeted Agents
The aim of this study was to evaluate the prognostic value of pretreatment metabolic tumor volume (MTV) and total lesion glycolysis (TLG) using 18F-FDG PET/CT in patients with metastatic renal cell carcinoma (RCC) after treatment with anti–vascular endothelial growth factor–targeted agents.Methods
Fifty-six patients with metastatic RCC who underwent 18F-FDG PET/CT for staging and recurrence evaluation were retrospectively enrolled. SUVmax, MTV, and TLG were measured using 18F-FDG PET/CT in all patients. The highest SUV in all the metastatic RCC lesions of each patient was defined as SUVmax. Metabolic tumor volume was defined as the total tumor volume greater than 40% of SUVmax. Total lesion glycolysis was calculated as (MTV) · (SUVmean). The prognostic significance of PET/CT parameters and clinical factors for progression-free survival (PFS) and overall survival (OS) were evaluated by univariate and multivariate analyses, along with other clinical factors.Results
The most common organ for metastases was lung (35 patients). In the univariate analysis, hypercalcemia, time from diagnosis to treatment, SUVmax, MTV, and TLG were significant prognostic factors affecting PFS (P < 0.05), and Karnofsky score, hypercalcemia, time from diagnosis to treatment, SUVmax, MTV, and TLG were significant prognostic factors affecting OS (P < 0.05). In the multivariate analysis, hypercalcemia, MTV, and TLG were independent prognostic factors affecting PFS (P < 0.05), and hypercalcemia, time from diagnosis to treatment, MTV, and TLG were independent prognostic factors affecting OS (P < 0.05). In subgroup analyses, the high MTV or TLG groups showed poor prognosis for PFS and OS in patients with intermediate or poor risk.Conclusions
Metabolic tumor volume and TLG are independent prognostic factors for predicting PFS and OS in patients with metastatic RCC. Furthermore, MTV and TLG could provide additional prognostic information in patients with clinically high-risk metastatic RCC treated with anti–vascular endothelial growth factor–targeted therapies.