The aim of this study was to evaluate the prognostic value of pretreatment metabolic tumor volume (MTV) and total lesion glycolysis (TLG) using F-FDG PET/CT in patients with metastatic renal cell carcinoma (RCC) after treatment with anti-vascular endothelial growth factor-targeted agents.
Fifty-six patients with metastatic RCC who underwent F-FDG PET/CT for staging and recurrence evaluation were retrospectively enrolled. SUVmax, MTV, and TLG were measured using F-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.
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.
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.
Clinical nuclear medicine. 2017 Mar 10 [Epub ahead of print]
Sang Hyun Hwang, Arthur Cho, Mijin Yun, Young Deuk Choi, Sun Young Rha, Won Jun Kang
From the *Department of Nuclear Medicine, and †Department of Urology, Urological Science Institute, Severance Hospital, and ‡Division of Medical Oncology, Department of Internal Medicine, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Korea.