Influence of Biological Parameters Assessed in [18F]FDG PET/CT on Overall Survival in Cervical Cancer Patients.

Abstract

The aim of this study was to estimate the influence of biological parameters assessed in [F]FDG PET/CT on overall survival (OS) in cervical cancer patients. Retrospective analysis was performed on a group of 371 patients with newly diagnosed and histologically confirmed cervical cancer. PET biological parameters in primary tumor including SUVmax, SUVmean, total lesion glycolysis (TLG), metabolic tumor volume (MTV), heterogeneity, and parameters referring both to primary tumor and metastatic lesions: SUVtotal, TLGtotal, and MTVtotal, were analyzed. Based on PET/CT results, 3 subgroups were identified: cervical only-with disease limited only to the cervix (38%), +regional nodes-where increased glucose accumulation in addition to the cervical area was also observed in regional lymph nodes (36%), and +distal metastases-where PET scan showed a disseminated disease (26%). Depending on the stage of the disease, in the cervical-only group, 5-year survival rate was 86%; in the +regional nodes group, it was 80%; whereas in the +distal metastases group, 5-year survival rate was only 55%. However, based on Cox regression model, significant influence on OS was found only in heterogeneity of primary tumor; more inhomogeneous tumors suggest worse prognosis (0.25 ± 0.04 vs 0.16 ± 0.09, P < 0.001), SUVtotal (76.6 ± 130.1 vs 45.4 ± 73.4, P = 0.002), and MTVtotal (79.03 ± 88.27 vs 63.00 ± 83.80 cm, P = 0.03). For heterogeneity, cutoff point suggesting worse prognosis was 0.18; for SUVtotal, 52.3; and for MTVtotal, 66.55 cm. Stage of disease assessed in [F]FDG PET/CT significantly influences survival rate in patients with cervical cancer. SUVtotal, MTVtotal, and heterogeneity of primary tumor are independent prognostic factors on OS in cervical cancer patients.