Prognostic value of volume-based 18F-FDG PET parameters in uterine cervical cancer: Optimum cut-off SUV for the determination of tumor boundary

1846 Objectives We investigated the optimum method determining the cut-off SUV for tumor boundary in patients with uterine cervical cancer to find the prognostic significance of volume-based metabolic parameters of 18F-FDG PET. Methods The subjects were 73 patients (mean age, 50.0 ± 12.8 y; range, 22.3 ~ 77.4 y) with uterine cervical cancer who underwent 18F-FDG PET for initial staging between Nov. 2000 and Mar. 2008. For finding prognostic significance, the maximum SUV (SUVmax), average SUV (SUVave), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of primary tumor were measured. In case of volume-based parameters such as SUVave, MTV and TLG, various cut-off SUVs (2.5, 3.0, 3.5, 4.0, SUVave of mediastinal blood pool (MBP) x 2SD) were adopted to delineate the boundary of tumor. Survival analysis for disease- or progression-free survival using PET parameters was performed by a Kaplan-Meier method. Patients were divided into 2 groups according to the optimal cut-off of each PET parameter determined retrospectively. Results Initial FIGO stage was I in 27, II in 32, and III/IV in 14 patients. Recurrence or disease progression occurred in 23 patients (31.5%). Mean clinical follow-up period was 44.7 ± 29.4 m (range, 2.2~107.8 m). SUVave was a significant prognostic factor (cut-off SUVave = 5.0, p Conclusions Both MTV and TLG were significant prognostic factors in uterine cervical cancer, irrespective of cut-off SUV for tumor boundary determination. In case of SUVave, the cut-off SUV of 4.0 may be suitable value for tumor boundary determination reflecting prognosis