Predictive Role of Preoperative Whole-Body 18F-FDG PET/CT for Risk Stratification of Early-Stage (FIGO I-IIA) Cervical Cancer Patients Treated by Surgery.

Abstract

The aim of the present study was to investigate the predictive value of maximum standardized uptake value (SUVmax) measured on preoperative 18F-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) in International Federation of Gynecology and Obstetrics (FIGO 2009) stage I-IIA cervical cancer patients who were treated with radical hysterectomy. A total of 47 patients with FIGO stage I-IIA cervical cancer who were evaluated preoperatively with biopsy and 18F-FDG PET/CT followed by radical hysterectomy were included in the study. Correlation between SUVmax and pathological risk factors or survival was studied. The mean SUVmax was significantly higher in patients with large tumor size (≥4 cm), advanced stage (IIA>IB>IA) and depth of invasion >50%. No significant difference was noted in SUVmaxbetween patients with and without pelvic lymph node involvement (P=0.639). SUVmax of the primary tumor with and without lymph-vascular invasion were 12.95 and 10.35, respectively (P=0.5). No significant difference was noted between patients with high SUVmax and low SUVmax with regards to overall survival (OS) and disease-free survival (DFS), using an optimal cut-off value of 7.65 for OS and DFS obtained from receiver operating characteristic (ROC) curve analysis. Patient with tumor size >4cm had 5.9 times more probability of mortality compared to tumor size <4cm (P=0.09). The present study observations showed that although SUVmaxis associated with pathological variables, it does not independently predict oncological outcomes in FIGO stage IA-IIA cervical cancer patients who were treated with radical hysterectomy. These findings suggest that SUVmax of primary tumor may be used for risk stratification, but not for prognostication insurgically treated early-stage cervical cancer patients. Not using other parameters of 18F-FDG PET/CT like metabolic tumor volume (MTV), tumor lysis glycolysis (TLG), small sample size,variation in calculation of SUVmax, histopathologic heterogeneity, inclusion of stage IA patients in the study were constraints of present study. Furtherstudies with large sample size using multi metabolic parameters of 18F-FDG PET/CT, including the SUVmax,SUVmean,SUVpeak, MTV and TLG are needed.