Value of Intratumoral Metabolic Heterogeneity and Quantitative 18F-FDG PET/CT Parameters in Predicting Prognosis for Patients With Cervical Cancer

OBJECTIVE. The purpose of this study is to evaluate the prognostic value of quantitative metabolic parameters from pretreatment PET/CT scans of patients with squamous cell cervical cancer. MATERIALS AND METHODS. This retrospective study included 120 patients with biopsy-proven squamous cell carcinoma of the cervix who underwent FDG PET/CT for initial tumor staging The primary tumor maximum standardized uptake value (SUVmax) and mean standardized uptake value (SUVmax), tumor glycolytic activity, metabolic tumor volume (MTV), and metabolic intratumoral heterogeneity index (calculated as the AUC for the cumulative standardized uptake value [SUV]-volume histogram [CSH] index) were obtained. Information on patient demographic characteristics and tumor staging were collected. Median follow-up was 27.5 months. Overall survival (OS) and progression-free survival (PFS) were calculated using a multivariate Cox proportional hazards regression model and log-rank (Mantel-Cox) test to generate Kaplan-Meier survival plots. RESULTS. The mean (+/- SD) age of the patients was 54.4 +/- 13.1 years. Twenty-two patients had stage I disease; 58, stage II; 23, stage III; and 17, stage IV. Thirty-three patients died, 82 were living, and five were lost to follow-up and were censored; 29 patients had disease progression. The median survival was 74.9 months (95% CI, 63.6-86.9 months). A higher MTV was significantly associated with reduced OS in multivariate analysis (hazard ratio, 1.085; 95% CI, 1.036-1.136; p = 0.0005). A higher AUC-CSH index (denoting lower tumor heterogeneity) was significantly associated with increased OS (hazard ratio, 0.662; 95% CI, 0.448-0.979; p = 0.04) and PFS (hazard ratio, 0.683; 95% CI, 0.471-0.991; p = 0.045) in multivariate analysis. Kaplan-Meier survival analysis using the median value for MTV (61 mL) significantly predicted OS (p = 0.0009). CONCLUSION. Tumor heterogeneity on pretreatment PET/CT is associated with OS and PFS in patients with cervical cancer. MTV is significantly associated with OS.