Improving the Prognostic Performance of SUVmax in 18F-Fluorodeoxyglucose Positron-Emission Tomography/Computed Tomography Using Tumor-to-Liver and Tumor-to-Blood Standard Uptake Ratio for Locally Advanced Cervical Cancer Treated with Concurrent Chemoradiotherapy

Abstract

Objective: We sought to evaluate whether the 18F-fluorodeoxyglucose uptake normalization of the primary tumor to both the liver and blood pool and lymph nodes to both the liver and blood pool can enhance the discrimination for prognosis prediction in patients with cervical cancer. Methods: A total of 156 patients with cervical cancer (International Federation of Gynecology and Obstetrics stages IIB–IV) treated with concurrent chemoradiotherapy (CCRT) were enrolled. The maximum standardized uptake value (SUVmax) of tumor (tSUVmax) and the lymph node (nSUVmax) divided by the SUVmean of the liver (tumor-to-liver ratio (TLR) and node-to-liver (NLR)) and blood pool (tumor-to-blood ratio (TBR) and node-to-blood ratio (NBR)) were investigated. Univariate and multivariate analyses of disease-free survival (DFS) and overall survival (OS) were performed using clinical and metabolic parameters. A receiver operating characteristic curve analysis was performed to compare the accuracy of the metabolic parameters. Results: The multivariate analysis revealed that NLR (hazard ratio ((HR): 3.54; 95% confidence interval (CI): 1.53–8.19; p = 0.0032) and NBR (HR: 3.38; 95% CI: 1.02–11.19; p = 0.0457)) were independent prognostic factors for DFS, while TLR (HR: 4.16; 95% CI: 1.19–14.50; p = 0.0252), TBR (HR: 3.01; 95% CI: 1.04–8.70; p = 0.0415), NLR (HR: 4.84; 95% CI: 1.58–14.81; p = 0.0057), and NBR (HR: 6.87; 95% CI: 1.55–30.54; p = 0.0113) were significant prognostic factors for OS. The normalization of tSUVmax to the liver or blood pool enhanced the discrimination for prediction of recurrence (tSUVmax vs. TLR; p = 0.0056 and tSUVmax vs. TBR; p = 0.0099) and death (tSUVmax vs. TLR; p < 0.0001 and tSUVmax vs. TBR; p = 0.0001). Conclusions: The normalization of tSUVmax was an independent prognostic factor and improved the discrimination for the prediction of tumor recurrence and death in patients with locally advanced cervical cancer treated with CCRT.