Three-dimensional positron emission tomography image texture analysis of esophageal squamous cell carcinoma: relationship between tumor 18F-fluorodeoxyglucose uptake heterogeneity, maximum standardized uptake value, and tumor stage

Objective To explore the relationship of a new PET image parameter, F-18-fluorodeoxyglucose (F-18-FDG) uptake heterogeneity assessed by texture analysis, with maximum standardized uptake value (SUVmax) and tumor TNM staging. Materials and methods Forty consecutive patients with esophageal squamous cell carcinoma were enrolled. All patients underwent whole-body preoperative F-18-FDG PET/CT. Heterogeneity of intratumoral F-18-FDG uptake was assessed on the basis of the textural features (entropy and energy) of the three-dimensional images using MATLAB software. The correlations between the textural parameters and SUVmax, histological grade, tumor location, and TNM stage were analyzed. Results Tumors with higher SUVmax were seen to be more heterogenous on F-18-FDG uptake. Significant correlations were observed between T stage and SUVmax (r(s)=0.390, P=0.013), entropy (r(s)=0.693, P<0.001), and energy (r(s)=-0.469, P=0.002). Correlations were also found between SUVmax, entropy, energy, and N stage (r(s)=0.326, P=0.04; r(s)=0.501, P=0.001; r(s)=-0.413, P=0.008). The American Joint Committee on Cancer stage correlated significantly with all metabolic parameters. The receiver-operating characteristic curve demonstrated an entropy of 4.699 as the optimal cutoff point for detecting tumors above stage IIb with an areas under the ROC curve of 0.789 (P<0.001). Conclusion This study provides initial evidence for the relationship between the new parameter of tumor uptake heterogeneity and the commonly used simplistic parameter of SUV and tumor stage. Our findings suggest a complementary role of these parameters in the staging and prognosis of esophageal squamous cell carcinoma. Nucl Med Commun 34:40-46 (C) 2012 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins. Nuclear Medicine Communications 2013, 34:40-46