PET/CT in the evaluation of treatment response to neoadjuvant chemoradiotherapy and prognostication in patients with locally advanced esophageal squamous cell carcinoma

Abstract

Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved. Objective To investigate the role of fluorine-18-fluorodeoxyglucose PET/computed tomography for the prognostication and evaluation of neoadjuvant chemoradiotherapy response in locally advanced esophageal squamous cell carcinoma. Methods All consecutive biopsy-proven esophageal squamous cell carcinoma patients with PET/computed tomography at baseline (PET 0 ) and 1 month after the completion of neoadjuvant chemoradiotherapy (PET 1 ) between January 2008 and December 2013, followed by esophagectomy, were included. Maximum and mean standard uptake values (SUV max and SUV mean ), metabolic tumor volume, and total lesion glycolysis of all lesions at PET 0 and PET 1 were analyzed. Logistic and Cox regressions were used to identify factors predictive of pathological complete remission (pCR), overall survival, and recurrencefree survival. Cut-offs were identified using leave-one-out cross-validation adjusted receiver operator curve-based methods. A Kaplan-Meier model was adopted to compare survivals between groups using log-rank tests. Results Of a total of 52 patients (45 men, age 21-78 years), pCR was achieved in 21 (40.4%). SUV max of primary tumor at PET 1 was independently predictive of pCR [P=0.013, odds ratio=0.736, 95% confidence interval (CI): 0.578-0.937]; using a leave-one-out cross-validationadjusted cut-off of 2.7, pCR could be predicted with a sensitivity of 71.0%, a specificity of 66.7%, a positive predictive value of 75.9%, and a negative predictive value of 60.9%. In the subset of 40 patients with standardized treatment included in survival analysis, total lesion glycolysis (P=0.002, hazard ratio: 1.029, 95% CI: 1.01-1.048) and SUV max (P=0.003, hazard ratio: 1.167, 95% CI: 1.055-1.290) of nodal metastasis at PET 0 were independently predictive of overall survival and recurrencefree survival, respectively. Conclusion Baseline total lesion glycolysis and SUV max of nodal metastases are significant independent predictors of survival, whereas post-treatment SUV max of the primary tumor is predictive of pCR. However, the predictive value of the latter is modest, which may limit its clinical utility. Nucl Med Commun 37:947-955