18 F-fluorodeoxyglucose positron emission tomography for predicting tumor response to radiochemotherapy in nasopharyngeal carcinoma

Purpose The aim of this study was to evaluate the value of 18 F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in predicting tumor response to radiochemotherapy in nasopharyngeal carcinoma (NPC). Materials and methods From July 2012 to March 2014, 46 NPC patients who had undergone PET scanning before receiving definitive intensity-modulated radiotherapy (IMRT) treatment in our hospital were enrolled. Factors potentially affecting tumor response to treatment were studied by multiple logistic regression analysis. Results After radiochemotherapy, 32 patients had a clinical complete response (CR), making the CR rate 69.6 %. Multiple logistic regression analysis demonstrated that the maximal standard uptake value (SUV max ) of the primary tumor was the only factor related to tumor response ( p = 0.001), and that the logistic model had a high positive predictive value (90.6 %). The area under the receiver operating characteristic (ROC) curve was 0.809, with a best cutoff threshold at 10.05. Patients with SUV max ≤ 10 had a higher CR rate than those with SUV max > 10 ( p < 0.001). Conclusion The SUV max of the primary tumor before treatment is an independent predictor of tumor response in NPC.