Figure 3: ROC curves of the ability of pretreatment primary tumor ADC (a) or metastatic adenopathy ADC (b) to predict the response to neoadjuvant chemotherapy in patients with nasopharyngeal carcinoma. The optimal pretreatment ADC cutoff values for the primary tumor and metastatic adenopathy were 0.897 × 10−3 mm2/sec and 1.031 × 10−3 mm2/sec, with areas under the ROC curves of 0.830 and 0.821, respectively.