PURPOSE: To investigate change in diffusion weighted imaging (DWI) between pre-treatment (pre-) and after induction chemotherapy (post-IC) for long-term outcome prediction in advanced nasopharyngeal carcinoma (adNPC). MATERIALS AND METHODS: Mean apparent diffusion coefficients (ADCs) of two DWIs (ADC RESULTS: Univariable analysis showed that high ΔADC% predicted good DFS, LRRFS, and DMFS p <
0.05), but did not predict OS (p = 0.40). Neither ADC CONCLUSION: Results suggest that ΔADC% was an independent predictor for long-term outcome and was superior to RECIST guideline for outcome prediction in adNPC. A ΔADC% threshold of ≥ 34.2% may be valuable for selecting patients who respond to treatment for de-escalation of treatment or post-treatment surveillance.