RT Journal Article SR Electronic T1 Diffusion-Weighted Imaging of Nasopharyngeal Carcinoma: Can Pretreatment DWI Predict Local Failure Based on Long-Term Outcome? JF American Journal of Neuroradiology JO Am. J. Neuroradiol. FD American Society of Neuroradiology DO 10.3174/ajnr.A4792 A1 B.K.H. Law A1 A.D. King A1 K.S. Bhatia A1 A.T. Ahuja A1 M.K.M. Kam A1 B.B. Ma A1 Q.Y. Ai A1 F.K.F. Mo A1 J. Yuan A1 D.K.W. Yeung YR 2016 UL http://www.ajnr.org/content/early/2016/05/05/ajnr.A4792.abstract AB BACKGROUND AND PURPOSE: Pretreatment prediction of patients with nasopharyngeal carcinoma who will fail conventional treatment would potentially allow these patients to undergo more intensive treatment or closer posttreatment monitoring. The aim of the study was to determine the ability of pretreatment DWI to predict local failure in patients with nasopharyngeal carcinoma based on long-term clinical outcome.MATERIALS AND METHODS: One hundred fifty-eight patients with pretreatment DWI underwent analysis of the primary tumor to obtain the ADC mean, ADC skewness, ADC kurtosis, volume, and T-stage. Univariate and multivariate analyses using logistic regression were performed to compare the ADC parameters, volume, T-stage, and patient age in primary tumors with local failure and those with local control, by using a minimum of 5-year follow-up to confirm local control.RESULTS: Local control was achieved in 131/158 (83%) patients (range, 60.3–117.7 months) and local failure occurred in 27/158 (17%) patients (range, 5.2–79.8 months). Compared with tumors with local control, those with local failure showed a significantly lower ADC skewness (ADC values with the greatest frequencies were shifted away from the lower ADC range) (P = .006) and lower ADC kurtosis (curve peak broader) (P = .024). The ADC skewness remained significant on multivariate analysis (P = .044). There was a trend toward higher tumor volumes in local failure, but the volume, together with T-stage and ADC mean, were not significantly different between the 2 groups.CONCLUSIONS: Pretreatment DWI of primary tumors found that the skewness of the ADC distribution curve was a predictor of local failure in patients with nasopharyngeal carcinoma, based on long-term clinical outcome.AbbreviationsLClocal controlLFlocal failureNPCnasopharyngeal carcinomaROCreceiver operating characteristic