P072 Multivariate Analysis of Multidomain Quality-of-Life Predictors Among Head and Neck Cancer Patients

(FDG-PET/CT). Methods: Posttreatment FDG-PET/CT was performed in 28 patients after completing definitive radiation therapy and was visually analyzed at 2 time points (4-8 weeks and 8 weeks after treatment). Pathological confirmation and clinical follow-up served as the reference standard. Results: The overall specificity, sensitivity, and accuracy ofFDG-PET/CTfordetectionofresidualdiseasewere93.3%, 76.9%, and 87.5%, respectively. Posttreatment, the specificity, sensitivity, and accuracy of FDG-PET/CT performed more than 8 weeks after treatment were higher than those performed before treatment (100% for all vs 87.5%, 66.7%, and 76.5%, respectively). Follow-up data were collected at a mean time point of 17.6 months posttreatment (range, 4.5-33.6 months). Fifteen patients had persistent disease at an average of 3.6 months after treatment, and 1 patient experienced a recurrence at 11.6 months posttreatment. Twenty-one patients survived (mean duration of follow-up, 20 months), 12 of whom remain disease-free, and the disease of 6 patients remains locoregionally controlled by salvage therapy. Conclusions: The assessment for treatment response using FDG-PET/CT was more accurate when performed 8 weeks after radiation therapy. Although PET/CT has not yet been established as a routine surveillance method, these encouraging preliminary results may advocate the effectiveness of this imaging modality in the detection of persistent or early failure after definitive radiation therapy. The opportunity for early salvage therapies prompted by a former diagnostic method may alter the long-term outcome for these patients with cancer.