S t a n d a r d i z e d U p t a k e V a l u e o f 2 -[ 1 8 F ] F l u o r o -2 -D e o x y -D -G l u c o s e i n P r e d i c t i n g O u t c o m e i n H e a d a n d N e c k C a r c i n o m a s T r e a t e d b y R a d i o t h e r a p y W i t h o r W i t h o u t C h e m o t h e r a p yPatients and Methods: We studied 63 patients with carcinomas of the head and neck who had an FDG-PET scan before radical RT. Tumor FDG uptake was measured with the semiquantitative standardized uptake value (SUV). All patients but one were treated with accelerated or hyperfractionated RT schedules. Thirteen patients received concomitant cisplatin-based chemotherapy.Results: In 25 patients who presented with any component of treatment failure, the SUV was significantly higher than in the remaining patients without any such failure. Patients having tumors with high FDG uptake had a significantly lower 3-year local control (55% v 86%, P ؍ .01) and DFS (42% v 79%, P ؍ .005) compared with patients having low uptake tumors. In the multivariate analysis, the only factor that retained its significance for DFS was SUV category, whereas T category was of borderline significance. For local control, T category remained a significant factor, whereas a lower local control was observed for tumors with a high SUV compared with those with low SUV.Conclusion: FDG uptake, as measured by the SUV, has potential value in predicting local control and DFS in head and neck carcinomas treated by RT. High FDG uptake may be a useful parameter for identifying patients requiring more aggressive treatment approaches.