Can 18-FDG-PET During Radiotherapy Replace Post-Therapy Scanning for Detection/Demonstration of Tumor Response in Head-and-Neck Cancer?

The high specificity and positive predictive value for the evaluation of tumor response with PET2 and PET3 might avoid unnecessary salvage surgery in patients with a CR. In contrast to PET3, the sensitivity of PET 2 was low, and the difference in OS between the CR and NCR groups was not significantly different. Therefore, the evaluation of the tumor response with FDG-PET at 4 months after RT completion cannot be replaced by FDG-PET during RT at 47 Gy.