Philip J, et al. - Authors pursued this research in order to determine the accuracy of FDG PET-CT for response assessment following definitive radiotherapy without chemotherapy in the case of head and neck squamous cell carcinoma. Results demonstrated that PET-CT had a high negative predictive value of 93% and positive predictive value of 88%. PET-CT could be beneficial in avoiding the surgical intervention following radiotherapy alone, as revealed by the high negative predictive value.