Positron emission tomography/computed tomography (PET/CT) has been widely used to assess tumor response following chemoradiotherapy of head and neck cancer. In general, a negative post-treatment PET/CT is associated with a good prognosis. Nevertheless, in the setting of re-irradiation, an increasingly adopted salvage treatment modality, this association remains unclear. In this report, we explored the prognostic significance of PET/CT following re-irradiation. Read more.