Role of PET in Radiation Oncology: A Theranostic Perspective on Detection of Radiation-Induced Complications.

Radiation therapy remains essential in managing thoracic and head and neck malignancies, yet radiation-induced injury to surrounding normal tissues continues to pose significant clinical challenges. Traditional assessment of radiation complications relies on clinical symptoms and anatomic imaging, often detecting injury only after irreversible damage has occurred. This article reviews the emerging role of fluorodeoxyglucose PET/computed tomography (FDG-PET/CT) as a theranostic tool for early detection and quantitative assessment of radiation-induced complications across multiple organ systems. FDG-PET/CT exploits the increased glycolytic activity of inflamed tissues to identify subclinical radiation-induced injury to the surrounding healthy tissue before the onset of clinical symptoms.