FDG-PET/CT in radiation treatment planning of head and neck squamous cell carcinoma.

Advances in the field of radiation oncology in the last decade resulted in an increasing number of opportunities to optimize therapy. Increased accuracy to deliver the dose to tumors while sparing normal tissues demands more precise delineation of the tumors. When considering to deliver a boost to more aggressive parts of tumors, intratumoral heterogeneity needs to be assessed accurately. Adaptive radiotherapy demands evaluation of response during the course of radiotherapy, in terms of both volumetric and functional changes. Molecular imaging with fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) has found its way into clinical practice for various indications in head and neck cancer and new applications are under investigation. In this review, an overview is provided of the current status and developments of the use of FDG-PET/CT in radiation oncology, describing the current status in radiation treatment planning, adaptation of therapy and the position compared to other imaging techniques.