Reirradiation of squamous cell carcinoma of the head and neck with external photons: A practical review of the literature

The modalities of management by reirradiation for recurrence or a second localization of head and neck squamous cell carcinoma (HNSCC) in previously irradiated terrain is challenging due to the great heterogeneity of data in the literature, mainly retrospective data reporting non-negligible risks of serious late toxicity events. With the recent development of more precise and conformal radiotherapy techniques such as intensity modulated radiotherapy (IMRT), volumetric modulated arc therapy (VMAT), stereotactic radiotherapy (SBRT), the benefit-to-risk ratio of reirradiation has evolved in recent years with encouraging results, but patient selection is crucial. The aim of this review is to discuss the role of HNSCC reirradiation in terms of patient selection and external photon radiotherapy techniques for definitive tumor reirradiation and postoperative reirradiation.