Stereotactic Body Radiation Therapy in the Management of Recurrent and/or Oligometastatic Head and Neck Cancer

Abstract

AbstractDerived from intracranial stereotactic radiosurgery, stereotactic body radiation therapy (SBRT) was introduced to clinical practice in 1991. Based on delivering precisely targeted high doses of radiation in one or several fractions, the concept of SBRT has been rapidly adopted by many institutions. This chapter aims to summarize the available literature regarding the use of SBRT in the reirradiation setting of recurrent and second primary head and neck cancer (HNC) as well as in oligometastatic HNC. Several studies have been published showing safety and efficacy of SBRT-based reirradiation in recurrent disease or a second malignancy. According to a meta-analysis of 10 papers published between 2006 and 2016, SBRT-based reirradiation seems to be a promising modality with acceptable safety and short overall treatment times in patients with inoperable recurrent or second primary HNC. However, overall survival following SBRT-based reirradiation remains moderate, which might be due to insufficient doses. There is thus a need for well-designed trials of SBRT-based reirradiation in terms of dose escalation and combination with systemic therapy. In HNC, the evidence for treatment of oligometastatic disease using SBRT is less clear when compared to other tumor types. We need to understand which patients benefit the most from local ablation, when the right moment is to intervene, how SBRT compares with surgery in operable patients and with other modalities (e.g. radiofrequency ablation), and what the impact of combination strategies is (e.g. with immune checkpoint inhibitors). All these unmet needs underline the importance of conducting dedicated studies in oligometastatic squamous HNC patients.