Osteoradionecrosis after treatment of head and neck cancer: a comprehensive analysis of risk factors with a particular focus on role of dental extractions.

In head and neck cancer (HNC), osteoradionecrosis (ORN) is one of the most significant complications of radiotherapy (RT). With an absence of effective non-surgical treatment, prevention of the development of ORN is the best approach. The purpose of this study was to identify the risk factors for the development of ORN in HNC. Records of 1,118 patients with HNC treated with radical RT (≥55Gy) from January 2010 to December 2019 were reviewed. After applying the exclusion criteria, 935 patients were included in the final analysis. In patients with confirmed ORN, exact RT doses were mapped. In total, 91 patients were found (9.7%) with a median (range) time of eight (3-89) months to the development of ORN. Smoking, having a primary site in the oropharynx, bone surgery before adjuvant RT, the addition of concurrent chemotherapy, the presence of xerostomia, dental extraction pre-RT, the time ≤20 days between dental extraction and start of RT, and receiving >55Gy RT dose were significant factors for its development. This comprehensive analysis including the precise RT dose mapping has shown the risk factors for the development of ORN. In practice, every effort should be made to avoid these risk factors without compromising the oncology treatment. The findings of this analysis may provide a basis for future prospective research on this topic.