Late complication of the oral cavity and oropharynx after interstitial neutron therapy with sources of <sup>252</sup>Cf
Radiotherapy is used to treat approximately 80% of patients with cancer of the head and neck. Despite enormous advances in radiotherapy planning and delivery, a significant number of patients will experience radiation-associated toxicities. Many effective management options are available for acute radiotherapy-associated toxicities, but treatment options are much more limited and of variable benefit among patients who develop late sequelae after radiotherapy. The present work is based on observations of 586 patients with oral and oropharynx cancer, for which interstitial neutron therapy was carried out in an independent version or in combination with remote radiation therapy. Radiation injuries occurred in 130 (22.2%) patients, in 92 (15.7%) they appeared in the form of radiation ulcers and in 38 (6.4%) - osteoradionecrosis of the lower jaw. The clinical picture and the course of radiation injuries after interstitial neutron therapy with sources of 252Cf did not differ significantly from radiation complications after photon irradiation.