Clinical features and dosimetric evaluation of carbon ion radiation-induced osteoradionecrosis of mandible in head and neck tumors

Background and purposeOsteoradionecrosis (ORN) affects the patient’s quality of life by making eating maintaining oral hygiene painful. This study aimed to analyze carbon ion radiotherapy (C-ion RT)-induced ORN mandible.Materials methodsA retrospective 199 patients with head neck tumors treated C-ion RT was performed from 2010 2019. Only 11 located in oropharynx floor mouth were analyzed. consisted 57.6 Gy or 64.0 (relative biological effectiveness) 16 fractions. The mandible analyzed for magnetic resonance imaging (MRI) changes bone exposure. relationship between radiation dose analyzed.ResultsFive (45.5%) had mandible. median follow-up time 68 months. onset times based on MRI exposure 9 15 months, respectively. Doses 30 teeth showed most significant effect, causing at 29.5 ± 6.7 cc 3.9 1.8 cc, respectively, cut-off values 16.5 (p = 0.002) 0.0059), respectively.ConclusionThis is first reporting incidence, time, risk-predictive dosimetry parameters RT-induced Our will be useful establishing clinical strategies near