@misc{oai:repo.qst.go.jp:00071324,
 author = {Ikawa, Hiroaki and Sasahara, Go and Takagi, Ryo and Koto, Masashi and Hasegawa, Azusa and Ujigawa, Kiyoto and Katakura, Akira and Tonogi, Morio and Tsuji, Hiroshi and Kamada, Tadashi and 伊川 裕明 and 佐々原 剛 and 高木 亮 and 小藤 昌志 and 長谷川 安都佐 and 外木 守雄 and 辻 比呂志 and 鎌田 正},
 month = {Oct},
 note = {Background and objectives: 
Osteoradionecrosis (ORN) of maxilla is a serious complication of radiotherapy (RT) for head and neck cancer, and many reports have been published on the management of ORN after RT. Similarly, carbon ion RT (CIRT) also occur same adverse event. Carbon ions have excellent dose localization properties and high biological effectiveness compared with photons. Therefore, CIRT is a promising option for the effective treatment of intractable head and neck tumors. On the other hand, there is no report about the management for ORN after CIRT. The aim of this study is to evaluate the clinical outcomes of surgical treatment for maxillary ORN in patients who underwent CIRT for head and neck cancer.
Methods: From April 1997 to March 2011, 409 patients with the head and neck cancers were treated with CIRT. Evaluation was performed on 9 patients whose maxilla has been done sequestrectomy. We reviewed the records to obtain cancer site, treatment modality, occurrence periods of ORN and follow-up details. And we evaluated the clinical results of sequestrectomy after CIRT.
Results: The median age of 9 patients (7 men, 2 women) was 62 years. Each prescribed total dose was 57.6 gray equvalents (GyE) in 4 patients and 64 GyE in 5 patients. The average time over which sequestrum began to expose in the 9 patients was 17.9 months after irradiation. The average time of progression to eventual sequestrectomy was 30.7 months after irradiation. In addition, masticatory function was maintained using dento-maxillary prosthesis in all 4 cases that were complaint of masticatory dysfunction. Also we could control the clinical symptoms for the 5 cases who were complaint of severe pain.
Conclusions: Although all of 9 patients have performed sequestrectomy, we could improve the QOL in all cases., 21th International Conferrence on Oral and Maxillofacial Surgery},
 title = {Outcomes of surgical treatment for osteoradionecrosis of the maxilla after carbon ion radiotherapy in patients with head and neck cancer},
 year = {2013}
}