@misc{oai:repo.qst.go.jp:00081594,
 author = {山本, 淳史 and Sung Hyun, Lee and 山岡, 恵士 and 鈴木, 優維 and 伊川, 裕明 and 金子, 崇 and 小藤, 昌志 and 谷本, 克之 and 辻, 比呂志 and 河野, 良介 and Yamamoto, Atsushi and Sung-Hyun, Lee and Yamaoka, Keisi and Suzuki, Yui and Ikawa, Hiroaki and Kaneko, Takashi and Koto, Masashi and Tanimoto, Katsuyuki and Tsuji, Hiroshi and Kohno, Ryosuke},
 month = {May},
 note = {[Purpose] QST hospital treats patients using carbon-ion radiotherapy (CIRT) with head and neck cancer. For the head and neck cancer, normal tissues such as brain and optic nerve are close to the irradiation field such that those may receive radiation damage due to the CIRT. Although a dose-volume histogram (DVH) is conventionally used for the clinical analysis, we have developed a dose-averaged LET (LETd) calculation tool. We clinically analyzed head and neck cancer patients using this tool.
[Methods] We used the Heavy Ion Plan (HIPLAN) treatment planning system in the CIRT. The clinical analysis tool developed and implemented in the HIPLAN can calculate the LETd and its standard deviation. For this study, we will select head and neck cancer patients, who were treated by the CIRT from October 2006 to December 2013. Those patients had follow-up more than 3 years and did not receive other radiotherapy. In this study, the12 patients were clinically analyzed using the analysis tool for local control, brain injury, and optic neuropathy.
[Results] By implementing the clinical analysis tool in HIPLAN, it is possible to easily calculate and analyze LETd for each patient. The LETds for 12 patients were calculated, and analyzed for local control, brain injury, and optic neuropathy. Out of 12 patients, 2, 12 and 8 patients developed local recurrence, brain injury and optic neuropathy. In this study, there was no new finding for the relation between the LETd and those clinical parameters.
[Conclusion] We developed the LETd calculation tool. The12 patients with head and neck cancer were clinically analyzed using this system for local control, brain injury, and optic neuropathy. Although we could not confirm the usefulness of the LETd analysis because of the small number of patients, we will continue to analyze more patients in the future., 第119回日本医学物理学会学術大会},
 title = {Clinical Analysis of Dose-averaged LET Calculation in Carbon-Ion Radiotherapy for Head and Neck Cancer},
 year = {2020}
}