@inproceedings{oai:repo.qst.go.jp:00054257,
 author = {Hasegawa, Azusa and Jingu, Keiichi and Takagi, Ryo and Morikawa, Takamichi and Mizoe, Junetsu and Kamada, Tadashi and Tsujii, Hirohiko and 長谷川 安都佐 and 神宮 啓一 and 高木 亮 and 森川 貴迪 and 溝江 純悦 and 鎌田 正 and 辻井 博彦},
 book = {International Journal of Radiation Oncology Biology Physics},
 issue = {3supplement},
 month = {Nov},
 note = {Purpose/Objective(s): To estimate the toxicity and efficacy of carbon ion radiotherapy for malignant head-and-neck tumors invading the skull base.
Material/Methods: Between April 1997 and March 2008, a total of 313 patients with head-and-neck tumors were treated with carbon ion radiotherapy with a phase II clinical trial. All of these patients had neither regional lymph node nor distant metastasis before carbon ion radiotherapy. The prescribed tumor doses were 57.6 or 64.0 GyE in 16 fractions over four weeks. Of the 313 patients, 104 patients with skull base invasion were analyzed. The patients consisted of 56 males and 48 females aged from 23 to 78 years with an average age of 55.7 years. Histologically, tumors were classified as follows: 49 were adenoid cystic carcinoma, 23 were malignant mucosal melanoma, 22 were adenocarcinoma, and 10 were 5 other histological types. The CTV ranged from 53.6 to 670.1 ml, with an average of 208.1 ml. Median follow-up time was 32.5 months (range, 2.6-152 months).
Results: Although acute grade 3 skin and mucosal reactions appeared in 4 patients (4 %) and 10 patients (10 %), almost all of the late skin and mucosal reactions were grade 1 or less. Three patients developed late grade 2 mucosal reaction. In regard to brain toxicity, patients were divided into two groups according to intracranial involvement; Group A was made up of 50 patients whose tumors abutted the cranial fossa, Group B consisted of 54 patients whose tumors displaced or invaded the frontal or temporal lobe. A late grade 2 brain reaction was detected in 3 patients (6 %) for Group A and in 11 patients (20 %) for Group B, which necessitated steroid administration. All these patients can now manage without any medication because these reactions improved within a short time. At the time of analysis, there was no evidence of any serious late brain reactions. The 5-year local control and overall survival rates of all patients were 76 % and 44 %, respectively. There were no significant differences in local control rates between histological types. In total 59 patients died, 31 were distant metastasis, 9 were in-field recurrence, 8 were marginal recurrences, 2 were meningeal disseminations, and 9 were due to other causes that are not associated with tumors. As for the tumor status studied, the 5-year local control rates were 75 % for Group A and 77 % for Group B. The 5-year overall survival rates were 45 % for Group A and 42 % for Group B. There was no significant difference in outcome between the two groups.
Conclusion: Our results showed acceptable brain toxicities and excellent therapeutic effectiveness for unresectable malignant head-and-neck tumors},
 pages = {S173--S173},
 title = {Carbon Ion Radiotherapy For Malignant Head-and-Neck Tumors Invading the Skull Base},
 volume = {78},
 year = {2009}
}