@misc{oai:repo.qst.go.jp:00064090,
 author = {Kamada, Tadashi and Imai, Reiko and Tsuji, Hiroshi and Imaizumi, Takeshi and Tsujii, Hirohiko and 鎌田 正 and 今井 礼子 and 辻 比呂志 and 今泉 猛 and 辻井 博彦},
 month = {Nov},
 note = {Purpose/Objective(s): Primary malignant bone tumors of the sacrum are extremely rare. Surgery has been considered as the mainstay of treatment for primary malignant bone tumors of the sacrum, and the definitive en bloc resection of tumor is mandatory to obtain long-term disease free survival. However, radical surgical intervention has been associated with morbidities including substantial neurological deficits. Due to the high linear energy transfer (LET) and the Bragg peak, carbon ion radiotherapy has been expected, to be more effective and safe in the treatment for sarcomas than low-LET radiation like photons. We evaluated the effectiveness and safety of carbon ion radiotherapy in patients with primary malignant bone tumors of the sacrum not suitable for surgical resection.
Materials/Methods: From 1996 to 2009, 175 (male/female: 112/66) patients with primary malignant bone tumors of the sacrum, not suited for resection, received carbon ion radiotherapy. Ages ranged from 13 to 87 (median 62 years). All 175 patients had primary disease presentation and no recurrent disease. Histologic diagnoses were as follows: chordoma in 123, osteosarcoma in 21, chondrosarcoma in 9, Ewing's tumors in 9, MFH (Malignant fibrous histiocytoma) in 6, MPNST (Malignant peripheral nerve sheath tumor) in 3, and other in 7 patients. Carbon ion radiotherapy was delivered in 16 fractions over 4 weeks. Total doses: 52.8 GyE (3.3 GyE / Fr) in 1, 57.6 GyE (3.6 GyE/Fr) in 2, 64.0 GyE (4.0 GyE/Fr) in 1, 67.2 GyE (4.2 GyE/Fr) in 39, 70.4 GyE (4.4 GyE/Fr) in 123, and.73.6 GyE (4.6 GyE / Fr) in 12 patients. Clinical target volumes ranged between 42 and 1497 cm3 (median 354 cm3).
Results: Median survival time was 37 (range: 2-131) months for all patients and all living patients were followed more than 6 months. At 5 years, actuarial overall local control (LC) rate and overall survival (OS) rate were 85% and 70%, respectivelv. Five-year actuarial LC rate and OS rate in 123 patients with chordoma were 89% and 87%, respectively and that of 84%' and 36% in 21 patients with osteosarcoma. Seven patients experienced grade 3 and/or 4 skin/soft tissue late reactions in this series.
Conclusions: This is one of the largest series of primary malignant bone tumors of the sacrum. Local control and overall survival at 5 years in patients with primary malignant bone tumors of the sacrum treated by carbon ion radiotherapy are almost similar to those in reported data on patients treated by surgical resection with/without adjuvant radiotherapy. Carbon ion radiotherapy is suggested to be an effective and safe treatment for primary malignant bone tumors of the sacrum especially for which surgical resection is not a viable option, and it appears to represent a promising alternative to surgery., ASTRO 52nd Annual Meeting},
 title = {Carbon ion radiotherapy for primary malignant bone tumors of the sacrum},
 year = {2010}
}