Biological Gain of Carbon-ion Radiotherapy for the Early Response of Tumor Growth Delay and against Early Response of Skin Reaction in Mice

• Published in: JOURNAL OF RADIATION RESEARCH 2005, Vol.46 (1), p.51-57
• Main Authors: Ando, Koichi, Koike, Sachiko, Uzawa, Akiko, Takai, Nobuhiko, Fukawa, Takeshi, Furusawa, Yoshiya, Aoki, Mizuho, Miyato, Yasuyuki
• Format: Article
• Language: English
• Subjects: Analysis; Animals; Carbon Isotopes - adverse effects; Carbon Isotopes - therapeutic use; Cell Proliferation - radiation effects; Dose-Response Relationship, Radiation; Female; Fibrosarcoma - pathology; Fibrosarcoma - radiotherapy; Gamma rays; Gamma Rays - adverse effects; Gamma Rays - therapeutic use; Growth; Health aspects; Male; Mice; Mice, Inbred C3H; Radiodermatitis - etiology; Radiodermatitis - pathology; Radiodermatitis - prevention & control; Radiotherapy; Radiotherapy Dosage; Skin; Skin - radiation effects; Treatment Outcome; Tumors
• ISSN: 0449-3060; 1349-9157
• DOI: 10.1269/jrr.46.51

The biological effectiveness of carbon ions relative to γ rays (RBE) was compared between the tumor growth delay and an early skin reaction of syngeneic mice. The RBE was larger for a tumor than skin when irradiated with large doses of high-LET (linear energy transfer) carbon ions. The intra-track damage (α term of a linear quadratic model) of a tumor and skin increased equally with an increase of the LET, while the inter-track damage (β term) of skin alone increased with the LET. These data provide evidence that high-LET radiotherapy could achieve therapeutic gain by minimizing the difference in response to fractionated irradiation between the tumor and normal tissue.