Evaluation of RBE of carbon-ion beams for epithelial thickness on mouse tongues

Abstract

To evaluate if D-methionine, the dextro-isomer of the common amino acid L-methionine, can prevent oral mucositis resulting from heavy ion irradiation during treatment for head and neck cancers. For the first study, RBE of carbon-ion beams for epithelial thickness on mouse tongues was evaluated. The head of female C3H mice, 8 weeks old, were irradiated by five fractionated doses of carbon ion beams (290MeV/u) or 150kV X-rays to induce oral mucositis (ulcers on tongue). Six days after the last irradiation, mice were sacrificed. Excised tongues were evaluated macroscopically and micro- scopically. The thickness of the lingual epithelium was measured. The RBE of 6-cm SOBP (290MeV/u) for epithelium on mouse tongues after fractionated doses is 1.82. It was almost the equivalent value as that for gut crypt survivals reported by enormous studies.