重粒子線照射による肺晩発障害機構の解明

Radiation induced pneumonitis and consequential pulmonary fibrosis are known serious side effects after thoracic radiation therapy. Since these side effects act as a dose-limiting factor, understanding the molecular and pathogenic mechanisms underlying these symptoms is essential for improvement of radiotherapy, including heavy ion radiotherapy. In this study, we aim to identify molecular mechanisms, which can become novel target for prevention or treatment of radiation induced pneumonitis and pulmonary fibrosis. C3H/He, C57BL/6J and C3B6F1 mice were locally irradiated in the thorax by carbon-ion beam (290MeV/n), and subsequently we performed histological analyses of the lung at different time points after irradiation. Previously our study showed pneumonitis and consequential pulmonary fibrosis developed 5-6 months after irradiation. Due to the fact that less than 5 months have passed since our first dose of radiation (2011.9.27), we are currently observing the pathological changes. We will report our results next year.