Progress on the fundamental biological studies for tumor therapy with heavy particles

Due to its unique physical and biological advantages, heavy ion beam has great advantages as tumor radiotherapy ray. Tumor therapy with heavy particles has achieved outstanding clinical outcome and is of the potential to become the most advanced radiotherapy in this century. Fundamental studies on the biological effects are of significance in providing theoretical principle and optimizing beam quality for tumor therapy with heavy particles. Meanwhile, the application of new techniques such as FLASH and GRID in tumor therapy with heavy particles requires fundamental biological studies as well, especially in improving clinical efficacy and security. In this article, we review the progress on the fundamental biological studies for tumor therapy with heavy particles and arouse discussion on the issues necessary for further elucidation. Key words: Heavy ion; Tumor radiotherapy; Relative biological effectiveness; Oxygen enhancement ratio