[Recent progress in radiation therapy].

Causing selective damage to tumors is an important issue in radiation therapy. This is usually addressed using either a biological or a physical approach. The former includes chemoradiotherapy and a combination of targeted drugs and radiation whereas the latter includes stereotactic radiotherapy, intensity-modulated radiotherapy and particle therapy. However, these sophisticated radiotherapy techniques are inadequate due to tumor movement and therefore 4-dimensional radiotherapy which addresses this problem is being clinically investigated.