Review of tumor radiosensitivity from the point of view of stereotactic ablative radiotherapy / 中华放射医学与防护杂志

ABSTRACT

With the technical advances, radiotherapy has ushered in a new era of 3-D and 4D, which are associated with significantly improved therapy precision and profound change in fractionation pattern. The radiotherapy with focused rays, represented by both 3D-conformal radiotherapy (3D-CRT) and intensity modulated radiation therapy ( IMRT ) , involves the delivery of high doses to the target volume, with a less attendant potential for damages to surrounding normal tissue. Radiotherapy has been able to deliver precise, efficient, low toxic access to therapeutic effects thanks to the advance in image-guided techniques, the combination of radiotherapy equipment with image-guided system, the availability of target position information before radiotherapy with 3D or 4D image modality, the stereotactic body radiation therapy (SBRT)/the stereotactic ablation radiosurgery (SABR). Conventional fractionated radiation has seen the therapeutic effect of convincing and promising. The conventional theory of radiobiology, which deems the tumor not sensitive to radiotherapy to have good reaction with SABR, has been unable to explain the mechanism of antitumor effects arising from such exposure modes. Therefore, it is now urgent to create new radiobiological theory and system for radiotherapy in order to better illustrate the principle and mechanism of new technologies, to establish its internal relation with conventional radiobiology and to lay theoretical groundwork for popularization and dissemination of SABR in clinical medicine.