Department of Therapeutic Radiology-Radiation Oncology, University of Minnesota Medical School, Minneapolis, Minnesota, USA.
Radiat Res. 2012 Mar;177(3):311-27. doi: 10.1667/rr2773.1. Epub 2012 Jan 9.
We have reviewed the studies on radiation-induced vascular changes in human and experimental tumors reported in the last several decades. Although the reported results are inconsistent, they can be generalized as follows. In the human tumors treated with conventional fractionated radiotherapy, the morphological and functional status of the vasculature is preserved, if not improved, during the early part of a treatment course and then decreases toward the end of treatment. Irradiation of human tumor xenografts or rodent tumors with 5-10 Gy in a single dose causes relatively mild vascular damages, but increasing the radiation dose to higher than 10 Gy/fraction induces severe vascular damage resulting in reduced blood perfusion. Little is known about the vascular changes in human tumors treated with high-dose hypofractionated radiation such as stereotactic body radiotherapy (SBRT) or stereotactic radiosurgery (SRS). However, the results for experimental tumors strongly indicate that SBRT or SRS of human tumors with doses higher than about 10 Gy/fraction is likely to induce considerable vascular damages and thereby damages the intratumor microenvironment, leading to indirect tumor cell death. Vascular damage may play an important role in the response of human tumors to high-dose hypofractionated SBRT or SRS.
我们回顾了过去几十年中关于人类和实验性肿瘤中辐射诱导的血管变化的研究。尽管报告的结果不一致，但可以概括如下。在接受常规分割放疗的人类肿瘤中，血管的形态和功能状态在治疗过程的早期得到了保持（如果没有改善的话），然后在治疗结束时下降。单次给予 5-10Gy 的剂量照射人类肿瘤异种移植物或啮齿动物肿瘤会导致相对较轻的血管损伤，但将辐射剂量增加到 10Gy/次以上会导致严重的血管损伤，从而导致血液灌注减少。关于接受高剂量超分割放疗（如立体定向体部放疗[SBRT]或立体定向放射外科[SRS]）的人类肿瘤中的血管变化知之甚少。然而，实验性肿瘤的结果强烈表明，对于剂量高于约 10Gy/次的人类肿瘤进行 SBRT 或 SRS 很可能会引起相当大的血管损伤，从而损害肿瘤内微环境，导致间接的肿瘤细胞死亡。血管损伤可能在人类肿瘤对高剂量超分割 SBRT 或 SRS 的反应中发挥重要作用。
