Nivet A, Schlienger M, Clavère P, Huguet F
Service de radiothérapie, centre hospitalier universitaire de Limoges, 2, avenue Martin-Luther-King, 87000 Limoges, France.
Service d'oncologie radiothérapie, hôpital Tenon, Assistance publique-Hôpitaux de Paris, 4, rue de la Chine, 75020 Paris, France; Sorbonne université, 21, rue de l'École-de-Médecine, 75006 Paris, France.
Cancer Radiother. 2019 Apr;23(2):161-167. doi: 10.1016/j.canrad.2018.05.009. Epub 2019 Mar 25.
A review of the literature has been conducted to better understand the effect of stereotactic radiotherapy on tumour vascularization and their consequences. High irradiation doses cause the death of endothelial cells by apoptosis through the ceramide pathway. Vascular consequences are multiple: increased permeability, decreased blood flow, increased hypoxia and tumoral necrosis. This necrosis causes an indirect death of the cancer cells in the days following the irradiation. The importance of indirect cell death in tumour control remains controversial, but it can explain the good clinical results of stereotactic radiotherapy. Stereotactic radiotherapy is a treatment of the tumour microenvironment. Tumour recurrence in this hypoxic environment is slower through disturbance of revascularization mechanisms but also more aggressive, with increased resistance to treatment and a higher risk of metastasis. In a longer time, vascular damage leads to chronic inflammation and a dysfunctional healing process resulting in vascular occlusion. This phenomenon is used in the treatment of arteriovenous malformations but is also responsible for damage to healthy tissues responsible for chronic complications. This is why high-dose irradiation can only be delivered using stereotactic radiotherapy, which reduces the irradiated volume.
为了更好地理解立体定向放射治疗对肿瘤血管生成的影响及其后果，我们进行了文献综述。高剂量照射通过神经酰胺途径诱导内皮细胞凋亡而死亡。血管方面的后果是多方面的：通透性增加、血流减少、缺氧增加和肿瘤坏死。这种坏死在照射后的几天内导致癌细胞间接死亡。间接细胞死亡在肿瘤控制中的重要性仍存在争议，但它可以解释立体定向放射治疗良好的临床效果。立体定向放射治疗是对肿瘤微环境的一种治疗。在这种缺氧环境中，肿瘤复发通过血管再生机制的紊乱而减缓，但也更具侵袭性，对治疗的抵抗性增加，转移风险更高。在更长的时间里，血管损伤会导致慢性炎症和功能失调的愈合过程，从而导致血管闭塞。这种现象被用于治疗动静脉畸形，但也会对导致慢性并发症的健康组织造成损害。这就是为什么高剂量照射只能通过立体定向放射治疗来实施，因为它可以减少照射体积。
