■放疗可提高胶质母细胞瘤患者的生存率。然而,处方剂量受到对正常组织有害副作用的限制。先前的实验研究表明,FLASH放射治疗(FLASH-RT)可以减少这些副作用。尽管如此,将FLASH-RT与常规放疗(CONV-RT)进行比较,建立同等的抗肿瘤疗效很重要。
■将具有GFP阳性NS1颅内胶质母细胞瘤模型的完全免疫功能的Fischer344大鼠用CONV-RT或FLASH-RT照射20Gy,25Gy或30Gy。监测动物的存活和急性皮肤副作用。安乐死后收获大脑,死后检查肿瘤。
■与对照动物相比,用20Gy和25Gy的CONV-RT和FLASH-RT照射的动物的存活率显著增加。在25Gy的FLASH-RT和CONV-RT照射的动物中达到最长的存活。30Gy的照射不会导致存活率增加,尽管肿瘤较小。肿瘤大小与照射剂量成反比,在用CONV-RT和FLASH-RT治疗的动物中。急性皮肤副作用轻微,但是只有一小部分动物活着来评估这些副作用。
■在本模型中,CONV-RT和FLASH-RT的剂量反应相似。安乐死后的肿瘤大小与辐射剂量成反比。
UNASSIGNED: Radiotherapy increases survival in patients with glioblastoma. However, the prescribed dose is limited by unwanted side effects on normal tissue. Previous experimental studies have shown that FLASH radiotherapy (FLASH-RT) can reduce these side effects. Still, it is important to establish an equal anti-tumor efficacy comparing FLASH-RT to conventional radiotherapy (CONV-RT).
UNASSIGNED: Fully immunocompetent Fischer 344 rats with the GFP-positive NS1 intracranial glioblastoma model were irradiated with CONV-RT or FLASH-RT in one fraction of 20 Gy, 25 Gy or 30 Gy. Animals were monitored for survival and acute dermal side effects. The brains were harvested upon euthanasia and tumors were examined post mortem.
UNASSIGNED: Survival was significantly increased in animals irradiated with CONV-RT and FLASH-RT at 20 Gy and 25 Gy compared to control animals. The longest survival was reached in animals irradiated with FLASH-RT and CONV-RT at 25 Gy. Irradiation at 30 Gy did not lead to increased survival, despite smaller tumors. Tumor size correlated inversely with irradiation dose, both in animals treated with CONV-RT and FLASH-RT. Acute dermal side effects were mild, but only a small proportion of the animals were alive for evaluation of those side effects.
UNASSIGNED: The dose response was similar for CONV-RT and FLASH-RT in the present model. Tumor size upon the time of euthanasia correlated inversely with the irradiation dose.