Split-dose experiments with hypoxic cells. Implications for fractionated and low-dose-rate radiotherapy.
Split-dose experiments with hypoxic cells. Implications for fractionated and low-dose-rate radiotherapy.
复制标题
缺氧细胞的分次剂量实验。
作者：
E. Hall;S. Lehnert;L. Roizin
已经开发了通过使用高细胞浓度产生培养的哺乳动物细胞的缺氧群体的技术。在这些条件下，氧仍然是剂量调节的，氧增强比约为3。分次剂量实验表明，亚致死辐射损伤的修复是完全抑制，如果缺氧维持在辐射暴露期间和整个存储间隔之间的剂量。这些发现在实际的放射治疗中具有重要意义：如果治疗是超分割的，那么缺氧水平如此低以至于亚致死损伤的修复受到抑制的肿瘤细胞不受缺氧的保护。
Techniques of producing hypoxic populations of cultured mammalian cells by using high cell concentrations have been developed. Under these conditions, oxygen is still dose-modifying and the oxygen enhancement ratio is approximately 3. Split-dose experiments indicate that repair of sublethal radiation damage is completely inhibited if hypoxia is maintained both during the radiation exposures and throughout the storage interval between doses. These findings have important implications in practical radiation therapy: tumor cells at such a low level of hypoxia that repair of sublethal damage is inhibited are not protected by the hypoxia, provided the treatment is hyperfractionated.