Logani S, Cho A S, Ali B H, Withers H R, McBride W H, Kozlov K L, Hall M O, Lee D A, Straatsma B R
Department of Ophthalmology, University of California Los Angeles, School of Medicine, USA.
Am J Ophthalmol. 1995 Oct;120(4):506-10. doi: 10.1016/s0002-9394(14)72665-0.
To compare single-dose and fractionated-dose radiotherapeutic effects on choroidal melanoma cells.
We determined the effects of gamma radiation on OM431 cell survival by exposing cells to either a single 9-Gy dose or two 4.5-Gy fractionated doses at intervals of 20 minutes to eight hours. The effects of single dosing and fractionated dosing at six hours were compared at doses of 2 to 12 Gy.
Tumor cell repair was most rapid during the first two hours. Maximum repair had occurred by six hours after radiation. Cell survival curves showed doses greater than 3 Gy of single-dose gamma radiation resulted in a greater number of cells killed than did equivalent fractionated doses.
Ocular melanoma in vitro is relatively radioresistant to low-dose fractionated radiotherapy. High single-dose radiotherapy would be more effective but would also result in more damage to normal tissue unless more focused modalities of radiotherapy are used.
比较单剂量和分次剂量放射治疗对脉络膜黑色素瘤细胞的效果。
我们通过将细胞暴露于单次9 Gy剂量或两次4.5 Gy分次剂量（间隔20分钟至8小时）来确定γ射线对OM431细胞存活的影响。在2至12 Gy的剂量下比较了6小时时单剂量和分次剂量的效果。
肿瘤细胞修复在前两小时最为迅速。放疗后6小时发生最大程度的修复。细胞存活曲线显示，大于3 Gy的单剂量γ射线照射比同等分次剂量杀死的细胞数量更多。
体外眼黑色素瘤对低剂量分次放疗相对具有放射抗性。高单剂量放疗会更有效，但除非使用更聚焦的放疗方式，否则也会对正常组织造成更多损伤。
