Takemasa K
Department of Radiology, School of Medicine, Keio University.
Nihon Igaku Hoshasen Gakkai Zasshi. 1992 Jul 25;52(7):1007-15.
This study was performed to determine the effect of the growth rate of monolayer cells on survival following fractionated irradiation. HeLa and RMUG cells that had different radiosensitivities and growth rates (Do value: 2.3 vs 1.5 Gy, doubling time: 17 vs 46 hours) were irradiated with 2 Gy every day. The fractions surviving after fractionated irradiation were compared with those given single doses. The dose modifying factor for fractionated irradiation was larger in RMUG than HeLa: 1.7 and 1.2, respectively. Two clones from ADGU cells that had the same radiosensitivity but different growth rates were also given fractionated irradiation, but there was no difference in surviving fractions. When recovery following two split doses was determined in each type of cell, the results of the fractions surviving after fractionated irradiation were correlated only with recovery between split doses. These suggest that the growth rates of monolayer cells may not modify the fractions surviving after fractionated irradiation, and the monolayer cell system is not suitable for determining the effect of growth rates on survival following fractionated irradiation.
本研究旨在确定单层细胞生长速率对分次照射后存活的影响。对具有不同放射敏感性和生长速率（Do值：2.3对1.5 Gy，倍增时间：17对46小时）的HeLa细胞和RMUG细胞每天照射2 Gy。将分次照射后的存活分数与单次剂量照射后的存活分数进行比较。RMUG细胞分次照射的剂量修正因子大于HeLa细胞，分别为1.7和1.2。对来自ADGU细胞的具有相同放射敏感性但不同生长速率的两个克隆也进行了分次照射，但存活分数没有差异。当在每种细胞类型中测定两次分割剂量后的恢复情况时，分次照射后存活分数的结果仅与分割剂量之间的恢复情况相关。这些结果表明，单层细胞的生长速率可能不会改变分次照射后的存活分数，并且单层细胞系统不适用于确定生长速率对分次照射后存活的影响。
