AN INCOMPLETE-REPAIR MODEL FOR SURVIVAL AFTER FRACTIONATED AND CONTINUOUS IRRADIATIONS
AN INCOMPLETE-REPAIR MODEL FOR SURVIVAL AFTER FRACTIONATED AND CONTINUOUS IRRADIATIONS
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DOI：
10.1080/09553008514550461
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发表时间：
1985-01-01
影响因子：
2.6
通讯作者：
THAMES, HD
中科院分区：
文献类型：
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作者：
THAMES, HD
不完全修复（IR）模型的生存后，分次或连续照射的概念，不完全修复的剂量当量。该模型给出了相当好的预测interfraction间隔，剂量每部分和剂量率对细胞存活在体内和组织反应的影响。该模型相比，致死，潜在致死（LPL）模型后，后者被推广到任意数量的分数和低剂量率，连续曝光。这2种模型显然是等效的，因为对每部分剂量和剂量率的大小有一定的限制。例如，在特定细胞系中，如果每部分的剂量远远超过4戈伊[格雷]，则分次模型的等效性失效（IR模型采用线性二次生存模型）。低剂量率模型的等效性打破了剂量率超过20 cGy/min。广义LPL模型的基础上的假设是用来给不完全修复模型的放射生物学解释。β/越大，α的晚反应正常组织的比率特征解释为，由于细胞周期的进展，在急性反应组织的靶细胞中潜在可修复损伤的相对较快的固定。根据这种解释，β/.α的由等效分级方案估计的比率与克隆形成细胞杀伤的参数直接相关。
An incomplete-repair (IR) model of survival after fractional or continuous irradiation is derived from the concept of dose-equivalent of incomplete repair. The model gives reasonably good predictions of the effect of interfraction interval, dose per fraction and dose rate on cell survival in vivo and on tissue responses. This model is compared to the lethal, potentially lethal (LPL) model after the latter was generalized to an arbitrary number of fractions and to low dose-rate, continuous exposures. The 2 models apparently are equivalent, given certain constraints on the size of dose per fraction and dose rate. For example, in a particular cell line the equivalence of fractionation models breaks down if dose per fraction is well in excess of 4 Gy [grays] (the IR model employs the linear-quadratic survival model). The equivalence of low dose rate models breaks down for dose rates well in excess of 20 cGy/min. The assumptions on which the generalized LPL model is based are used to give a radiobiological interpretation to the incomplete-repair model. The larger .beta./.alpha. ratio characteristic of late-responding normal tissues is interpreted in terms of the relatively faster fixation of potentially reparable lesions in the target cells of acutely responding tissues, on account of progression in the cell cycle. According to this interpretation the .beta./.alpha. ratios estimated from isoeffective fractionation regimens are directly related to the parameters of clonogenic cell killing.