Okumura Y, Norimura T, Okajima S
Strahlentherapie. 1983 Feb;159(2):109-14.
The cure rate of tumors was analysed by a model, and applied to human cancer. The cure rate increased linearly when plotted on a probit scale against dose in logarithm. The coefficient of variation, the ratio of one standard deviation to the dose of 50% cure, was taken as an indicator. The minimum value of the coefficient of variation was 5% obtained theoretically, and 10% clinically. This difference might be due to the variability existing in cancer of patients. The complications to the normal tissues, which was induced by the radiotherapy of cancer, were also analysed. The coefficient of variation for the complication showed the same tendency to that of the cure rate. The cures without complications were affected by the coefficients of variation for the cure rate and for the complication rate. The coefficient of variation for the cure rate is determined by the stochastic effect of cell killing and the error in dose estimation. When the physical error was 5%, its effect on the cure rate could be negligible. But when its error became more than 10%, a significant difference of the cure rate would be observed clinically in some tumors. The accuracy of the dose estimation was emphasized.
通过一个模型分析了肿瘤的治愈率，并将其应用于人类癌症。当以概率尺度对对数剂量作图时，治愈率呈线性增加。变异系数，即一个标准差与50%治愈率剂量的比值，被用作一个指标。变异系数的理论最小值为5%，临床最小值为10%。这种差异可能是由于患者癌症中存在的变异性。还分析了癌症放疗对正常组织的并发症。并发症的变异系数与治愈率的变异系数表现出相同的趋势。无并发症的治愈情况受治愈率和并发症率变异系数的影响。治愈率的变异系数由细胞杀伤的随机效应和剂量估计误差决定。当物理误差为5%时，其对治愈率的影响可忽略不计。但当误差超过10%时，在某些肿瘤中临床上会观察到治愈率的显著差异。强调了剂量估计的准确性。
