Wideröe R
Rofo. 1975 Nov;123(5):475-81. doi: 10.1055/s-0029-1230239.
The Ellis formula for the sterilization of tumors is compared with isoeffect curves for sterilizing doses as a function of the fractionation number N. Using cell parameters from human kidney cells irradiated in cell cultures we get a good agreement over a wide range of N values. The exponents obtained from the calculations are 0,26-0,30 and 0,36 for 200 keV X-rays, Co-60 rays and high energy electrons respectively. A reduction of tumor cells to 10(-8) seems sufficient for tumor sterilization. For normal tissue Ellis has proposed another formula (for X-rays) where a time factor T0,11 concerns homeostatic repair and proliferation of normal alls. The Ellis formula can be simplified when we assume that all treatment schemes be given with the same weekly dose-rate, i.e. have the same "hardness". Cell survivals according to this formula have been calculated and tolerance doses for other radiations giving the same effect computed. Only for electrons do the tolerance doses exceed the sterilizing doses. The Ellis formula does not represent isoeffects and can only be regarded as an approximation. Tolerance doses can be calculated giving the same cell survivals for all N-values, i.e. isoeffects, and a comparison with sterilizing doses shows a good agreement with clinical experience. However, the influence of the overall-dose rate still is an unsolved problem which can only be solved experimentally.
将用于肿瘤灭菌的埃利斯公式与作为分次照射次数N的函数的灭菌剂量等效应曲线进行了比较。使用细胞培养中照射的人肾细胞的细胞参数，我们在很宽的N值范围内得到了很好的一致性。对于200keV X射线、钴-60射线和高能电子，计算得到的指数分别为0.26 - 0.30和0.36。将肿瘤细胞减少到10^(-8)似乎足以实现肿瘤灭菌。对于正常组织，埃利斯提出了另一个公式（针对X射线），其中时间因子T0.11涉及正常细胞的稳态修复和增殖。当我们假设所有治疗方案以相同的每周剂量率给予，即具有相同的“硬度”时，埃利斯公式可以简化。根据该公式计算了细胞存活率，并计算了产生相同效果的其他辐射的耐受剂量。只有对于电子，耐受剂量超过了灭菌剂量。埃利斯公式并不代表等效应，只能被视为一种近似。可以计算出对于所有N值都具有相同细胞存活率的耐受剂量，即等效应，并且与灭菌剂量的比较显示与临床经验有很好的一致性。然而，总剂量率的影响仍然是一个未解决的问题，只能通过实验来解决。
