Lindenberger J, Hermeking H, Kummermehr J, Denekamp J
Radiother Oncol. 1986 May;6(1):15-27. doi: 10.1016/s0167-8140(86)80106-2.
The response of two human tumour xenografts to single dose and fractionated X-rays has been tested using regrowth delay as the assay. The tumours were line transplanted cells from a moderately well-differentiated squamous carcinoma of the tonsillar fossa (XJ) and an undifferentiated carcinoma of the floor of the mouth (XR). Comparison of the dose response curves for single doses in air, clamped, or after misonidazole administration, led to estimates of the hypoxic fraction (approximately 15%) and the sensitizer enhancement ratio (less than or equal to 1.6). When 5 daily fractions were used, the effect of misonidazole (miso) was lost and reoxygenation appeared to be effective in both tumours. Comparison of single doses and 5 fractions in clamped tumours, and in those sensitized by miso, allowed the sparing effect of fractionation to be estimated. When analysed by the linear quadratic model the alpha/beta ratios were found to be in the range of 6.4-9.2 Gy and 6.8-16.0 Gy for the two tumours. These values are in good agreement with murine tumours (assayed in vivo or in vitro), with human tumour cells assayed in vitro, and with analyses of fractionated clinical data for skin cancer.
使用再生长延迟作为测定方法，测试了两种人肿瘤异种移植对单次剂量和分次X射线的反应。这些肿瘤是来自扁桃体窝中度分化良好的鳞状细胞癌（XJ）和口底未分化癌（XR）的细胞系移植瘤。比较空气中单次剂量、钳夹后或给予米索硝唑后的剂量反应曲线，得出了乏氧分数（约15%）和敏化剂增强比（小于或等于1.6）的估计值。当采用每日5次分割照射时，米索硝唑（miso）的作用消失，再氧合在两种肿瘤中似乎都有效。比较钳夹肿瘤以及米索硝唑致敏肿瘤中的单次剂量和5次分割照射，可估计分割照射的 sparing 效应。当用线性二次模型分析时，发现两种肿瘤的α/β比值在6.4 - 9.2 Gy和6.8 - 16.0 Gy范围内。这些值与小鼠肿瘤（体内或体外测定）、体外测定的人肿瘤细胞以及皮肤癌分次临床数据的分析结果高度一致。
