Rofstad E K, Brustad T
Radiother Oncol. 1987 May;9(1):45-56. doi: 10.1016/s0167-8140(87)80218-9.
The radioresponsiveness of five human melanoma xenograft lines given fractionated irradiation in vivo was studied using specific growth delay and cell survival in vitro as endpoints. Superfractionation (3 fractions of 2.0 Gy with 4-h intervals each day) as well as conventional fractionation (1 fraction of 2.0 Gy each day) were used. The total dose was varied within the ranges 12 to 30 Gy and 10 to 30 Gy, respectively. The rankings of the melanomas in radioresponsiveness were almost identical, irrespective of the endpoint and the fractionation regime considered. The radioresponsiveness was found to be positively correlated to the initial slope of the in vitro cell survival curves, i.e. the alpha and the surviving fraction at 2.0 Gy (conventional dose rate; 3.0 Gy/min) and the D0 (low dose rate; 1.25 cGy/min). There was no relationship between the radioresponsiveness and any known growth or microenvironmental parameter. It is concluded that the differences in radioresponsiveness among the melanomas for the fractionation regimes studied here were governed mainly by the intrinsic repair capacity of the tumour cells and not by microenvironmental factors. The potential of in vitro cell survival curve parameters in predicting the clinical radioresponsiveness of tumours is discussed.
以体内特定生长延迟和体外细胞存活为终点，研究了5种人黑色素瘤异种移植瘤系在体内接受分次照射后的放射反应性。采用了超分割照射（每天3次，每次2.0 Gy，间隔4小时）以及常规分割照射（每天1次，每次2.0 Gy）。总剂量分别在12至30 Gy和10至30 Gy范围内变化。无论考虑的终点和分割方案如何，黑色素瘤在放射反应性方面的排名几乎相同。发现放射反应性与体外细胞存活曲线的初始斜率呈正相关，即α以及2.0 Gy（常规剂量率；3.0 Gy/min）时的存活分数和D0（低剂量率；1.25 cGy/min）。放射反应性与任何已知的生长或微环境参数之间均无关联。得出的结论是，此处研究的分割方案中黑色素瘤之间放射反应性的差异主要由肿瘤细胞的内在修复能力决定，而非微环境因素。讨论了体外细胞存活曲线参数在预测肿瘤临床放射反应性方面的潜力。
