Rowley R, Hopkins H A, Betsill W L, Ritenour E R, Looney W B
Br J Cancer. 1980 Oct;42(4):586-95. doi: 10.1038/bjc.1980.283.
The effects of local tumour radiation over the dose range 7.5-30 Gy on the growth and cell kinetics of rat hepatoma H-4-II-E have been investigated. A plot of growth delays against log surviving fraction was linear below a fraction of 0.03, but failed to extrapolate to the origin. Following a single dose of 15 Gy to the tumour, DNA-precursor incorporation, labelling and mitotic indices were depressed for 7 days. Tumour cellularity, measured as DNA/g tumour, was reduced and the rate of increase of total clonogenic cells slower than after complete tumour recovery. From Day 7 to Day 9 all indices of proliferation recovered to about control levels, clonogenic cell numbers increased more rapidly and tumour cellularity was restored. Repopulation of the tumour therefore appeared to take place mainly after Day 7. Incorporation of [3H]-TdR into tumour DNA reached twice the control values on Day 9. The rate of tumour growth accelerated after the initial decrease, and maximum tumour growth rate was also twice the control values on Day 13. Accelerated growth rates in irradiated tumours, above those of control tumours, occurred 10-16 days after treatment. The effectiveness of sequential therapy may therefore be improved if given during this period of of accelerated tumour growth.
研究了局部肿瘤辐射剂量范围在7.5 - 30 Gy对大鼠肝癌H - 4-II - E生长和细胞动力学的影响。在存活分数低于0.03时，生长延迟与对数存活分数的关系图呈线性，但不能外推至原点。对肿瘤单次给予15 Gy剂量后，DNA前体掺入、标记和有丝分裂指数在7天内受到抑制。以DNA/克肿瘤衡量的肿瘤细胞密度降低，总克隆细胞的增加速率比肿瘤完全恢复后要慢。从第7天到第9天，所有增殖指标恢复到约对照水平，克隆细胞数量增加更快，肿瘤细胞密度恢复。因此，肿瘤的再增殖似乎主要发生在第7天之后。在第9天，[3H]-TdR掺入肿瘤DNA达到对照值的两倍。肿瘤生长速率在最初下降后加速，在第13天最大肿瘤生长速率也是对照值的两倍。照射后肿瘤的生长速率在治疗后10 - 16天高于对照肿瘤。因此，如果在肿瘤加速生长的这段时间给予序贯治疗，其有效性可能会提高。
