Wheldon T E, Hingston E C, Ledda J L
Eur J Cancer Clin Oncol. 1982 Oct;18(10):1007-15. doi: 10.1016/0277-5379(82)90250-4.
Thermotolerance in vivo was investigated using the rat fibrosarcoma SSBla. Hyperthermia was administered using water-bath heating, with the tumour blood supply occluded by clamping during the heating procedure. Single-dose heat treatments (10-60 min at 43.5 degrees C) yielded linear dose-response curves, with response evaluated as tumour re-growth delay. In thermotolerance studies split-dose treatments were given in which a single 'priming' treatment of 30 min at 43.5 degrees C was followed 24 or 48 hr later by a variable treatment (10-90 min), again at 43.5 degrees C. Split-dose responses produced generally less uniform results, though the dose-response curves were still approximately linear. Comparison of the slopes of the dose-response curves for single-dose and split-dose treatments gave a 'thermotolerance ratio' (TTR) of 4.09 and 3.45 at 24 and 48-hr intervals respectively. Data analysis using Monte Carlo simulation techniques also suggests that the distribution of tumour sensitivities to a second heat treatment may be considerably broader than the distribution of sensitivities to a first treatment. Uniformity of tumour response to a single heat treatment may therefore conceal a spectrum of capacities for development of thermotolerance amongst individual tumours.
利用大鼠纤维肉瘤SSB1a研究体内热耐受性。采用水浴加热进行热疗，在加热过程中通过夹闭阻断肿瘤血液供应。单剂量热疗（43.5℃下10 - 60分钟）产生线性剂量反应曲线，反应以肿瘤再生长延迟来评估。在热耐受性研究中，采用分割剂量治疗，即先在43.5℃下进行30分钟的单次“预激”治疗，24或48小时后再进行一次可变时长（10 - 90分钟）的治疗，同样在43.5℃。尽管剂量反应曲线仍大致呈线性，但分割剂量治疗产生的结果通常不太一致。单剂量和分割剂量治疗的剂量反应曲线斜率比较得出，在24小时和48小时间隔时的“热耐受性比率”（TTR）分别为4.09和3.45。使用蒙特卡罗模拟技术进行数据分析还表明，肿瘤对第二次热疗的敏感性分布可能比第一次治疗的敏感性分布宽得多。因此，肿瘤对单次热疗反应的一致性可能掩盖了各个肿瘤之间热耐受性发展能力的差异。
