Hiraoka M, Miyakoshi J, Jo S, Takahashi M, Abe M
Jpn J Cancer Res. 1987 Jan;78(1):63-7.
Radiosensitizing effects of step-up heating (SUH) and step-down heating (SDH) on the tumor and skin were studied by using mammary adenocarcinoma transplanted to the foot of the C3H/He mouse. The tumor and skin responses were assessed by the tumor growth delay method and the skin reaction scoring method, respectively. Neither SDH (44 degrees, 10 min----42 degrees, 30 min) nor SUH (42 degrees, 30 min----44 degrees, 10 min) alone caused a substantial tumor or skin response. When the heat treatment was given immediately after irradiation, the thermal enhancement ratio (TER) was higher in SDH than in SUH for tumors as well as the skin. A therapeutic gain factor (TGF) of 1.2 was obtained in SUH, while no therapeutic benefit was found in SDH. SDH was applied at various times (0 to 3 hr) before or after irradiation. When SDH was given before irradiation, the TER was consistently high to almost the same degree for tumors and the skin regardless of the time interval, resulting in minimal or no therapeutic gain. With SDH after irradiation, the TER for the skin decreased with increase in the time interval, while the TER for the tumor was moderately enhanced. Therefore, the TGF increased with increase in the time interval and reached 2.2 when SDH was given 3 hr after radiation. SUH is slightly advantageous over SDH in terms of the TGF, and SDH should be given 3 hr after irradiation when selective tumor heating is not possible.
采用移植于C3H/He小鼠足部的乳腺腺癌，研究了升温加热（SUH）和降温加热（SDH）对肿瘤和皮肤的放射增敏作用。分别采用肿瘤生长延迟法和皮肤反应评分法评估肿瘤和皮肤反应。单独的SDH（44℃，10分钟----42℃，30分钟）和SUH（42℃，30分钟----44℃，10分钟）均未引起明显的肿瘤或皮肤反应。当在照射后立即进行热处理时，对于肿瘤和皮肤，SDH的热增强比（TER）高于SUH。SUH获得了1.2的治疗增益因子（TGF），而在SDH中未发现治疗益处。在照射前或照射后的不同时间（0至3小时）应用SDH。当在照射前给予SDH时，无论时间间隔如何，肿瘤和皮肤的TER始终保持在几乎相同的高水平，导致最小或无治疗增益。照射后给予SDH时，皮肤的TER随时间间隔增加而降低，而肿瘤的TER则适度增强。因此，TGF随时间间隔增加而增加，当在照射后3小时给予SDH时达到2.2。就TGF而言，SUH比SDH略具优势，当无法进行选择性肿瘤加热时，应在照射后3小时给予SDH。
