Efficacy of microwave hyperthermia under condition of decrease in tumor blood flow

热疗的疗效强烈依赖于温度。然而，目前包括微波设备在内的热疗设备无法将肿瘤温度均匀地提高到42ﾟC以上。人们认为，提高肿瘤温度的一种方法是降低组织血流量，从而减少肿瘤的热损失，同时提高温度。在本研究中，我们试图寻找诱导肿瘤血流量减少的新材料，并利用我们所获得的材料来研究在肿瘤血流量减少的情况下微波热疗的效果。我们得到了以下两个结果：1.我们发现，血管紧张素转换酶抑制剂盐酸替莫普利、血管紧张素II受体1型拮抗剂氯沙坦和可溶性抗肿瘤素A4衍生物AC7700选择性地减少肿瘤组织血流量。尤其是AC7700诱导的肿瘤血流不可逆性停滞。微波热疗对体积大于5 cm~3的肿瘤的治疗效果并不因盐酸替莫普利减少肿瘤组织血流量而增强。

The efficacy of hyperthermia therapy is strongly dependent on temperature. However, current hyperthermia equipment including microwave apparatus have revealed an inability to uniformly raise tumor temperatures to above 42ﾟC.It has been considered that one approach to increasing temperatures in the tumors is to lower tissue blood flow thereby decreasing heat loss from the tumor and concurrent lyincreasing temperatures. In this study, we tried to find new materials which induce tumor blood flow reduction and using the material we investigated efficacy of microwave hyperthermia under condition of decrease in tumor blood flow. We obtained the following two results.1. We discovered that temocapril hydrochloride, an angiotensin converting enzyme inhibitor, losartan, angiotensin II receptor type 1 antagonist, and AC7700, a soluble combretastatin A4 derivative decrease tumor tissue blood flow selectively. In particular, AC7700 induced irreversible stoppage of tumor bloodflow.2. Therapeutic efficacy of microwave hyperthermia on tumors with the volume of above 5 cm3 was not enhanced by decreasing tumor tissue blood flow due to temocapril hydrochloride.