Hase M, Sako M, Hirota S
Department of Radiology, Kobe University School of Medicine.
Nihon Igaku Hoshasen Gakkai Zasshi. 1990 Nov 25;50(11):1402-14.
The induction heating to ferromagnetic implants (Ferromagnetic Induction Heating: FIH) has been developed for the purpose of selective hyperthermia on deep-seated tumors. In this investigation, the procedure of FIH combined with hepatic arterial embolization (HAE) was experimentally studied on VX2 liver tumor of rabbit. The induction heating unit is composed of radiofrequency generator (500 KHZ, 6-12 KW) and circular applicator (60 cm in diameter). Ferromagnetic implant used was pure iron particles (100 mu in size), which were suspended in tenacious polysaccharide solution to be injectable through a needle. After HAE with gelatin sponge powder had been made, iron particle suspension was injected into the cavity of tumor with subsequent exertion of induction heating (9KW) for 15 minutes. The measurement of temperature was made on the tumor and the liver parenchyma by fluoroptic thermometer with thin, flexible probe which readily passed through a needle. The temperature measured at peripheral area of tumor elevated at range from 2.5 to 7.1 degrees C, corresponding to the dose of iron particles injected; 2.5 degrees C with 1 g, 4.9 degrees C with 2 g, 7.1 degrees C with 3 g. In contrast, the temperature of liver parenchyma elevated at range of less than 2.5 degrees C, to indicate a successful selective heating of liver tumor. An additional experiment for the effect of heat on normal liver of rabbit were made using a microwave heating system. The histological and serologic examinations after heating of below 40 degrees C did not show any abnormal findings. After heating of 42-43 degrees C, however, serum GOT and GPT transiently elevated more than 3 times to that of before heating. Histologically, there were extensive degeneration and necrosis of liver tissue. From the results we concluded that FIH combined with HAE could provide an intensive therapeutic effect for treatment of well-localized liver tumors with minimal damages to the liver parenchyma, because of selective heating of the tumor.
为了对深部肿瘤进行选择性热疗，已开发出对铁磁性植入物的感应加热技术（铁磁性感应加热：FIH）。在本研究中，对兔VX2肝肿瘤进行了FIH联合肝动脉栓塞术（HAE）的实验研究。感应加热装置由射频发生器（500千赫，6 - 12千瓦）和圆形施加器（直径60厘米）组成。使用的铁磁性植入物是纯铁颗粒（尺寸为100微米），将其悬浮在粘性多糖溶液中以便通过针头注射。在用明胶海绵粉进行HAE后，将铁颗粒悬浮液注入肿瘤腔内，随后施加感应加热（9千瓦）15分钟。通过带有细的、可弯曲探头的荧光温度计对肿瘤和肝实质进行温度测量，该探头可轻松穿过针头。在肿瘤周边区域测得的温度升高范围为2.5至7.1摄氏度，这与注入的铁颗粒剂量相对应；注入1克时为2.5摄氏度，2克时为4.9摄氏度，3克时为7.1摄氏度。相比之下，肝实质的温度升高范围小于2.5摄氏度，表明成功实现了对肝肿瘤的选择性加热。使用微波加热系统对兔正常肝脏进行了热效应的额外实验。在低于40摄氏度加热后，组织学和血清学检查未显示任何异常发现。然而，在42 - 43摄氏度加热后，血清谷草转氨酶（GOT）和谷丙转氨酶（GPT）瞬时升高至加热前的3倍以上。组织学上，肝组织出现广泛的变性和坏死。从结果我们得出结论，FIH联合HAE由于对肿瘤的选择性加热，可为治疗定位良好的肝肿瘤提供强烈的治疗效果，同时对肝实质的损伤最小。
