Magnetic induced hyperthermia using thermosensitive ferromagnetic material

使用热敏铁磁材料的磁感应热疗

• 批准号: 16390389
• 负责人: OGAWA Jun-ichi
• 金额: $ 7.81万
• 依托单位: Akita University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-16390389/
• 关键词: hyperthermia; Curie point; malignant tumor; thermosensitive magnetic particle; magnetic field; thermal self regulation; 低侵襲; 回転磁場

Background : Magnetic induction heating of thermosensitive material can be used to produce highly localized hyperthermia in deep-seated tumors. The Curie temperature is a transition point at which the development of a particular temperature within the material results in loss of its magnetic properties ; as such, when this temperature is reached, there is cessation of current, and thus heat production stops. Low Curie temperature improves the performance of automatic temperature control throughout the tumor can be achieved by the self-regulating character of thermosensitive materials. We have developed the thermosensitive ferromagnetic particles, which was designed to produce enough heat by eddy current and also to have low Curie point at 43 degrees temperature to provide automatic temperature control.Method : Thermosensitive ferromagnetic particles (diameter : 40-150μm, dose : 500mg) were placed into the 1%-agar and intra-lesional temperatures were measured continuously using ceramics … More thermometer during exposure to magnetic field (600A, 188kHz) by induction heating system.Results : When exposed to magnetic field, these ferromagnetic particles show a sharp rise in the rate of heat production at temperatures at the Curie point in 5 minutes, and the tissue temperature stabilized at the Curie point with good temperature homogeneity throughout the volume heated.Conclusion : This minimally invasive method is attractive for ; 1)constant automatic temperature control in tumor was provided by low Curie point without measuring temperature, 2)the diameter of thermosensitive ferromagnetic particle is 40-100μm, which is larger than capillary blood vessel and lymphatic vessel, particles remain into the injected site, so this method make it possible to be received treatment as outpatients repeatedly without percutaneous puncture every treatment, like RF cauterization. Those results showed that the magnetic induced hyperthermia using thermosensitive ferromagnetic particle, which have low Curie point at 43 degrees temperature to provide automatic temperature control, might be made shift for clinical use in future. Less

背景：热敏材料的磁感应加热可用于在深部肿瘤中产生高度局部热疗。居里温度是一个转变点，在该转变点处，材料内的特定温度的发展导致其磁特性的损失;因此，当达到该温度时，电流停止，从而停止产热。低居里温度提高了肿瘤全自动控温的性能，可以通过热敏材料的自调节特性来实现。方法：将热敏铁磁微粒（直径40-150μm，剂量500 mg）置于1%琼脂中，用陶瓷连续测量病灶内温度，并将其置于1%琼脂中，用扫描电镜观察病灶内温度的变化 ...更多信息 暴露于磁场时的温度计结果：当暴露于磁场时，这些铁磁颗粒在居里点温度下的产热速率在5分钟内急剧上升，组织温度稳定在居里点，整个加热体积具有良好的温度均匀性。这种微创的方法是有吸引力的; 2）热敏性铁磁颗粒直径40-100μm，大于毛细血管和淋巴管，颗粒滞留在注射部位，因此，这种方法使得可以作为门诊患者反复接受治疗，而无需每次治疗都进行经皮穿刺，如RF烧灼。这些结果表明，使用热敏铁磁颗粒的磁诱导热疗，具有低居里点（43 ℃），以提供自动温度控制，可能会在未来的临床应用转移。少