磁感应热疗的体模实验及热场分析

The clinical application of magnetic induction hyperthermia and analysis of thermal field

目的研究在不同磁场强度条件下磁热籽阵列的热场分布与升温规律。方法单纯琼脂模体实验：在体积10cm×10cm×10cm琼脂体模内分别按照直径3．0cm、体积3．0cm×3．0cm×2．6cm和直径5．0cm、体积5．0cm×5．0cm×2．6cm的圆柱体阵列植入磁热籽。将其置于频率为100kHz的交变磁场中，磁场强度从60Gs开始按5Gs分档直至120Gs，依次实施分档升温测定实验。离体肌肉-琼脂混合模体实验：以不规则形琼脂体模模拟肿瘤靶区，分别使用90Gs和120Gs的磁场强度实施升温实验和温度场测量。结果单纯琼脂体模升温实验显示40min的加热时间内不同直径圆柱体区域内植入磁热籽阵列中心点的最终温度随磁场强度增大而相应提高，升温至50℃的时间相应缩短，升温规律相同。离体肌肉一琼脂混合体模的升温热场分析显示不同磁场强度下磁热籽植入密度与靶区内的升温关系密切，热场均匀度与植入磁热籽密度和分布相关。结论磁场强度对磁热籽升温影响明显；在磁场达到一定强度后对磁热籽的升温影响减弱。提高磁场强度只在一定程度上对磁热籽加热有益；温度场分布与磁场强度和磁热籽植入密度关系密切。欲达到处方温度，低中磁场强度磁热籽植入密度较中高磁场强度时要密；在一定体积区域内需有足够的磁热籽密度方能达到处方温度值；磁热籽按照一定排序才能使温度场分布均匀，并非简单有序排布，但基本符合外密内疏的大原则。

Objective To study the laws of heating and thermal field of heating seed arrays in different magnetic field intensity during the magnetic induetion hyperthermia. Methods 3.0cm× 3.0 cm×2.6 cm and 5.0 cm×5.0 cm×2. 6 cm of magnetic heating seed was implanted respeetively in 10. 0cm× 10. 0 cm× 10. 0 cm pure agar phantom. The regions was divided into one file per 5 Gs in the range of 60 - 120 Gs magnetic induction. The temperature measurement experiments were implemented in each sub-file. Muscle-agar mixture model was used in the magnetic induction 60 Gs and 90 Gs to implement GTV-heating simulation experiments and thermal field analysis. Results The pure agar phantom heating experiments show that the heating is of basically the same rule when seeds with various diameters were implanted in the magnetic thermal array. Along with the increase of magnetic induction, the final temperature of the focal point heated for 40 min increased aecordingly, and time required for heating to 50℃ was shortened con＇espondingly. The thermal field analysis of muscle-a mixture agar mixture model showed that the implantation density of magnetic heating seed is closely associated with the temperature of the target area and thermal field in different magnetic field intensity. Conclusions The magnetie induction has a significant impact on heating of the seeds, as the magnetic medium, and this impact is trending downwards when the magnetic field reaches a certain intensity. Within a certain size, adequate magnetic heating seed density is necessary to achieve the desired temperature required for the temperature value. The heating seeds should be put in a certain order to heat the venue evenly, not in a simply order, but in line with the principle of outer dense and inner sparse.