Dowlatshahi K, Babich D, Bangert J D, Kluiber R
Rush-Presbyterian-St. Luke's Medical Center Chicago, Illinois 60612.
Lasers Surg Med. 1992;12(2):159-64. doi: 10.1002/lsm.1900120208.
The extent of coagulative necrosis caused by interstitial laser hyperthermia was measured for different quantities of laser energy in a rat mammary tumor model. Continuous wave Nd:YAG laser at a power level of 5 W was focused onto a 600 mu diameter bare tip quartz fiber and placed inside a 19-gauge needle, which allowed the para-axial flow of normal saline at 1 cc/min. A microthermocouple soldered to the outside of the probe continuously provided the interstitial temperature. After the probe was inserted into the tumor, it was withdrawn as laser energy was administered at a rate sufficient to maintain the temperature within 42-45 degrees C. Tumors were excised after 48 hours, fixed in formalin, cut in 3 mm slices, and the coagulated surfaces measured microscopically. Laser fiber transmission loss was 1% per 1,000 J of laser energy and the average time required to coagulate 1 cc of tumor was 2 minutes. There was a statistically significant correlation between the volume of tumor necrosis and the level of laser irradiation (r = 0.71, P less than 0.001). It is concluded that the described technique is an efficient method of tumor coagulation by interstitial laser hyperthermia and proportionally larger volumes of necrosis are created with greater amounts of laser energy.
在大鼠乳腺肿瘤模型中，针对不同激光能量剂量，测量了间质激光热疗所致的凝固性坏死范围。功率为5W的连续波Nd:YAG激光聚焦于直径600μm的裸尖石英光纤上，并置于19号针内，该针允许以1cc/分钟的速度轴向旁流生理盐水。焊接在探头外部的微型热电偶持续提供间质温度。将探头插入肿瘤后，以足以将温度维持在42 - 45摄氏度的速率施加激光能量时，探头会被抽出。48小时后切除肿瘤，用福尔马林固定，切成3mm薄片，并在显微镜下测量凝固表面。激光光纤传输损耗为每1000J激光能量1%，凝固1cc肿瘤所需的平均时间为2分钟。肿瘤坏死体积与激光照射水平之间存在统计学显著相关性（r = 0.71，P < 0.001）。得出的结论是，所描述的技术是通过间质激光热疗进行肿瘤凝固的有效方法，并且随着激光能量增加会产生成比例更大体积的坏死。
