Milne P J, Parel J M, Manns F, Denham D B, Gonzalez-Cirre X, Robinson D S
Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami School of Medicine, Miami, Florida 33136, USA.
Lasers Surg Med. 2000;26(1):67-75. doi: 10.1002/(sici)1096-9101(2000)26:1<67::aid-lsm10>3.0.co;2-9.
The size (0.5-1.0 cm) of early nonpalpable breast tumors currently detected by mammography and confirmed by stereotactic core biopsy is of the order of the penetration depth of near infrared photons in breast tissue. In principle, stereotactically biopsied tumors, therefore, could be safely and efficiently treated with laser thermotherapy. The aim of the current study is to confirm the controlled heating produced by clinically relevant power levels delivered with an interstitial laser fiber optic probe adapted for use with stereotactic mammography and biopsy procedures.
STUDY DESIGN/MATERIALS AND METHODS: Temperature increases and the resultant thermal field produced by the irradiation of ex vivo (porcine and human) and in vivo (porcine) tissue models appropriate to the treatment of human breast tissue by using cw Nd:YAG laser radiation delivered with a interstitial fiber optic probe with a quartz diffusing tip, were recorded with an array of fifteen 23-gauge needle thermocouple probes connected to a laboratory computer-based data acquisition system.
By using a stepwise decreasing power cycle to avoid tissue charring, acceptably symmetric thermal fields of repeatable volumetric dimensions were obtained. Reproducible thermal gradients and predictable tissue necrosis without carbonization could be induced in a 3-cm-diameter region around the fiber probe during a single treatment lasting only 3 minutes. The time-dependences of the temperature rise of the thermocouples surrounding the LITT probe were quantitatively modeled with simple linear functions during the applied laser heating cycles.
Analysis of our experimental results show that reproducible, symmetric and predictable volumetric temperature increases in time can be reliably produced by interstitial laser thermotherapy.
目前通过乳腺X线摄影检测到并经立体定向核心活检确诊的早期不可触及乳腺肿瘤大小（0.5 - 1.0厘米）与近红外光子在乳腺组织中的穿透深度相当。因此，原则上，经立体定向活检的肿瘤可以通过激光热疗安全有效地治疗。本研究的目的是确认使用适用于立体定向乳腺摄影和活检程序的间质激光光纤探头传递临床相关功率水平所产生的可控加热效果。
研究设计/材料与方法：使用配备石英扩散尖端的间质光纤探头，通过连续波Nd:YAG激光辐射，对适用于人类乳腺组织治疗的离体（猪和人）及活体（猪）组织模型进行照射，用连接到基于实验室计算机的数据采集系统的十五个23号针状热电偶探头阵列记录温度升高及由此产生的热场。
通过使用逐步降低功率的周期以避免组织烧焦，获得了可接受的对称热场，其体积尺寸可重复。在仅持续3分钟的单次治疗过程中，可在光纤探头周围直径3厘米区域内诱导出可重复的热梯度和可预测的无碳化组织坏死。在施加激光加热周期期间，用简单线性函数对围绕激光诱导热疗（LITT）探头的热电偶温度上升的时间依赖性进行了定量建模。
对我们实验结果的分析表明，间质激光热疗能够可靠地产生可重复、对称且可预测的随时间变化的体积温度升高。
