Injury depth control from combined wavelength and power tuning in scanned beam laser thermal therapy.
Injury depth control from combined wavelength and power tuning in scanned beam laser thermal therapy.
复制标题
扫描光束激光热疗中组合波长和功率调谐的损伤深度控制。
DOI：
10.1117/1.3647581
复制
发表时间：
2011
影响因子：
3.5
通讯作者：
Vakoc,BenjaminJ
中科院分区：
文献类型：
--
作者：
Villiger,Martin;Soroka,Andrew;Tearney,GuillermoJ;Bouma,BrettE;Vakoc,BenjaminJ
激光热疗是治疗食道癌前病变的一种可能方法。动态地将热损伤轮廓与特定的损伤边界相一致有望提高这种治疗的有效性，并避免并发症。在这项工作中，我们研究了波长调谐作为一种机制，通过利用接近1900 nm的吸水率的强烈变化来实现对损伤深度的这一目的控制。我们开发了一个数值模型，逐步模拟光子在组织中的传播，吸收的热的扩散，以及由此产生的组织损伤。将该模型与猪食道活体标本的实验结果进行了比较，结果表明该模型具有良好的一致性。结合功率调谐，1860至1895 nm范围内的波长敏捷性与固定波长源相比，将损伤范围扩展到1 mm以上，同时改善了对浅层深度的控制，避免了组织表面的汽化。将两个或三个不同波长以不同的比例组合在一起可以提供类似的控制，并可能为血管内皮损伤的治疗提供一种改进的策略。
Laser thermal therapy represents a possible method to treat premalignant epithelial lesions of the esophagus. Dynamically conforming the thermal injury profile to a specific lesion boundary is expected to improve the efficacy of such a treatment and avoid complications. In this work, we investigated wavelength tuning as a mechanism to achieve this aimed control over injury depth by using the strong variation of water absorption close to 1900 nm. We developed a numerical model simulating in steps the photon propagation in the tissue, the diffusion of the absorbed heat, and the resulting tissue damage. The model was compared with experimental results on porcine esophageal specimensex vivoand showed good agreement. Combined with power tuning, the wavelength agility in the range of 1860 to 1895 nm extends the injury range compared to a fixed wavelength source beyond 1 mm, while at the same time improving control over shallow depths and avoiding vaporization at the tissue surface. The combination of two or three discrete wavelengths combined at variable ratios provides similar control, and may provide an improved strategy for the treatment of endothelial lesions.