Deep photothermal effect induced by stereotactic laser beams in highly scattering media

• Published in: Optics letters Vol. 46; no. 17; p. 4248
• Main Authors: Baez-Castillo, L, Ortiz-Rascón, E, Carrillo-Torres, R C, Bruce, N C, Garduño-Mejía, J, Lucero-Acuña, A, Álvarez-Ramos, M E
• Format: Journal Article
• Language: English
• Published: United States 01-09-2021
• Subjects: Gold; Humans; Lasers; Nanoparticles; Neoplasms; Phantoms, Imaging
• ISSN: 1539-4794
• DOI: 10.1364/OL.433429

Plasmonic photothermal therapy (PPTT), as an increasingly studied treatment alternative, has been widely regarded mostly as a surface tissue treatment choice. Although some techniques have been implemented for interstitial tumors, these involve some grade of invasiveness, as the outer skin is usually broken to introduce light-delivering optical fibers or even catheters. In this work, we present a potential non-invasive strategy using the stereotactic approach, long employed in radiosurgery, by converging multiple near infrared laser beams for PPTT in tissue-equivalent optical phantoms that enclose small gel spheres and simulate interstitial tissue impregnated with plasmonic nanoparticles. The real-time in-depth monitoring of temperature increase is realized by an infrared camera face-on mounted over the phantom. Our results show that a significant reduction in the surface heating can be achieved with this configuration while remarkably increasing the interstitial reach of PPTT, assuring a ∼6
temperature increase for the simulated tumors at 10 mm depth and ∼4
at 15 mm depth and opening up new possibilities for future clinical applications.