Optical Coherence Tomography/Angiography-Guided Tumor Ablation With a Continuous-Wave Laser Diode

Meng-Tsan Tsai,Ting-Yen Tsai,Hsiang-Chieh Lee,Wen-Ju Chen,Chun-Chieh Wang,Ya-Ju Lee

doi:10.1109/access.2020.2976557

Abstract

Laser ablation can be an effective modality for treatment, but it is complicated to apply continuous-wave (CW) light sources for laser ablation because of the unpredictable photothermal damage. In this study, an integrated theranostic system combining a low-cost CW laser diode with optical coherence tomography (OCT)/angiography (OCTA) was utilized for the in vivo ablation of tumor tissues. To examine the effect of laser exposure on tissue scattering characteristics, the OCT backscattering intensities of non-ablated and ablated tissues were analyzed, and the effect on the skin microvasculature produced by laser ablation was quantitatively evaluated. Moreover, the integrated system and the proposed method were implemented for the treatment of skin tumor on the mouse model. The obtained results indicate that the developed laser ablation system can effectively remove tumor tissues with controllable photodamage under OCT/OCTA guidance and that the system cost may be significantly reduced by using the CW laser diode.

Highlights

Laser therapy has become an alternative treatment solution in addition to conventional surgical resection by using highintensity light to shrink or damage tissue [1], [2]
To explore the feasibility of using the CW laser diode for tissue ablation, mouse ear skin was exposed to the laser beam with an average incident power of 4 W on the sample for different times followed by repeatedly scanning with optical coherence tomography (OCT)/OCT angiography (OCTA)
To examine the relationship between the induced photodamage and the exposure time, a selected skin area was scanned with OCT/OCTA before laser exposure, after which it was exposed to the 450-nm laser beam for 20 seconds (s) and scanned with OCT/OCTA again

Summary

Introduction

Laser therapy has become an alternative treatment solution in addition to conventional surgical resection by using highintensity light to shrink or damage tissue [1], [2]. Its effects are produced via two main mechanisms corresponding to thermotherapy and photocoagulation [3], [4]. The optical energy of laser light is absorbed by the tissue leading to the thermal effect and tissue evaporation. When a high-intensity or high-power laser is applied, the irradiated cells can be severely damaged, changing the tissue composition. Photocoagulation is mainly caused by the absorption of red blood cells, leading to their coagulation and the formation of thrombi.

Methods

Results

Discussion

Conclusion