Assessing the Outcomes of Focused Heating of the Skin by a Long‐Pulsed 1064 nm Laser with an Integrated Scanner, Infrared Thermal Guidance, and Optical Coherence Tomography

Abstract

Background and Objective: Long-term benefits can be predicted by the incorporation of more intelligent systems in lasers and other devices. Such systems can produce more reliable zones of thermal injury when used in association with non-invasive monitoring and precise laser energy delivery. The more classical endpoint of tumor destruction with radiofrequency or long-pulsed (LP) 1064 nm laser is the non-specific appearance of tissue graying and tissue contraction. Herein we discuss combining non-invasive LP 1064 nm Nd:YAG treatment with the assistance of optical coherence tomography (OCT) and the forward-looking infrared (FLIR) thermal camera while testing literature-based formulae for thermal destruction. Study Design/Materials and Methods: The skin on the forearm and back of two consenting volunteers was marked and anesthetized with lidocaine with epinephrine. The parameters of a scanner-equipped LP 1064 nm Nd:YAG laser were adjusted to achieve an epidermal/superficial dermal heating of between 50°C and 60°C over a specified time course. Experimental single treatments examined various adjusted parameters including, fluence, pulse overlap, pulse duration, scan size, and pulse rate. A FLIR camera was used to record skin temperature. Outcome measures included skin temperature, post-treatment appearance, and OCT assessment of skin and vascular damage. The clinical response of each treatment was followed daily for 4 weeks. Results: Optimal protocols initially raised the skin temperature to between 55°C and 60°C, which was carefully maintained using subsequent laser passes over a 60-second time course. Immediately post laser, clinical responses included erythema, edema, and blistering. Immediate OCT revealed increased vascularity with intact, dilated blood vessels. Prolonged exposure above 60°C resulted in subepidermal blistering and an absence of blood flow in the treatment area with prolonged healing. Conclusion:The LP 1064 nm laser can be used to achieve heat-related tissue injury, though the narrow parameters necessary for the desired endpoint require the assistance of IR thermal regulation to avoid unacceptable outcomes. The use of the laser scanner ensures precise energy delivery over a defined treatment area. Future studies might explore this as a selective hyperthermic method for the treatment of non-melanoma skin cancer. Lasers Surg. Med.

Combining Nd:YAG laser with optical coherence tomography for nonsurgical treatment of basal cell carcinoma

“…The Nd:YAG laser is especially helpful in clearing pigmented lesions and removing tattoos due to deep penetration and good absorbance by residual pigment. This deep penetration also allows the Nd:YAG laser to excel at clearing BCCs due to selective targeting and destruction of vascular structures 8,10 . Prior studies, using aggressive laser parameters, reported effective treatment of BCCs 11 .…”

“…This deep penetration also allows the Nd:YAG laser to excel at clearing BCCs due to selective targeting and destruction of vascular structures. 8,10 Prior studies, using aggressive laser parameters, reported effective treatment of BCCs. 11 Herein, we examine the efficacy of less-destructive protocols while utilizing noninvasive imaging to improve cosmetic outcome and efficacy.…”

Far-infrared transparent conductors

“…As an important part of the optical fiber communication system, the photodetector is a component that converts optical signals into electrical signals. It is widely applied in optical communication 12 , laser guidance 19 , biosensing 20 , etc. If the transparent electrode is replaced from the traditional ITO to our FIRTC, the applicable band of the photodetector can be complemented to far-infrared region, which will promote the development of far-infrared search and guidance technology.…”

“…Although TC in the visible, near-infrared, and mid-infrared bands have been developed, TC in the far-infrared band have not been designed. This greatly limits the development of far-infrared electromagnetic shielding 13 , 14 , infrared thermal camouflage 15 , photo detection 16 – 19 , biosensing 20 technologies, and other fields. Therefore, we focus on far-infrared transparent conductors.…”

Controlled hyperthermia and monitored protocol for basal cell carcinoma: interim report

“…We have previously demonstrated excellent control of skin tissue temperature using an integrated FLIR imaging system in normal skin with a LP Nd:YAG 1064nm laser, and defined optimal time and temperature parameters to impact skin tissue responses 3 . Outcomes were defined clinically and by dynamic OCT both to recognize incipient or frank blistering and necrosis, and assess tissue blood flow.…”