Mehrabi Joseph N, Kelly Kristen M, Holmes Jon D, Zachary Christopher B
Department of Dermatology, University of California Irvine, Irvine, California, 92697.
Beckman Laser Institute, Laser Microbeam and Medical Program, University of California Irvine, Irvine, California, 92612.
Lasers Surg Med. 2021 Aug;53(6):806-814. doi: 10.1002/lsm.23377. Epub 2021 Jan 15.
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.
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 sub-epidermal blistering and an absence of blood flow in the treatment area with prolonged healing.
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. © 2021 Wiley Periodicals LLC.
背景与目的：通过在激光及其他设备中纳入更智能的系统，可以预测其长期效益。当与非侵入性监测和精确的激光能量传递结合使用时，此类系统能够产生更可靠的热损伤区域。使用射频或长脉冲（LP）1064纳米激光破坏肿瘤的更传统的终点是组织变灰和组织收缩的非特异性表现。在此，我们讨论在光学相干断层扫描（OCT）和前瞻性红外（FLIR）热成像仪的辅助下，结合非侵入性LP 1064纳米钕钇铝石榴石激光治疗，并测试基于文献的热破坏公式。
研究设计/材料与方法：对两名自愿受试者前臂和背部的皮肤进行标记，并用含肾上腺素的利多卡因进行麻醉。调整配备扫描仪的LP 1064纳米钕钇铝石榴石激光的参数，以在特定时间过程中使表皮/真皮浅层加热至50°C至60°C之间。实验性单次治疗检查了各种调整参数，包括能量密度、脉冲重叠、脉冲持续时间、扫描尺寸和脉冲频率。使用FLIR热成像仪记录皮肤温度。观察指标包括皮肤温度、治疗后外观以及对皮肤和血管损伤的OCT评估。对每次治疗的临床反应进行为期4周每天的随访。
最佳方案最初将皮肤温度升高至55°C至60°C之间，并在随后60秒的时间过程中通过后续激光照射仔细维持该温度。激光治疗后立即出现的临床反应包括红斑、水肿和水疱。激光治疗后立即进行的OCT显示血管增多，血管完整且扩张。在60°C以上长时间暴露会导致表皮下水疱形成，治疗区域血流缺失，愈合时间延长。
LP 1064纳米激光可用于实现与热相关的组织损伤，尽管达到预期终点所需的参数范围较窄，需要红外热调节的辅助以避免出现不可接受的结果。使用激光扫描仪可确保在限定的治疗区域精确传递能量。未来的研究可能会探索将其作为一种治疗非黑色素瘤皮肤癌的选择性热疗方法。《激光外科学与医学》。©2021威利期刊有限责任公司。
