Strasswimmer John, Grande Donald J
Wellman Center for Photomedicine, Massachusetts General Hospital, & Department of Dermatology, Harvard Medical School, Boston, Massachusetts, USA.
Lasers Surg Med. 2006 Jan;38(1):22-5. doi: 10.1002/lsm.20277.
Photodynamic therapy (PDT) in dermatology is traditionally performed with topical aminolevulinic acid (ALA) and continuous-wave (CW) illumination with blue or red light. Recently, several authors have reported success with laser and other pulsed-light sources for PDT. While the clinical benefits on sun-exposed skin are apparent, no study has demonstrated that the pulsed light sources are responsible for the observed response.
A placebo-controlled study of two pulsed light sources previously reported for PDT: the pulsed dye laser (PDL) or broadband flashlamp filtered intense pulsed light (IPL). Sun-hidden skin was prepared with microdermabrasion and acetone scrub followed by ALA under occlusion. Laser or IPL was delivered under conditions previously reported to produce a clinical response. Control areas were exposed to standardized CW blue light or to no light. A second control area was prepared and received light and the ALA vehicle.
IPL and PDL demonstrated a faint dose-response effect on PDT activation, but were less potent than a smaller fluence of CW blue light. Ambient light activated ALA-treated skin.
Both IPL and PDL are capable of activation of PDT but produce dramatically less PDT reaction than the standard CW blue-light broadband source. Physicians desiring a robust PDT response might select CW sources over pulsed sources. Ambient light may activate a PDT reaction.
皮肤科的光动力疗法（PDT）传统上是使用外用氨基乙酰丙酸（ALA）并采用蓝光或红光连续波（CW）照射来进行的。最近，有几位作者报告了使用激光和其他脉冲光源进行PDT取得成功。虽然对暴露于阳光下的皮肤的临床益处是明显的，但尚无研究表明脉冲光源是观察到的反应的原因。
一项对先前报道用于PDT的两种脉冲光源的安慰剂对照研究：脉冲染料激光（PDL）或经宽带闪光灯滤光的强脉冲光（IPL）。对隐蔽部位的皮肤进行微晶磨皮和丙酮擦洗处理，然后在封闭状态下涂抹ALA。在先前报道能产生临床反应的条件下进行激光或IPL照射。对照区域暴露于标准化的连续波蓝光或不进行光照。准备第二个对照区域，使其接受光照和ALA载体。
IPL和PDL对PDT激活表现出微弱的剂量反应效应，但比小剂量的连续波蓝光效力低。环境光可激活经ALA处理的皮肤。
IPL和PDL都能够激活PDT，但与标准的连续波蓝光宽带光源相比，产生的PDT反应要小得多。希望获得强烈PDT反应的医生可能会选择连续波光源而非脉冲光源。环境光可能会激活PDT反应。
