光动力疗法无需预照射孵育时间即可有效治疗光化性角化病。
Photodynamic Therapy Effectively Treats Actinic Keratoses Without Pre-Illumination Incubation Time.
作者信息
Gandy Jessica, Labadie Brian, Bierman Dina, Zachary Christopher
出版信息
J Drugs Dermatol. 2017 Mar 1;16(3):275-278.
BACKGROUND: Actinic keratoses (AKs) are dysplastic lesions of the epidermis that have the potential to progress to non-melanoma skin cancers (NMSC). Traditional photodynamic therapy (PDT) requires a pre-illumination incubation time, which adds to overall in-office time and has been linked to pain. Our group has found a novel protocol to effectively treat AKs with PDT that eliminates the pre-illumination incubation period and uses 2 back-to-back cycles of 16 minute 40 seconds.
METHODS: The patient was prepped with soapy water and isopropyl alcohol, and thick AKs were descaled with a curette. Next, 5-aminolevulinic acid (ALA) was applied to the treatment areas and the patient was immediately placed under the blue light for 33 minutes and 20 seconds (two cycles of 16m/40s).
RESULTS: During therapy, the patient reported no pain. At one week, treated areas revealed a good reaction. The procedure was repeated at one month to treat residual AKs. At a 4-month follow-up, the patient's face and scalp showed near clearance of any AKs.
CONCLUSION: During PDT, the photosensitizer aminolevulinic acid (ALA), or in Europe methyl aminolevulinate (MAL), is utilized as a synthetic precursor that preferentially accumulates in dysplastic cells. The precursor then converts to PpIX via the heme pathway and causes apoptosis of the cells when excited, most commonly by either blue-violet (400-430 nm) or red (630-635 nm) light. Shorter incubation times are associated with reduced pain because less PpIX will have accumulated in the treated tissue by the start of the exposure to the light. The doubling of the light exposure time allows comparable levels of the photosensitizing molecule to accumulate and be activated so as to produce an equivalent reaction. The associated reduction in pain along with a more convenient treatment schedule makes this PDT protocol more tolerable and convenient to some patients.
J Drugs Dermatol. 2017;16(3):275-278.
.背景
光化性角化病（AKs）是表皮发育异常性病变，有发展为非黑素瘤皮肤癌（NMSC）的可能。传统光动力疗法（PDT）需要预照射孵育时间，这增加了总的门诊治疗时间并与疼痛相关。我们团队发现了一种用PDT有效治疗AKs的新方案，该方案消除了预照射孵育期，采用两个连续的16分40秒周期。
方法
用肥皂水和异丙醇对患者进行预处理，并用刮匙刮除较厚的AKs。接下来，将5-氨基酮戊酸（ALA）涂抹于治疗区域，然后立即将患者置于蓝光下照射33分20秒（两个16分40秒的周期）。
结果
治疗期间，患者未报告疼痛。一周时，治疗区域显示出良好的反应。一个月时重复该操作以治疗残留的AKs。在4个月的随访中，患者的面部和头皮上的AKs几乎完全清除。
结论
在PDT过程中，光敏剂5-氨基酮戊酸（ALA）或在欧洲使用的甲基氨基酮戊酸酯（MAL）被用作合成前体，其优先在发育异常的细胞中蓄积。该前体随后通过血红素途径转化为原卟啉IX（PpIX），并在被激发时（最常见的是通过蓝紫光（400 - 430nm）或红光（630 - 635nm））导致细胞凋亡。较短的孵育时间与疼痛减轻相关，因为在开始光照时，治疗组织中积累的PpIX较少。光照时间加倍可使光敏分子积累并被激活到相当的水平，从而产生等效反应。相关的疼痛减轻以及更便捷的治疗方案使这种PDT方案对一些患者而言更易于耐受且更方便。
《皮肤药物学杂志》。2017年；16（3）：275 - 278。
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