Efficacy of Topical Calcipotriol-assisted AFL-PDT in Actinic Keratosis

Efficacy of Topical Calcipotriol-assisted Ablative Fractional Laser Photodynamic Therapy for the Treatment of Actinic Keratosis: 12-month Follow-up Results of a Prospective, Randomised, Comparative Trial

Vitamin D(Vit D) is a pro-differentiation agent that enhances the accumulation of protoporphyrin IX (PpIX) after MAL(methyl-aminolevulinate) incubation in actinic keratosis and may have significant benefit for the treatment of actinic keratosis by ablative fractional laser-primed photodynamic therapy (AFL-PDT).

Photodynamic therapy (PDT) with methyl-aminolevulinate (MAL) is effective in the treatment of actinic keratosis (AK). Many strategies have been studied to improve the production of protoporphyrin IX (PpIX), to improve efficacy of PDT. Pre-treatment of the skin with fractional laser resurfacing is a novel alternative technique to improve the efficacy of PDT for AK. The investigators' previous studies showed that ablative fractional laser primed PDT (AFL-PDT) offered higher efficacy than conventional MAL-PDT in the treatment of AK. But, reduced response rates are also observed in thicker skin lesions, which may be due to insufficient PpIX accumulation within the target tissue.

Cellular differentiation leads to increased synthesis of PpIX from MAL and consecutively, differentiation therapy enhances photosensitization effect. Topical calcipotriol is a well-known pro-differentiation hormone and was demonstrated to influence the effect of PDT on keratinocytes.

The aim of this study was to evaluate efficacy of topical vitamin D in AFL-PDT for AK treatment. Consequently, the investigator compared efficacy, recurrence rate, cosmetic outcome and safety between VitD - AFL-PDT and conventional AFL-PDT.

Inclusion Criteria:

• Korean patients aged ≥ 18 years who had biopsy-confirmed Actinic keratosis lesions

Exclusion Criteria:

• calcium metabolic disorder patients
• photosensitivity disorder patients
• lactating or pregnant women
• patients with porphyria or a known allergy to any of the constituents of the MAL cream and lidocaine
• patients with systemic disease, history of malignant melanoma, tendency of melasma development or keloid formation, any AK treatment of the area in the previous 4 weeks, or any conditions associated with a risk of poor protocol compliance; and patients on immunosuppressive treatment