Efficacy of Iontophoresis-assisted AFL-PDT in Actinic Keratosis
Condition: Actinic Keratosis
MeSH terms: Keratosis, Actinic; Keratosis
Study type: Interventional
Phase: Phase 1

Summary: 
      Iontophoresis is a transdermal drug-delivery technique that enhances the transport of ionic
      species across membranes and may have significant benefit for the treatment of actinic
      keratosis (AK) by ablative fractional laser-primed photodynamic therapy (AFL-PDT).
    

Detailed description: 
      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. Our previous studies showed that ablative fractional laser-primed PDT (AFL-PDT)
      offered higher efficacy than conventional MAL-PDT in the treatment of many diseases, such as
      AK, actinic cheilitis, Bowen's disease and basal cell carcinoma.1-4 Iontophoresis can be
      another method to improve efficacy of PDT. Iontophoresis is a transdermal drug-delivery
      technique which uses a mild electric current to enhance the transport of ionic species across
      membranes. Iontophoresis has been widely used to enhance drug delivery. Mizutani K et al.5
      reported 5 AK patients successfully treated with direct-current pulsed iontophoresis-assisted
      5-aminolevulinic acid (ALA)-PDT. Boddé HE et al.6 studied iontophoretic transport of ALA
      quantitatively in vitro and demonstrated enhanced transport of ALA by iontophoresis.

      Until now, appropriate incubation time for AFL-PDT has not been elucidated. In our previous
      study, we investigated the efficacy of AFL-PDT with a short incubation time.7 Although
      AFL-PDT with a short incubation time (2 h) showed enhanced efficacy than conventional MAL-PDT
      with the standard incubation time, standard AFL-PDT with 3-h incubation time showed
      significantly higher efficacy than AFL-PDT with a short incubation time.

      The aim of our study was to evaluate efficacy of iontophoresis in AFL-PDT for AK treatment.
      Consequently, we compared efficacy, recurrence rate, cosmetic outcome and safety between
      iontophoresis-assisted AFL-PDT with 2-h incubation time and conventional AFL-PDT with 2-h and
      3-h incubation times.
    

Intervention name(s): lidocaine/prilocaine (5%) application; 2940-nm Er:YAG AFL pretreatment; MAL application; Iontophoresis application; irradiation with red light-emitting diode lamp
Intervention type(s): Drug; Device; Drug; Device; Device
Intervention description(s): For AFL pre-treatment, lidocaine/prilocaine (5%) cream (EMLA; Astra Pharmaceuticals, LP, Westborough, MA, USA) was applied to the treatment area under occlusion for 30 min; After the anaesthetic cream was removed, AFL therapy was performed using a 2940-nm Er:YAG AFL (Joule; Sciton Inc., Palo Alto, CA, USA) at 300-550 µm ablation depth, level 1 coagulation, 22% treatment density and a single pulse; Immediately after AFL treatment, an approximately 1-mm-thick layer of MAL (Metvix, PhotoCure ASA, Oslo, Norway) was applied to the lesion and on 5 mm of surrounding normal tissue.; In Group A, ionotophoresis was performed on MAL-applied sites. We used iontophoresis (vitaliont II®, ITC Inc, Korea) with a patch. The active electrode was the anode, and 0.50-mA/cm2 current was applied to each AK lesion for 10 min.; After incubation for 2 (Group A and B) or 3 hours (Group C), the dressing and cream were removed, and the area was cleansed with saline. The area was irradiated with a red light-emitting diode lamp (Aktilite CL 128; PhotoCure ASA, Oslo, Norway) with peak emission at 632 nm, placed 5 cm away from the skin surface, and a total light dose of 37 J/cm-2. All patients wore protective goggles during illumination.
Intervention MeSH terms: Lidocaine; Prilocaine; Lidocaine, Prilocaine Drug Combination
Allocation: Randomized
Intervention model: Factorial Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Treatment
Keywords: Ablative fractional laser; Iontophoresis; Actinic keratosis; Photodynamic therapy