Actinic Keratosis
Conditions
Keywords
Ablative fractional laser, Iontophoresis, Actinic keratosis, Photodynamic therapy
Brief 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.
Interventions
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.
Sponsors
Study design
Eligibility
Inclusion criteria
* Korean patients aged ≥ 18 years who had biopsy-confirmed AK lesions
Exclusion criteria
* 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 * metal-containing device (cardiac pacemaker, orthopaedic implants, gynaecological devices) * cardiac arrhythmia * large skin erosion
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Differences of short-term complete response rates between three groups | Short-term complete response rates were evaluated at 3 months | The lesions were classified as either complete response (complete disappearance of the lesion) or incomplete response (incomplete disappearance of the lesion) |
| Differences of long-term complete response rates between three groups | Long-term complete response rates were evaluated at 12 months | The lesions were classified as either complete response (complete disappearance of the lesion) or incomplete response (incomplete disappearance of the lesion) |
| Differences of recurrence rates between three groups | Recurrence rates were evaluated at 12 months | In addition, the recurrence rate was evaluated 12 months after treatment. For the histopathologic evaluation of treatment response, at the 12-month follow-up visit, a 3-mm punch biopsy of the treated AK lesion was performed in all cases of clinically incomplete response. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Differences of cosmetic outcomes between three groups | The overall cosmetic outcome was assessed 12 months after treatment | Cosmetic outcomes were graded as excellent (slight redness or pigmentation change), good (moderate redness or pigmentation change), fair (slight-to-moderate scarring, atrophy, or induration), or poor (extensive scarring, atrophy, or induration) |
Other
| Measure | Time frame | Description |
|---|---|---|
| Difference of adverse events (erythema, post-inflammatory hyperpigmentation, edema, itching, oozing, bleeding) rates between groups | Within 12 months after each treatment | Adverse events reported by the patient were noted at each follow-up visit, including severity, duration and need for additional therapy. All events due to PDT were described as phototoxic reactions (i.e., erythema, post-inflammatory hyperpigmentation, oedema, itching, oozing, bleeding and so forth). |