Effect of retinoid pretreatment on outcomes of patients treated by photodynamic therapy for actinic keratosis of the hand and forearm.

BACKGROUND/OBJECTIVE: Photodynamic therapy (PDT) with 5-aminolevulinic acid (ALA) has been shown to be useful in both spot and field treatments of actinic keratoses (AK). This study evaluates the safety and efficacy of pretreatment of AK lesions on the dorsal hands and forearms with tazarotene gel (0.1%) twice a day for one week before broad-area ALA PDT. METHODS: Ten subjects aged 75.4 ± 11.6 years (mean plus minus SD) with at least four AK lesions on their dorsal forearm or hand were randomized so that one dorsal hand or forearm was pretreated with tazarotene gel (0.1%) twice daily for one week before ALA PDT with blue light. The other hand or forearm (control) was not pretreated. After seven days, ALA was applied to both sides and incubated 60 minutes before irradiation with blue light. ALA was applied first only to the AK lesions and then to the entire treatment area (defined as the extensor surface of the hand or forearm between the elbow and the base of the fingers) before 60-minute incubation. The ALA area on the control side was occluded during the 60-minute incubation. Efficacy and adverse effects were evaluated within 48 hours and eight weeks later. RESULTS: For both the pretreated and control group, lesion counts of the target areas decreased significantly from baseline to eight weeks after ALA PDT. Reduction percentages of the target area, however, did not differ significantly between the two groups. When reduction percentages of the entire treatment area for both groups were compared the difference between the two groups was of borderline significance (P=0.0547). When the entire treatment area was analyzed, lesion counts of the tazarotene group differed significantly from baseline at eight weeks (P=0.0002), but this was not the case with the control group (P=0.0365). Adverse events were limited to those expected after ALA PDT. Erythema was significantly more severe (P=0.0029) in the pretreated arm five minutes after ALA PDT. CONCLUSION: Pretreatment of AK lesions on the dorsal hand and forearm with tazarotene gel (0.1%) may enhance the therapeutic effect of ALA PDT without serious side effects.

Photodynamic Therapy for Actinic Keratoses of the Upper Extremities using 10% Aminolevulinic Acid Gel, Red Light, and Adapalene Pretreatment.

BACKGROUND: Actinic keratoses (AKs) are sun-induced cutaneous lesions that may progress to squamous cell carcinoma (SCC). Photodynamic therapy (PDT) is an ideal treatment option for AKs because it allows for treatment of field cancerization, selective destruction of diseased tissue, good cosmetic outcomes, and limited downtime. OBJECTIVES: This study sought to determine the efficacy and safety of pretreating AKs of the dorsal hands and forearms with adapalene gel, an inexpensive and over-the-counter retinoid, prior to debridement of the target area and PDT with aminolevulinic hydrochloride acid (ALA, 10%) gel and narrowband red light. METHODS: Fifteen patients with AK lesions of the right or left dorsal hands or forearms were pretreated with adapalene gel (0.1%) twice daily for one week prior to ALA-PDT. The other hand or forearm was treated with ALA-PDT (standard therapy), but not pretreated. For PDT, all treated areas were debrided with sandpaper, degreased with acetone, incubated for one hour with 10% ALA gel under occlusion, and illuminated with narrowband red light (~635 nm). All patients experienced one PDT treatment session. RESULTS: Eight weeks after treatment, 12 subjects in the adapalene-pretreated group achieved 50% to 100% clearance compared to 10 subjects in the standard therapy group. The median lesion count reduction in the adapalene-pretreated group was -79% compared to -57% in the standard therapy group, and this difference was significant (P=0.0164). The treatment was well-tolerated and the level of patient satisfaction was high. CONCLUSIONS: Pretreatment with adapalene gel twice daily for one week may enhance efficacy in a single ALA-PDT treatment of AK lesions of the dorsal hand or forearm.