Background/Objective Actinic keratoses (AKs) and superficial non-melanoma skin cancers (NMSC) arevery common in elderly and appear with significantly higher incidence inimmunosuppressed patients. In this pilot our goal is to compare efficacy of ALAPhotodynamic Therapy (PDT) versus topical application of conventional therapy with imiquimod (Aldara) cream, for the treatment of AKs.
Method According to IRB approved protocol ‘split’ technique is followed. 20% 5-aminolevulinic acid (5%-ALA Levulan, Kerastick) is applied on lesional skin, followed by exposure to 417 nm blue light (Blu-U, DUSA), for 16 minutes and 40 sec, with total light dose of 10 J/cm2 delivered intreated area. ALA incubation time is 2–3 hours. Topical application ofimiquimod is applied on lesional skin and on equivalent body sites, three timesweekly for 12 weeks. Clinical evaluation and photography are obtained to monitor skin responsesdue to PDT and topical imiquimod, that are graded according toprearranged scale, before and after treatment, on day(s) 0, 15, 30 postexposure. Partial, complete clearance and re-occurrence of skin lesions aremonitored in bi-monthly intervals during 18 month follow-up. Number of the PDT treatments ranges from 2–5 sessions, every 2–4 weeks apart, pending onresponse. Patient pain or discomfort, patient preference and cost effectivenessfor the applied modalities have been monitored as well.
Results This pilot indicates that ALA-PDT is an efficient and safe method for thetreatment of AKs in healthy and immunosuppressed patients. Clinicalresponses (erythema, edema, scaling, pruritus) are more pronounced onpost-treatment days 1–5 on ALA-PDT treated sites and resolve in 12–15 days withcomplete skin recovery. Topical application of imiquimod results in redness, scaling and crusting of lesional skin but onset of symptoms is demonstratedfollowing 7–10 days of application and duration of treatment is much longer (12 weeks total) compared to PDT. Treatment compliance and reproducibility arebetter when ALA-PDT is applied in clinic compared to topical imiquimodprotocol. In immunocompetent participants the two modalities have somehowequivalent efficacy in AK clearance, in 12 and 18 month follow up. PDT has superior cosmetic outcome. In immunosuppressed patients where topicalimiquimod had no efficacy, PDT demonstrated pronounce reaction andresulted to AK and actinic cheilitis clearance.
Conclusion ALA-PDT is safe and efficient field therapy for AKs and furthermore superficialNMSC, devoid of systemic side effects, and can be optimal choice ofchemoprevention, particularly in immunosuppressed patients.