Combination of ablative fractional laser and daylight‐mediated photodynamic therapy for actinic keratosis in organ transplant recipients – a randomized controlled trial

Summary Background Topical photodynamic therapy ( PDT ) for actinic keratoses ( AK ) is hampered by pain during illumination and inferior efficacy in organ‐transplant recipients ( OTR ). Objectives We assessed ablative fractional laser (AFL)‐assisted daylight photodynamic therapy (PDT) (AFL‐d PDT ) compared with daylight PDT (d PDT ), conventional PDT (c PDT ) and AFL alone (AFL) in field treatment of AK in OTR. Methods In each patient, four areas in the same region were randomized to one treatment with AFL‐d PDT , d PDT , c PDT and AFL. AFL was delivered with a 2940‐nm AFL at 2·3 mJ per pulse, 1·15 W, two stacks, 50‐μs pulse‐duration, 2·4% density. In d PDT and AFL‐d PDT , methyl aminolaevulinate (MAL) was applied for 2·5 h without occlusion during daylight exposure. For c PDT , MAL was occluded for 3 h followed by red‐light (630 nm) irradiation at 37 J cm −2 . The primary end‐point was complete response (CR) 3 months post‐treatment. Results Sixteen patients with 542 AK (grades I–III) in field‐cancerized skin of the scalp, chest and extremities were treated during August and September 2012. After 3 months, CR (AK I–III) rates were 74% after AFL‐d PDT , 46% after d PDT , 50% after c PDT and 5% after AFL ( P  <   0·001). CR rates in AFL‐d PDT , d PDT and c PDT were also significantly different ( P  =   0·004). Median maximal pain scores differed significantly during AFL‐d PDT (0), d PDT (0), AFL (0) and c PDT (5) ( P  <   0·001). Erythema and crusting were more intense following AFL‐d PDT than d PDT and c PDT , but only transient hypopigmentation was observed. Conclusions AFL‐d PDT is a novel PDT modality that enhances CR with excellent tolerability compared with d PDT and c PDT in difficult‐to‐treat AK in OTR.