Dermatol Ther (Heidelb). 2025 Dec 30. doi: 10.1007/s13555-025-01567-z. Online ahead of print.
ABSTRACT
INTRODUCTION: Several treatments are available for actinic keratosis (AK), many of which are hampered by local inflammation, pain, long duration, and slow healing. Indoor daylight photodynamic therapy (idl-PDT) is an effective, well-tolerated, first-line treatment for both AK and field cancerization, but its feasibility is limited by the long time required for illumination (2 h). The objective of our study was to evaluate the efficacy of idl-PDT with an illumination time of 1 h versus 2 h in the treatment of scalp AK.
METHODS: We conducted an intrapatient, comparative study of idl-PDT with two illumination durations, 1 h versus 2 h, using methyl aminolevulinate (MAL, Metvix®) and a white light-emitting diode (LED) light (Dermaris®) for the treatment of scalp AK. Patients were evaluated 3 months and 6 months after one session of idl-MAL-PDT for AK response rate, both overall and by AK grade, and tolerability. Physicians’ and patients’ satisfaction were also investigated.
RESULTS: A total of 55 patients were enrolled with a total of 955 AK (grade I-II). The AK clearance rate was 72.9% in 1 h-half and 71.1% in 2 h-half after 3 months, and 76.2% in 1 h-half and 78.9% in 2 h-half after 6 months. No statistically significant difference in efficacy (overall, grade I and II AK) was observed between the two illumination times, both at 3 and 6 months. The local skin reaction score and pain numeric rating scale (NRS) were very low, and comparable between the two treatment arms. Both physicians and patients expressed very good opinion on effectiveness and cosmetic outcome. Overall, 96.4% of patients would undergo idl-PDT again.
CONCLUSIONS: The efficacy of idl-PDT in treating grade I and II AK of the scalp was comparable using 1 h or 2 h as illumination time. Both treatment schedules were well tolerated, with a very high rate of satisfaction from both physicians and patients. This trial was retrospectively registered on the 4th of December 2025.
TRIAL REGISTRATION: ClinicalTrials. gov identifier, NCT07290959.
PMID:41467928 | DOI:10.1007/s13555-025-01567-z
