The impact of occlusive vs non-occlusive application of methyl aminolevulinate on the efficacy and tolerability of daylight photodynamic therapy for actinic keratosis

Photodiagnosis Photodyn Ther. 2024 Apr:46:104049. doi: 10.1016/j.pdpdt.2024.104049. Epub 2024 Mar 14.

Abstract

Background: Conventional photodynamic therapy (c-PDT) is an effective treatment for actinic keratoses (AKs) and nonmelanoma skin cancer which exploits the photosensitizing properties of methyl aminolaevulinate (MAL). Daylight photodynamic therapy (DL-PDT) is an alternative to c-PDT which does not require the application of MAL in occlusion and that is better tolerated by patients. The impact of occlusion on the efficacy of DL-PD has not been investigated by previous studies.

Objective: To compare the efficacy and tolerability of occlusive and non-occlusive DL-PDT.

Methods: We conducted a prospective intraindividual left/right comparison study. AKs of the face or scalp were marked in two symmetrical treatment areas. The two target areas were randomly assigned to DL-PDT with occlusive and non-occlusive application of MAL. The efficacy and cosmetic outcome were determined by a "blinded" investigator.

Results: Lesions in occluded areas showed a better response in the clearance rate of the lesions (65.5% vs 35.0 %, p < 0.001 %), and cosmetic outcome (P < 0.001). There was no difference in phototoxicity or pain between occluded and non-occluded areas.

Conclusion: The occlusive application of MAL improves the efficacy of DL-PDT in clearing AKs and does not increase the incidence of side effects.

Keywords: Actinic keratosis; Photodynamic therapy; Treatment efficacy.

Publication types

  • Randomized Controlled Trial
  • Comparative Study

MeSH terms

  • Aged
  • Aged, 80 and over
  • Aminolevulinic Acid* / adverse effects
  • Aminolevulinic Acid* / analogs & derivatives
  • Aminolevulinic Acid* / therapeutic use
  • Female
  • Humans
  • Keratosis, Actinic* / drug therapy
  • Male
  • Middle Aged
  • Photochemotherapy* / adverse effects
  • Photochemotherapy* / methods
  • Photosensitizing Agents* / therapeutic use
  • Prospective Studies
  • Sunlight
  • Treatment Outcome

Substances

  • Aminolevulinic Acid
  • Photosensitizing Agents
  • methyl 5-aminolevulinate