TOPLINE:

Ablative fractional laser (AFXL)-assisted daylight photodynamic therapy (dPDT) achieved greater 2-year sustained lesion-specific clearance for actinic keratosis than dPDT alone, with no cutaneous squamous cell carcinomas developing on treated fields during follow-up.

METHODOLOGY:

• Researchers conducted an investigator-initiated intraindividual randomised controlled, evaluator-blinded trial including 57 patients with at least two actinic keratoses located on both sides of the head at a dermatology outpatient clinic from 2018 to 2023.
• Patients received AFXL-dPDT on one randomly assigned side of the head and dPDT alone on the contralateral side, either naturally in the daylight (n = 18) or artificially by a daylight lamp (n = 39).
• Primary outcomes included 1- and 2-year lesion- and patient-specific sustained clearance, as well as the progression rate to cutaneous squamous cell carcinoma or Bowen disease.
• Researchers utilised the intention-to-treat methodology, in which all dropout patients and those receiving re-treatment were documented as non-cleared, and the per-protocol analysis included 46 patients at a follow-up of 2 years.

TAKEAWAY:

• AFXL-dPDT achieved significantly higher 2-year sustained lesion-specific clearance than dPDT alone (56.3% vs 43.0%; P = .003), with similar superiority at 1 year (67.0% vs 53.0%; P = .001).
• Patient-specific partial clearance was higher with AFXL-dPDT than with dPDT alone at 1 year (57.9% vs 45.6%; P = .13) and maintained higher at 2 years (45.6% vs 31.6%; P = .064).
• AFXL-dPDT showed significantly higher patient-specific complete clearance than dPDT alone at 1 year (29.8% vs 15.8%; P = .035) and demonstrated higher levels at 2 years (15.8% vs 7.0%; P = .070).
• None of the patients developed cutaneous squamous cell carcinoma during the follow-up period, and no significant differences in the progression rate to Bowen disease were observed between the treatment groups (1.1% vs 0.0%; P = .25).

IN PRACTICE:

"Laser pretreatment seems to improve the long-term outcomes of dPDT and achieves a high long-term clearance for AKs [actinic keratoses] of all grades on patients with multiple AKs or field cancerization," the authors wrote. "More studies on the long-term outcomes of AFXL-dPDT, including cSCC [cutaneous squamous cell carcinoma] risk, are warranted, as well as controlled trials comparing different AK field treatment options head-to-head," they added.

SOURCE:

This study was led by Vivian Lindholm, Department of Dermatology, Allergology and Venereology, Helsinki University Hospital and University of Helsinki, Helsinki, Finland. It was published online on April 15, 2026, in Clinical and Experimental Dermatology.

LIMITATIONS:

The study was only blinded for the evaluator. Lesions were not histologically confirmed. The follow-up duration may have been short for the assessment of the risk for cutaneous squamous cell carcinoma.

DISCLOSURES:

This non-sponsored investigator-initiated study was supported by the Clinical Research Institute HUCH and the Helsinki University Hospital's Inflammation Centre. One author reported receiving a congress fee from UCB Pharma and speaker honoraria from Orion Oy and Galderma. Additional disclosures are noted in the original article.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.