The study included five subjects with grade I–III AK, according to Olsen’s classification , on the face or scalp. The subjects were randomly recruited through the daily consultation of the cutaneous oncology agenda of the Department of Dermatology at the Hospital Italiano de Buenos Aires in November 2016.
All subjects were male with a mean age of 70 years (range 60–80 years). They presented with phototype I (3 subjects; 60%) and II (2 subjects; 40%). All subjects provided written informed consent prior to participation in the study.
The study followed a split-face design. The region of interest on the face or scalp was divided into two areas, each receiving a single session of DL-PDT or topical 5% 5-FU treatment.
Prior to DL-PDT, the treatment area was cleansed with 0.9% saline solution. Organic SPF 30 sunscreen was applied to the treatment area as well as all areas of the face/scalp exposed to sunlight. Subsequently, surface curettage was performed to remove lesion crusts and scales. A thin layer of 16% MAL cream was applied (1 g per area), and the subjects left the clinic with instructions to initiate direct exposure to sunlight within 30 min of MAL cream application. Moreover, they were instructed to allow 2 h of exposure for optimal treatment results, as previously recommended [1, 8]. At the end of the 2-h exposure, subjects removed the residual MAL cream using wet towels and applied sunscreen for continued protection.
For the opposite treatment area, subjects were instructed to apply 5-FU cream at home for a period of 21 days. Following cleansing of the treatment area with soap and water, 5-FU cream was applied homogeneously on the lesion and surrounding area 1 h before bedtime to allow the treatment to act throughout the night. In the morning, the residual 5-FU cream was removed with water, and SPF 30 sunscreen was applied.
Assessments included lesion (AK) counts, safety, subject satisfaction, and subject photography using a conventional camera. Evaluations were conducted 48 h, 7 days, and 14 days after treatment, as well as at 1- and 3-month follow-ups.
All subjects provided written informed consent prior to their participation in the study.