Photodynamic therapy and skin lesions

Actinic keratoses are the most common epithelial pre-cancerous lesions that could potentially lead to invasive cancer. Researchers continue to look for the best treatment and management of these lesions. Aminolaevulinic acid-based photodynamic therapy (ALA-PDT) using blue light was approved by the FDA in 1999 as a safe and effective treatment for actinic keratoses.

Dusa Pharmaceuticals Inc. of Wilmington, Mass., has investigated the long-term efficacy and safety of its FDA-approved ALA-PDT for treating actinic keratoses on the face and scalp.

As reported in the December issue of the British Journal of Dermatology, 110 patients with discrete actinic keratosis lesions on their faces or scalps (as determined by sight and feel) were treated with a topical solution of ALA, followed by photoactivation with Dusa Pharmaceuticals’ blue-light illuminator. Patients were treated two months later for any lesions that remained and were monitored for 12 months. Each patient had six to 12 lesions, two of which were not treated with ALA-PDT but were instead biopsied to confirm actinic keratosis (91 percent were histopathologically confirmed).

More than 80 percent of the actinic keratosis lesions cleared up completely after two ALA-PDT treatments, with a recurrence rate of 24 percent for any lesion and 19 percent for confirmed actinic keratosis lesions (as evaluated over 12 months). The percentage of lesions was similar in all skin types, and no negative pigmentation effects were discovered.

The researchers believe that their results show ALA-PDT is both an effective and safe therapy for the treatment of actinic keratoses on the face and scalp, with an acceptable rate of recurrence.