Browsing by Subject "hexylaminolevulinate"

Actinic keratoses are premalignant skin lesions caused by sun UV-radiation. A small portion of these lesions progress into invasive squamous cell carcinoma over the years. Actinic keratoses are a growing problem in the healthcare around the world. P53 mutations are found in actinic keratosis and adjacent areas. Treatment options include surgical removal, cryotherapy, local treatment creams such as immunomodulators, and photodynamic therapy (PDT). Aminolevulenic acid (ALA) is an endogenous light-sensitizer used in PDT and methylaminolevulinate (MAL) and hexylaminolevulinate (HAL) are its esters. Either artificial light or daylight can be used as a light source in PDT. In PDT light activates the photosensitizer, which initiates a photochemical reaction and target cell destruction. The most common side effects of PDT are erythema and pain during treatment. The benefits of PDT are good cosmetic outcome and the possibility to treat large areas. In the present study 3 light-sensitizers (BF-200 ALA, MAL, HAL 0,2 % and 2 %) were tested on healthy volunteers to compare the skin irritation, pain and fluorescence caused by the treatment. Fluorescence intensity reflects PpIX production capacity. The second part of the present study was a clinical study comparing BF-200 ALA and MAL in treatment of actinic keratoses with daylight-PDT. Each patient received both light-sensitizers on opposite sides of the head and the results were evaluated 3 months after treatment. On healthy skin BF-200 ALA, MAL and HAL 2 % caused more irritation compared to HAL 0,2 %. HAL 2 % didn't differ from ALA and MAL-groups in severity of reactions, erythema or fluorescence photobleaching. In HAL-treated areas pain was smaller than in ALA- and MAL-groups. However, in lesional skin there might be differences in absorption, distribution and PpIX formation. Both BF-200 ALA and MAL were effective in daylight-PDT and there were no significant differences between the groups in either efficacy or pain caused by the treatment. Long-term follow up is still required to confirm if the results sustain.