Daylight photodynamic therapy for actinic keratoses in São Paulo, Brazil

To the Editor, There have been several studies about daylight photodynamic therapy (D-PDT) for actinic keratoses (AKs); however, all of them have been performed in Europe. Until now, there have been no studies about D-PDT on other continents. The aim of this study is to present the initial results of a study of the efficacy and safety of D-PDT for AKs in São Paulo, Brazil, and to validate this method in that city.