ALA 3x reduced NMSC development versus VEH (5 vs 12 lesions, P=0.0014). Conclusion 2 or 3 ALA–PDT treatments with 1-hour incubation can significantly reduce occurrence of AKs after 1 year in patients at high risk of NMSC versus VEH–PDT (NCT02239679). J Drugs Dermatol. 2020;19(5)452-458. doi10.36849/JDD.2020.4930.Background Previous results fro…[Read more]