A recent therapeutic approach, with the goal of establishing a tumor specific therapeutic alternative to chemo-or radiotherapy, focuses on enhancing the functionality of the already administered fluorescent dye used for tumor visualization to additionally act as a photosensitizing agent in photodynamic therapy (PDT) . In PDT, photosensitizers are optically excited followed by a transition to the triplet state, which further reacts with biological substrate or surrounding oxygen to form highly reactive oxygen species (ROS) . These species induce a high oxidative stress and a pronounced level of photodamage inside the tumor cells, resulting in cell death. As 5-ALA and thus PPIX are specifically enriched in brain tumors, their application in PDT was expected to be a promising approach. Several studies were performed to investigate the potential of 5-ALA-PDT for PDT applications . Eskiler et al. demonstrated the effectiveness of 5-ALA-PDT in the treatment of breast cancer , whereas its photodamaging capabilities on rhabdomyosarcoma were shown by Atif et al. .