Fractionated ALA-PDT in PAM212 cells

In recent years the therapeutic search for cutaneous T-cell lymphoma (CTCL) and especially for mycosis fungoides (MF) has continued and several innovative therapies are under study. Photodynamic therapy (PDT) after topical photosensitization with 5-aminolevulinic acid (ALA) might be an alternative treatment modality. The following results of research in the last years led to the clinical application of ALA-PDT in patients with CTCL: ALA and light inactivated erythrocytic, lymphocytic and myelocytic leukemic cells in vitro; ALA-PDT was effective in T-cell-derived cell lines; selective PpIX accumulation could be demonstrated in CD71 positive lymphocytes; and selective clinical CTCL photosensitization after topical ALA application was observed. Indeed, clinical studies in a limited number of patients revealed complete, partial or no response of CTCL lesions treated by different ALA-PDT treatment protocols. However, further studies are required in larger numbers of CTCL patients to determine the optimal ALA and light dose combination, frequency of treatment, overall response rate, and duration of disease remission.