Comparison of aminolevulinic acid (ALA)-thermogel-PDT with methyl-ALA-thermogel-PDT in basal cell carcinoma

Background: Aminolevulinic acid (ALA) and light irradiation is a treatment option in basal cell carcinomas (BCC). The development of ALA-esters with potential for greater penetration depth promises higher therapeutic success. In a pilot study, we hypothesized that the cytotoxic effect of methyl-ALA (mALA) photodynamic therapy (PDT) leads to a higher success rate compared with ALA-PDT when both are topically applied in a thermogel. Methods: Twenty-four patients with 112 superficial BCC were treated with either 10% ALA-or mALA-thermogel. After an accumulation time of at least 3 h, the lesions were illuminated with a diode laser. The power density was 0.1 W/cm(2) and the energy density was 120 J/cm(2). After intervals of 12 weeks and 6 months, the therapeutic efficacy was assessed by clinical examination. Results: Sixty percent of the tumors were treated successfully in the first session. All but 3% of the remaining tumors could be treated with a second or third course of therapy. Conclusion: Although mALA should have a greater penetration depth, the therapeutic outcome of this preliminary study showed no difference between treatments. The final proof of this preliminary result will require further study. (C) 2007 Published by Elsevier B.V.