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

SummaryBackgroundAminolevulinic 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.MethodsTwenty-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/cm2 and the energy density was 120 J/cm2. After intervals of 12 weeks and 6 months, the therapeutic efficacy was assessed by clinical examination.ResultsSixty 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.ConclusionAlthough 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.