Treatment of superficial basal cell carcinoma by topical photodynamic therapy with fractionated 5‐aminolaevulinic acid 20% vs. two‐stage topical methyl aminolaevulinate: results of a randomized controlled trial

摘要

Summary Photodynamic therapy (PDT) is a frequently used treatment for a type of skin cancer called superficial basal cell carcinoma (sBCC). It works by using a cream called a porphyrin precursor, which is applied to the affected skin area and covered with a dressing. After several hours and after removing the occlusive dressing, the area is irradiated with intense visible light which causes the death of cancer cells. There are two porphyrin precursors available in the Netherlands, 5aminolevulinic acid 20% (ALA) and methylaminolevulinic acid (MAL). In conventional MAL PDT, skin receives one illumination (treatment with light) which is repeated one week later. In the case of ALA, skin receives two different illuminations, two hours apart. This is called fractionated ALAPDT. In this study, from the Netherlands, we investigated whether this fractionated ALAPDT is superior to conventional MALPDT. 162 patients were randomly assigned to one of two groups. 82 patients were treated with fractionated ALAPDT and 80 patients with conventional MALPDT. After 12 months a total of 6 treatment failures (recurrence of the sBCC) occurred after ALAPDT and 13 after MALPDT. Although there were twice as many treatment failures in the MALPDT group, this difference was not statistically significant. Secondly, we investigated pain scores in both treatment groups because PDT is known to cause a severe burning sensation. We found that ALAPDT resulted in more pain and side effects, such as erythema (skin redness, like sunburn), wounds/erosions and vesicles (small blisters) compared to MALPDT. In conclusion, there is a trend toward better efficacy of ALAPDT compared to MALPDT for the treatment of sBCC, although the difference was not significant.