Multicentre intraindividual randomized trial of topical methyl aminolaevulinate-photodynamic therapy vs. cryotherapy for multiple actinic keratoses on the extremities

Background Methyl aminolaevulinate-photodynamic therapy (MAL-PDT) is an effective treatment in facial/scalp actinic keratosis (AK). Objectives The aims of this study were to compare efficacy, safety, cosmetic outcome and patient preference of MAL-PDT vs. cryotherapy in patients with AK at other locations. Methods A multicentre, controlled, randomized, open, intraindividual, right-left comparison was performed. Patients with nonhyperkeratotic AK were treated once with MAL-PDT and cryotherapy on either side of the body. At week 12, lesions showing noncomplete response were retreated. The primary efficacy variable was the lesion response at week 24. Investigator's assessment of cosmetic outcome, patient's preference in terms of cosmetic outcome and a patient preference questionnaire were also analysed at week 24. Results In total, of 121 patients with 1343 lesions (98% located on the extremities and the remainder on the trunk and neck) were included. Both treatments provided a high mean percentage reduction in lesion count at week 24 with significantly higher efficacy for cryotherapy: 78% for MAL-PDT and 88% for cryotherapy (P = 0.002, per protocol population). Investigator's assessment of cosmetic outcome was significantly better for MAL-PDT than cryotherapy (P < 0.001), 79% of lesions having an excellent cosmetic outcome with MAL-PDT vs. 56% with cryotherapy at week 24. The cosmetic outcome achieved by MAL-PDT compared with cryotherapy was also preferred by patients (50% vs. 22%, respectively, P < 0.001), and 59% of patients would prefer to have any new lesions treated with MAL-PDT compared with 25% with cryotherapy (P < 0.001). Both treatment regimens were safe and well tolerated. Conclusions MAL-PDT showed inferior efficacy for treatment of non-face/scalp AK compared with cryotherapy. However, both treatments showed high efficacy, and MAL-PDT conveyed the advantages of better cosmesis and higher patient preference.