Short incubation fractional CO2 laser-assisted photodynamic therapy vs. conventional photodynamic therapy in field-cancerized skin: 12-month follow-up results of a randomized intraindividual comparison study

Background Topical methyl aminolevulinate photodynamic therapy (MAL-PDT) with 3 h incubation is recommended as a field directed treatment. Skin pretreatment with ablative CO2 fractional laser (AFXL) prior to MAL-PDT enhances drug penetration and could minimize incubation time. Objectives To evaluate and compare the safety and the preventive effect in the development of new non-melanocytic skin cancers (NMSCs) of AFXL-assisted MAL-PDT with 1-h incubation with that of conventional MAL-PDT in patients with clinical and histological signs of field cancerization. Methods Forty-two patients with two mirror cancerized areas of face or scalp were randomized to field treatment with 1-h incubation AFXL-assisted PDT or conventional PDT (CPDT). All patients underwent two treatment sessions 1 week apart. Irradiation was performed using a red light-emitting diode lamp at 37 J/cm(2). Patients were followed up at 3, 6, 9 and 12 months for the evaluation of development of new NMSCs lesions. Results All patients completed the study. There was no statistically significant difference with respect to the total number of new actinic keratoses at any point of follow-up as well as to the mean time of occurrence of new lesions between treatment fields. Both treatment regimens were safe and well tolerated. Conclusion Ablative CO2 fractional laser pretreatment may be considered as an option for reducing photosensitizer occlusion time while providing the same preventative efficacy as CPDT in patients with field-cancerized skin.