Short incubation fractional CO 2 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 CO ₂ 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 CO ₂ 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.
(© 2018 European Academy of Dermatology and Venereology.)