Background and Objective: Port wine stains are commonly located on UV-exposed skin areas. We therefore examined the longterm interaction between UV radiation and copper vapor laser light (578 nm, yellow light) and whether the thermal influence from laser light had a carcinogenic potential itself.
Study DesigdMateriaZs and Methods:
The study was conducted in lightly pigmented hairless h r h r C3HPI'if mice and included 8 groups of 17-20 mice. Intensities of 0.5, 1.0, and 1.4 W were used, corresponding to calibrated Hexascan fluences of 15.9,31.8, and 44.6 J/cm2. Beam diameter was 1 mm and pulse duration 250 msec. UV irradiation of the mice was performed 4 days weekly and started the day after laser treatment. The UV simulated solar ultraviolet radiation came from one Phillips TL 12 and five Bellarium-S SA-1-12 tubes. The daily dose was 1.3 J/cm2, equivalent Results: No tumors appeared in groups receiving laser light only.
The time to first (P < 0.011, second (P < 0.01), and third (P < 0.02) tumor was significantly delayed in the group treated with 1.4 W before UV irradiation (P < 0.01) compared with those receiving UV radiation only. No significant differences could be demonstrated for the groups treated with 0.5 and 1.0 W. ConcZusion: One laser treatment with the copper vapor laser did not accelerate UV-induced photocarcinogenesis, and the laser exposure did not have a malignant potential itself.