Comparison of Photodynamic Therapies for Active Keratosis
Posted: Thursday, August 2, 2018
Metal halide white light may be a “reasonable alternative” to using sunlight in photodynamic therapy (PDT) for patients with actinic keratosis, according to research by Kayla Marra, MD, of Thayer School of Engineering, Dartmouth College, and colleagues published in Photochemistry and Photobiology. The potential benefit of this treatment, according to the researchers, is it “would be independent of uncontrolled factors such as weather” and so may be used in climates with “less reliable weather patterns without sacrificing efficacy.”
In PDT, a light-sensitizing agent is applied to affected areas and, when exposed to strong light, produces oxygen that kills nearby cells. Light-sensitizing agents are usually held by cancer cells longer than healthy cells.
For their preclinical study, Dr. Marra and colleagues assessed blue LED light, metal halide white light, and natural sunlight in 30 female mice. Immediately after treatment and 24 hours later, biopsies from each mouse were taken for analysis.
The study bioassays suggested that blue light was slightly inferior to both sunlight and white light, although there was no significant difference between the latter two. Their findings indicate that metal halide white light may prove to be an alternative to daylight PDT. “[Metal halide white light] should allow a more controlled treatment that is independent of weather and yet should have similar response rates with limited pain during treatment,” concluded Dr. Marra and colleagues.