(HealthDay News) — A two-step irradiance protocol with topical δ-aminolevulinic acid (ALA) and photodynamic therapy (PDT) minimizes pain while maintaining comparable clinical outcomes for the treatment of non-melanoma skin cancer lesions, according to a study published online Feb. 6 in Lasers in Surgery and Medicine.
Nathalie C. Zeitouni, M.D.C.M., from the Roswell Park Cancer Institute in Buffalo, N.Y., and colleagues reviewed the clinical experience of ALA-PDT use in 14 Caucasian patients: nine men and five women, ages 18 to 80 years, with a total of 51 superficial and 73 nodular basal cell carcinomas (BCCs) and three Bowen’s disease lesions. Each lesion received ALA for approximately four hours, receiving an initial irradiance of 30 to 50 mW/cm² for 20 J/cm², followed by 150 mW/cm², for a total fluence of 200 to 300 J/cm². A visual analog scale (VAS) was used to assess pain. At six to 12 months, clinical outcome was determined.
The researchers found that for both irradiances the median VAS scores were 1.0. Xylocaine (1 percent) was required for pain control in five of 127 lesions. Lesion location strongly influenced pain, while lesion type, number, and size did not. Of the BCCs, 84.1 percent achieved complete responses, which compared favorably with reported results for single ALA-PDT treatments. A complete response was also seen in two of three Bowen’s disease lesions and in 37 percent of nodular BCCs, which were also within the range of reported outcomes.
“In conclusion, we have validated a simple approach to minimize the pain experienced by patients undergoing topical ALA-PDT for cutaneous cancers,” the authors write. “We conclude that the protocol offers significant benefit to patients.”