KISSIMMEE, FLA. – Using a needle-free device to inject nodular basal cell carcinomas with intralesional 5-aminolevulinic acid before photodynamic therapy led to complete, years-long remissions and few side effects in a small case series.
“This approach represents an interesting alternative to Mohs, for sure,” Dr. Daniel Barolet said at the annual meeting of the American Society for Laser Medicine and Surgery. “The secret is in the injector nozzle, which lets you inject with multiple openings to get the best uniformity around the tumor.”
Mohs micrographic surgery remains the standard for basal cell carcinoma (BCC) in high-risk sites, and the number of Mohs surgeries has approximately doubled since 2001, said Dr. Barolet, adjunct professor of dermatology at McGill University in Montreal.
Mohs, however, can cause scarring, and BCCs recur in about 4% of patients. In contrast, photodynamic therapy (PDT) is associated with less scarring and pain, fewer complications, shorter recovery times, and lower costs, although the recurrence rate is about 14%, he noted.
Since PDT alone does not efficiently penetrate thick tumor volumes, it works best with pretreatment using agents such as aminolevulinic acid (ALA).
Using needles to inject the tumor, however, can cause pain, vascular damage, vasoconstriction, deep purpura, necrosis, and infection. “Because of this, no-needle injection is an interesting avenue for PDT,” he noted. Needle-free devices currently are used to inject insulin and to administer some vaccines. They are “virtually painless,” noninvasive, and tissue sparing, he said.
To explore the potential role for needle-free injection in ALA-PDT, Dr. Barolot used a prototype high-speed jet to deliver intralesional 5-ALA in the nodular facial BCCs of four patients. He then performed photoactivation with a red light–emitting diode, with continuous wave at 630 nm, irradiance at 50 mW/cm2, and total fluence 50-100 J/cm2.
Patients had no evidence of clinical or histopathologic recurrence for up to 7 years after treatment, Dr. Barolet reported. They experienced mild crusting at treated sites for up to a week after treatment, but no other adverse effects. Two patients needed a second treatment 2 months after the initial treatment to achieve complete remission. “Excellent cosmesis was obtained,” he added, pointing to before and after photos that showed no evidence of lesions several months after treatment.
Multicenter clinical trials are needed to further evaluate the modality, but the preliminary data suggest that intralesional PDT is a reasonable alternative to Mohs for BCCs in high-risk body sites, as long as lesions are few in number and do not affect large areas of the body, Dr. Barolet said.
The modality is especially well suited to “tricky” areas of the body that are difficult to treat with Mohs, he said.
“Developing a user-friendly, disposable no-needle injector will make it much easier for users,” he added. For low-risk BCCs in low-risk sites, conventional treatments such as surgical excision remain the best option, he said.
Dr. Barolet reported no funding sources for the study and said he had no relevant financial disclosures.