Photodynamic Therapy With Aminolevulinic Acid Topical Solution andVisible Blue Light in the Treatment of Multiple Actinic Keratoses of the Faceand Scalp

Abstract

To determine the safety and efficacy of photodynamic therapy (PDT) using 20% wt/vol aminolevulinic acid hydrochloride (hereinafter "ALA") and visible blue light for the treatment of multiple actinic keratoses of the face and scalp.Design: Randomized, placebo-controlled, uneven parallel-group study.Interventions: Patients (N = 243) were randomized to receive vehicle or ALA followed within 14 to 18 hours by PDT. Follow-up visits occurred 24 hours and 1, 4, 8, and 12 weeks following PDT. Target lesions remaining at week 8 were re-treated.Main Outcome Measure: Clinical response based on lesion clearing by week 8.Results: Most patients in both groups had 4 to 7 lesions. Complete response rates for patients with 75% or more of the treated lesions clearing at weeks 8 and 12 were 77% (128/166) and 89% (133/149), respectively, for the drug group and 18% (10/55) and 13% (7/52), respectively, for the vehicle group (PϽ.001, Cochran-Mantel-Haenszel general association test). The 95% confidence interval for the difference in response rates at week 8 was 46.9% to 71.0% and at week 12, 65.3% to 86.3%. The week 12 response rate includes 30% of patients who received a second treatment. Most patients experienced erythema and edema at the treated sites, which resolved or improved within 1 to 4 weeks after therapy, and stinging or burning during light treatment, which decreased or resolved by 24 hours after light treatment. Conclusion:Findings indicate that topical ALA PDT is an effective and safe treatment for multiple actinic keratoses of the face and scalp.

Effects of light irradiation upon photodynamic therapy based on 5-aminolevulinic acid–gold nanoparticle conjugates in K562 cells via singlet oxygen generation

“…40 Some studies have demonstrated that blue or green light is more potent than red light in activating PpIX. 39,41 The same PDT result in our study (Figure 8) also demonstrated that the mercury lamp (central wavelength = 395 nm) and two types of LEDs (central wavelength = 399 nm, 502 nm) were more effective than the red LED (central wavelength = 621 nm). The reason that most researchers have chosen a red light for PDT relates to the depth tissue, as an increased amount of red light is absorbed at greater depths.…”

A review of BF-200 ALA for the photodynamic treatment of mild-to-moderate actinic keratosis

“…While MAL and ALA have been approved for topical treatment of AK and basal cell carcinoma, only few studies exist that investigate the use of hexyl-ALA for epidermal neoplasms [62]. Another approach to circumvent the short half-life of ALA in solution is the immediate preparation before use, as in a two-chamber applicator device containing ALA and alcohol to produce a 20% ALA solution [63].…”

Targeted phototherapy

“…Because the photosensitizer is preferentially absorbed by hyperproliferative tissue and the light source is directly targeted at the lesional tissue, photodynamic therapy achieves dual selectivity, minimizing damage to adjacent healthy structures. The photosensitizers are aminolevulinic acid (ALA) and methyl aminolevulinate (MAL), porfimer sodium (Photofrin), benzoporphyrin derivative monoacid ring A, tin ethyl etiopurpurin, and lutetium texaphyrin [45][46][47][48].…”