From the Guidelines
For activating 5-aminolevulinic acid (5-ALA) on the face, a light dose of 37-50 J/cm² is typically recommended. This recommendation is based on the most recent and highest quality study available, which suggests that this energy density is effective in activating protoporphyrin IX and triggering the photodynamic reaction while minimizing damage to surrounding healthy tissue 1. The treatment involves applying 5-ALA topically to the face, allowing it to incubate for 1-3 hours, then exposing the area to red light (usually 630-635 nm wavelength) at this energy density.
Some key considerations for this treatment include:
- The exact J/cm² may be adjusted based on the specific condition being treated (such as actinic keratosis, superficial basal cell carcinoma, or acne), skin type, and device being used.
- Treatment parameters should be monitored carefully as excessive light exposure can cause increased pain, erythema, and potential scarring, while insufficient energy may result in inadequate treatment outcomes.
- Patients should be advised about post-treatment photosensitivity and the need to avoid sun exposure for 24-48 hours after the procedure.
- Alternative treatment protocols, such as daylight PDT, may also be effective and potentially less painful than traditional red light PDT 1.
- The choice of light source and treatment parameters should be based on the proposed clinical indications, priorities for a portable compact source, flexibility, treatment times, and cost 1.
It is essential to note that the efficacy and safety of ALA-PDT can vary depending on the specific treatment protocol and patient population, and therefore, treatment should be individualized and monitored closely to optimize outcomes 1.
From the FDA Drug Label
LEVULAN KERASTICK for topical solution plus blue light at 6-10.9 J/cm², has been used to treat actinic keratoses of the face or scalp in 342 subjects in seven clinical trials Phase 3 trials ALA-018 and ALA-019 were two, identically designed, multicenter, two-arm trials using LEVULAN KERASTICK topical solution plus illumination from the BLU-U Blue Light Photodynamic Therapy Illuminator for 1000 seconds (16 minutes and 40 seconds) for a nominal exposure of 10 J/cm²
The joules per centimeter (J/cm) needed to activate 5-aminolevulinic acid (5ALA) on the face is 6-10.9 J/cm², with a nominal exposure of 10 J/cm² 2.
From the Research
Activation of 5-Aminolevulinic Acid (5ALA)
- The activation of 5-aminolevulinic acid (5ALA) requires a specific amount of energy, typically measured in joules per centimeter (J/cm).
- However, the provided studies do not directly mention the exact amount of joules per centimeter required to activate 5ALA on the face.
- Study 3 discusses the use of 5ALA with daylight photodynamic therapy for the treatment of actinic keratoses on the face and scalp, but it does not provide information on the energy required for activation.
- Study 4 investigates the topical application of 5ALA and its derivatives on mouse skin, but it focuses on the accumulation of protoporphyrin IX (PpIX) and does not mention the energy required for activation.
- Studies 5, 6, and 7 provide information on the properties and applications of 5ALA, but they do not address the specific question of energy required for activation on the face.
Energy Requirements for Activation
- Since the provided studies do not directly address the question, there is no clear answer to the amount of joules per centimeter required to activate 5ALA on the face.
- Further research or studies specifically focused on the energy requirements for 5ALA activation on human skin would be necessary to provide a definitive answer.
- The existing studies provide valuable information on the properties and applications of 5ALA, but they do not offer a direct solution to the question of energy requirements for activation on the face 3, 4, 5, 6, 7.