From the Guidelines
Photodynamic therapy (PDT) offers the lowest recurrence rate for facial actinic keratoses, as it treats both visible and subclinical lesions across the entire field, addressing the concept of "field cancerization". This treatment involves applying a photosensitizing agent such as aminolevulinic acid (ALA) or methyl aminolevulinate (MAL) to the affected areas, allowing it to incubate for 1-3 hours, then activating it with specific wavelengths of light 1. The complete protocol typically involves 1-3 treatment sessions spaced 2-4 weeks apart, with follow-up evaluations at 3 and 6 months.
Some key points to consider when using PDT for facial actinic keratoses include:
- The treatment works by generating reactive oxygen species that selectively destroy atypical cells while largely sparing normal tissue 1
- While PDT may cause temporary discomfort, redness, and swelling during and after treatment, these side effects typically resolve within a week
- For optimal outcomes, patients should avoid sun exposure for 48 hours after treatment and use high-SPF sunscreen consistently thereafter to prevent new lesions from forming
- Response rates to two cycles of PDT mainly on the scalp and face range from 69% to 91% in three randomized trials, with a 3- to 4-month follow-up period 1
In comparison to other treatments, PDT has been shown to have a lower recurrence rate than cryosurgery and topical treatments such as 5-fluorouracil (5-FU) and imiquimod 1. For example, a study found that the proportions of the intention-to-treat population maintaining clearance at 12 months were 1% for cryosurgery, 33% for 5-FU 5%, and 76% for imiquimod 1.
Overall, PDT is a highly effective treatment for facial actinic keratoses, offering a low recurrence rate and a high response rate, making it a recommended treatment option for patients with this condition.
From the FDA Drug Label
INDICATIONS AND USAGE: Fluorouracil Cream USP is recommended for the topical treatment of multiple actinic or solar keratoses. The success rate with Fluorouracil Cream USP is approximately 93%, based on 113 lesions in 54 patients. Eighty-eight lesions treated with the cream produced 7 failures.
The treatment for facial actinic (solar) keratoses that yields the lowest recurrence rate is not directly stated in the provided drug labels. However, based on the available information, Fluorouracil Cream USP has a success rate of approximately 93% 2.
- The recurrence rate is not explicitly mentioned in the provided drug labels.
- Methyl aminolevulinate (TOP) does not provide direct information on recurrence rates in the given text.
From the Research
Treatment Options for Facial Actinic Keratoses
- The treatment for facial actinic keratoses with the lowest recurrence rate is ablative fractional laser-assisted photodynamic therapy with a 3-hour incubation time (3h-AFL-PDT) 3.
- This treatment has been shown to have a significantly lower recurrence rate (7.5%) compared to conventional methyl aminolevulinate photodynamic therapy (3h-MAL-PDT) (22.1%) at 12 months 3.
Comparison of Treatment Options
- A study comparing the efficacy of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) and methyl aminolevulinate-PDT (MAL-PDT) for facial actinic keratoses found no significant difference in recurrence rates between the two treatments at 6 or 12 months 4.
- Another study found that topical pretreatments with imiquimod, adapalene, 5-fluorouracil, and calcipotriol were more successful than photodynamic therapy alone in treating actinic keratoses 5.
Efficacy of Photodynamic Therapy
- Photodynamic therapy using methyl aminolevulinate is an effective first-line treatment for actinic keratosis, with high clearance rates and superior cosmetic outcomes 6.
- A study evaluating the efficacy of four regimens of methyl aminolevulinate mediated by red light to treat actinic keratoses found that the primary outcome will be the complete remission of the lesion at six months, and secondary outcomes will include treatment success, recurrence rate, and emergence of squamous cell carcinoma 7.