Photodynamic Therapy The Experience with Actinic Keratoses in the United States

In the United States, the 20% 5-ALA product is currently the only commercial product available for use by physicians. It is a 20% weight/ volume ALA solution with 48% ethanol. It is produced in the form of a kerastick (Fig. 6.2). The kerastick has a dermatologic applicator at one of its ends for accurate application of the ALA medicine. The applicator tip is attached to flexible plastic tubing which contains two glass vials. One of the vials contains the ALA in a powder form and the other glass vial contains the ethanol solvent. The vials on the kerastick are broken by light manual pressure to the tubing and then the contents are mixed by rotating the contents of the kerastick back and forth for several minutes, with 3 min being the recommended time frame for proper mixing of the medicine. Once fully mixed together, the ALA is ready for patient application. Preparation of the patient includes washing of the skin with a mild cleanser followed by one or two applications of the ALA. Some clinicians advocate the use of an acetone scrub or a microdermabrasion proce dure to allow an even deeper penetration of the ALA. Once the drug has been incubated for the time period chosen, the ALA is washed off the skin and the patient is then ready for the appropriate light therapy.

The first clinical trial with 20% 5-ALA was a Phase II clinical trial reported in 2001. In this clinical trial, 36 individuals with nonhyperkera-totic AKs of the face and scalp were evaluated for its safety and efficacy. The patients had the ALA applied to individual AK lesions. The drug was allowed to incubate on the individual lesions for 14-18 h without occlusion and the patient was then subjected to a blue light source

Actinic Keratosis Laser Treatment
Fig. 6.2. 20% topical ALA

(wavelengths of 410-430 nm) for 16 min and 40 sec. The blue light source provided a dose of 10 J/cm2 to the affected lesions. The results of the trial showed that nonhyperkeratotic AKs were effectively treated with the ALA-PDT plus the blue light source. Specifically, 66% of the treated AKs responded to the therapy after one treatment. For those AKs which did not respond (n = 16), retreatment was undertaken after 8 weeks. This improved the efficacy rate to 85% at the 16-week follow-up period. The treatments were well tolerated by the participants in this trial. All patients noted burning and stinging during their light therapy, and facial erythema was reported in 96% of the participants; all resolved by the first 4-week follow-up.

This aforementioned study led to the Phase III clinical trial, which was a placebo-controlled multicenter analysis looking at a larger number of individuals (n=243) using a similar protocol as reported in the Phase II trial. Two applications of either the ALA solution (L) or a vehicle placebo (V) were applied to the individual AK lesions, incubation times for the drug remained at 14-18 h, and the patients received 16 min, 40 s of blue light therapy. Results of the clinical trials showed significant differences between the active ALA and the placebo (Fig. 6.3); more than 70% of the lesions were resolved at 12 weeks. Lesions which were not clear were retreated at 8 weeks. At the conclusion of the study, 88% of the patients with active medicine had a > 75% response rate compared to 20% in the vehicle/ placebo group of patients. (Fig. 6.4). The treatments were well tolerated by the study partici

Levulan PDT system Phase III studies: efficacy results. p < 0.001. From Dusa Pharmaceuticals

Patient CR rate at week 12

Patient CR rate at week 12

Levulan PDT system Phase III studies: efficacy results. p < 0.001. From Dusa Pharmaceuticals

Levulan Photodynamic Therapy

L-Pts with ^75% AKs cleared

L-Pts with >100% AKs cleared

V-Pts with >75% AKs cleared

L-Pts with S100% AKs cleared

L-Pts with ^75% AKs cleared

L-Pts with >100% AKs cleared

V-Pts with >75% AKs cleared

L-Pts with S100% AKs cleared pants. Patients noted that during their light therapy, there was stinging and burning. Some of the patients did have associated erythema and edema from the therapy. These symptoms resolved at 1 week after the light treatment. No noncutaneous adverse effects were seen in the Phase III trials. An important outcome of this trial was patient and physician assessment of improvement in the cosmetic appearance of the skin as a result of the ALA therapies. Ninety four percent of the patients and 92% of the investigators rated the cosmetic improvement as good to excellent.

Ala Pdt Treatment

Fig. 6.4. a Pretreatment. b One week after ALA-PDT treatment. c One month after ALA-PDT treatment

Recently, a long-term clinical trial has looked at both efficacy and recurrence rates associated with ALA therapy. This study showed that 69% of 32 AKs studied in four individuals remained clear at the end of 4 years; 9% were found to be recurrent; 22% were described as "uncertain" as to whether the lesions were actually recurrent or whether new lesions developed in the same area.

How To Deal With Rosacea and Eczema

How To Deal With Rosacea and Eczema

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