Comparison Between 5-aminolevulinic Acid Photodynamic Therapy Versus Cryotherapy for Actinic Keratosis Treatment

Evaluation of the Formulation of 5-aminolevulinic Acid With Dimethylsulfoxide in Photodynamic Therapy for Treatment of Actinic Keratosis

This study aims to compare in a prospective and randomized way actinic keratosis treatment with 5-aminolevulinic acid photodynamic therapy versus cryotherapy, from the standpoint of therapeutic efficacy, pain, and cosmetic results.

Actinic keratosis is a skin lesion induced by chronic sun exposure with a significant prevalence and malignant potential for squamous cell carcinoma, which makes essential its treatment. Today there are several possible therapies, where cryotherapy is usually applied in our practice. Photodynamic therapy (PDT)is another method also widespread for keratosis which involves the administration of a topical precursor drug which produces endogenous photosensitising substances activated by specific light, selectively destroying the diseased tissue. This study aims to evaluate the use the drug formulation for photodynamic therapy 5-aminolevulinic acid (5-ALA) associated with dimethyl sulfoxide, comparing its efficacy with conventional cryotherapy, and also pain and cosmetic results. This project enrolled 137 outpatients from the Department of Cutaneous Oncology of Barretos Cancer Hospital - Pio XII Foundation, with symmetrical and comparable keratosis in their upper limbs. With the same patient as controls, side arm and therapy to be used were randomized: cryotherapy or photodynamic therapy. For cryotherapy was utilized bottles of liquid nitrogen (Cry-ac, 500ml); and for photodynamic therapy was utilized incoherent red light lamp with a total dosis of 37J/cm² . There was one or two sessions of each therapy , at 0 and 3 months; and three assessments for evaluation were done at 0, 3 and 6 months of onset. The evaluations on efficacy were in terms of area regression, and classified as complete response or no response. Pain was assessed by visual analogue scale, and numerical scale. Cosmesis was evaluated with the presence or not, objectively, of hyper, hypopigmentation or scar retraction. Finally, patient's preference regarding utilized therapeutics was noted by the researcher.

Inclusion Criteria:

• Patients older than 18 years.
• Patients with actinic keratoses "symmetrical", ie, comparable in the upper limbs ( with the same grade, I, II or III).
• Patients in accordance with informed consent.

Exclusion Criteria:

• Patients with concomitant skin diseases, congenital or acquired (albinism, vitiligo, xeroderma, Gorlin, etc.)
• Immunosuppression (HIV, transplanted patients, etc.)
• Pregnancy or lactation
• Patients who do not agree with the informed consent initially or during the protocol.
• Presence of pigmented lesions near the keratoses.
• Patients with porphyria.
• Patients who have undergone less than 2 months with some kind of treatment for keratosis in the upper limbs.