Cutaneous Absorption and Intralesional Penetration of Topical Amino-Levulinic Acid in Basal Cell Carcinoma and Squamous Cell Carcinoma as Measured by In Situ Fluorescence and Intensified Video Fluorescence Microscopy

OBJECTIVES: Characterize the penetration of topically applied aminolevulinic acid (ALA) into the lesions of patients with primary basal cell and squamous cell carcinomas. Quantitate the depth of fluorescence achievable with varying application periods of ALA in these patients. Compare the results of tissue fluorescence with surface fluorescence measurements in these patients. OUTLINE: This is a randomized study. Patients are stratified according to lesion type (superficial basal cell carcinoma (BCC) vs nodular BCC vs squamous cell carcinoma). Patients within each group are randomized to receive one of two application times: 4-5 or 20-24 hours in duration. Aminolevulinic acid is topically applied either in a cream mixture or an alcohol base and an occlusive dressing placed over the lesion. After the randomized treatment duration has expired, the dressing is removed and quantitative protoporphyrin IX fluorescence measurements from the tumor and surrounding skin are mapped using a fluorometer. Routine surgical excision is then performed on the carcinoma. Patients return after one to two weeks for a follow-up examination and suture removal. PROJECTED ACCRUAL: 54 patients will be accrued within 10 years.