Topical Aminolevulinic Acid in Patients With Nonmelanoma Skin Cancer

OBJECTIVES: * To evaluate the distribution and depth of protoporphyrin IX (PpIX) within different types of nonmelanoma skin cancers after topical aminolevulinic acid (ALA) administration. * To obtain in vivo measurements of ALA-induced PpIX formation within different zones of the tumors as measured by fluorescence detection methods. * To correlate the level of PpIX fluorescence detected by non-invasive optical measurements with morphological characteristics of the tumors. * To establish a skin cancer tissue bank. OUTLINE: Topical aminolevulinic acid (ALA) is applied to the center of the tumor surface. Patients then undergo punch tumor biopsy of the area where the ALA is applied followed by surgery to remove the tumor. Tissue samples are assessed for protoporphyrin (PpIX) levels by fluorescence confocal microscopy and hyperspectral imaging. Excess tumor tissue may be stored in a skin cancer tissue bank. Surface measurements (from a total of 5 surface sites) of PpIX fluorescence are taken at baseline and at 2 hours after ALA application using an optical fiber-based hand-held dosimeter.