Abstract
Photodynamic therapy (PDT) is a treatment modality using a photosensitizer, light and oxygen to cause photochemically-induced selective cell death. Topical PDT is most suitable for thin lesions such as superficial basal cell carcinoma and actinic keratoses in dermatology. Results with PDT as treatment of thicker lesions such as nodular basal cell carcinoma appear to have a limited role because the photosensitizer or the light cannot penetrate deeply enough into the thicker tumor volume. In this preliminary study we use intralesional administration of 5-aminolevulinic acid to enhance the efficacy of the photosensitivity of nodular basal cell carcinomas, thus improving clinical cure.