Photodynamic Therapy
Pronunciation: foh-toh-dye-NAM-ik THER-ah-pee
A treatment modality combining photosensitizing agents with specific wavelength light to selectively destroy abnormal cells. Used for superficial skin cancers and pre-cancerous lesions.
Full Definition
Photodynamic therapy (PDT) utilizes the interaction between photosensitizing medications, molecular oxygen, and specific wavelength light to generate reactive oxygen species that selectively destroy target cells. The process involves topical application of photosensitizers such as aminolevulinic acid (ALA) or methyl aminolevulinate, followed by an incubation period allowing preferential uptake by abnormal cells. Subsequent illumination with appropriate wavelength light activates the photosensitizer, creating cytotoxic singlet oxygen. PDT is particularly effective for actinic keratoses, superficial basal cell carcinomas, and Bowen's disease, offering excellent cosmetic outcomes with tissue selectivity that spares normal skin architecture.
Usage
Usage note: Specify photosensitizer and light source when documenting treatment.
In Context
- "Photodynamic therapy was selected for treatment of multiple facial actinic keratoses." — treatment planning note
- "The patient experienced expected erythema and peeling following photodynamic therapy." — post-treatment assessment