Photodynamic Therapy
Pronunciation: foh-toh-dy-NAM-ik THER-ah-pee
A treatment modality combining a photosensitising agent with a specific light source to destroy target cells; used in cosmetic dermatology for actinic keratoses, acne, and skin rejuvenation.
Full Definition
Photodynamic therapy (PDT) involves the topical or systemic application of a photosensitiser—commonly 5-aminolaevulinic acid (5-ALA) or methyl aminolaevulinate (MAL)—followed by activation with a defined wavelength of light (red, blue, or broadband). The photochemical reaction generates reactive oxygen species that selectively damage abnormal or metabolically active cells. In cosmetic dermatology, PDT is used for field treatment of actinic keratoses, inflammatory acne, sebaceous gland reduction, and as an adjunct skin-rejuvenation procedure. Editors should ensure that the photosensitiser identity, concentration, incubation time, and light source specifications are all documented when editing clinical study methods or protocol documents.
Usage
Usage note: Expand to 'photodynamic therapy (PDT)' on first use. Specify photosensitiser and light source in all clinical documentation. Do not conflate with LED therapy or IPL.
In Context
- "The patient underwent three sessions of photodynamic therapy with MAL and red-light activation for field-directed actinic keratosis management." — Clinical case report
- "PDT must not be confused with IPL in this document; they rely on entirely different photobiological mechanisms." — Manuscript editorial comment