Photodynamic therapy (PDT)
PDT is a biooxidative therapy
Light is utilized to activate a photosensitizer chemical applied to a skin problem (or given as an IV or pill to reach non-topical areas) to destroy harmful cells. To be effective light must be able to reach the problem area, where it will destroy harmful cells.Light is unable to penetrate very far into skin.
What is PDT used for?
Clinically used for isolated skin cancers and other areas where light can be applied
- FDA-approved for treatment of many skin cancers and pre-cancers usually in a clinical setting. E.g superficial or nodular basal cell carcinoma and Bowen’s Disease, Efficacy of photodynamic therapy for the treatment of Bowen’s disease: An updated systematic review and meta-analysis of randomized controlled trials, with a cure rate of 70-90%. An oxidizing, light-sensitizing agent, such as topical 5-aminolevulinic acid (5-ALA), is applied to the lesion. The 5-ALA is then activated by a strong blue light. Theoretically, this will selectively destroy BCCs while causing minimal damage to surrounding normal tissue.
- Used to treat esophageal cancer, early-stage squamous cell cancer, head and neck cancer
- Cutaneous T-cell lymphoma
- Age-related macular degeneration
- Acne, actinic keratosis
- Non-small cell lung cancer
What PDT is not used for
- Areas where light can’t reach. Can only penetrate to just under the skin
- Cancers that have spread to many areas
Side-effects of PDT
Typically causes some redness, pain, and swelling. Patients must strictly avoid sunlight for at least 48 hours to prevent UV exposure further activating the medication and causing severe sunburn.
