Photodynamic therapy or PDT is also known as blue light therapy, and it’s one of the treatment options we offer here at Associated Dermatologists. It’s commonly used to treat pre-cancerous lesions in a clinical setting. During a typical treatment, a light-sensitive agent is applied to the skin, which is then activated with a special blue light. The light source operates at a targeted wavelength used to activate the topical agent.

Exposure to the blue light causes the topical agent to react with oxygen, forming a chemical that kills cancerous cells. The drug remains in active cells longer, so it will be more present in cancerous cells after a period of time. That is why there is generally a period of time between drug application and treatment with the blue light. It’s referred to as the drug-to-light-interval, which ensures your treatment targets the appropriate cells. While PDT may be used to treat some localized cancers, it is more commonly used in the treatment of precancerous cells. Your doctor can help determine if PDT is an appropriate treatment option for you.