What is Photodynamic Therapy (PDT)?
Photodynamic therapy (PDT) is a treatment for non-melanoma skin cancers. It works by using oxygen and light to create a photochemical reaction which selectively destroys cancer cells.
A topical photosensitising agent called Metvix concentrates in cancerous cells which become active when light of a certain wavelength is directed towards it. The reaction between the agent, light and oxygen kills the cancer cells.
What is involved in Photodynamic Therapy (PDT)?
Patients are booked in for two appointments on a day as part of a session of treatment, the first session to prepare the skin, the later session to treat the skin. A nurse will clean the area to be treated and will gently scrape the skin using a curette surgical device. This increases the amount of drug the skin can absorb.
A topical cream called Metvix (the photosensitiser) is then applied to the area in a fine layer and a dressing is placed over the area.
The area must then be kept away from sun exposure for a 3 hours period. Where the face is being treated patients may be placed in a preparation or recovery room to wait. Alternatively it may be possible to cover the area with clothing or a hat and the patient may be able to leave the clinic and later return.
Three hours later the dressing and cream is removed. The light source Actilite is set at a specific distance from the skin and shone onto the treated area. Depending on the size of the area being treated, it may be necessary to move the lamp during the treatment. Treatment typically takes 30 minutes. The nurse may use a cooling water or air spray to make the treatment more comfortable.
For actinic keratosis one treatment session is required. For superficial bccs it is necessary to return for a second treatment 7 days later.
What are the risks or potential side effects of Photodynamic Therapy (PDT)?
An immediate side effect of PDT is the treated area being sensitive to light. This may cause a burning and stinging sensation, swelling and redness, crustiness itchiness, and peeling and blisters.
The sensitivity normally lessens after 24 hours but it is recommended to keep the treated area protected from light exposure using a dressing. A local anaesthetic spray is sometimes applied during the procedure to ease the pain.
A sunburn reaction, which can include blistering may occur as the cancer cells die off and this may take several weeks to heal. It can cause some scarring and loss of pigmentation.
Is there any preparation needed before having Photodynamic Therapy (PDT)?
Avoid exposure to sunlight for 48-72 hours before the treatment. Bring along loose fitting clothing which will cover the treated area after leaving the surgery to protect from direct sunlight and avoid further inflammation/irritation.
What aftercare is required for Photodynamic Therapy (PDT)?
A review with a Dermatologist is required 3 months later to ensure that the non-melanoma skin cancer has been fully treated.
What is the cost of Photodynamic Therapy (PDT)?
Photodynamic therapy (PDT) is priced based on the size of the area being treated (normally up to 3 lesions or 4 and more) and the pricing is per day of treatment. So for patients having treatment 7 days apart, they would be charged on each day.
Pictures of Photodynamic Therapy (PDT)