Photodynamic therapy (PDT) is a treatment that involves the use of a light-sensitive medication and a light source to destroy abnormal cells. PDT is ideal to treat parts of the body where a light source can easily reach including the face, scalp, hands, feet, chest or legs.
Some PDT treatments utilise sunlight, while others require a specific wavelength of light to be placed over the affected area. When the light is applied, the photosensitising agent begins to react to kill the cancerous or precancerous cells.
Studies have shown that PDT can be as effective as surgical excision when treating certain kinds of cancers and pre-cancerous lesions. The process is extremely precise, as it targets only the affected area, and has the advantage of being less invasive than surgery with little to no scarring.
Conditions treated with PDT include:
- Bowen’s disease - otherwise known as IEC or superficial SCC
- Basal Cell Carcinoma (BCC)
- Actinic Keratosis - dry, scaly patches of skin caused by damage from years of sun exposure, that could become cancerous if not treated.
Our clinic uses either one of two sensitising agents: Metvix or 5-Aminolevulinic Acid (ALA). The costs of these treatments varies depending on the treatment type and the size of the area affected.
Depending on the size of the area affected and the type of cells being targeted, there are a number of treatment options:
ALA (5-AMINOLEVULINIC ACID)
ALA used to treat large areas of Actinic Keratosis. It is application process can take up to 45 minutes, where the ALA is applied directly on to the lesion. This is followed by a waiting period of between 2-3 hours indoors before the ALA is activated by either a blue or red light for approximately 15 minutes.
ALA is not recommended for patients with skin sensitivity to blue light, porphyria, or anyone with an allergy to porphyrins.
Localised areas Actinic Keratosis can be treated by the application of an ALA patch. The patch will specifically target the affected area will remain in place for about 4 hours. The area will then be exposed to a red light source for 15 minutes.
METVIX (METHYL ESTER OF ALA)
Metvix is another form of ALA, developed for increased uptake by the skin cancer cells in superficial Basal Cell Carcinomas and Bowen’s Disease. It is also approved for treatment of some types of Actinic Keratoses of the face and scalp.
On the day of treatment, the doctor will usually scrape the area with a scalpel before applying Metvix cream. After about 3 hours the cream will be washed off. The area will then be exposed to a red light source for 15 minutes. PDT using this method of Metvix application is carried out over two cycles about one week apart.]
METVIX DAYLIGHT ACTIVATED
Metvix Daylight used to treat large areas of Actinic Keratosis. On the day of treatment the doctor will usually scrape the area with a scalpel before applying Metvix Daylight Activated cream. This will take approximately 45 minutes. The area must then be exposed to sunlight for at least 2 hours. The cream will be washed off.
The benefits of Metvix Daylight Activated is that it utilised natural sunlight to activate the Metvix without the need for an artificial light source, which can at times become uncomfortable. However, in the case where treatment occurs on a day where natural sun levels are low, an artificial light source can be applied with the same results.
What to expect from your PDT treatment
Prior to Treatment
Having PDT does require a number of hours between the application stage and the activation stage to ensure adequate absorption of the photosensitising agents. You will need to attend the clinic for both stages of treatment, however you may return home for period in between.
Application requires that the area be treated in clean and, for men, shaven. Please wash the area, without applying any moisturisers, sunscreen or makeup.
You will be asked to wear protective eyewear during the activation stage, to protect your eyes from the light source. The area will then be exposed to the light source for the recommended time period. You may feel a slight discomfort during this stage. This is caused by the reaction taking place between the photosensitising agent and oxygen, and is completely normal. Our nurse will be applying the light and will supervise the entire process.
After your treatment, your skin will become more sensitive. Try to avoid exposure to sunlight or bright indoor light for at least 48 hours. Use a soap-free cleanser to wash the treated area 2 – 3 times per day, followed by a soothing gel, such as Aloe Vera, which can be stored in the fridge.
5-7 days after your treatment you can start to apply moisturiser twice a day, and continue for this for the next four weeks. A sunscreen of at least 30+ should be applied to the area every morning, as the skin will be more sensitive to light. The following products are recommended and are available at our clinic:
- NeoStrata Facial Cleanser
- ASAP Soothing Gel
- NeoStrata Bionic Face Serum
- NeoStrata Daytime Protection Cream
- La Roche Posay Sunscreen
There are a number of common side-effects that you may experience after your treatment. These will settle within a few weeks of treatment and include:
- Associated pain and swelling
- Burning sensation (ranging from moderate to severe)
- Drying and cracking of skin, scabbing, scaling, skin blisters, pimples
- Flushing, redness, loss of skin colour
- Itching, stinging, tenderness
Any pain you experience can be relieved with Paracetamol, Ibuprofen or Panadeine. Remember, it is normal to see a reaction and these side effects are common. However, if you are concerned, or feel you are having a stronger reaction than expected, please phone the clinic immediately to arrange a consultation with your treating doctor.