Photodynamic therapy for head and neck cancer

Photodynamic therapy| uses a combination of laser light of a specific wavelength and a light-sensitive drug to destroy cancer cells.

The light-sensitive drug (the photosensitising agent) is injected into a vein. It circulates in the bloodstream and is taken up by cells throughout the body. The drug is taken up more by cancer cells than healthy cells. It doesn't do anything until it is exposed to laser light of a particular wavelength. When a laser is shone on to the cancer, the drug is triggered to interact with oxygen, which then destroys the cancer cells.

There is a delay of four days between the injection and the activation of the drug using laser light. The laser light used in PDT is focused through a fibre-optic tube, and is shone for only a few minutes. The doctor holds the fibre-optic tube very close to the cancer so that the correct amount of light is delivered and the PDT causes the minimum amount of damage to normal, healthy cells.

In early-stage cancer of the head and neck PDT may be used to try to cure the cancer and is usually given as part of research trials. PDT can sometimes be used to shrink an advanced cancer to reduce symptoms, but it cannot cure an advanced cancer.

Your doctor can advise you whether PDT may be an appropriate treatment in your situation.

Side effects of PDT

After injection of the photosensitising drug, people are highly sensitive to light. They need to take precautions to avoid exposure of their skin and eyes to direct sunlight or bright indoor lighting for a specified period (usually about two weeks). Appropriate clothing and eyewear must be worn to prevent reactions to light.

Other temporary side effects may include pain| (which can be controlled with painkillers), swelling of the treated area, difficulty in swallowing and bleeding.

We have further information about PDT| which gives more information.