Photodynamic therapy for lung cancer

Photodynamic therapy (PDT) uses a photosensitising drug combined with a laser light to destroy cancer cells. It may be used for people with small early stage non small cell lung cancer who don't want to have conventional surgery, or can't have surgery for one of the following reasons

• There are tumours in both lungs
• Other medical conditions make having an anaesthetic impossible
• The cancer has come back in the lung after previous surgery

You may also have photodynamic therapy if you have advanced lung cancer and the tumour is blocking an airway and making you breathless.

You can have PDT along with other types of lung cancer treatment. It can be done more than once if needed.

You usually have PDT as an outpatient procedure. In the first step, your doctor injects a photosensitising drug into your bloodstream. Cells all over the body absorb the drug but it stays in cancer cells longer than in normal cells. The drug makes the cells sensitive to laser light. About 2 to 4 days after the injection most of the drug has left normal cells but stays in the cancer cells.

In the second step a few days later, you go into the outpatient clinic. Under local anaesthetic or general anaesthetic, you have a bronchoscopy. The doctor puts a tube down the bronchoscope that shines a very bright light at the tumour. The light triggers the drug to destroy the cancer cells. The PDT also seems to shrink tumours by damaging blood vessels in the tumour so that it can't get the nutrients it needs. Researchers think that PDT might also activate the immune system to attack the tumour cells.

You may need to stay in hospital overnight after the procedure. You need to have another bronchoscopy 48 hours later to remove the damaged tissue from the area where the tumour was. This is called debridement.

An advantage of PDT is that it does not cause much damage to healthy tissues. It has a few side effects, but these are often quite mild. Some people feel sick or have a metallic taste in their mouth on the day of the drug injection.

The most difficult side effect is that the light sensitising drug makes your skin sensitive to light for around 6 weeks or more after treatment. You have to avoid bright sunlight and bright indoor light during this time. If you have to go outside, you will need to cover all your skin and wear sunglasses. Indoors, you should have your curtains drawn during the day when the sun is brightest. 

You can go outdoors safely in the early morning or after the sun has gone down. If your skin is exposed to bright light it may become blistered, red or puffy. Check carefully with your doctor or nurse before you go home and make sure you understand all the restrictions you will have to follow.

After the bronchoscopy and light treatment you may have some discomfort or pain in the treatment area. Your doctor or nurse will prescribe painkillers for you to take for a few days. You may need to take it easy for the first few days and avoid any strenuous activity. Your throat may feel sore when you swallow for a while. You may also cough up some blood and mucus for a few days.

You can ask your doctor or specialist nurse for written information about photodynamic therapy. You can also phone the Cancer Research UK nurses on freephone 0808 800 4040, from 9am to 5pm, Monday to Friday.

Our lung cancer organisations page has details of people who can give information about photodynamic therapy for lung cancer. Some organisations can put you in touch with a cancer support group. Our lung cancer reading list has information about books and leaflets on lung cancer treatments.