Photodynamic therapy for advanced oesophageal cancer

PDT is a relatively new treatment. It is one option for treatment doctors can use to relieve symptoms of oesophageal cancer, such as difficulty swallowing. In PDT, you have a drug called a photosensitising agent injected into your bloodstream. The drug circulates throughout your body and is absorbed by the body’s cells.

The drug makes cells sensitive to light. When the area to be treated is exposed to laser light, the cells in the beam are killed. The laser light used in PDT flows down very thin glass strands called fibre optics. The doctor passes the fibre optic cable down an endoscope - a sort of flexible telescope your doctor uses to look inside your throat. The doctor places the fibre optic cable close to the cancer to deliver the proper amount of light. When the light shines on the cancer cells, the drug is activated and kills the cells.

For difficulty swallowing, PDT is another option to straight laser therapy. This is where a surgeon uses a laser to burn away tumour that he or she can see in the oesophagus. You will need to talk to your doctor about the treatment options that are most suitable for you - there may be particular reasons why one is better than the other in your case.

In January 2007, NICE issued guidance to say that PDT was safe enough, and worked well enough, for use on the NHS. NICE say there is evidence that it is slightly more likely to shrink tumours than laser therapy. But for easing swallowing, there is not much difference between them. There is a slightly lower risk of causing a tear in the oesophagus with PDT than with laser therapy. But there is a risk of causing narrowing of the oesophagus (stricture) that may later need stretching.

First you have to go to the hospital to have an injection of the light sensitising drug. You would usually have this 2 to 4 days before you have the actual treatment. This gap allows the drug to circulate throughout your body.

Remember - once you have had the injection, you will become increasingly sensitive to light. It is not just the treatment area that is sensitive - it is your whole body. There is information below about taking precautions to avoid skin damage.

When you are due to have your treatment, you will have to come back to the hospital to the endoscopy suite in the X-ray department. You will have a sedative before the treatment starts, so it is a good idea to take someone with you to the hospital to be with you on the journey home. Do not drive yourself to the hospital.

The procedure is the same as for the endoscopy you probably had when you were diagnosed. You have your sedative, and a spray to numb the back of your throat. Then the doctor will put the end of the endoscope into your mouth and ask you to swallow it.

The doctor uses the endoscope to get the light cable into exactly the right place, next to the tumour. The treatment only takes a few minutes. After the endoscopy, you have a rest to get over the sedative. Then you can usually go home. Your doctor will give you some painkilling medicine to take at home.

An advantage of PDT is that it does not damage healthy tissues. It does have a few side effects, but these are often quite mild. The most difficult side effect to cope with is light sensitivity. The side effects of PDT are

• Sensitivity to light for around 6 weeks or more after treatment
• Blistered, red or swollen skin if exposed to bright light
• Feeling or being sick
• Metallic taste in the mouth
• Soreness on swallowing

The light sensitising drug circulates through your whole body. So all of your skin will become sensitive to light. You will have to avoid bright sunlight and bright indoor light. If you must 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.

Most of these side effects are very short term. If you have the metallic taste or feel sick, this will probably only last for the day you have the drug injection, at most. The soreness on swallowing will last a few days. But your skin may remain sensitive to bright light for up to 6 weeks. Check this carefully with your doctor before you go home and make sure you understand all the restrictions you will have to follow.