Radiotherapy treatment for breast cancer

How does radiotherapy work?

Radiotherapy kills cells by using X-rays to damage the cells in the body that are growing. Fortunately in the normal breast only a few cells are growing at any one time whereas in a cancer there are many more growing cells so radiotherapy produces much more damage to the cancer cells than the normal tissue. Radiotherapy is used frequently after women have had breast surgery.

Radiotherapy can be given:

• after breast-conserving surgery because it has been shown that it dramatically reduces the chances of cancer returning

• after mastectomy, but it tends to be restricted to women in whom the chances of the cancer returning without radiotherapy are significant

• to the lymph glands under the arm if only some of the lymph glands have been removed and these are affected by cancer

• to control some cancers not suitable for surgery, for example it can dry up cancers that are bleeding

• to shrink cancers before an operation

• to treat cancers that recur or spread to other parts of the body (bones or brain)

• to the lymph nodes in the lower neck (supraclavicular region) and to the nodes behind the breast bone known as the internal mammary nodes if these are affected or are at risk of being affected.

Who gets radiotherapy after mastectomy?

Studies have shown that radiotherapy after mastectomy in some women not only reduces the chances of the cancer returning but also improves survival. If you have a large cancer or involved nodes, or the cancer is very close to the back of the breast making it more difficult for the surgeon to get a good clear margin, you are more likely to receive radiotherapy after mastectomy. Trials are ongoing to try to identify exactly who benefits and, more importantly, who can safely avoid radiotherapy. After mastectomy radiotherapy can be given to the chest wall, under where the breast was, to the nodes alongside the breastbone (internal mammary nodes) and to the nodes in the axilla and supraclavicular region.

Side effects

There are relatively few side effects from radiotherapy. You may find that you become tired more easily. A few days after starting radiotherapy you may also find that your skin looks red and feels a little sore, rather like you have spent too much time in the sun.

Towards the end of treatment you can also get some bleeding from the treated skin. As with sunburned skin, your skin can feel sore when you put water on it. Generally radiotherapists prefer women to keep the treated area dry and apply local creams.

You should follow the advice given by your own radiotherapist as to how your skin is managed. You need to make sure that you are careful about not exposing radiotherapy-treated skin to the sun. If you do, you need to use sun block.

Some patients who have radiotherapy after breast surgery or to treat a breast cancer do get a slight cough. This is caused by the fact that when radiotherapy is given to the breast a small part of the lung underneath the breast also receives some of the radiotherapy dose. This can cause slight scarring in the lung, which results in irritation and development of a cough.

Very occasionally you can also become breathless. There are good treatments for this so, if you experience these problems, discuss with your doctor. These symptoms usually settle quickly when suitable treatment is started.

How is radiotherapy given?

Radiotherapy is a course of treatment given in the hospital radiotherapy department. It is usually given daily from Monday to Friday and lasts between three and six weeks.

Most radiotherapy is given as external radiotherapy. This means that nothing is in contact with your skin. Another option is to give internal radiotherapy by placing wires or a balloon containing radioactivesubstances into the breast. These wires and balloons are placed under general anaesthetic.

It is possible to give radiotherapy during surgery – known as intraoperative radiotherapy. A balloon or device can also be placed in the breast to deliver radiotherapy to a part of the breast after surgery. These types of local radiotherapy are currently undergoing trials. The results so far look promising, but it will be necessary to wait some years to find out if they are safe in the long term.

Planning your treatment

Your first visit to the radiotherapy department will be a planning visit. You will be asked to lie under a machine called a simulator which then takes X-rays and scans of the area that is going to be treated. Planning usually includes a CT scan, so the exact doses and direction of the beams to be used can be worked out.

These scans and X-rays allow the doctors to work out exactly how the treatment should be delivered. Often marks will be placed on your skin to help the radiographer who gives the treatment to position you accurately when you attend for your radiotherapy.

If you are having radiotherapy to the breast you will need to have good movement of your shoulder and arm. If the movement of your shoulder is limited it is important to inform your doctors so that you can get some help from a physiotherapist to improve the range of movement so radiotherapy can be given effectively.

As well as a standard dose of radiotherapy, women who have had a lumpectomy may also be given an extra dose to the localised area around where the cancer was situated in the breast. This is known as a boost.

This extra dose appears to be more important in younger rather than older women and significantly reduces the chances that the cancer will return in the breast. The boost is usually given as an extra few days at the end of treatment using the radiotherapy machine but it can also be given by placing wires in the breast – called interstitial radiotherapy.

KEY POINTS

• Radiotherapy is usually given to the breast after a breast cancer lump has been removed

• Radiotherapy is sometimes given after mastectomy to the remaining tissue on the chest and to the lymph nodes in the armpit or neck if they are involved with cancer

• A course of radiotherapy usually lasts from three to six weeks