Radiotherapy for chronic myeloid leukaemia (CML)

Radiotherapy is a treatment that uses high energy rays, similar to X-rays, to kill cancer cells. There are different ways of giving radiotherapy. External beam radiotherapy means the treatment is given from outside the body, using a large machine, called a linear accelerator.

Radiotherapy is only used in particular circumstances in chronic leukaemia. Doctors generally only use it as part of a bone marrow or stem cell transplant. For this, you have radiotherapy to the whole body. Doctors call this whole body irradiation or total body irradiation (TBI). After chemotherapy, you have the radiotherapy to kill off your remaining bone marrow cells. You then have your own marrow, or your donor marrow given through your drip. TBI is usually just 1 or 2 treatments.

There are different ways of doing bone marrow or stem cell transplants. Not all of them use radiotherapy. You may have more chemotherapy instead.

Radiotherapy to the spleen for CML

Your doctor may suggest radiotherapy if your spleen is very enlarged. An enlarged spleen can be uncomfortable or painful. Radiotherapy can help to relieve these symptoms by shrinking the spleen. You usually have treatment 3 times over a week. This works well for most people. If your spleen enlarges again, you can usually have the treatment once again, because you only need a very low dose.

Side effects of TBI 

If you have TBI, it is highly likely that you will have

• sickness
• tiredness

Your doctor will make sure you have anti sickness drugs to help you. TBI also causes hair loss, but it is likely that you will have lost your hair as a side effect of the high dose chemotherapy. You will be at a high risk of infections for a while afterwards and will be in a single room in hospital. There is information about the procedures for bone marrow and stem cell transplants in the cancer treatment section of CancerHelp UK. And more about how transplants are used for chronic myeloid leukaemia in this section.

Side effects of radiotherapy to the spleen

Generally, radiotherapy can cause a skin reaction in the treatment area. This is similar to sunburn. You may also feel increasingly tired as you go through a course of treatment. The radiotherapy dose you have for an enlarged spleen is very low. Also the treatment course is short, so it is unlikely that you will have bad side effects. You may feel sick, as well as tired. Your blood cell counts may fall afterwards. But these usually recover quite quickly.

TBI can have long term effects. It can affect your skin and you will need to be extra careful in the sun for several months after treatment. Talk to your specialist about exact precautions you should take to protect your skin in the sun.

There are other long term effects that are more permanent. The treatment can cause

• Clouding of the lens of the eye (cataracts)
• Loss of ability to have a baby or father a child
• A small risk of developing a second cancer later in life

Many years after treatment, it is possible that you will develop cataracts. This means the lens inside your eye clouds over and it becomes increasingly difficult to see. Your doctor may arrange a shield for your eyes during the treatment to try to prevent this side effect. These days, cataracts are fairly easy to treat with surgery. The clouded lens is removed and a manmade one put in its place.

Unfortunately, you will be unable to get pregnant or father a child after TBI and high dose chemotherapy. In women, the treatment is likely to cause an early menopause. Men may be able to bank sperm before their treatment. There is more about infertility and TBI in the about bone marrow and stem cell transplants section of CancerHelp UK.

Bone marrow and stem cell transplants can increase your risk of getting a second cancer. Not surprisingly, this is a worrying thought for many people. Remember that it is a very small risk. And it is less of a risk to your health than the chronic leukaemia you already have.

If you would like more general information on radiotherapy, look at the main radiotherapy section in CancerHelp UK. It will tell you more about this type of treatment including

• What radiotherapy involves
• Planning radiotherapy treatment
• Possible radiotherapy side effects
• Follow up care after radiotherapy

For further information and support contact one of the chronic leukaemia organisations. They will be happy to help. Some have free fact sheets and booklets they can send you.

You can also contact our cancer information nurses. They would be happy to help.