Radiotherapy for DCIS

Radiotherapy uses high-energy rays called radiation to treat cancer. It destroys cancer cells in the area where the radiotherapy is given, while doing as little harm as possible to normal cells.

Radiotherapy helps to reduce the risk of DCIS coming back in the area it is given to. You have it after surgery to destroy any remaining DCIS cells. It also helps reduce the risk of invasive cancer developing.

After breast-conserving surgery, your cancer doctor will usually recommend you have radiotherapy to the breast if the DCIS is high grade. It is sometimes given for larger intermediate-grade DCIS. You will not usually be recommended radiotherapy if the DCIS is low grade.

You usually start radiotherapy about 4 to 6 weeks after surgery.

Your cancer doctor and breast care nurse will explain why radiotherapy is recommended for you. It is important to talk to them about any concerns you have.

Macmillan is also here to support you. If you would like to talk, you can:

• Call the Macmillan Support Line for free on 0808 808 00 00
• Chat to our specialists online
• Visit our breast cancer forum to talk with people who have been affected by breast cancer, share your experience, and ask an expert your questions.

You have the radiotherapy as an outpatient. It is usually given using equipment that looks like a large x-ray machine. This is called external beam radiotherapy (EBRT) or external radiotherapy. The person who operates the machine is called a therapy radiographer. They will give you information and support during your treatment.

You usually have radiotherapy as a series of short daily treatments. Each treatment is a called or a session. You usually have sessions from Monday to Friday, over 1 to 3 weeks.

Some people may be offered more treatment to the area where the DCIS was. This is called a radiotherapy boost. Your cancer doctor will tell you how many treatments you will need.

If you have radiotherapy to your left breast, you will usually be asked to take a deep breath and hold it briefly. This is called deep inspiration breath hold (DIBH). You do this at each of your planning and treatment sessions. DIBH helps protect your heart during radiotherapy treatment to your left side.

Your heart is behind the left side of your chest. DIBH moves the heart away from the area being treated. It also keeps you still and reduces the risk of late effects. A website called respire.org.uk explains more about DIBH.

You may have intensity-modulated radiotherapy (IMRT). This is another type of external radiotherapy. It shapes the radiotherapy beams and allows the radiographer to give different doses of radiotherapy to different areas. This means you have lower doses of radiotherapy to healthy tissue surrounding the tumour.

External radiotherapy does not make you radioactive. After your treatment, it is safe for you to be with other people, including children.

Your radiographer will explain what happens during treatment. At the beginning of each session, they make sure you are in the correct position. Usually, you lie with your arms above your head. If your muscles and shoulder feel stiff or painful, a physiotherapist can show you exercises that may help.

When you are in the correct position, the radiographer leaves the room and the treatment starts. The treatment is not painful and only takes a few minutes.

The radiographers can see and hear you from outside the room. You can usually talk to them through an intercom, if you need to.

During treatment, the radiotherapy machine may stop and move into a new position. This is so you can have radiotherapy from different directions.

If your muscles and shoulder feel stiff or painful, a physiotherapist can show you exercises that may help.

Radiotherapy to the breast may cause side effects that happen months or years after radiotherapy. These are called late effects. Newer ways of having radiotherapy are helping reduce the risk of late effects. If you are worried about late effects, talk to your cancer doctor, breast care nurse or radiographer.

The most common late effect is a change in how the breast or chest area looks and feels.

Radiotherapy can damage small blood vessels in the skin. This can cause red, spidery marks to show. These are called telangiectasia. They may be more common if you had boost doses of radiotherapy.

After radiotherapy, your breast may feel firmer and shrink slightly in size. If your breast is noticeably smaller, you can have surgery to reduce the size of your other breast. If you had breast reconstruction using an implant before radiotherapy, you may need to have the implant replaced.

You may find the treated area sore or uncomfortable for some time. This usually improves over years. It is not uncommon to get pain in the muscle or ribs at the edge of the breast if you overdo things. Very rarely, radiotherapy may cause lung problems or problems with the ribs.

If you have radiotherapy to the left breast, very rarely it can cause heart problems. Tell your cancer doctor, nurse or radiographer if you notice any problems with your breathing, or have any pain in the chest area. We have more information about the late effects of breast cancer treatment.