Radiotherapy to treat DCIS
Radiotherapy treats cancer by using high-energy rays to destroy the cancer cells, while doing as little harm as possible to normal cells. It reduces the risk of DCIS coming back and of developing an invasive cancer in that breast.
Radiotherapy is given after surgery. The doctors will recommend whether you need radiotherapy based on:
the size of the area of DCIS
whether the margins of the normal tissue removed were clear enough
whether you had a breast lump or discharge from the nipple.
If you’ve been advised to have radiotherapy, your cancer specialist will explain why it’s recommended in your situation. It’s important to talk about any concerns you may have with your specialist and your breast care nurse.
Radiotherapy is effective for all types of DCIS (high- and low-grade). However, as high-grade DCIS is more likely to become an invasive cancer, radiotherapy is more beneficial to people with a higher grade DCIS.
We have more information about radiotherapy treatment available.
Radiotherapy is normally given in the hospital radiotherapy department as a series of short daily sessions. It uses equipment similar to a large x-ray machine. Each treatment session takes 10-15 minutes and they are usually given Monday-Friday, with a rest at the weekend. Before you start treatment, your doctor will explain everything to you and discuss any possible side effects.
A course of radiotherapy for DCIS usually lasts five weeks. It’s given to you as an outpatient, so you come in for treatment and can then go home again afterwards.
Radiotherapy doesn’t make you radioactive, and it’s perfectly safe for you to be with other people, including children, after treatment.
To make sure the radiotherapy is as effective as possible, it has to be planned carefully. This is to ensure the radiotherapy rays are aimed precisely at the treatment area and cause the least possible damage to the surrounding healthy tissues.
Treatment is planned by a clinical oncologist. The planning is very important and may take a few visits. A CT scan of the area to be treated is often done as part of planning.
Marks will usually be drawn on your skin to help the radiographer (who gives you your treatment) position you accurately and to show where the rays will be directed. These marks must stay visible throughout your treatment. Permanent marks (like tattoos) may be used. These are tiny, and will only be done with your permission. You may feel a little discomfort while they’re being done.
Radiotherapy is normally given to the whole breast. You may also be given an extra dose to the exact area where the DCIS was. This is known as a booster dose.
At the beginning of each session of radiotherapy, the radiographer will position you carefully on the couch and make sure you’re comfortable. During your treatment, you’ll be alone in the room, but you can talk to the radiographer who will watch you from the next room. Radiotherapy is not painful, but you’ll have to lie still for a few minutes during the treatment.
You’ll need to be able to position your arm so that the radiotherapy machine can give the treatment effectively. Sometimes, your muscles and shoulder joint may feel stiff. If you can’t move your shoulder normally, it may be painful or difficult to give the treatment.
A physiotherapist may teach you some exercises to make the position for treatment feel easier.
This video is of an oncologist explaining how radiotherapy is given and showing the machine.
Side effects of radiotherapy
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You may develop side effects over the course of your treatment. These usually disappear gradually over a few weeks or months after treatment finishes. Your doctor, nurse or radiographer will discuss this with you so you know what to expect. Let them know about any side effects you have during or after treatment, as there are often things that can be done to help.
It’s not unusual to feel worse before you start to feel better after radiotherapy. Some people can find this a very difficult time and they may feel low or even depressed for a while. The clinical oncologist can advise you about what to expect.
You may develop red, dry or itchy skin in the area being treated. If you have dark skin, it may get darker or have a blue or black tinge. Your doctor can prescribe creams to soothe your skin if it becomes sore and flaky. Usually, any skin reaction settles down 2-4 weeks after radiotherapy. You’ll be given advice on how to look after your skin during radiotherapy.
Here are some tips that may help ease skin irritation:
Don’t use perfumed soaps, talcum powder, deodorants, antiperspirants, creams or lotions unless they’ve been prescribed by your cancer specialist.
Have showers rather than baths and turn away from the spray as it can be painful on your skin. If you do have a bath, avoid soaking the affected area for too long.
Pat the area dry gently with a soft towel - don’t rub or dry the area with a hairdryer.
Wear loose clothing as this may be more comfortable and less likely to irritate your skin.
It’s very important to avoid exposing the treated area to strong sunshine for at least a year after treatment finishes. Use sunscreen with a high sun protection factor (SPF) of at least 30 to protect your skin whenever it’s exposed.
You’re likely to feel tired during treatment and this may continue for a month or two after it finishes. Pace yourself and save your energy for the things you have to do, and that you enjoy. Get plenty of rest, but balance this with some physical activity such as short walks, which will give you more energy.
We have information on coping with tiredness (fatigue).
Aches and swelling
You may notice a dull ache or shooting pains in the breast, which lasts for a few seconds or minutes. Sometimes, your breast might become swollen during treatment, but this usually improves quickly after treatment is finished. Some women continue to have occasional aches and pains in the breast area after radiotherapy.
Long-term side effects
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Radiotherapy to the breast can sometimes lead to long-term side effects, but most of these are rare.
How the breast looks and feels
After radiotherapy, some women develop red ‘spidery’ marks (telangiectasia) on the skin because small blood vessels have been damaged. These affect how the breast looks but are harmless. Your skin may also have a slightly darker tone. It’s not unusual for the breast to feel firmer, and over months or years, it may shrink slightly in size.
Let your surgeon or breast care nurse know if you’re unhappy with the shape of the treated breast or if it isn’t the same size as your other breast. There are often reconstructive techniques that can be done to improve this.
Other long-term side effects
Radiotherapy may cause a small amount of permanent scarring to your lung. If your lungs are healthy, this will not cause you any symptoms. The doctors take a lot of care when planning radiotherapy to minimise the amount of radiation that your lung receives.
Although some women may worry about the effects of radiotherapy on the heart, it is now very carefully planned to avoid including the heart in the treatment area. It very rarely causes heart problems, and only women who had DCIS in their left breast are at risk.
We have more information about how lifestyle changes can help you look after your heart.
Rarely, radiotherapy weakens the ribs in the treated area, making them more likely to fracture.
If you’re worried about the risk of developing particular side effects from radiotherapy, talk it over with your cancer specialist.
We have more information about the possible long-term side effects of breast radiotherapy.