Radiotherapy to lymph nodes

If the surgeon removed some lymph nodes from your armpit and they contained cancer cells, you may have radiotherapy to the rest of the lymph nodes.

If you had all the lymph nodes in your armpit removed, you may not need radiotherapy to this area.

Having radiotherapy for breast cancer in men

You will have radiotherapy as an outpatient. It is usually given using equipment that looks like a large x-ray machine. You might hear it called external beam radiotherapy (EBRT).

You usually have radiotherapy as a series of short, daily treatments. These are called sessions. The treatments are given from Monday to Friday, with a rest at the weekend. The person who operates the machine is called a radiographer. They will give you information and support during your treatment.

You usually have radiotherapy for 3 weeks.

External radiotherapy does not make you radioactive. It is safe for you to be around other people, including children, after your treatment.

Planning your radiotherapy treatment

You will have a hospital appointment to plan your treatment. You will usually have a CT scan of the area to be treated. During the scan, you need to lie in the position that you will be in for your radiotherapy treatment.

Your radiotherapy team use information from this scan to plan:

  • the dose of radiotherapy
  • the area to be treated.

You may have some small, permanent markings made on your skin. The marks are about the size of a pinpoint. They help the radiographer make sure you are in the correct position for each session of radiotherapy.

These marks will only be made with your permission. If you are worried about them, talk to your radiographer.

Support from Macmillan

Macmillan is here to support you. If you would like to talk, you can do the following:

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

What is radiotherapy?

Radiotherapy uses high-energy x-rays to destroy cancer cells, while doing as little harm as possible to normal cells.

Normal cells can also be damaged by radiotherapy, which may cause side effects. But careful planning and newer ways of giving radiotherapy have reduced the risk of damage to healthy tissue and nearby organs.

Cancer cells cannot repair themselves after radiotherapy, but normal cells usually can.

You may have radiotherapy to reduce the risk of the cancer coming back in the chest area and in the nearby lymph nodes.

You usually start radiotherapy 4 to 6 weeks after surgery, unless you are having chemotherapy.

Radiotherapy after surgery

Sometimes after surgery, you may be offered radiotherapy to the lymph nodes under your arm.

If you had a wide local excision (WLE), you will usually need radiotherapy to the area where the cancer was removed.

Some men may need radiotherapy after a mastectomy. Your cancer doctor may advise this if:

  • the cancer was large
  • there were cancer cells in the lymph nodes in the armpit
  • there were cancer cells close to the edge of the removed breast tissue.

Treatment sessions

Your radiographer will explain what happens during treatment. At the beginning of each session, they make sure you are in the correct position. 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, your radiographer leaves the room and the treatment starts. The treatment itself is not painful and it only takes a few minutes.

The radiographers can see and hear you from outside the room. There is usually an intercom, so you can talk to them if you need to during your treatment.

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

Side effects of radiotherapy for breast cancer in men

Radiotherapy can cause side effects in the area of your body that is being treated. You may also have some general side effects, such as feeling tired.

After treatment finishes, it may be 1 to 2 or weeks before side effects start getting better. After this, most side effects usually slowly go away.

Your cancer doctor, specialist nurse or radiographer will tell you what to expect. They will give you advice on what you can do to manage side effects. If you have any new side effects or if side effects get worse, tell them straight away.

Skin irritation

Your skin in the treatment area may get red, dry and itchy. Dark skin may get darker or have a blue or black tinge.

Your specialist nurse or radiographer will give you advice on looking after your skin. If it becomes sore and flaky, your doctor can prescribe creams or dressings to help this.

Skin reactions usually start to improve 2 weeks after radiotherapy finishes.

Here are some tips:

  • Do not put anything on your skin in the treatment area without checking with your specialist or radiographer.
  • Have cool or warm shower rather than a bath if you can. Turn away from the spray to protect the treated area.
  • Pat the area dry gently with a soft towel – do not rub.
  • Wear loose clothing that is less likely to irritate your skin.

You need to avoid exposing the treated area to the sun for at least a year after treatment finishes. Use suncream with a high sun protection factor (a minimum of 30 SPF) to protect your skin if it is exposed.


This is a common side effect that may last for up to 2 months after treatment. Try to get plenty of rest and pace yourself. Balance this with some physical activity, such as going for short walks, which will give you more energy.

Hair loss

If you have hair on your chest, you will lose it from the treatment area during radiotherapy. It will grow back after treatment is over.

Aches and swelling

You may have a dull ache or shooting pains in the treated area that last for a few seconds or minutes. You may also notice that the area becomes swollen.

These effects usually improve quickly after treatment. You might still have aches and pains in the area after radiotherapy.

Late effects of radiotherapy for breast cancer in men

Radiotherapy to the breast may cause side effects that happen months or years after radiotherapy. These are called late effects.

Newer ways of giving radiotherapy are helping reduce the risk of these late effects happening. If you are worried about late effects, talk to your cancer doctor or specialist nurse.

Radiotherapy can damage small blood vessels in the skin. This can cause red, spidery marks (telangiectasia) to show on your chest.

It is rare for radiotherapy to cause heart problems. This can only usually happen if you had treatment to your left side. Problems with the ribs in the treated area or with the lungs are also rare. Tell your cancer doctor if you notice any problems with your breathing or have any pain in the chest area.



About our information

  • References

    Below is a sample of the sources used in our breast cancer in men information. If you would like more information about the sources we use, please contact us at

    European Society for Medical Oncology. Primary breast cancer: ESMO clinical practice guidelines for diagnosis, treatment and follow-up. Annals of oncology 26 (supplement 5): v8–v30. 2015. 

    Gradishar WJ, et al. Breast cancer in men. UpToDate online. June 2018.

    Morrow M, et al. Chapter 79: malignant tumors of the breast. DeVita, Hellman and Rosenberg’s cancer: principals and practice of oncology (10th edition). Lippincott Williams and Wilkins. 2014.

    National Institute for Health and Care Excellence (NICE). Early and locally advanced breast cancer: diagnosis and management. July 2018.

    National Institute for Health and Care Excellence (NICE). Advanced breast cancer: diagnosis and treatment. Clinical Guideline 81. February 2009, updated August 2017. 

    Scottish Intercollegiate Guidelines Network. SIGN 134. Treatment of primary breast cancer: a national clinical guideline. September 2013.


  • Reviewers

    This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert medical and health professionals and people living with cancer. It has been approved by Senior Medical Editors, Dr Rebecca Roylance, Consultant Medical Oncologist; and Dr Mark Verrill, Consultant Medical Oncologist.

    Our cancer information has been awarded the PIF TICK. Created by the Patient Information Forum, this quality mark shows we meet PIF’s 10 criteria for trustworthy health information.