A trial looking at a new way of giving radiotherapy after surgery for breast cancer (FORUM)

Please note - this trial is no longer recruiting patients. We hope to add results when they are available.

Cancer type:

Breast cancer




Phase 2

This trial is looking at a system called ‘Mammosite’ to give radiotherapy to just part of the breast after surgery to remove breast cancer.

Doctors often treat early breast cancer with surgery to remove the cancer, followed by radiotherapy. We know from research that having radiotherapy after surgery reduces the risk of the cancer coming back in the breast.

If cancer does come back, it is most often in the same area of the breast. So researchers think it may be safe to give radiotherapy just to the area of the breast where the cancer was.

You usually have radiotherapy to the whole breast. This means that other parts of the body such as the lungs, ribs and heart (if the cancer is on the left hand side) are also exposed to some radiation. This can cause side effects months, or even years after treatment.

In this trial, researchers are looking at a system called Mammosite, which gives radiotherapy only to the area of the breast where the cancer was removed.

The aims of the trial are to see if Mammosite radiotherapy

  • Is as good as standard radiotherapy at stopping breast cancer coming back
  • Causes fewer side effects after treatment

Who can enter

You can enter this trial if

  • You have been diagnosed with breast cancer or DCIS
  • You have had surgery to remove just the area containing the cancer (breast conserving surgery)
  • The tumour in your breast was no bigger than 3cm across or 2cm if it was DCIS
  • You have breast cancer that is grade 1 or 2, or grade 3 as long as the tumour was no bigger than 0.5cm
  • Tests show you have a breast cancer that responds to hormones (hormone receptor positive breast cancer)
  • Your surgeon was able to remove the cancer with a border of healthy tissue round it (a clear margin Open a glossary item) of at least 2mm, and there is at least 7mm between where the cancer was removed and your skin (your doctor can advise you about this)
  • Your cancer has not spread to the lymph nodes Open a glossary item or anywhere else in the body
  • You are female
  • You are at least 50 years of age
  • You are willing to use reliable contraception during the trial if there is any chance you could become pregnant

You cannot enter this trial if you

  • Have cancer in both breasts, or more than one area of DCIS in one breast
  • Have breast cancer that is thought to be fast growing (grade 3 breast cancer)
  • Have had plastic surgery to your breast
  • Are having chemotherapy
  • Have had any other type of cancer, apart from non melanoma skin cancer
  • Are pregnant or breastfeeding

Trial design

The trial will recruit about 100 women. Everybody taking part will have radiotherapy to part of the breast using the Mammosite system.

Before you have surgery, the trial team may ask your permission to put a small tube with a balloon attached into the space left behind when the cancer is removed (the 'surgical cavity'). This is called a 'cavity evaluation device' or CED. It allows the doctors to assess the cavity to see if the Mammosite system would be suitable for you. If you don't have a CED put in during surgery, you will have an extra ultrasound scan.

To have Mammosite radiotherapy, a small tube with a balloon attached (an applicator) is put into the surgical cavity. If you had a CED put in during surgery, this will just be replaced with the Mammosite applicator 2 to 4 weeks later. If you didn't have a CED, the doctors will put the applicator in place 3 to 6 weeks after surgery. To do this, the doctor makes a small cut in the breast and inserts the tube. They use an ultrasound scan to check that it is in the right place and then gently inflate the balloon to fill the surgical cavity. You can usually have this done under local anaesthetic Open a glossary item. And you may have a drug to make you sleepy (a sedative Open a glossary item). Occasionally, it is done under general anaesthetic.

A few days later you start radiotherapy, which you have twice a day for 5 days. The end of the tube that is outside your breast is attached to a machine that contains a very small radioactive source Open a glossary item. The source is attached to a wire. It travels along the tube to the balloon and gives radiotherapy to that area of the breast. It is then pulled back into the machine. This takes less than 10 minutes each time. At the end of your treatment, the balloon is deflated and the tube is gently removed from your breast.

Hospital visits

You will see the trial doctors and have some tests before you have treatment. The tests include

  • Physical examination
  • Ultrasound scan

You have another ultrasound scan or an X-ray or CT scan before you start radiotherapy to make sure the tube and balloon are in the right place. You go to hospital every day for 5 days to have radiotherapy. You have 2 doses each day, 6 hours apart.

You will have follow up appointments after

  • 1 week
  • 1, 3 and 6 months
  • 1 year, 18 months and 2 years
  • Then once a year for at least 10 years

The researchers will take photographs of your breasts before the treatment starts, and then 2 years and 5 years after you finish radiotherapy. The photographs will help them to see if there are any changes in how your breasts look. These photographs will not show your face.

You will be asked to fill out some questionnaires before you start treatment and again 1 month and 3 months after you finish treatment. They will ask about any side effects you have and how you have been feeling. This is called a quality of life study. You can fill in the questionnaires during a hospital visit, or the trial team can post them to you to fill in at home. It will take about half an hour each time.

If you are having your treatment at Clatterbridge Centre for Oncology, the trial team may also ask you to take part in an interview. This will take about an hour and will include questions about your experience of having this treatment. If you don’t want to take part in an interview, you don’t have to. You can still take part in the trial.

Side effects

As this is a new way of giving radiotherapy, doctors don’t yet know if it is as good as standard radiotherapy at stopping breast cancer coming back. And you may be at risk of the same side effects as with standard radiotherapy for breast cancer.

Having the Mammosite tube put into your breast is a minor operation. As with all types of surgery, there is a risk of bleeding, bruising and infection, but this is rare. There is also a risk that the tube could move or cause an allergic reaction. You may have a small scar where the tube goes through the skin.

There is a risk that after the tube has been put in, there may be technical problems that mean you cannot have the radiotherapy using this system. If this happens, the doctors will remove the tube and you will have standard radiotherapy to the whole breast.

Recruitment start:

Recruitment end:

How to join a clinical trial

Please note: In order to join a trial you will need to discuss it with your doctor, unless otherwise specified.

Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Chief Investigator

Dr Zafar Malik

Supported by

Clatterbridge Cancer Centre NHS Foundation Trust
Experimental Cancer Medicine Centre (ECMC)

Questions about cancer? Contact our information nurses

Freephone 0808 800 4040

Last review date

CRUK internal database number:

Oracle - 514

Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Harriet wanted to try new treatments

A picture of Harriet

“I was keen to go on a clinical trial. I wanted to try new cancer treatments and hopefully help future generations.”

Last reviewed:

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