A pilot study of patients with oligometastases from breast cancer treated with stereotactic ablative body radiosurgery.

Stereotactic ablative body radiotherapy (SABR) is a new form of cancer treatment involving high precision radiotherapy. Standard radiotherapy treatment is usually delivered in small doses over many treatments (usually 5 to 20 treatments). SABR treatment is different as it uses a dose of radiation delivered in 1 or 2 treatments that is much higher than standard radiotherapy dosages with the aim of destroying all cancer cells at the site of treatment. The total dose of radiation may be 5-10 times higher than standard radiotherapy doses. SABR treatment appears to be effective in controlling cancer in other sites elsewhere in the body, including the lung, kidney and the liver. We aim to test the ability of this new technique to control the cancer spots that have spread from the breast to the bones and that are being treated with SABR. Initially you will be assessed to check that you are suitable to join the study. This screening period may last for a number of weeks and will involve the following procedures. All of the tests that you will undergo during this screening period would normally be done as part of your standard care, even if you were not participating in this study. * Medical history * Physical examination with a focus on where the cancer has spread to in the body * CT scan (Chest/Abdomen/Pelvis) * CT of extremity (only if the cancer is present on an extremity) * Whole body bone scan * Other investigations, for example an MRI scan (magnetic resonance imaging) may be ordered by your doctor Also as part of this study you will be required to have a special scan called an 18F-PET/CT (stands for fluoride-positron emission tomography/computer tomography) scan. This involves an injection of a radioactive material/tracer and then a scan to see where your breast cancer has spread to. If the tests show that the research study is suitable for you, and you still wish to take part, you can join the study and begin the treatment. You will have either a single session of SABR treatment (20Gy in 1 fraction per area to be treated) or in some cases where there is not enough time available or for technical reasons you may be required to return for two or three sessions (i.e. You may receive 28Gy in 2 fractions). In order to deliver this treatment, you may need to attend a ‘planning CT scan’ session, where you will receive a CT scan and your body measurements are taken in the position that you will be lying in for your radiotherapy. This visit takes approximately one hour. Once the radiotherapy treatment has been planned, a further ‘mock-up’ visit may be required to ensure that the radiotherapy plan can be smoothly delivered when it comes to the time of treatment. This session will take between 45 minutes and 90 minutes. When the treatment starts, the total time required to deliver the treatment will be approximately one hour. Follow-up will involve a visit at approximately 1 month, and every 3 months until two years after the SABR treatment. At each visit, a doctor will review your general health and whether anything new has happened to you since the last study visit (including any bad reactions or injuries), any side effect’s you may be experiencing, an assessment of how well you can perform daily activities and a review of any further anti-cancer treatments you may have undergone. At 12 and 24 months after your SABR treatment, you will have a CT scan and whole body bone scan, as well as a another 18F-PET/CT scan (at 12 months only), which will be very similar to the scan before your treatment. The purpose of this scan is to assess the effect of the treatment on your bone lesion(s).