Radiotherapy for soft tissue sarcomas

Radiotherapy treats cancer by using high-energy x-rays to destroy cancer cells. Radiotherapy is an important part of treatment for soft tissue sarcomas, particularly those affecting the arms or legs.

Radiotherapy for soft tissue sarcomas can be given:

  • after surgery to destroy any remaining cancer cells and to reduce the risk of the cancer coming back
  • before an operation, either to shrink the tumour and make it easier for the surgeon to remove it, or to avoid having to amputate the limb
  • on its own
  • to relieve symptoms and control sarcomas that can’t be removed.

Radiotherapy for sarcomas is often given using a technique called conformal radiotherapy. With this type of radiotherapy, the radiation beams are shaped to the part of the body that needs to be treated.

Radiotherapy for sarcomas is normally given as a series of short daily treatments in the hospital radiotherapy department. The number of treatments will depend on the type, size and position of the sarcoma. Your doctor will discuss the treatment and possible side effects with you during the planning stage.

Radiotherapy

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

Radiotherapy is an important part of treatment for soft tissue sarcomas, particularly those affecting the arms or legs. It is usually given after surgery to destroy any remaining cancer cells and to reduce the risk of the cancer coming back. The wound must be healed before radiotherapy starts.

Sometimes, radiotherapy is given before an operation (neo-adjuvant radiotherapy), either to shrink the tumour and make it easier for the surgeon to remove it successfully, or to avoid having to amputate the limb.

Radiotherapy is sometimes given on its own and may be the only treatment needed. Radiotherapy is also given to relieve symptoms and control sarcomas that can’t be removed.

Radiotherapy for sarcomas is normally given as a series of short daily treatments in the hospital radiotherapy department. High-energy x-rays are directed from a machine at the area of the cancer.

The treatments are usually given from Monday–Friday, with a rest at the weekend. The number of treatments will depend on the type, size and position of the sarcoma. A course of treatment for early cancer will usually last about six weeks. Each treatment takes about 10–15 minutes. Your doctor will discuss the treatment and possible side effects with you.

Radiotherapy for sarcomas is often given using a technique called conformal radiotherapy. The radiation beams are shaped to the part of the body that needs to be treated. For some people, a more complex technique called intensity-modulated radiation therapy (IMRT) may be used. IMRT delivers a high dose of radiation to the tumour and varies the dose given to nearby healthy tissue. This can help to reduce side effects.


Planning your radiotherapy

To make sure the radiotherapy is as effective as possible, it has to be carefully planned. Planning ensures the radiotherapy rays are aimed precisely at the cancer and cause the least possible damage to the surrounding healthy tissues. The treatment is planned by a specialist doctor known as a clinical oncologist. Planning is important and may take a few visits.

If your sarcoma is in your arm or leg, you may need to have a plastic mould made. The mould helps to keep the limb still during radiotherapy treatment sessions. It is made in the mould room on your first visit to the radiotherapy department. Your doctor or specialist nurse will tell you more about moulds if you need one.

As part of the planning, you will have a CT scan taken of the area to be treated. At the same time, therapy radiographers will take measurements from you, which are needed for treatment planning. This session will usually take about 30 minutes.

You may also need to have an MRI scan. This uses powerful magnetic fields to give a detailed picture of part of your body, which can give additional useful information.

The radiographer’s measurements and the information from the scans are fed into the radiotherapy planning computer to help your doctors plan your treatment more precisely.

The radiographer gives you your treatment. Marks may be drawn on your skin, or on the mould, to help them position you accurately and to show where the rays are to be directed. These marks must stay visible throughout your treatment, but they can be washed off once your course of treatment is over. Often, very small tattoo marks are also made on the skin. These marks are permanent and will only be done with your permission. It is a little uncomfortable while the tattoo is being made, but it is a good way of making sure that treatment is directed accurately.

At the beginning of your radiotherapy, you will be told how to look after the area being treated.


Treatment sessions

At the beginning of each session of radiotherapy, the radiographer will position you carefully on the treatment couch and make sure you’re comfortable. Once you’re in the correct position the radiographers will leave the room and you’ll be given your treatment. They will tell you how long your treatment will take before you start. Radiotherapy isn’t painful, but you will have to lie still for a few minutes during the treatment.

The radiographers will be able to see you and many treatment rooms also have an intercom in the treatment room so they can talk to you during your treatment.


Stereotactic radiotherapy

This is a new way of giving radiotherapy that may sometimes be used to treat small soft tissue sarcomas.

Stereotactic radiotherapy treatment is given using a specially adapted radiotherapy machine, sometimes called CyberKnife, which delivers beams of radiotherapy from many different angles. The beams overlap at the tumour. This gives the tumour a very high dose of radiotherapy while surrounding tissues only get a very small dose.

CyberKnife is only available in a small number of hospitals in the UK. Your specialist can give you more information if this is an option for you.


Brachytherapy

Sometimes, radiotherapy is given internally by putting radioactive material (the source) close to the tumour or the area where the tumour was before surgery. This is called brachytherapy. It is not commonly used to treat soft tissue sarcomas.

Your specialist can discuss brachytherapy and its side effects with you if they think it will be helpful.

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Possible side effects

During radiotherapy, you may develop some side effects. You may also develop some late effects after your treatment has finished.

Who might I meet?

You will meet many different specialists before, during and after radiotherapy treatment.