Types of radiotherapy

External beam radiotherapy

External beam radiotherapy is a cancer treatment that uses high doses of radiation to destroy cancer cells and shrink tumours. It works by damaging tumour cells to stop them from growing or causing them to die.

External beam treatment is normally given on a machine called a linear accelerator. The machine aims beams of radiation at the cancer and moves around the patient without touching them. The treatment, which is painless, is normally given in short daily treatment sessions from Monday to Friday. The number of treatment sessions will depend on the area being treated.

TomoTherapy

TomoTherapy is one of the most advanced integrated cancer treatment systems available. TomoTherapy is a specialist linear accelerator machine with a built-in CT scanner that combines intensity modulated radiotherapy (IMRT) with image guided radiotherapy (IGRT).

TomoTherapy utilises multiple radiation beams from numerous directions that constantly adjust to achieve the three-dimensional shape of the tumour. The radiation dose is matched to the shape of a patient’s tumour or treatment area, focusing higher radiation doses and minimising exposure to healthy surrounding tissue. This high-precision method is particularly useful when tumours are wrapped around vital organs.

The TomoTherapy machine takes a scan before each treatment session. The 3D imaging allows accurate visualisation of the treatment area; therefore treatment is delivered exactly where it is needed without exposing healthy cells to higher doses of radiation.

TomoTherapy is the optimum radiotherapy treatment technique for various tumour sites, for example head and neck cancers and prostate cancer.

Volumetric modulated arc therapy (VMAT)

VMAT is a type of intensity modulated radiotherapy (IMRT) technique.

The radiotherapy machine rotates around the patient during treatment, delivering a continuous beam of radiation in an arc. As the machine moves it constantly reshapes and changes the intensity of the radiation beam as it moves around the body to adjust to the dose and shape of the tumour.

Giving radiotherapy in this way makes it very accurate and provides high dose conformance to the target, while reducing risk to critical structures and uses a lower overall dose of radiation.

Intensity modulated radiotherapy (IMRT)

IMRT is an advanced mode of high-precision radiotherapy which is used to treat many different types of cancer. It utilises multiple radiation beams from numerous directions that constantly adjust to achieve the three-dimensional shape of the tumour.

The radiation dose is matched to the shape of a patient’s tumour or treatment area, focusing higher radiation doses while minimising exposure to surrounding healthy tissue. This high-precision method is particularly useful when tumours are wrapped around vital organs.

QEHB has the ability to offer private patients IMRT using a TomoTherapy machine or linear accelerator. Your clinician will chose the machine that is most clinically appropriate for your treatment.

Deep inspiration breath hold (DIBH)

DIBH is a technique used to treat patients having radiotherapy to the left breast or chest wall and is used to minimise any radiation to the heart.

A deep breath is taken in and held for up to 30 seconds whilst radiotherapy treatment is given. Taking a deep breath and holding it moves the heart away from the left breast and chest wall area being treated.

This process is only used when treating the left breast or chest wall and will need to be completed several times on each visit.

QEHB use a specialist camera system for DIBH that shines red lights onto the skin surface to monitor breathing and does not require equipment to rest on or touch the skin.

For some people when breathing normally their heart is not in the radiation beam so DIBH is not necessary.

DIBH is not suitable for all patients.

Image guided radiotherapy (IGRT)

IGRT is the use of a variety of imaging techniques, such as X-rays or CT scans, alongside radiotherapy treatment.

Imaging allows us to confirm the position of the patient and tumour whilst targeting the radiotherapy beam more precisely. The image is taken before treatment commences and is matched to the planning images to target the treatment beam more precisely and reduce the dose to the surrounding healthy tissue.

IGRT is often used alongside other types of radiotherapy such as IMRT.

Stereotactic radiotherapy (SABR)

SABR is a specialised type of radiotherapy treatment used to treat small, well-defined tumours. It is sometimes called stereotactic body radiotherapy. Treatment is provided by a highly experienced specialist multi-disciplinary team and treatment at QEHB can be given on a linear accelerator (linac) or a specially designed CyberKnife machine.

Multiple small beams of radiation are used to deliver radiotherapy treatment which is shaped to the size of the tumour. The tumour itself receives a high dose of radiation, while the individual beams that travel through the surrounding healthy tissues are of a low dose. SABR can be given with fewer treatments than standard radiotherapy (usually between three and eight treatments).

SABR is known by a number of different names and this can be confusing. The names may relate to the area of the body being treated, the type of machinery being used or the length of treatment. They include:

• stereotactic body radiotherapy (SBRT)
• stereotactic radiosurgery (SRS)
• stereotactic radiation therapy (SRT)

QEHB has a range of equipment to deliver SABR so treatment can be tailored to the individual patient and their condition, which ultimately increases the number of patients who can benefit from this advanced technique.

Some of the SABR treatments are delivered using CyberKnife, but many are delivered on our Elekta Versa accelerator which is a top-of-the-range product from Elekta. QEHB staff member Jason Cashmore worked closely with Elekta to undertake some of the underpinning physics development work on this equipment as part of his PhD.

CyberKnife

CyberKnife is one of the most advanced and sophisticated radiation therapy systems available for delivering stereotactic radiosurgery (SRS) and stereotactic radiotherapy (SRT).

SRT is a highly focused and accurate type of radiotherapy used to treat very small, precise areas. It delivers a high dose of radiotherapy from different angles but gives a low dose to surrounding normal tissue. If only one treatment is given, it is often referred to as SRS.

CyberKnife is a unit which has a radiotherapy machine mounted on a robotic arm. This means treatment can be delivered from multiple angles, so normal tissue around the area being treated receives a much lower dose than with conventional radiotherapy.

CyberKnife has X-ray cameras that monitor the position of the tumour and sensors that monitor the patient's breathing throughout treatment. The robot repositions the radiotherapy beam during treatment to minimise damage to healthy tissue while delivering high doses of radiation with sub-millimetre accuracy.

Stereotactic radiotherapy is potentially suitable for the treatment of small well-defined tumours in areas including:

• the lungs
• the liver
• the lymph nodes
• the spine
• the prostate
• the brain

You can discuss with your consultant whether CyberKnife is suitable for you, what the various treatment options involve and the advantages and disadvantages of these, including side effects. The wide range of equipment, techniques and specialist staff within the Radiotherapy department at QEHB means we can tailor treatment to your needs.

Radiosurgery is established as a minimally invasive and effective treatment for selected patients with early stage prostate cancer confined to the prostate capsule. CyberKnife radiosurgery has been available in Birmingham since 2013 and planning for this treatment involves experts from different disciplines, all available at QEHB. Typically, a course of CyberKnife treatment to the prostate requires only five treatments.

Brachytherapy

At QEHB, we have the specialist facilities and expertise to offer internal radiotherapy, known as brachytherapy, to private patients.

Brachytherapy treats cancer with radiation delivered from inside the body. This may involve implanting radiation directly into the tumour, or placing a radiation source close to it for a predetermined length of time. As the radiation does not travel far the advantage of this treatment is that it gives a high dose of radiotherapy directly to the tumour, but a low dose to normal tissues.

In women, brachytherapy can be used to treat cancers of the cervix, womb or vagina. It can be used on its own or can be combined with other treatments, such as external radiotherapy. Treatment courses may be between one to three hospital visits and does not require an overnight stay.

Brachytherapy involves putting a small hollow tube (applicator) into the vagina and/or womb and maybe done under a general anaesthetic. The radioactive source (the material that gives off the radiation) is put into the applicators using a treatment machine which is operated by radiographers. The treatment machine will deliver a high dose of radiation directly to the area requiring treatment in a short period of time whilst minimising dose to surrounding tissue.

In men, brachytherapy is a common procedure used to treat prostate cancer and is recognised as an alternative to traditional, external beam radiotherapy.

Permanent seed brachytherapy involves having tiny radioactive seeds implanted in the prostate gland. Radiation from the seeds destroys cancer cells in the prostate. This treatment may be recommended if the cancer is contained within the prostate gland (localised prostate cancer). It may be provided in combination with a form of external radiotherapy and/or hormone therapy.

Selective internal radiation therapy (SIRT)

SIRT is a specialised treatment for a variety of cancers in the liver. SIRT is a type of internal radiotherapy as radiation is given via the blood stream. Sometimes it is referred to as radioembolisation.

SIRT treatment requires two visits to the hospital as a day case. On the first visit, a radiology specialist carries out a procedure under local anaesthetic to map the blood supply to the liver and a scan is performed. On the second visit, tiny radioactive beads are injected via the bloodstream into the liver, again under local anaesthetic. The beads lodge inside the liver tumours and the radioactivity selectively kills off the tumour tissue, leaving the normal liver intact.

Side effects from SIRT treatment are usually mild and it has proven effective in treating a variety of cancers in the liver, even those at an advanced stage.

QEHB has one of the largest liver units in Europe and is the only hospital outside of London to offer both SIRT and CyberKnife radiotherapy for liver tumours.