Many specialist hospitals now use a technique known as conformal radiotherapy. Conformal radiotherapy uses the same radiotherapy machine as normal radiotherapy treatment. However, a device called a multi-leaf collimator is used to arrange the shape of the beams so that they 'conform' to the area of the cancer. This ensures that a higher dose of radiation is given to the tumour. Healthy surrounding cells and nearby structures receive a lower dose of radiation, so the possibility of side effects is reduced. The multi-leaf collimator consists of a number of metal bars which are fixed to the radiotherapy machine. Each bar can be adjusted so that the radiation beams can be shaped to the treatment area.

Conformal radiotherapy may be used to treat a number of different cancers, including cancer of the head and neck, prostate, gullet (oesophagus), some types of lung cancer and brain tumours. It is especially useful if the tumour is close to important organs or structures in the body, because high doses of radiotherapy can be given with minimal risk to the healthy tissue.

Although conformal radiotherapy is commonly used to treat some types of cancer, research studies are being carried out to see whether it can help to control other types of cancer better than standard radiotherapy, while causing fewer side effects. Your specialist can tell you if conformal radiotherapy would be suitable in your situation.

High-resolution intensity-modulated radiotherapy, which is sometimes called three-dimensional IMRT (3D-IMRT) also uses a multi-leaf collimator. During this treatment the layers of the multi-leaf collimator are moved while the treatment is being given. This method is able to shape the treatment beams very precisely and allows the dose of radiotherapy to be altered in different parts of the treatment area.

Research studies have shown that IMRT has fewer side effects than traditional radiotherapy treatment. However, it’s possible that by shaping the treatment area so precisely, microscopic cancer cells just outside the treatment area may not be destroyed. This means that the risk of the cancer coming back in the future could be higher with these specialised radiotherapy techniques. Research studies currently being carried out should show whether this is the case.

TomoTherapy

This is a specialist form of IMRT. The radiotherapy is given by a machine that rotates, much like a CT scanner rotates when taking a scan. Before each treatment the TomoTherapy machine takes a scan to locate the tumour. It then plans treatment to deliver the radiation precisely to the tumour, minimising radiation to healthy tissue. It’s a very new treatment and not widely available in the UK.

This type of radiotherapy is used much less often than the other types of radiotherapy, but may be given to people who are having a stem cell transplant as part of their treatment. A large single dose, or six to eight smaller doses of radiation, is given to the whole body to destroy the cells of the bone marrow. Very high doses of chemotherapy are also given. This treatment is followed by giving stem cells by a drip into a vein, to replace the bone marrow that has been destroyed.

This type of radiotherapy is described in our section on stem cell and bone marrow transplants.

Proton therapy is only used to treat cancers affecting the eye, such as melanoma. It is given using a machine called a Cyclotron. The cyclotron uses proton radiation rather than x-rays to kill the cancer cells. The proton beam is aimed directly at the cancer and causes very little damage to surrounding healthy tissues. Some very rare cancers may be treated with high-dose proton therapy. This treatment is not available in the UK but the Department of Health can arrange for people who need this type of radiation to have it at centres in the USA or Europe, paid for by the NHS.

Stereotactic radiotherapy is mainly used to treat brain tumours, but can also be used to treat secondary brain cancer and some non-cancer conditions.

This technique directs the radiation from many different angles so that the dose going to the tumour is very high and the dose affecting surrounding healthy tissue is very low. Before treatment, several scans are analysed by computers to ensure that the radiation is precisely targeted, and the patient's head is held still in a specially-made frame while having the radiotherapy. Several doses are given.

This treatment is available only in some specialist hospitals and isn't suitable for all patients with brain tumours. Your clinical oncologist can discuss whether it may be appropriate in your case.

Gamma knife

This type of stereotactic radiotherapy does not in fact use a knife but very precisely targeted beams of gamma radiotherapy from hundreds of different angles. Only one session of radiotherapy, taking about four to five hours, is needed.

For this treatment you will have a specially-made metal frame attached to your head. Then several scans and x-rays are carried out to find the precise area where the treatment is needed. During the radiotherapy, you lie with your head in a large helmet, which has hundreds of holes in it to allow the radiation beams through.

This treatment is available only in specialist hospitals and is not suitable for all people with brain tumours. You can discuss with your clinical oncologist whether it may be appropriate for you.