What are the different types of Radiotherapy?
External beam radiotherapy is a treatment that uses electricity to create the radiotherapy beams which help to destroy cancer cells. These are called photons and electrons. The beams are delivered using a machine called a Linear Accelerator or linac. A linac is operated by radiographers.
A CT or MRI scan is carried out before treatment so that the radiotherapy can be planned accurately, and minimise damage to healthy tissue.
It is important that the radiotherapy field covers the whole cancer, plus a border around it. This helps the radiotherapy to work as well as possible in treating the cancer. Doctors try to give as low a dose as possible to the surrounding healthy tissue to reduce the risk of side effects.
IGRT uses imaging scans and X-rays to make sure the radiotherapy treatment is as accurate as possible.
Imaging panels on the linac are able to take pictures before or during your treatment. These images are to ensure that you are positioned correctly and that the treatment is accurate. This helps reduce the dose of radiation given to the healthy tissue around the tumour, and reduces side effects.
IMRT can shape the radiotherapy very closely around the tumour. The radiotherapy machine aims the beams at the tumour from many different directions. This gives very precise doses to the cancer or to specific areas within the tumour.
IMRT uses small beams to help lower the dose of radiation to normal healthy cells nearby. It can also vary the strength of the beams across the tumour.
This treatment uses many small beams of radiation to precisely target the tumour. It allows us to deliver very high doses of radiotherapy to very small areas of the body, which helps to reduce the side effects of treatment. A course of stereotactic radiotherapy is normally given over 1-5 treatment days.
Only a small number of people have tumours that are suitable for treatment with stereotactic radiotherapy. Here at the Royal Surrey County Hospital it can be used to treat small tumours in the lung and spine, and also certain types of tumour in the brain and skull.
Superficial treatment is used to treat lesions that do not require a dose of radiation to a great depth, such as skin and bone cancers or scars. This type of treatment can be given using either kilo-voltage x-rays on the superficial machine, or using electrons on a linac.
Sometimes a thin lead shield may be placed near the area to be treated in order to protect any healthy tissue. The machine is fitted with an applicator which is moved to rest gently over the treatment area. This should not cause any discomfort.
The treatment can usually be delivered the same day.
Internal radiotherapy implants are radioactive metal wires, seeds, or tubes put into your body, inside or close to a tumour. The radioactive metal is called a source and is left inside the body for a period of time. In many types of cancer the source is taken out after a few minutes.
In some types of cancer, small metal implants, or seeds, are left in the body permanently. These implants are made of radioactive gold or contain radioactive iodine. They give a very high dose of radiation to the area of the cancer cells. For most types of implants the radioactivity only travels a few millimetres through body tissue and so it can’t be detected outside the body.
Follow this link for more information about brachytherapy.