What is Radiation Therapy?
What is radiation therapy?
Radiation therapy (also called radiotherapy) uses radiation, such as high-energy x-rays (photons), gamma rays, electron beams or protons, to damage the DNA in cells located in very specific areas of the body. Cancer cells can’t repair the damage caused by radiation therapy. However, healthy non-cancerous cells are much better at recovering from exposure to radiation. Consequently, cancer cells are more susceptible to radiation. Radiation damage kills the cancer cells and stops them from growing and multiplying.
Radiation therapy is a safe and effective treatment for many types of cancer. It involves the controlled application of radiation to cancers anywhere in the body. It is targeted to where ever the cancer is located in the body and can be used to improve survival, cure the patient, or relieve symptoms such as pain. Focusing the radiation on the area to be treated reduces the impact of treatment on healthy areas of the body, limiting side effects and preserving quality of life.
Radiation oncology teams are made up of the doctor (the Radiation Oncologist), the radiation therapist, the radiation oncology medical physicist, and nursing staff. Additionally, various allied health specialists (dieticians, speech pathologists, psychologists, physiotherapists and dentists) may become part of this team depending on the location of the cancer. The team tailors treatments for individual patients to ensure the best outcome for each patient whilst also making sure the specific needs of individual patient are met.
What can I expect if I’m having radiation therapy?
Radiation therapy is different for each patient with cancer. Treatment is prescribed based on several factors, including:
- the type, size and location of the cancer
- whether the cancer has spread to other areas of the body
- the intention of treatment, e.g. symptom relief or cure
- whether radiation therapy is being used alone or with other forms of treatment such as chemotherapy or immunotherapy
- the patient’s general health and personal preferences.
Patients do not experience pain during the delivery of each fraction or treatment. It is similar to having an X-ray or CT scan.
What types of radiation therapy are there?
Radiation therapy can be delivered using one of two techniques, either External Beam Radiation Therapy or Brachytherapy.
External beam radiation therapy often requires multiple short visits to the treatment centre over a few days to several weeks (usually Monday to Friday). A machine, called a linear accelerator, rotates around you as you lie on a treatment table. Generally a small dose of radiation (known as a fraction) is delivered each time, adding up to the total dose. This minimises damage to healthy cells, as the cells can recover between treatments, and maximises the damage caused to cancerous cells. Linear accelerators can deliver pinpoint accurate treatment to a very small cancer or treat a larger cancer close to sensitive parts of the body using techniques known as intensity modulated radiation therapy.
Brachytherapy may require a short hospital stay to implant the radiation ‘seeds’ or sources into the body. After the seeds are implanted, or brachytherapy session with removable sources is over, the patient can continue their normal daily activities. Depending on the type of brachytherapy used, patients may be required to follow some simple radiation safety guidelines for a short period to ensure that other people are not exposed to the radiation.
Do I have to avoid pregnant women and young children during treatment?
If you undergo External Beam radiation therapy you will not be a danger to other people and can be around pregnant women and young children whilst in the treatment phase. However, just as you shouldn’t have a CT whilst you are pregnant, you shouldn’t have radiation therapy either if you think that you are pregnant. This is because for the short period of time when you are having the treatment each day, during the fraction, you will be exposed to radiation and this can cause harm to an unborn baby.
Brachytherapy is slightly different. This comes in a number of forms and can be low, medium or high dose rate treatment. With some of these treatments you won’t be radioactive after each treatment, however with other treatments you might have a slightly higher level of background radiation. So it is best to check with your Radiation Oncologist as to the rules in regards to being around young children and pregnant women if you undergo this treatment.
How does radiation therapy help patients?
Approximately half of the Australians and New Zealanders diagnosed with cancer (over 100,000) each year could benefit from radiation therapy. Radiation therapy is a part of the treatment program in around 40% of all patients cured of their cancer. It also has a very important place in helping patients with cancer that cannot be cured. In patients with advanced cancer, radiation therapy is commonly used to shrink tumours, and/or treat cancers that have spread. This provides relief from pain and other symptoms, which is vital for improving a cancer patient’s quality of life.
Many radiation therapy treatments are non-invasive and most are delivered in the outpatient setting, i.e. without being admitted to hospital. Radiation therapy often has minimal side effects. Each visit for treatment usually takes around 20 to 30 minutes. This means that most patients can continue with normal daily activities throughout treatment.
Page last updated: 24/11/2020