News and info hub

Radiotherapy Explained

Did you know that if you have been diagnosed with cancer, you have a one in two chance of having radiation therapy? This form of cancer treatment uses high doses of radiation to kill cancer cells and shrink tumours. At low doses, radiation is used in x-rays to see inside your body. The type or radiation therapy that you receive depends on your type of cancer, its size and location, and other factors such as your general health, age and medical history. As radiation therapy affects nearby healthy cells, as well as cancer cells, it does have side effects. Learn what to expect with radiation therapy and how to deal with the aftereffects.

Radiation therapy (also known as radiotherapy) uses high-energy particles or rays, such as x-rays, gamma rays, electron beams or protons to destroy or damage cancer cells. 1 The particles or rays work by making small breaks in the DNA inside cells, which prevents the cells from growing and dividing and causes them to die. 1 Radiation therapy is used to cure or shrink early-stage cancer, to prevent cancer from recurring or spreading, and to treat symptoms of advanced cancer or to treat cancer that has returned. 1

More than half of people affected by cancer will get radiation therapy and it can either be given alone or in conjunction with other treatments. 1

  • Neoadjuvant or pre-operative radiation therapy – is given before surgery to shrink the tumour.
  • Adjuvant radiation therapy – is given after surgery to prevent the cancer from coming back.
  • Palliative radiation therapy – is used in advanced cancer when the cancer has spread too much to be cured. Here, radiation helps to treat symptoms like pain, difficulty swallowing or breathing, bowel obstruction.

Radiation therapy is usually a local treatment where the rays or particles are aimed at, and only affect, the parts of the body needing treatment. External radiation uses a machine that directs high-energy rays from outside the body. The treatment is done during outpatient visits to a hospital or treatment centre and occurs daily over several weeks. Brachytherapy involves implanting a radioactive source into the body near the tumour for a period. Sometimes radioactive drugs, given by mouth or put into a vein, travel through the body, and collect in certain body parts affected by the tumour. This is called systemic radiation.

Radiation therapy requires a highly trained medical team to plan and administer your treatment. The team includes: 1

Radiation oncologist

Doctor who oversees your radiation treatment plan

Radiation physicist

Person responsible for keeping the radiation equipment in good working order


This person helps the radiation oncologist plan the treatment

Radiation therapist/technologist

Operates the radiation equipment and positions you for your treatment

Radiation therapy nurse

Can provide you with information on the treatment and how to manage side effects

Planning is needed to ensure the highest possible dose is administered to the cancer, while avoiding damage to surrounding healthy cells as much as possible. This planning may include CT scanning, permanent ink marks on your skin or the making of a plastic mask if you are having radiation to your head and neck.

Like most cancer treatments, radiation therapy causes side effects that occur due to damage to the healthy cells and tissues near the treatment area. 3 Side effects vary from person to person and depend on what type of cancer you have, what part of your body is being treated, the type of the radiation therapy and the dose, and your general health. 3,4 Some people may get no or mild side effects, while others may experience severe side effects. Reactions to the radiation therapy often start during the second or third week of treatment or they may last for several weeks after the last treatment. 3 Physical side effects of radiation therapy include: 3

Skin changes – dryness, itching, blistering or peeling.

Fatigue – feeling tired or exhausted almost all the time.

Late effects – radiation therapy may result in the development of a new type of cancer, however this risk is low and is outweighed by the benefits of having radiation therapy.   

Download How to prepare for radiotherapy and manage side-effects for more information on specific side effects caused by radiation therapy.                                                

About Life Oncology 

Life Oncology is a dedicated oncology and radiotherapy service under the Life Healthcare brand. Our prime objective is to revolutionise the cancer treatment journey by embracing a patient-centric and value-based model, supporting our patients and their families throughout their treatment journeys. To support this journey, we ensure that our care is coordinated, integrated, and personalised.

Check the download section on the Life Oncology page here for more cancer educational information.

The information is shared on condition that readers will make their own determination, including seeking advice from a healthcare professional. E&OE. Life Healthcare Group Ltd does not accept any responsibility for any loss or damage suffered by the reader as a result of the information provided.



  1. American Cancer Society. How Radiation Therapy Is Used to Treat Cancer. [online] 2019 Dec 27 [cited 2022 Jul 18]. Available from: URL:
  2. What happens during radiotherapy. [online] [cited 2022 Jul 18]. Available from: URL:
  3. Net. Side Effects of Radiation Therapy. [online] [cited 2022 Jul 18]. Available from: URL:
  4. Side effects: Radiotherapy. [online] 2020 Feb 25 [cited 2022 Jul 18]. Available from: URL: