What Is Radiotherapy?

Radiotherapy (or radiation therapy) is a treatment that uses radiation to kill cancer cells. After surgery, radiotherapy is often thought of as the most effective cancer treatment, although the degree of success will differ from person to person. 

Radiation therapy is used to treat cancer. The aim of the treatment can be to cure the cancer (curative radiotherapy), support other treatments by making them more effective, reduce the likelihood of cancer returning post-surgery (adjuvant radiotherapy), or to simply ease cancer symptoms (palliative treatment). 

How Does Radiotherapy Work?

Radiotherapy generally uses photons (sometimes electrons) to deliver high doses of radiation to an area of the body, with the aim of damaging the DNA of cancer cells and shrinking tumours. When these cells are damaged, they are unable to divide and die. The death of the cancer cells is not immediate, usually requiring days or weeks of treatment after which they continue breaking down for weeks or months. Unfortunately, the radiation can damage healthy cells surrounding the cancer, which causes side effects. The aim of radiation is to deliver doses that are damaging enough to the cancer cells while causing minimal damage to the healthy cells. This will look different for each person and cancer type.

How Is Radiotherapy Delivered?

There are several types of radiotherapy. Radiation therapy can be used by itself, or combined with other treatments. Your doctor or medical team will decide what is most appropriate for you and your cancer.

External Radiotherapy / External Beam Radiation Therapy

This is a local treatment method which utilises a large machine that can move around you while you lie still, carefully aiming radiation at the cancer from different directions. The machine is generally operated from outside the room, which will have a window or camera for monitoring. The session is brief and painless. 

Internal Radiotherapy (Internal Radiation Therapy)

Treatment is from inside the body, via either a solid or liquid source of radiation.

Radiotherapy Implants (Brachytherapy)

These are radioactive implants which can be placed near the cancer, with or without surgery. The length of time in which it will remain in your body varies from minutes to permanently (the latter would involve small amounts of radiation, diminishing over time). While the implants are generally painless, the radiation could be harmful to others therefore a hospital stay might be recommended. 

Radioactive Liquid (Systemic Therapy)

In this type of treatment, radiotherapy is administered in liquid form via injection, an IV drip, a drink, or a swallowed capsule. It then travels through the blood, seeking the cancer out. This method may lead you to become radioactive, giving off radiation via body fluids for several days, which means that safety measures need to be taken to reduce risk to others. 

What Does A Course Of Radiotherapy Involve?

There are various ways that a treatment course can be carried out, depending on the type and location of the cancer, tumour size and proximity to normal tissue, whether you have had or are due to have other treatments, your age, and your overall health and medical history. Your doctor’s treatment plan will detail the type of radiotherapy, how many sessions or doses, and how often the treatment should be administered. If radiotherapy is the best option it will be recommended by your medical team, however, it is still your choice to have it or not. 

What Could Radiotherapy Look Like For Me?

First, your doctor might require a CT scan to assess the specifications of the cancer, such as its location and size. The targeted areas are then marked on your body, or on a plastic mask if the radiotherapy is for your head or neck. 

You may undergo several radiotherapy sessions or doses. Treatment is usually administered in a hospital and a long stay is not required, however for safety, it may be necessary for you to stay longer after implants or radioisotope therapy. 

Treatments are generally done on weekdays, with a break over the weekend, however, sometimes weekend treatments or multiple doses a day are possible. Curative radiotherapy could last between 1-7 weeks, while palliative radiotherapy varies from one treatment to a few weeks.

Sometimes radiotherapy alone is all the treatment needed, other times it is combined with treatments such as medication or surgery. Radiotherapy can be administered before, during, or after other treatments, often to improve the chance that the relevant treatments will work.

What Should I Be Concerned About When It Comes To Radiotherapy?

Side effects are generally caused by damage that the radiation has caused to nearby healthy tissue. Possible side effects include: sore skin, fatigue, nausea, loss of appetite, diarrhoea, mouth sores, inflammation of the oesophagus, hair loss in the targeted area.

Side effects can often be treated or prevented, and many go away on their own after treatment ends. Generally patients feel well at the start of radiotherapy, but deteriorate as treatment progresses. It can take weeks or months after finishing your course before you feel better, so it is best to take time off for this period. Some people may choose not to undergo radiotherapy due to the effects on their quality of life.

As a body part can only safely receive a certain amount of radiation in a lifetime, you may not be able to have radiotherapy in the same area again. Radiation can be harmful to others, therefore depending on the type of treatment it may be advised that you avoid close contact for a certain period afterwards. Women should avoid falling pregnant during or soon after radiotherapy treatment, as the radiation could harm the baby. 

Cost is another factor to consider. Radiotherapy can be expensive depending on what type of radiotherapy you are getting and how many treatments you need to undergo. 

If you are worried about the process of radiotherapy, make sure to chat to your doctor or radiographer, or consult with a team that can help you to reduce the overwhelm by addressing several medical and practical considerations at once.