When people hear the word “radiotherapy”, many immediately think of advanced-stage cancer. In reality, though, radiotherapy can be used at many different stages of cancer.
Radiotherapy is a treatment that uses high-energy rays or particles to damage the DNA of cancer cells so that they can no longer continue to grow and divide. Depending on the case, radiotherapy may be used on its own or combined with surgery, chemotherapy, immunotherapy and other treatments.
How does radiotherapy work?
Cancer cells are able to grow and divide quickly.
High-energy radiation can damage the DNA of cancer cells. When the damage is great enough, the cell can no longer divide and will eventually die.
This does not happen immediately after a single session of radiation. Cancer cells may continue to die for weeks or even months after radiotherapy has finished.
Surrounding healthy tissue can also be affected, so the radiotherapy plan is calculated carefully in order to deliver a suitable dose to the tumour while limiting damage to healthy organs.
When does a patient need radiotherapy?
Not every cancer needs radiotherapy.
Your doctor will weigh up:
- The type of cancer
- The location and size of the tumour
- The stage of the disease
- Whether surgery is possible
- Other treatments already being used
- Overall state of health
- The goal of treatment
Radiotherapy is commonly used in the following situations.
1. Radiotherapy as the main treatment
For some cancers that are sensitive to radiation, radiotherapy may be used instead of surgery, or as the main treatment.
Depending on the disease, your doctor may also combine radiotherapy with chemotherapy or other methods to make treatment more effective.
2. Radiotherapy before surgery
Radiotherapy given before an operation is also called neoadjuvant radiotherapy.
The aims may be to:
- Shrink the tumour
- Make surgery more straightforward
- Reduce the risk of cancer cells being left behind in the treated area
Not every cancer needs radiotherapy before surgery. This depends on the particular disease and on the treatment strategy.
3. Radiotherapy after surgery
This is one of the more common situations.
Once the tumour has been removed by surgery, there may still be cancer cells too small to be seen with the naked eye or on imaging.
Radiotherapy after surgery may be used to destroy the cells that remain and reduce the risk of the cancer coming back in the treated area.
For example, radiotherapy is often part of the treatment plan for some people with breast cancer after breast-conserving surgery.
4. Radiotherapy combined with chemotherapy
Some cancers are treated with concurrent chemoradiotherapy.
This means the patient receives chemotherapy and radiotherapy during the same phase of treatment.
The aim is to improve control of the cancer cells, but side effects may also be greater, so close monitoring is needed.
5. Radiotherapy when cancer comes back
If the cancer returns, your doctor may consider radiotherapy to control the tumour or to relieve symptoms.
Whether radiotherapy can be given again depends on the area treated previously, the total dose already received and the length of time since the last course of treatment.
6. Radiotherapy to relieve symptoms
Radiotherapy is not always aimed at curing cancer.
In advanced or metastatic cancer, radiotherapy may be used to:
- Relieve pain caused by bone metastases
- Reduce bleeding
- Ease difficulty swallowing
- Ease breathlessness
- Relieve pressure caused by the tumour
This is known as palliative radiotherapy. The main aim is to control symptoms and improve quality of life.
What types of radiotherapy are there?
External beam radiotherapy
This is the most common form.
A machine positioned outside the body produces high-energy beams and focuses them on the area containing the tumour.
The total treatment dose is usually divided into a number of smaller sessions, called fractions, rather than giving the whole dose at once.
Internal radiotherapy – brachytherapy
A radioactive source is placed inside or very close to the tumour.
This approach is used in some cancers, such as cervical cancer and prostate cancer, or in other conditions depending on the case.
Systemic radiotherapy
Some radioactive medicines or substances can be swallowed or given into the body through a vein.
They travel through the body and gather more in certain types of cell or tissue that need treatment.
What side effects does radiotherapy have?
Side effects are not the same in every patient.
They depend largely on:
- The part of the body being treated
- The total radiation dose
- The number of treatment sessions
- The radiotherapy technique
- Any other treatments given alongside
Some common side effects may include:
- Fatigue
- Skin changes in the treated area
- Loss of hair in the treated area
- Nausea or digestive upset if the abdomen is treated
- Difficulty swallowing or a dry mouth if the head and neck are treated
Fatigue is one of the most common side effects. The others depend very much on the area being treated.
This also means that radiotherapy does not make all the hair on the body fall out as many people assume. Hair is mainly affected in the area receiving the radiation.
How many radiotherapy sessions are needed?
There is no single figure.
Some people need only a few sessions, while others may be treated over several weeks.
The number of sessions depends on:
- The type of cancer
- The location and size of the tumour
- The goal of treatment
- The total dose required
- The patient's state of health
- The other treatments being combined with it
So “the more sessions, the more serious the disease” is not an accurate way of understanding it.
The regimen is designed around the radiation dose required and the way of dividing that dose that best suits each individual case.
Is radiotherapy only for end-stage cancer?
No.
This is a fairly common misunderstanding.
Radiotherapy may be used:
Early stage → as curative treatment in some diseases.
Before or after surgery → to improve control of the disease.
Combined with chemotherapy → in some treatment regimens.
Advanced or metastatic cancer → to relieve symptoms and improve quality of life.
So the fact that your doctor has recommended radiotherapy does not automatically mean the disease has reached its final stage.
What should you ask your doctor before radiotherapy?
You could ask:
- What is the goal of my radiotherapy?
- How many sessions of radiotherapy will I need?
- Will radiotherapy be combined with any other treatment?
- Which side effects are most likely for the area I am having treated?
- What do I need to prepare before and during radiotherapy?
- Which signs should I report to my doctor straight away?
Understanding the goal of treatment helps patients feel less anxious and take a more active part in their radiotherapy.
Track your treatment journey on Halza
Cancer treatment may involve many appointments, tests, imaging scans, surgery, chemotherapy or radiotherapy.
With Halza, you can store your health records and results so that it is easy to look back over the information at each stage of treatment.
Radiotherapy does not mean “the disease is already severe”. It is one of the tools for treating cancer and can be used from the early stages through to advanced disease, depending on the goal of treatment and the features of each condition.
The information in this article is for reference only and does not replace the advice, diagnosis or treatment plan of an oncologist or a radiation oncologist.
Frequently asked questions
Is radiotherapy the same as chemotherapy?
No.
Chemotherapy uses anti-cancer drugs and can usually affect many areas of the body.
External beam radiotherapy is usually a local treatment, with the radiation focused on the area containing the tumour or the area that needs treating.
Is radiotherapy painful?
While the radiation is being delivered into the body, patients usually cannot feel it and the session itself does not cause pain directly.
Side effects may nevertheless appear during treatment or afterwards.
Does radiotherapy leave the patient “radioactive”?
With external beam radiotherapy, the patient does not become a source of radiation after the session and can be around other people as normal.
Some forms of internal radiotherapy, or treatment with systemic radioactive substances, may call for temporary safety measures as advised by the medical team.
References
- National Cancer Institute – Radiation Therapy to Treat Cancer
- National Cancer Institute – Radiation Therapy Side Effects
- American Cancer Society – Radiation Therapy
- American Cancer Society – External Beam Radiation Therapy
- NHS – Side Effects of Radiotherapy
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