What is external beam radiation therapy?

External beam radiation therapy is a type of radiation that delivers high-energy X-ray beams to your treatment site. It’s delivered by a machine called a ‘linear accelerator’ or 'linac' for short.

Depending upon the treatment location, different energies of radiation are used for external beam therapy.

  • Low-energy radiation – doesn’t penetrate very deeply into the body, and is used mainly to treat surface sites, particularly on or just under the skin.
  • High-energy radiation – used to treat deeper sites in the body.

What is intensity modulated radiation therapy (IMRT)?

IMRT improves on 3D conformal radiation therapy by modifying the intensity of the radiation within each of the radiation beams.

This allows more precise adjustment of radiation doses to the tissues within the target area.

What is brachytherapy?

Brachytherapy involves placing radioactive sources in or next to the cancer.

This is usually done at the same time, or after, external beam radiation therapy.

Brachytherapy is very important in the treatment of vaginal, cervical and uterine cancers in women and prostate cancers in men.

At GenesisCare, we provide two main types of brachytherapy:

  • Low-dose-rate brachytherapy – this technique gives off low energy gamma rays. It’s mainly used to treat low to intermediate risk early stage prostate cancer.
  • High-dose-rate brachytherapy – this is an internal radiation treatment. It involves temporarily placing radiation near the cancer using a needle or special applicator, controlled by a machine. It’s given over the course of several minutes, but the entire procedure typically takes a few hours. You may be able to go home immediately after this treatment. High dose rate brachytherapy is mainly used to treat aggressive gynaecological or prostate cancers.

What is volumetric modulated arc therapy (VMAT)?

Volumetric Modulated Arc Therapy, also known as ‘RapidArc’, is a more advanced version of IMRT.

In this treatment, radiation is delivered simultaneously, instead of from multiple fixed angles. The radiation is delivered as the linear accelerator rotates around your body.

VMAT allows for even greater beam intensity control and improved radiation dose matching to the tumour volume. This means radiation toxicity and exposure to surrounding healthy tissues and organs is reduced.

Why is radiation used with other treatments?

While radiation therapy can be used on its own to manage cancer, it is often more effective when it’s combined with other treatments.

This is because different treatments target cancer via different pathways. For example:

  • External beam radiation therapy can be applied before surgery to shrink a tumour, making it easier to remove
  • External beam radiation therapy can be given after surgery to get rid of any microscopic disease that remains

When radiation therapy is combined with chemotherapy, cancer cells can become more sensitive to the radiation.

This makes the radiation treatment more effective in killing cancer cells and improves the result.

Combining these treatments also treats the whole body – whereas radiation therapy only focuses on the cancer area. By treating the whole body, the therapy is helping to get rid of any disease that may be present in other parts of the body.

Deciding the type of approach to your treatment will depend on your specific condition and overall health – and you will decide on this with your medical team.

What type of radiation is used in radiation therapy?

Radiation therapy usually involves X-ray as well as electron radiation.

In external beam radiation therapy, a machine called a linear accelerator generates both types of radiation electrically.

X-rays emitted by a linear accelerator are of a much higher energy than that used for standard X-rays. This means their effect is much more intense – and, as a result, they damage the cancerous cells within their path.

Electron radiation produced by a linear accelerator doesn’t reach as deeply into the body as X-rays radiation.

Electron radiation is most useful for treating skin lesions or tumours that are just a few centimetres below the skin surface without affecting deeper structures.

Your radiation oncologist will determine the most appropriate type of radiation for you based on the location of your cancer.

Will I be radioactive after receiving radiation treatment?

You won’t be radioactive if you receive external beam radiation therapy. That’s because the machine administering the radiation, called a ‘linear accelerator’ only produces radiation when activated. It doesn’t leave any residual radioactivity in your body after treatment.

You may be radioactive if you receive low dose rate brachytherapy for prostate cancer.

That’s because low dose rate brachytherapy involves permanently implanting radioactive iodine seeds inside your prostate gland. These seeds give off low energy gamma rays as they break down over several months.

Most of the seeds' radioactivity is absorbed internally, though you will need to take some precautions for a few months after your treatment. Your radiation oncologist will discuss this with you in detail.

Are there any side effects from radiation therapy?

Side effects do exist, and they vary from person to person.

The most common side effects are tiredness and skin changes. Other side effects depend on the part of your body being treated.

Your radiation oncologist and nurse will explain the side effects specific to your treatment area. They will also give you advice on how to manage these and look after yourself during treatment.

Does radiation therapy hurt?

Not at all. Radiation therapy is painless. In fact, you don’t see or feel the actual treatment. Most people continue with their usual daily routine during the treatment course.

Who decides if I need this treatment?

Your radiation oncologist will recommend the treatment that’s best suited to treat your condition.

Can I eat and/or drink before treatment?

Yes. You can eat and drink as you normally would while you’ve having radiation therapy treatments, unless your radiation oncologist says otherwise.

Sometimes, your doctor might ask you to change your diet to help reduce any side effects. Your medical team will give you advice on the best way to manage these.

What should I wear to my treatment appointments?

We recommend you wear comfortable clothes that are easy to change in and out of. For most treatment areas, you’ll be given a gown to change into.

How long does treatment take?

We suggest you allow 20 minutes for your first treatment and 10 minutes for each appointment after that.

Most of this time is spent setting you up in the correct position. The actual radiation treatment only takes a few minutes.

Should I follow a special diet during radiation treatment?

Your body uses a lot of energy during radiation treatment, so it is important to include high energy and protein foods in your diet.

Ask your radiation oncologist or nurse if you need help with diet or a referral to see a dietician.

Can I exercise during treatment?

Yes. Many people find light exercise helps them feel better during their treatment. Talk to your radiation oncologist about the most suitable types of exercise you can do.

Will treatment make me sick?

Because radiation therapy is a targeted treatment, it only affects the area being treated.

If your abdomen is being treated, you may experience some nausea or vomiting. If your pelvis or bowel is being treated, you may experience some diarrhoea.

Your radiation oncologist and nurse will help you manage these side effects.

Will I lose my hair?

Radiation therapy only affects the hair that is in the treatment area. You may lose some or all of the hair in the specific area that’s being treated.

How often will I have radiation treatments?

Most people have radiation treatments once a day, Monday to Friday. A complete treatment course can be anywhere from 1-8 weeks.

Can I go to work during my radiation treatment?

You can continue to work if you feel well enough. As your treatment course continues, you may find you feel more tired, and lacking in energy, than usual.

Speak with your radiation oncologist or nurse about what to expect based on the treatment you are receiving.

What can I do to help myself during therapy?

Looking after your health and wellbeing is very important. Your radiation oncologist and nurse will give you specific advice on how to look after yourself during your radiation treatment.

You should always aim to:

  • Get plenty of rest – aim for 8 hours of sleep every night, and nap during the day if possible
  • Eat healthy foods – eat a diet with plenty of fresh produce (remembering to avoid any particular foods as recommended by your medical team)
  • Take care of the skin in the treatment area – your nurse will give you tips on how to do this

What happens when my radiation treatment is over?

When you’ve finished your radiation therapy course, you might need to attend regular follow up appointments. Your radiation oncologist will discuss this with you when you’re nearing the end of your course of treatment.

Radiation therapy uses radiation to kill or damage cancerous (abnormal) cells and stop them from growing and multiplying.

It is one of the best-established, most effective and well tolerated therapies for treating almost all cancers, extending lives, and reducing suffering.
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Radiation therapy can be delivered:

From a machine outside of the body – this is called external-beam radiation therapy

By placing radioactive material inside the body – this is known as brachytherapy
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External beam radiation therapy, the radiation oncology team uses a machine called a linear accelerator, or linac.

A linac uses electricity to form a stream of fast-moving subatomic (electron) particles. This creates high-energy radiation that is used to kill cancerous cells.
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Stereotactic radiosurgery (SRS) delivers high doses of radiation with sub millimetre precision positioning. It is often used to treat small tumours with well-defined edges.

It is most commonly used to treat primary brain or spinal tumours – as well as secondary brain tumours.
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Brachytherapy involves radiation delivered from a tiny source implanted directly into or next to the tumour.

These sources produce gamma-rays, which have the same effect on cancer cells as X-rays.
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  • WHAT IS RADIATION THERAPY? Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed in nisl ac lacus iaculis iaculis a in elit.
  • TREATMENT TYPES Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed in nisl ac lacus iaculis iaculis a in elit.
  • RADIATION THERAPY EXTERNAL BEAM Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed in nisl ac lacus iaculis iaculis a in elit.
  • STEREOTACTIC (SABR, SRS, GAMMA) Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed in nisl ac lacus iaculis iaculis a in elit.