Conventional Radiation Therapy

What is conventional radiation therapy?

Radiation therapy shrinks or destroys tumours using high-energy X-rays. Conventional (also called fractionated) radiation therapy delivers a part (fraction) of the complete radiation dose over several sessions.

By delivering a fraction of the total radiation dose at one time, any damage to normal cells caused by radiation can be repaired between treatments. In this way, healthy cells are protected from permanent injury or death.

You may be given radiation therapy as your only treatment, or you may also undergo surgery, chemotherapy, or both (concurrent chemo-radiation).

3D conformal radiation therapy (3D-CRT) vs conventional radiation therapy

3D-CRT, also known as three-dimensional conformal radiation therapy, uses 3D images on a computer to shape beams of radiation in a focused (conformed) way. Compared to conventional radiation therapy, it delivers a higher dose of radiation to a more targeted area.

3D conformal radiation therapy vs intensity-modulated radiation therapy (IMRT)

IMRT is considered an advanced form of 3D-CRT. The technology uses multiple small photon or proton beams with variable intensity to treat tumours in a precise way. It allows stronger doses to be delivered to certain parts of the tumour, while limiting exposure to surrounding healthy tissue.

Why do you need conventional radiation therapy?

You may need conventional radiation therapy if you have:

• Liver cancer
• Lung cancer
• Kidney cancer
• Prostate cancer
• Colorectal cancer
• Gynaecological cancer (female cancers like uterus, cervix or ovary cancer)
• Metastatic cancer (cancer that has spread to another part of your body)

Radiation therapy is usually intended to cure your cancer. However, sometimes the tumour may be too far advanced for the treatment to provide a cure. In this case, you will be given radiation therapy to relieve your pain. This is known as palliative radiation therapy.

What are the risks and complications of conventional radiation therapy?

The side effects of radiation therapy depend on your individual health along with factors such as:

• Body part exposed to radiation
• Dosage of radiation used

Common side effects may include:

• Fatigue
• Swelling
• Headache
• Diarrhoea
• Blurry vision
• Skin changes
• Taste changes
• Trouble swallowing
• Temporary hair loss
• Sexual and fertility problems
• Nausea and vomiting
• Urinary issues

Most side effects are manageable and will subside once your treatment has ended.

How do you prepare for conventional radiation therapy?

Before you start your therapy, you doctor will plan and prepare for it by ordering:

• Radiation simulation to find a comfortable position for you to lay still during treatment.
• Computerised tomography (CT) scans to determine and plan the area of your body to be treated.

Your doctor will then decide with you the type of radiation and dosage of radiation based on your condition, general health and treatment goals.

The aim of such preparation is to maximise the radiation to your cancer cells while minimising harm to your surrounding healthy tissue.

What can you expect in a conventional radiation therapy session?

During your initial consultation, a treatment plan will be drawn up. You will then return daily for several weeks to receive the complete radiation dose.

Estimated duration

Each treatment session usually takes 10 – 30 minutes. Treatment sessions are typically:

• Conducted 5 days a week as an outpatient procedure.
• Spread out over several weeks to allow recovery between sessions.

During the procedure

You will lay down according to the position determined during your radiation simulation session. Be still and breathe normally. For some patients with lung or breast cancer, you might be asked to hold your breath while the machine delivers the treatment.

You should not feel any pain during your session.

If you have any concerns or feel uncomfortable, you will be able to speak to your radiation therapy team through the available video and audio connections.