Radiotherapy is the careful use of high energy x-rays (radiation) to treat cancer. A machine called a linear accelerator (or linac) produces x-rays and delivers them to the area requiring treatment.

Radiotherapy is the use of a beam of carefully focused radiation to destroy. Healthy cells in the treated area may also be temporarily damaged by radiation, leading to side effects, but with time most of these subside as the healthy cells repair.

Radiotherapy can be used to:

• Cure cancer (radical treatment)
• Shrink cancers before surgery (neoadjuvant treatment)
• Reduce the chances of a cancer coming back after surgery (adjuvant or post-operative treatment)
• Relieve symptoms caused by an inoperable primary or cancer (palliative treatment)

To ensure the radiation dose is delivered accurately and personalised to you, a CT scan of the area to be treated is performed first. This is sometimes known as ‘simulation’ or radiotherapy planning.

Precise treatment planning helps reduce the dose to other normal tissues to keep side effects to a minimum.

The scan takes just a few minutes and is painless. You will need to lie very still, often with your hands above your head.

Tiny but permanent ink marks (sometimes known as ‘tattoos’) are placed on the skin by the radiographers to ensure the treatment is delivered precisely. The tattoos are usually very discrete and fade with time.

After the scan, the oncologist identifies the area to be treated and works closely with the radiographers and dosimetry team to finalise the radiotherapy plan to ensure that as little damage as possible occurs to normal cells during the treatment.

During treatment, the radiographers will carefully position you on a couch beneath the linac, usually lying on your back wearing a gown, and move the treatment machine to the correct position.

When all the checks are complete the radiographers will leave the room and ask you to lie still, but remain in contact with you using CCTV and an intercom system.

The linac will then deliver two to three radiation beams directed at the treatment area, from different angles, each usually lasting approximately a minute.

The treatment is painless. The machine does not touch you. You can breathe normally (unless you are having Deep Inspiration Breath Hold radiotherapy for left breast cancer). You may hear a buzzing noise in the background; this is quite normal.