Radiation therapy

Also known as radiotherapy, radiation therapy uses a controlled dose of radiation to kill cancer cells or injure them so they cannot multiply.

The radiation is usually in the form of focused x-ray beams targeted at the cancer. Treatment is painless and carefully planned to do as little harm as possible to healthy body tissue near the cancer.

Learn more about:

• Chemoradiation
• Linear accelerator
• Radiation therapy on its own
• Stereotactic body radiation therapy (SBRT)
• Side effects of radiation therapy
• Video: Radiation therapy for pancreatic cancer

Chemoradiation

For stage 3 cancers that cannot be removed with surgery (locally advanced cancers), radiation therapy may be given with chemotherapy to slow the growth of the cancer. This is known as chemoradiation. The chemotherapy drugs make the cancer cells more sensitive to radiation therapy. For cancers that are at a stage where they can be removed by surgery, chemoradiation may also be used before or after the surgery.

How it is given

For a course of chemoradiation, the radiation therapy is delivered over a number of treatments known as fractions. Each fraction delivers a small dose of radiation that adds up to the total treatment dose. Your radiation oncologist will let you know your treatment schedule. Many people have treatment as an outpatient once a day, Monday to Friday, for up to six weeks.

Each radiation therapy session takes 10–15 minutes. You will lie on a table under a machine called a linear accelerator that delivers radiation to the affected parts of your body. The machine does not touch you, but it may rotate around you to deliver radiation to the area with cancer from different angles. This allows the radiation to target the cancer more precisely and limits the radiation given to surrounding tissues.

Linear accelerator

This is a general illustration of a linear accelerator (LINAC). It’s large and often kept in a separate room. A CT scan machine is usually attached to the linear accelerator. The machine used for your treatment may look different. There may also be imaging devices on or near the linear accelerator, which help position you accurately on the couch.

Radiation therapy on its own

Radiation therapy may also be used on its own over shorter periods to relieve symptoms. For example, if a tumour is pressing on a nerve or another organ and causing pain or bleeding, a few doses of radiation therapy may shrink the tumour enough to relieve the symptoms.

SBRT

A newer radiation technique called stereotactic body radiation therapy (SBRT) delivers a higher dose of radiation per treatment session over a shorter period of time. SBRT is not standard practice for pancreatic cancer but is being investigated in clinical trials. SBRT may be a treatment option as part of a clinical trial at some cancer centres.

Side effects of radiation therapy

Radiation therapy can cause side effects, which are mainly related to the area treated. For pancreatic cancer, the treatment is targeted at the abdomen.

Side effects of radiation therapy to the abdomen may include:

• tiredness
• nausea and vomiting
• diarrhoea
• poor appetite
• reflux (when stomach acid flows up into the oesophagus)
• skin irritation.

Most side effects start to improve a few weeks after treatment, but some can last longer or appear later. Late side effects are uncommon, but may include damage to the liver, kidneys, stomach or small intestine.

Talk to your radiation oncologist or radiation oncology nurse about ways to manage these side effects.

For more on this, see our general section on Radiation therapy.

Video: Radiation therapy for pancreatic cancer

In this video experts explain how radiation therapy is used to treat pancreatic cancer and people who have had the treatment talk about their experiences.