Radiotherapy for rectal cancer

The radiotherapy team plans your external beam radiotherapy before you start treatment. This means working out the dose of radiotherapy you need and exactly where you need it.

External beam radiotherapy directs radiotherapy beams at the cancer from a machine. This is different to internal radiotherapy which means giving radiotherapy to the cancer from inside the body.

Side effects tend to start a week after the radiotherapy begins. They can include feeling tired, sore skin, diarrhoea and passing urine more often.

There are 2 types of internal radiotherapy for rectal cancer. High dose rate brachytherapy (HDR) and contact x-ray brachytherapy (Papillon). Internal radiotherapy gives radiotherapy from inside the rectum.

Most side effects gradually go away in the weeks or months after treatment. But some side effects can continue. Or you might notice some that begin months or years later.

Radiotherapy uses high energy rays similar to x-rays to kill cancer cells. It can shrink the cancer, relieve symptoms and help you feel more comfortable.