Brachytherapy is the most common type of internal radiation therapy. As with external beam radiation therapy, the main treating specialist for brachytherapy is a radiation oncologist. Procedures for brachytherapy may vary between hospitals. Here we describe the general process, but your treatment team can give you more specific information.

Learn more about:

How brachytherapy works

In brachytherapy, sealed radioactive sources are placed inside the body, close to or inside the cancer. The sources produce gamma rays, which have the same effect on cancer as the x-rays used in external beam radiation therapy, but act only over a short distance. It is a way of giving a high dose of radiation to the cancer with a very low dose to surrounding tissues and organs.

The type of brachytherapy used depends on the type of cancer. It may include “seeds”, needles, wires or small mobile sources that move from a machine into the body through applicators (thin plastic tubes). Brachytherapy may be used alone or with external beam radiation therapy.

Dose rates

You may be told you are having high-dose-rate, low-dose-rate or pulsed-dose-rate brachytherapy.

  • High-dose-rate (HDR) – Uses sources that release high doses of radiation in short sessions, each lasting a number of minutes. The sources will be removed at the end of each session.
  • Low-dose-rate (LDR) – Uses sources that release radiation over days, weeks or months. The sources may be temporary or permanent.
  • Pulsed-dose-rate (PDR) – Uses sources that release radiation for a few minutes every hour over a number of days. The sources will be removed at the end of treatment.

This information was last reviewed in December 2017
View who reviewed this content
View our editorial policy

Support services

Coping with cancer?
Ask a health professional or someone who’s been there, or find a support group or forum

Need legal and financial assistance?
Pro bono legal and financial matters, no interest loans or help with small business

Looking for transport, accommodation or home help?
Practical advice and support during and after treatment

Cancer information

Deciding on specialist care
How to find and choose a surgeon, oncologist or other specialist

Patient rights and responsibilities
What you can reasonably expect from your health care professionals

View our publications
Guides and fact sheets for people with cancer, their families and friends