What does brachytherapy mean?
Brachytherapy is a form of internal radiation therapy used primarily to treat cancers. The term comes from the Greek 'brachys', meaning 'short', referring to the short distance between the radioactive source and the tumour. Rather than aiming radiation beams at the body from an external machine, clinicians place sealed radioactive material — often in the form of tiny seeds, wires, or capsules — directly inside or immediately beside the diseased tissue. This proximity allows a high dose of radiation to destroy tumour cells while sparing nearby healthy organs, which makes brachytherapy especially valuable for prostate, cervical, breast, and certain other localised cancers. Treatments are classified as permanent, where low-dose sources are left in place to decay naturally, or temporary, where high-dose sources are inserted and removed during short sessions. Brachytherapy may be used alone or combined with surgery and external radiotherapy, and it remains one of the most precisely targeted tools in modern oncology.
nounA form of radiation therapy in which a sealed radioactive source is placed inside or immediately next to the area being treated, allowing a high dose of radiation to be delivered to a tumour while minimising exposure to surrounding healthy tissue.
- The medical technique of treating disease, especially cancer, by placing a radioactive source inside or very close to the target tissue.
"After her diagnosis, she opted for brachytherapy rather than weeks of external radiotherapy sessions."
"The urologist recommended permanent seed brachytherapy to treat his early-stage prostate cancer."
"High-dose-rate brachytherapy allows clinicians to deliver a precise radiation dose in just a few outpatient sessions."
Brachytherapy's early pioneers called it 'curietherapy' — after Marie Curie herself — because the first treatments used radium tubes inspired by her discoveries.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of brachytherapy
The word brachytherapy derives from the ancient Greek adjective 'brachys', meaning 'short', combined with 'therapeia', meaning 'healing' or 'treatment'. It was coined in the early twentieth century alongside the development of radiation medicine, when physicians began placing radium sources directly within tumours. Its prefix 'brachy-' also appears in words such as brachycephalic ('short-headed'), reflecting the same Greek root. In its earliest decades the technique was sometimes known as curietherapy, honouring Marie Curie's pioneering work on radium.
How brachytherapy is actually used
Brachytherapy is a formal medical term used almost exclusively in clinical and scientific contexts; it is uncountable in general use, though phrases like 'a course of brachytherapy' are common.
Easily confused with brachytherapy
Teletherapy delivers radiation from an external source at a distance from the body, whereas brachytherapy places the radioactive source inside or directly against the tissue being treated.