{"entity":{"id":"cobalt-60-teletherapy","kind":"technology","name":"Cobalt-60 teletherapy","aka":[],"tldr":"The machine that made curative radiotherapy widely available from the 1950s: a sealed cobalt-60 source in a rotating head. Linacs replaced it in rich countries, but cobalt units still treat many patients where power and servicing are unreliable.","summary":"The first cobalt-60 units were installed in Canada in 1951 and for thirty years were the workhorse of radiotherapy worldwide, delivering megavoltage gamma rays with far better depth dose than the X-ray tubes before them. Linear accelerators, with sharper beams, higher output and no decaying source, replaced them in high-income countries from the 1980s. Cobalt units remain in service in many low- and middle-income countries because they need little electricity and maintenance, though their source replacement and security are growing concerns and the IAEA is helping countries move to linacs.","status":"historic","asOf":"2026-09-16","links":[{"label":"Wikipedia","url":"https://en.wikipedia.org/wiki/Cobalt_therapy"}],"tags":["radiation-wave1"],"related":[],"cancers":[],"sections":["radiation"],"technologies":["imrt-igrt","global-oncology-access"],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"notes":[],"principle":"A high-activity cobalt-60 source emits 1.25 MeV gamma rays; the shielded head rotates around the patient to deliver megavoltage external beam therapy.","strengths":["Simple and robust","Low running cost","Made megavoltage therapy available worldwide"],"limitations":["Source decays and must be replaced","Broader penumbra and lower dose rate than a linac","Security of the radioactive source"],"since":1951},"route":"/technologies/cobalt-60-teletherapy/","neighbours":{"section":[{"id":"radiation","kind":"section","name":"Radiation Therapy","route":"/fronts/radiation/"}],"technology":[{"id":"global-oncology-access","kind":"technology","name":"Global oncology and access in low- and middle-income countries","route":"/technologies/global-oncology-access/"},{"id":"imrt-igrt","kind":"technology","name":"IMRT / IGRT (modern external beam)","route":"/technologies/imrt-igrt/"},{"id":"radiotherapy-access-gap","kind":"technology","name":"Radiotherapy access and the global machine gap","route":"/technologies/radiotherapy-access-gap/"}]}}