ideasIdea
Modernised cobalt-60 machines as a deliberate bridge where linacs cannot be kept running
In places where sophisticated machines break down, a modern version of the older cobalt radiotherapy unit, upgraded with image guidance, could treat more people reliably while infrastructure catches up.
Cobalt-60 teletherapy units are mechanically simple, tolerate power instability, and need far less maintenance than linacs, but were abandoned in rich countries because of inferior beam characteristics and source-security concerns. A modernised unit with a multileaf collimator and cone-beam image guidance, with secure source logistics through the IAEA, might deliver adequate conformal treatment for common indications. This is controversial and must be tested rather than assumed.
Hypothesis
For cervical, breast, and palliative indications, plans from a modernised cobalt unit will meet contemporary dose-constraint standards in at least 90% of cases, and unit uptime will exceed 95% in settings where linac uptime is under 70%.
Rationale
Appropriate technology beats the best technology if the best is switched off. The dosimetric gap between cobalt and 6 MV photons is modest for many pelvic and breast targets, and the maintenance gap is large.
What would test it
A planning study comparing cobalt-MLC and linac plans on 200 anonymised LMIC treatment scans against agreed constraints, followed by a two-site operational pilot measuring uptime and treatment completion.
Maturity
speculative
Who has to act
engineering
Cost to try
Medium ($1M to $50M)
Years to first evidence
4
Bottlenecks it attacks
- Most of the world has almost no cancer care · Seven in ten cancer deaths happen in low- and middle-income countries, where radiotherapy, pathology, surgery and drugs are scarce.
- Surgery and radiotherapy cure most, get least · Surgery and radiotherapy cure more people than drugs do, but attract a fraction of the research investment.