Medical Uses of Radiation

🏥 Medical Uses of Radiation

Radioactive isotopes are invaluable in medicine for both diagnosis (finding what's wrong) and treatment (fixing it).

For diagnosis, a patient is given a small amount of a gamma-emitting isotope that concentrates in the organ being investigated. Gamma cameras outside the body detect the emitted gamma rays and build up an image of the organ's function. The isotope must have a short half-life (hours) so it decays quickly and reduces the patient's total radiation dose. Technetium-99m (half-life: 6 hours) is the most widely used medical tracer.

For treatment (radiotherapy), high-energy gamma rays are directed at tumour cells from multiple angles. By rotating the beam around the patient, the tumour receives a high total dose while surrounding healthy tissue receives a much lower dose. Cancer cells are more vulnerable to radiation than healthy cells because they divide rapidly.