Medical Uses of Radiation
Part of Uses & Hazards of Radiation — GCSE Physics
This deep dive covers Medical Uses of Radiation within Uses & Hazards of Radiation for GCSE Physics. Revise Uses & Hazards of Radiation in Atomic Structure for GCSE Physics with 17 exam-style questions and 5 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 2 of 16 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 2 of 16
Practice
17 questions
Recall
5 flashcards
🏥 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.
Quick Check: Why must medical tracers use isotopes with a short half-life?
A short half-life means the isotope decays quickly after the scan, reducing the total radiation dose to the patient and minimising the risk of radiation damage.