Medical Uses of Radiation (OCR GCSE Physics A (Gateway Science Suite)): Revision Notes

4.3.3 Medical Uses of Radiation

Uses of Radiation in Medicine (Physics only)

Tracers

Technetium is commonly used as a medical tracer due to its properties:

• It has a half-life of 6 hours, which is ideal for medical imaging. This allows it to circulate through the body long enough to be detected but decays quickly enough to minimise radiation exposure.
• Technetium decays into a harmless isotope that the body can safely excrete.
• As a gamma emitter, it produces radiation that can pass through body tissues without being absorbed, making it effective for imaging while causing minimal harm.

Chemotherapy

Gamma rays are used in chemotherapy to target and destroy cancerous cells:

• The gamma rays are directed at the area containing the cancer, where the cells absorb the radiation, leading to their destruction.
• While effective, this treatment can also affect nearby healthy cells, which may result in side effects due to the difficulty in targeting the rays precisely.