# A hospital uses a gamma-emitting radioactive isotope in chemotherapy treatment to destroy cancerous cells in a patient. Explain why a gamma emitter is chosen for this purpose, and describe one significant hazard associated with this treatment.

> OCR A-Level Physics A (H556) — 6.1 Capacitors · Explain · 5 marks

> Gamma radiation is used in chemotherapy to target cancerous cells inside the body. The radioactive source is positioned outside the patient and the beam is directed towards the tumour.

## Mark scheme (5 marks)

1. Gamma radiation has the most penetrating power / can pass through body tissue to reach internal tumours
2. Gamma radiation is least ionising, so it is less likely to damage healthy tissue as it travels through compared to alpha or beta
3. The cancerous cells absorb the energy from the gamma radiation and are killed / destroyed
4. It is difficult to accurately target only the cancerous cells / the gamma beam cannot be directed with complete precision
5. Surrounding healthy cells may also be irradiated and destroyed, causing harmful side effects to the patient

## Key terms

- [cancerous cells](https://www.gradenine.co.uk/glossary/cancerous-cells)

## Related

- [Revision notes for OCR A-Level Physics A (H556)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/a-hospital-uses-a-gamma-emitting-radioactive-a86a1606) · Published by Druglandscape Ltd.