# A patient is given a radionuclide tracer that accumulates in tumour cells. Describe what happens to the tracer inside the patient's body and explain how a gamma camera produces an image of the tumour.

> AQA A-Level Physics (7408) — 3.10.6 Radionuclide Imaging and Therapy · Describe and Explain · 5 marks

## Mark scheme (5 marks)

1. The tracer is taken up / absorbed / concentrated in the tumour cells (more than in surrounding healthy tissue)
2. The radionuclide emits gamma radiation from inside the body
3. Gamma radiation passes out of the body and is detected by the gamma camera
4. The camera detects more gamma radiation / counts from where the tracer has accumulated (the tumour)
5. This produces an image showing the location / position / shape of the tumour

## Key terms

- [radionuclide tracer](https://www.gradenine.co.uk/glossary/radionuclide-tracer)
- [gamma camera](https://www.gradenine.co.uk/glossary/gamma-camera)
- [accumulate](https://www.gradenine.co.uk/glossary/accumulate)

## Related

- [Revision notes for AQA A-Level Physics (7408)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe and 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-patient-is-given-a-radionuclide-05ea147b) · Published by Druglandscape Ltd.