Radiotherapy Viva Questions 2^nd September 2004

1. What is ISO9000? How is it related to your RT centre?

2. How does it affect physicists and radiographers?

3. Describe the main features of a linear accelerator?

4. What type of magnet is used in beam bending? (270°)

5. Why is a 270° magnet used?

6. What is the difference between a sealed and an unsealed chamber?

7. In what situations would they be used?

8. What is the difference between the local secondary standard and a field instrument?

9. Why is Sr-90 used?

10. Describe the Sr-90 checks on a field instrument.

11. What are the errors involved?

12. Describe how you would determine the HVL for different orthovoltage energies?

13. Why are the metal sheets placed about midway between the tube and the ionisation chamber? (Backscatter).

14. What is the approximate shape of the radiation distribution in a plane parallel to the anode-cathode axis? (Heel Effect).

15. Briefly describe the role of CT simulation in treatment planning.

16. What is virtual simulation?

17. Why would you expect the dose calculations to be slightly different for manual and computerised planning?

18. Sketch the field layout for breast treatment based on two beams.

19. Based on the environmental survey in your portfolio – what is the dose limit for members of staff?

20. How could your measurements have been made more accurate? (More measurements).

21. What is a risk assessment? What should it address with respect to a RT department?

22. What placements did you do during your training? (Non-Ionising Radiations, Vascular Labs and Instrumentation, Nuclear Medicine).

23. What did you learn from Nuclear Medicine?

24. Briefly describe a daily QA procedure on a gamma camera.

25. What do you understand by Clinical Governance?