PET/CT Workshop

1. PET/CT Workshop Presented at VCUHS by Jennifer Love and Mark Crosthwaite

2. Radiation Safety and Quality Control Presented by Jennifer S. Love, CNMT, NCT

3. Radiation Safety and Quality ControlObjectives • Apply and calculate exposure rate using time, distance and shielding in the PET arena. • Integrate ALARA and MPD concepts in the molecular imaging department.

4. Objectives • Compare and describe: well counter, dose calibrator, and survey meter. • Apply and evaluate CT and PET quality control procedures

5. A L A R AAs Low As Reasonably Achievabletime…distance…shielding

6. Back to Basics Radiation Units Roentgen: a unit for measuring the amount of gammma or x-rays in air Rad: a unit for measuring absorbed energy from radiation Rem: a unit for measuring biological damage from radiation

7. Radiation Units

8. Radiation Units 1 rem = 1000 mrem 1 Curie = 1000 mCi 1 mCi = 37 MBq 1 Ci = 3.7x1010 dps = 3.7x1010Bq = 2.22x1012 dpm

9. Useful Terminology

10. External Radiation Dose Gamma, beta, or neutron radiation emitted by radioactive material OUTSIDE the body, exposing the skin, lens of the eye, extremities, and the whole body.

11. Internal Radiation Dose Alpha, beta, or gamma radiation emitted by radioactive material INSIDE the body, exposing internal organs such as: thyroid, lung, bone, and GI system.

12. Total Effective Dose EquivalentTEDE • The sum of the effective dose equivalent (for external exposures) and the committed effective dose equivalent (for internal exposures).

13. Shallow Dose EquivalentSDE • Applies to the external exposure of the skin of the whole body or the skin of an extremity, is taken as the dose equivalent at a tissue depth of 0.007cm

14. Lens Dose EquivalentLDE • Applies to the external exposure of the lens of the eye and is taken as the dose equivalent at a tissue depth of 0.3cm

15. Deep Dose EquivalentDDE • Applies to external whole body exposure, is the dose equivalent at a tissue depth of 1cm

16. Whole body or Extremity? • Whole body for purposes of external exposure = head, trunk (including male gonads), arms above the elbow, or legs above the knee. • Extremity = hand, elbow, arm below the elbow, foot, knee, or leg below the knee.

17. NRC Occupational Dose Limits

18. A L A R AAs Low As Reasonably Achievabletime…distance…shielding

19. TIME

20. Distance

21. Inverse Square Law I (D)2 = i (d)2

22. I (D)2 = i (d)2 I = original amount of radiation D = original distance i = new intensity d = new distance

23. Example… At 1 meter, Ted the Technologist reads that the activity level from a source is 40 mR/hr. What is the activity reading at 2 meters away from the source? I = 40 mR/hr D = 1m i = ? d = 2m 40mR/hr (1m)2 = i (2m)2 40mR/hr = i (4) i = 10mR/hr

24. SHIELDING!

25. Half Value Layer Thickness of the attenuator; for each HVL, the radiation is reduced by 50% exponentially.

26. Example… 100mR/hr – (1HVL) = 50mR/hr – (1HVL) = 25mR/hr – (1HVL) = 12.5mR/hr

27. Department Layout • Control room • Hot lab • Patient prep room • Waiting room • Scan room

28. Patient Dose • Dose preparation • Dose administration • Post-dose measurements

29. Radioactive Materials • Package receipt • Storage of radioactive materials • Disposal of radioactive materials - decay in storage

30. Sign, sign, everywhere a sign…

31. Posting Requirements • Radiation Area • High Radiation Area • Very High Radiation Area • Airborne Radioactivity Area • Radioactive Materials