I ntegrated M anagement & E ducational C onsultancy S ervices

1. www.imecs-cpd.co.uk IntegratedManagement &Educational ConsultancyServices “Radiology Update Seminar for The Dental Team” Dr. Richard DeCann & Mr. Tim Reynolds IMECS Radiography Consultants Tel:07855 183117 email: info@imecs-cpd.co.uk

2. www.imecs-cpd.co.uk What do dentists need to know? • UK radiation dose distributions • Nature and effects of radiation • Clinical implications of IRR1999 and IR(ME)R 2000 • Patient safety and selection criteria • Optimisation of radiographic techniques • Quality assurance and record keeping

3. www.imecs-cpd.co.uk What do nurses need to know? • Principle foundations of dental radiographic techniques • Equipment used • Methods of processing films and the practice of digital radiography • Hazards of exposure to ionising radiations • Have an understanding of the regulatory requirements

4. www.imecs-cpd.co.uk What must nurses be able to do? • Prepare the equipment and materials • Prepare and care for patients • Process radiographs • Properly mount radiographs • Undertake quality assurance measures in processing

5. www.imecs-cpd.co.uk The Discovery of X-Rays Prof. W. Roentgen November 1895

6. Comparison between dose sources in the UK www.imecs-cpd.co.uk UK Dose Distribution

7. Medical dose compared with other man made sources www.imecs-cpd.co.uk Man Made Dose Distribution

8. General medical dose compared with dental Comparing Medical Doses www.imecs-cpd.co.uk

9. Number of general medical examinations compared with dental Radiological Examinations in the UK www.imecs-cpd.co.uk

10. Up to 50% of the medical dose delivered in the UK is unnecessary Potential for Dose Saving www.imecs-cpd.co.uk

11. Workshop • List the characteristics of x-rays e.g. travels in straight lines www.imecs-cpd.co.uk

12. www.imecs-cpd.co.uk Nature of Ionising Radiation • Travels in straight lines at the speed of light • Obeys the inverse square law • Penetrates, excites and ionises matter • Chemical and biological effect • Photographic and fluoroscopic effect • Unaffected by magnetic or electric fields

13. Electromagnetic Spectrum Energy low high micro waves cosmic rays X & gamma rays radio waves visible light www.imecs-cpd.co.uk

14. X-Ray Tube electron beam target cathode anode X-ray beam

15. Workshop • What units are used to measure radiation exposure and dose ? www.imecs-cpd.co.uk

16. Units of Radiation Measurement • Exposure = COULOMBS PER KILOGRAM Kinetic Energy Released per unit Mass (KERMA) • Absorbed Dose = GRAY Joules per Kilogram www.imecs-cpd.co.uk

17. Dose Reference Levels • PA DRLs DOH 4Mgy HPA 2mGy Recommended 1 – 1.5mGy OPG DRLs DOH 66mGy HPA 20mGy Recommended 10 – 15mGy

18. Units of Radiation Measurement • Exposure = COULOMBS PER KILOGRAM Kinetic Energy Released per unit Mass (KERMA) • Absorbed Dose = GRAY Joules per Kilogram • Dose Equivalent = SIEVERT Gray x Q (x-rays=1, protons=10, alpha=20) • Effective Dose = SIEVERT Biological Effect (dose equivalent x tissue sensitivity) www.imecs-cpd.co.uk

19. Dose Reference Levels • PA DRLs DOH 4Mgy HPA 2mGy Recommended 1 – 1.5mGy (Effective dose 0.002mSv) OPG DRLs DOH 66mGy HPA 20mGy Recommended 10 – 15mGy (Effective dose 0.007mSv)

20. Units of Radiation Measurement • Exposure = COULOMBS PER KILOGRAM Kinetic Energy Released per unit Mass (KERMA) • Absorbed Dose = GRAY Joules per Kilogram • Dose Equivalent = SIEVERT Gray x Q (x-rays=1, protons=10, alpha=20) • Effective Dose = SIEVERT Biological Effect (dose equivalent x tissue sensitivity) www.imecs-cpd.co.uk

21. Round collimator at 6cms diameter = 29cm

22. DRL = mGy/cm2

23. DRL = mGy/cm2

24. Thyroid collars

25. Effective Dose and Kilo-voltage • 60 kV 70kV

26. Excitation and Ionisation

27. Excitation and Ionisation X-ray photon

28. Excitation and Ionisation Ionised electron X-ray photon

29. Excitation and Ionisation

30. Excitation and Ionisation

31. Excitation and Ionisation

32. www.imecs-cpd.co.uk Radiobiology • Random interactions causing direct and indirect tissue damage • Critical body macromolecules: protein, DNA (damage with incomplete or misrepair) • H2O affected because of large size and content • Ionised water becomes chemically reactive and can affect DNA by indirect action • Formation of free radicals: HO2 (peroxyls) H2O2 (peroxides)

33. Ionisation and free radicals • RH + Radiation = RH+ + electron R H H2O HO H

34. RadiobiologyThe exposure of a cell to radiation may result in: • The premature death of the cell • Prevention or delay in cell division • Changes in cell structure and/or functions which may be passed on to daughter cells www.imecs-cpd.co.uk

35. What is damaged? • DNA • Any of the cytoplasmic organelles • I bet they say MITOCHONDRIA www.imecs-cpd.co.uk

36. Stochastic Deterministic What Type of Damage Can Occur? www.imecs-cpd.co.uk

37. Somatic Genetic Who is Affected? www.imecs-cpd.co.uk

38. Variations with Age at Exposure www.imecs-cpd.co.uk

39. www.imecs-cpd.co.uk IntegratedManagement &Educational ConsultancyServices “Radiology Update Seminar for The Dental Team” Dr. Richard DeCann & Mr. Tim Reynolds IMECS Radiography Consultants Tel:07855 183117 email: info@imecs-cpd.co.uk

40. www.imecs-cpd.co.uk Legislative Framework • Two sets of regulations have been introduced in the UK in the last 13 years • Ionising Radiations Regulations 1999 (IRR 99) • Ionising Radiations (Medical Exposures) Regulations 2000 (IR(ME)R 2000)

41. IRR 1999 • Is about: • Environment • Workers • Members of the public www.imecs-cpd.co.uk

42. Public Protection

43. IRR 1999 • Is about: • Environment • Workers • Members of the public • Management of radiationm protection www.imecs-cpd.co.uk

44. www.imecs-cpd.co.uk IRR 1999 • HSE notification • Risk assessment

45. Risk Assessment Window Surgery 2 4M Waiting room Exposure Switch Mains isolator

46. Staff Risk Assessment

47. Staff Risk Assessment

48. www.imecs-cpd.co.uk IRR 1999 • HSE notification • Risk assessment • Contingency plans • Dose restriction/limitation • Training • RPS/RPA • Controlled areas

49. Controlled areas

50. ?Fire regulations