Robert Boyle Prof of Medical Physics Trinity College, g, Dublin IAEA, Vienna

Transcription

1 The Blue Book Published, 1988, by predecessor of Radiological Protection Institute of Ireland (RPII) Prof fjim Ml Malone Robert Boyle Prof of Medical Physics Trinity College, g, Dublin IAEA, Vienna

2 Problems with Blue Book Changes in Legislation, Technology, Clinical Practice, Building Style, Building Materials Changes in Dose Limits and Constraints Use of Upper Floors Need illustrated floor plans Advice on Ceilings, Higher levels of walls Practical Tips and Solutions OBJECTIVES Preference for comprehensive local l solution Not to innovate, but to produce a reliable practical manual or code.

3 Issues, 1: Equipment

4 Issues 2: New Problems Ward walls not solid Theatre workloads not consistent with modern practice. Other recovery rooms, endo suites, lithotripsy, cardiac pacing Radionuclides in Theatres PET shielding

5 Issues 3: Dose Constraints Category of Personnel Dose Constraint t 1998 msv/year Dose Constraint t 2001 msv/year Exposed Worker All others

6 Issues 4: Medical Physics Medical PhysicsSupport Deficits in numbers, leadership and academic involvement/connectivity i i Often poor, or inadequate training, and narrow or inadequate experience Risk of litigation and difficulties with public accountability

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8 Design Code (2 nd edition) About 100 pages incl. Appendices 1. Legal and Administrative Framework 2. Radiation Protection, Project Management and Building Projects 3. Rdil Radiology Room Design and Layout 4. Nuclear Medicine 5. Shielding Calculations 6. Some Practical Considerations RPII, 3 Clonskeagh Square, Dublin 14, Ireland

9 1. Statutory Framework The Radiological Protection Act, 1991 (Ionising Radiation) Order 2000 (SI No. 125 of 2000) European Communities (Medical Ionising i Rditi Radiation Protection) Regulations 2002, 2007 (SI. No. 478 of 2002 & SI. No. 303 of 2007) RPII Licensing System and Requirements Related EU Directives

10 2. Radiation Protection, Project Management and Building Projects The Radiation Safety Committee The Radiation Protection Advisor Project Teams, New Building Design Cycle, Refitting Buildings Dose Limits and Dose Constraints Risk Assessments Site visits essential Issue of New Build versus Conversion/Refit

11 Radiology Room Design and Layout Radiology Room Types General Comments on Shielding Radiography Rooms General Chest Room Mammography DXA Dental Fluoroscopy Rooms General Fluoroscopy Interventional Radiology and Cardiology CT Shared Function Rooms (A&E, Theatres, wards) Equipment in Trailers

12 3. Radiology Room Design and Layout General Radiology Two-corridor Design Large enough for trolleys, table and chest radiology Typical room sizes given Generally 2mm Lead assess on individual basis Primary Beam absorber Staff entrance behind protective screen Typical screen lengths presented Chest stand positioned to minimise scatter entering protective ti console Changing cubicles Specific Requirements for each type of facility Examples of Good Layouts

13 3. Radiology Room Design and Layout Dental Surgery No shielding required if: < 20 exps/wk and 2m between patient and all boundaries CT Separate staff area Other staff present Need good view of door and patient Scanner angled for access and visibility MSCT: 3-4mm Pb

14 DXA and CT

15 Design Criteria ia Corrido Corridor Corridor

16 9/3/2009

17 Mobile X Ray Equipment

18 Equipment not in Rooms

19 Equipment not in Rooms

20 Equipment not even in Building Re shielding often means complete refit Hospital can t do without equipment for 6 months Trailer arrives Trailer

21 5. Shielding Calculations X Ray Review of two widely used Shielding Methodologies BIR, 2000 NCRP, 2004 Variables Distance from Barrier Workload Occupancy BIR: Workload is based (ESD) and (DAP) NCRP: Workload based on beam on time. in ma min per week Issue of New Build versus Conversion/Refit

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23 Workload

24 Workload Either DAP (BIR) or ma min/week min/week (NCRP) Try and base figures on real audit/projection Historical i or published data can mislead il If no other option, use published data Transparency and accountability to the public Defendable legally (reasonable patient, not reasonable doctor)

25 Occupancy

26 Occupancy Occupancy of adjoining areas to be assessed Try and get real information Consider rooms on other side of corridor Extremes: Office, 100%; Unattended carpark, 2.5 to 5 % Reservation about NCRP door value in new builds, and Remember: Transparency and accountability to the public Defendable legally (reasonable patient, not reasonable doctor)

27 General Radiographic Room Ceiling (BIR method)

28 General Radiographic Room Ceiling (NCRP method) General Rm Window, scatter only, at 10 m

29 6. Practical Considerations Building Materials Lead sheet and lead products Concrete and concrete Blocks Barium Plaster Brick Gypsum Wallboard Lead Glass Lead Acrylic Walls Floors and Ceilings Doors Windows Staff Areas Joints, Services, Openings and Perforations Assessment ofshielding Nuclear Medicine ALWAYS NEED TO VISIT AND SEE IMPLEMENTATION

30 9/3/2009

31 Lead Codes Code No NominalThickness (mm) Weight (kgm 2 ) Cost (Relative) When installed as part of a new build, lead is not very dear relative to other costs

32 Some Data 2:

33 Some Data Figure C 6 Also f room; Some Data Table C2 Also f room; Some Data Table C2 and C3,4,or Fig C6 and page 101

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35 Advice for imaging facilities located on upper floors Issues Advice for shielding of windows on upper floors Transparent, Accountable Defendable

36 CONCLUSION RPII 3 Clonskeagh Square, Dublin 14 Ireland