Reports and Activities of International Commission on Radiation units and Measurements ICRU

Transcription

1 Reports and Activities of International Commission on Radiation units and Measurements ICRU Hans-Georg Menzel Chairman ICRU Main Commission CERN (retired) Bethesda, 12 Oct. 2016

2 The definition of appropriate quantities, and their associated units, is a fundamental necessity for any scientific endeavour and for any practical applications of scientific knowledge.

3 It all began in W C Röntgen demonstrates his x rays in Würzburg on Geheimrat von Kölliker s hand

4 Early 20 th century: Lack of knowledge about the risks of exposure to radiation numerous injuries

5 First International Congress of Radiology, London 1925 The urgent need for an internationally recognized unit for radiation exposure in medicine led to the creation of the International X-Ray Unit Committee 1950 renamed: Int. Commission for Radiological Units and Measurements ( ICRU)

6 2nd Congress of Radiology, Stockholm 1928 The International X ray and Radium Protection Committee established 1950 named International Commission on Radiological Protection (ICRP) Mandate: provide guidance for practical radiation protection Chairman: Rolf Sievert

7 Absorbed Dose Following its mandate by the Int. Congress of radiology, ICRU introduced in 1953: The absorbed dose, D, is the quotient of the mean energy imparted by ionizing radiation to matter of mass dm d D d m Absorbed dose is a metrological sound quantity Primary standards exist for some materials the unit is J/kg; special name for the unit: gray

8 ICRU Mission Statement: To develop and promulgate internationally accepted recommendations on radiation related quantities and units, terminology, measurement procedures, and reference data for the safe and efficient application of ionizing radiation to medical diagnosis and therapy, radiation science and technology, and radiation protection of individuals and populations.

9 ICRU is member of the CCU: Consultative Committee for Units, which reports to the International Committee for Weights and Measures (CIPM)

10 ICRU History & Leadership: First International Congress of Radiology 1925: International X-ray Unit Committee Stockholm 1928 Officially Recognized Propose and Develop Unit for Medical Radiation Applications Laurie Taylor H.O. Wyckoff A. Allisy A.W. Wambersie P.M. DeLuca, Jr Hans Menzel Present

11 Organization of Activities: Medical Applications: Diagnostic Therapeutic Non-Ionizing Non-Medical Applications: Radiation Processing Environmental Quantities and Units Basic Data: Cross Sections Material Specification Radiation Constants

12 Medical Imaging Science Medical Imaging - Assessment of Image Quality (Report 54) 1995 Absorbed Dose Specification in Nuclear Medicine (Report 67) 2002 Image Quality in Chest Radiography (Report 70) 2003 Patient Dosimetry of X Rays used in Medical Imaging (Report 74) 2005 Radiation Dosimetry and Image Quality Assessment in Computed Tomography (Report 87) 2012

13 Medical Radiation Oncology Prescribing, Recording, and Reporting Photon-Beam Therapy Supplement (Report 62) 1999 Prescribing, Recording, and Reporting Electron Beam Therapy (Report 71) 2004 Prescribing, Recording, and Reporting Proton-Beam Therapy (Report 78) 2007 Prescribing, Recording, and Reporting Intensity-Modulated Photon-Beam Therapy (IMRT) (Report 83) 2010 Prescribing, Recording, and Reporting Stereotactic Treatments with Small Photon Beams (in press)

14 Work About to be published: Medical Radiation Oncology Area

15 Reports with Radiation Protection Focus

16 ICRU Report No. 53 (1994) Ground level spectrometry Airborne spectrometry Determination of dose quantities

17 ICRU Report No. 68 (2002) Measurements on individuals (physical, biological) environmental measurements + modelling (luminescence, mass spectrometry) Radionuclides in environment

18 ICRU Report No. 69 (2003) Whole Body counter Types of detectors Measurement geometries Background reduction Calibration

19 Reference Data for Cosmic Radiation Exposure of Aircraft Crew

20 Low Dose Exposures

21 Radon Measurements (new) All ICRU Reports are published by OUP

22 Q(L) System of radiation protection dosimetry ICRU Operational quantities Ambient dose equivalent, H*(d) Directional dose equivalent, H (d, ) Personal dose equivalent, H p (d) Physical quantities Fluence, Kerma, K Absorbed dose, D Related by calibration and calculation Monitored quantities Instrument responses Comparison & estimation ICRP Protection quantities Organ absorbed dose, D T Organ equivalent dose, H T Effective dose, E 6 w R

23 ICRU is currently reviewing/revising operational quantities New dose conversion coefficients for effective dose in ICRP 116 extend to much higher energies than ICRP74 / ICRU57 Dose conversion coefficients for operational quantities underestimate those for E at high enrergies ICRU tissue cannot be manufactured Reduced dose limit for the lens of the eye: new modeling required

24 Current Report Activities Radiation Monitoring for Protection of the Public after Major Releases of Radionuclides to the Environment Methods for Initial-phase Assessment of Individual Doses Following Acute Exposure to Ionizing Radiation

25 Thank you for the invitation and for your interest.