1. East Asian Workshop, Mito, Japan, 2006 IRB CRPA1 SOME ASPECTS OF SOLID STATE DOSIMETRY IN EUROPE Mária Ranogajec-Komor Ruđer Bošković Institute, Zagreb (IRB) Croatian Radiation Protection Association (CRPA)

2. East Asian Workshop, Mito, Japan, 2006 IRB CRPA2 OUTLINE IM (Individual monitoring)  Implementation of standards in IM  Integration of dosimetric methods for external exposure  Quality control and reliability of reported doses MD (Medical Dosimetry)  X-ray diagnostic (children)  CT (of head) EM (Environmental monitoring)  Dosimetry systems  Intercomparison

3. East Asian Workshop, Mito, Japan, 2006 IRB CRPA3 Why is IM, MD and EM important? Nuclear power plants in Europe The art of life lies in a constant readjustment to our surroundings. Okakura Kakuzo Japanese scholar, 1863-1913

4. East Asian Workshop, Mito, Japan, 2006 IRB CRPA4 Why is IM, MD and EM important? Diagnostic and therapeautic X-ray units: Most of European countries are in the 1 st cathegory according to the number of units/1000 inhabitants UNSCEAR Report to General Assembly, (New York, UN) (1993).

5. East Asian Workshop, Mito, Japan, 2006 IRB CRPA5 Why is IM, MD and EM important? Other medical and industrial application of ionising radiation Dosimetry research facilities Database for EU+Schwitzerland, August 2004 http://www.eurados-db.npl.co.uk/EURADOS_facilities_summary_html

6. East Asian Workshop, Mito, Japan, 2006 IRB CRPA6 IM: IM: Implementation of standards Various standardisation/ accreditation/ approval bodies are in each country The accreditation bodies in Europe operate within mutual agreements. Numerous existing standards (ISO, IEC, IAEA, national) and documents of relevance like international recommendations, technical reports (ICRP, ICRU, IAEA, EUR, RPD, national). Harmony is needed in standards

7. East Asian Workshop, Mito, Japan, 2006 IRB CRPA7 IM: IM: Implementation of standards ISO/IEC 17025 represents the best available techniques for the quality of laboratory work (ISO and IEC are meant for manufacturers and industry). IEC 1066 (1991) for IM and EM ISO: International Standard Organization IEC: International Electrotechnical Committee

8. East Asian Workshop, Mito, Japan, 2006 IRB CRPA8 IM System of IM service in Croatia (HR) STATE OFFICE OF RP Registration ACCREDITED INSTITUTIONS USERS MINISTRY OF HEALTH Used dosimeters New dosimeters Report Measured dose Report: overdose, lost dosimeters, etc. Database

9. East Asian Workshop, Mito, Japan, 2006 IRB CRPA9 IM A catalogue of IM services within Europe Total number of estimated IM services: 200 Catalogue of dosemeters and dosimetric services within Europe: 104 Results : The data indicates that the services in Europe almost exclusively monitor their workers in terms of personal dose equivalent ( H p (10) ). Calibration: air kerma Personal dose: H p (10)

10. East Asian Workshop, Mito, Japan, 2006 IRB CRPA10 IM Data on IM dosimetric services who responded to the questionnaire Country code ServicesWorkers controlled Dosimeter system for photons B360001F, 2TLD BG5124501F, 5TLD CZ4204202F, 2TLD D8529001F, 2TLD, 3V EST110501TLD F8242800 H2300001F, 1TLD HR237001F, 1TLD I12441702F, 10 TLD PL3350002F, 3TLD YU251002TLD 2910472764030F, 69TLD, 5V F: film (443 000) TLD: (273 070) thermoluminescent V: various (glass, electronic, OSL) (11 570) 6F, 2TLD 1 RPL, 5F, 2TLD F: film (200 000) RPL: glass (200000) TLD: (273 070) thermoluminescent V: various (glass, electronic, OSL) (11 570)

11. East Asian Workshop, Mito, Japan, 2006 IRB CRPA11 IM Data on IM dosimetric services in Croatia (HR) – 2006 Accredited institution No of workers Dosimeter system EKOTEH2677F (188 TLD) IMI1024F IRB1222TLD Total46812F, 1 TLD Data from SRP, D. Kubelka

12. East Asian Workshop, Mito, Japan, 2006 IRB CRPA12 IM: IM: Electronic dosemeters and other new developments Objective: First evaluation (implementation and use) of Active Personal Devices (APD) for IM Legal status Technical characteristics Advantages and disadvantages Used in NPP – Energy dependence and mechanical properties critical – differences in intercomparison – increasingly used

13. East Asian Workshop, Mito, Japan, 2006 IRB CRPA13  Inventory of problems of non-dosimetric origin in individual monitoring that impair the quality of external dose assessments : lost, mislaid or damaged dosimeters, failure of processing equipment including data processing,...  88 services from 26 European countries participated in the study.  Overview on QC actions and possible sources of uncertainties was analysed in Europe. IM QC and reliability of IM systems (external radiation)

14. East Asian Workshop, Mito, Japan, 2006 IRB CRPA14 Introducing new dosimetry systems RPL- (France) Proposal of WG2 of Eurados IM Perspectives in IM

15. East Asian Workshop, Mito, Japan, 2006 IRB CRPA15 EURADOS (European Radiation Dosimetry) Membership:  recently 50 voting and 200 associate members Activity:  several Working Groups 4. Numerical dosimetry 7. Internal dosimetry 5. Air crew dosimetry 6. Computational dosimetry 3. EM 2. IM1. Irradiation facilities 9. RP of medical staff http://www.eurados-online.de/ 8. Complex mixed fields

16. East Asian Workshop, Mito, Japan, 2006 IRB CRPA16 Produce every four years a report on Current state of the art External photon, beta, neutron Internal, direct, indirect Workplace, external, radon, aircrew Address a special topic E.g. electronic, neutron, beta, extremity Organise every four years an intercomparison Monitoring services external, internal radiation Organise every four years a workshop IM Perspectives in IM Proposal of WG2 of Eurados

17. East Asian Workshop, Mito, Japan, 2006 IRB CRPA17 MEDICAL DOSIMETRY X-ray diagnostic Therapy Nuclear medicine – conventional radiology – CT – interventional radiology 77% Natural radiation 20% Medical irradition 3% Other man-made irradiation

18. East Asian Workshop, Mito, Japan, 2006 IRB CRPA18 MEDICAL DOSIMETRY 1.Dose measurements after the characterisation of dosimetry systems 2. The exact knowledge of doses delivered to different organs or to the whole body is needed (patient and phantom) to estimate the exposure of population to estimate the risk to specify radiation protection measures to assess the justification of the procedure in terms of overall patient benefit and safety measures

19. East Asian Workshop, Mito, Japan, 2006 IRB CRPA19 MEDICAL DOSIMETRY The determination of the doses received by patients in X-ray diagnostics is complicated very low doses at low and variable energies considerable variation in radiation doses delivered to patients (different X- ray equipment, different personnel)

20. East Asian Workshop, Mito, Japan, 2006 IRB CRPA20 MEDICAL DOSIMETRY Use of baby-fix and arrangement of dosimeters

21. East Asian Workshop, Mito, Japan, 2006 IRB CRPA21 MEDICAL DOSIMETRY Lateral chest radiography (age: under 3 years) Posteroanterioral (PA) and lateral chest radiography (age: 3 years and older)

22. East Asian Workshop, Mito, Japan, 2006 IRB CRPA22 MEDICAL DOSIMETRY Mean value of the surface skin dose measured on children during X-ray diagnostics of chest

23. East Asian Workshop, Mito, Japan, 2006 IRB CRPA23 MEDICAL DOSIMETRY Standard deviations of dosimetric measurements

24. East Asian Workshop, Mito, Japan, 2006 IRB CRPA24 MEDICAL DOSIMETRY Factors which influence the standard deviation  technical conditions (kV, mAs),  feature of patients (age, height, weight etc.),  absorption and scattering of radiation,  PA and lateral projection  different X-ray units  working method of personnel.

25. East Asian Workshop, Mito, Japan, 2006 IRB CRPA25 MEDICAL DOSIMETRY Risk estimation of radiation damage in X-ray diagnostics of respiratory tract of children *ICRP, Publ. 60, 1990 **Number of children examined 1 patient with damage

26. East Asian Workshop, Mito, Japan, 2006 IRB CRPA26 3. For the risk estimation highly statistical dose measurements are needed 2.Importance of standardisation of technik and methods reduction of large variation in absorbed dose MEDICAL DOSIMETRY 1.The evaluated risks are not alarming all patient protection measures should be carried out SUMMARY

27. East Asian Workshop, Mito, Japan, 2006 IRB CRPA27 MEDICAL DOSIMETRY-CT The highest doses result from CT (in diagnostics) CT accounts for 2-3% of all X-ray examinations - it contributes about 20% of the population doses. Important task: radiation protection of patients.

28. East Asian Workshop, Mito, Japan, 2006 IRB CRPA28 MEDICAL DOSIMETRY-CT Dosimetry: TLD CT: SOMATOM DR-H SCT-4500TE (Siemens) (Shimadzu) Installation: 1987, Hospital A 1994, Hospital B Condition, number of patients, number of dosimeters

29. East Asian Workshop, Mito, Japan, 2006 IRB CRPA29 MEDICAL DOSIMETRY-CT Distribution of radiation doses for both eyes measured during CT of the head

30. East Asian Workshop, Mito, Japan, 2006 IRB CRPA30 MEDICAL DOSIMETRY-CT The ratio of the minimum to the maximum of the measured surface doses varies by a factor of 4 to 7 (gonades, chest, thyroid). 10-11 (eye lens)

31. East Asian Workshop, Mito, Japan, 2006 IRB CRPA31 MEDICAL DOSIMETRY-CT  the dose varies according to the position, size and shape of the patients' bodies;  the distance of the primary X-ray beam from the organ significantly varies from one patient to another;  the number of scans varied by a factor of 2;  the total mAs also varied by a factor of 2. This is understandable when we consider the following:

32. East Asian Workshop, Mito, Japan, 2006 IRB CRPA32 3 in New Zealand, 5 in Sweden and the United Kingdom 3.5 in Japan (depending on the CT scanner unit). Measured on a hypothetical average adult phantom. MEDICAL DOSIMETRY-CT USA: 250 CT systems - typical dose is 22-68 mGy Japan: from 18 to 80 mGy (adults). Factor of dose variations: Literature (UNSCEAR, 1993): Surface doses during CT of head :

33. East Asian Workshop, Mito, Japan, 2006 IRB CRPA33 Dose measurements in medicine - TL and RPL dosimetry Benefits:  facilitate the control of X-ray equipment;  identify equipment requiring additional safety measures;  facilitate patient risk assessment  aid in directing efforts toward reducing total radiation doses. MEDICAL DOSIMETRY SUMMARY

34. East Asian Workshop, Mito, Japan, 2006 IRB CRPA34 From the point of view of radiation protection of patients, an optimum factor for X-ray examinations should be decided by considering not only the image quality but also the absorbed dose resulting from medical procedures. This aim can be achieve  by frequent dosimetry  by permanent education of personnel. MEDICAL DOSIMETRY CONCLUSIONS

35. East Asian Workshop, Mito, Japan, 2006 IRB CRPA35 ENVIRONMENTAL DOSE MEASUREMENT (EM) PROBLEMS: society worries about environmental quality human activities can increase radiation dose in the environment TASK: collection of well documented data on radiation doses in the environment

36. East Asian Workshop, Mito, Japan, 2006 IRB CRPA36 Environmental radiation external exposure Terrestrial Cosmic Dubrovnik, Croatia Fujijama, JapanEM

37. East Asian Workshop, Mito, Japan, 2006 IRB CRPA37 EM REQUIREMENTS for dose measurements: to measure the man-made contribution to environmental radiation (1:10) to follow the changes in natural environmental radiation ( Early Warning Network Systems) under variable environmental conditions (UV sunlight, humidity, temperature) SOLUTION: TLD, RPL, in-situ gamma spectrometry

38. East Asian Workshop, Mito, Japan, 2006 IRB CRPA38 EM their application to environmental dosimetry requires performance under laboratory and field conditions performance testing and procedural specifications may be found in national and international standards  International Electrotechnical Committee (IEC). TLD Systems for Personal and Environmental Monitoring. International Standard - IEC 1066 (1991)

39. East Asian Workshop, Mito, Japan, 2006 IRB CRPA39 EM Test methods for EM Batch homogenity: Detection threshold: Linearity: Energy dependence: 80-100 keV, 137 Cs E: evaluated value C: conventional true value i: number of group l i : half-width of confidence interval RPL 0.96-1.04 0.1 1.52μGy 1.1

40. East Asian Workshop, Mito, Japan, 2006 IRB CRPA40 EM Intercomparison To reach international standards there is a need for INTERCOMPARISONS (large scale) US DOE, EML 12 1972-2002 EC1984-1994 NRPB1985 COMECOMA1989 EURADOS1999-2002 to improve environmental monitoring methods to serve as periodic quality control AIM:

41. East Asian Workshop, Mito, Japan, 2006 IRB CRPA41 Intercomparison of EM Field irradiation Lab irradiation

42. East Asian Workshop, Mito, Japan, 2006 IRB CRPA42 Protocol of EM Intercomparison 3 sets of RPL/TLD field fading (pre-irradiated) transport calibration + control dosimeters - in the shield HR shield H D1D1 D2D2 H1 H2 HR1HR2 shield D

43. East Asian Workshop, Mito, Japan, 2006 IRB CRPA43 Intercomparison in EM The suitability of RPL and new high sensitivity TL detectors for EM shorter monitoring period influence of climatic conditions on fading and dose according to the season or the location Expected answers

44. East Asian Workshop, Mito, Japan, 2006 IRB CRPA44 EM Perspectives in EM to support a suitable infrastructure for the characterisation and intercomparison of EM systems RPL system in RBI, Zagreb

45. East Asian Workshop, Mito, Japan, 2006 IRB CRPA45PERSPECTIVES The important thing is not to stop questioning. Albert Einstein US (German-born) physicist (1879 - 1955)

46. East Asian Workshop, Mito, Japan, 2006 IRB CRPA46 PERSPECTIVES HVALA 有難うございました The author is grateful to Chiyoda Technol Corporation, Japan for the support of participation