COMPARISON OF PERSONNEL RADIATION MONITORING DOSIMETERS DESIGNED FOR MEDICAL FIELD Kirill SKOVORODKO, Birute GRICIENE, Milda PETKELYTE Radiation Protection Division, Vilnius University Hospital Santaros Klinikos kirill.skov@gmail.com
THE MEDICAL PROCEDURES INCLUDING IONIZING RADIATION Interventional radiology and cardiology Nuclear medicine Radiotherapy Conventional radiology According to Radiation protection centre annual report 2015
DISTRIBUTION OF WORKERS IN SANTAROS CLINICS IN 2016 BY CATEGORY Brachytherapy 2 % Nuclear medicine 10% Interventional radiology 37% Conventional radiology 51% Nuclear medicine Conventional radiology Interventional radiology Radiotherapy
The purpose of this study To compare active dosimeters To compare the lowest measurement range of accumulated dose for different instruments To identify dosimeters accuracy with small doses, short low energies and pulsed fields To check APD response to different radiation sources and activities which are commonly used in nuclear medicine department
MATERIALS AND METHODS The tests with continuous and pulsed X-ray fields were made with Siemens AXIOM Iconos R200 Digital R/F. Conformity to annual quality control requirements were verified with Multisensor Accu-Gold digitizer module AGDM with AGMS D. For simulation of X-ray field dispersion two 10 litters containers, 25 cm x 25 cm field size and large focus were used. ATOMTEX AT1121 X-ray and gamma radiation dosimeter were used as a reference points in both X-ray and gamma tests. This dosimeter was metrologicaly verified by Vilnius Metrology Centre. Siemens AXIOM Iconos R200 Digital R/F
MATERIALS AND METHODS 137 Cs - 7.48 MBq ; 18 F - 250 MBq; 99m Tc - 301 MBq were used for gamma rays dose measurement. Activity of the sources were measured with dose calibrators Veenstra VDC-404, VDC-405 and PITAGORA. Radionuclide calibrators were metrologicaly verified by Center for Physical Sciences and Technology.
THE MAIN CHARACTERISTICS OF APDS PROVIDED BY MANUFACTURERS APD model Energy range Personal dose Detector type equivalent range (Hp(10)), Sv AT1121* 15 kev 10 MeV 0.01 μsv 10 Sv Scintillation AT3509 15 kev 10 MeV 1 μsv 10 Sv Silicon diode EPD Mk 2.3 16 kev 7 MeV 10 μsv 10 Sv Silicon diode PM1621 10 kev 20 MeV 1 μsv 9.99 Sv GM tube PM1203M 60 kev 1.5 MeV 10 μsv 9.99 Sv GM tube PM1703MO-1 33 kev 3.0 MeV 0.1 µsv 9.99 Sv Scintillation and GM tube 1610B-01 20 kev 10.0 MeV 0.05 μsv 20.0 Sv GM tube RAD-60s 30 kev 6 MeV 1 μsv 9.99 Sv Silicon diode DoseAware 33 kev 118 kev 1 μsv 10 Sv Silicon diode * - reference point dosimeter.
THE MAIN CHARACTERISTICS OF APDS PROVIDED BY MANUFACTURERS APD model Energy range Personal dose Detector type equivalent range (Hp(10)), Sv AT1121* 15 kev 10 MeV 0.01 μsv 10 Sv Scintillation AT3509 15 kev 10 MeV 1 μsv 10 Sv Silicon diode EPD Mk 2.3 16 kev 7 MeV 10 μsv 10 Sv Silicon diode PM1621 10 kev 20 MeV 1 μsv 9.99 Sv GM tube PM1203M 60 kev 1.5 MeV 10 μsv 9.99 Sv GM tube PM1703MO-1 33 kev 3.0 MeV 0.1 µsv 9.99 Sv Scintillation and GM tube 1610B-01 20 kev 10.0 MeV 0.05 μsv 20.0 Sv GM tube RAD-60s 30 kev 6 MeV 1 μsv 9.99 Sv Silicon diode DoseAware 33 kev 118 kev 1 μsv 10 Sv Silicon diode * - reference point dosimeter.
THE PARAMETERS OF THE PULSE AND CONTINUOUS X-RAY EXPOSITIONS No. kv ma ms Measured ref. dose (μsv) 1. (N=10) 50 100 100 0.9 2. (N=10) 60 100 100 0.9 3. (N=10) 70 100 100 1 4. (N=10) 81 500 20 0.7 5. (N=10) 81 200 50 1.13 6. (N=10) 81 100 100 1.87 7. (N=10) 81 50 200 2.2 8. (N=10) 100 100 100 2.4 9. (N=10) 121 100 100 3,1 10.* 93 6.74 36 sec. 5.1 * - fluororadiography mode
THE EXPERIMENTAL DATA OF THE GAMMA RAY MEASUREMENTS Source Energy (kv) Activity (MBq) Reference dose (μsv) 137 Cs 662 7.48 1.5 99m Tc 140 301 7.15 18 F 511 250 5.2
Extremities dosimetry with DoseAware
CONCLUSION and DISCUSSION Our study results showed that PM1610B-01 equipped with Geiger-Muller tube, provides information in pulsed mode, but it is necessary to perform corrections. The results of tests performed with gamma rays showed that all devices are suitable for nuclear medicine field. However, AT3509 tends to show higher doses. The response of DoseAware, RADOS-60S PM1621, PM1610B-01, AT3509 and EPD Mk 2.3 showed a good result to continuous mode, however PM1610B-01 and AT3509 tends to show higher dose values. APDs for medical personnel is important mean to obtain information about the doses, to self-educate staff and control exposure.
CONCLUSION Out of the 8 tested APDs, AT3509 and PM1610B-01 are most fitting for X-ray with short-pulsed low-dose mode, even if some corrections in calculating and estimating are necessary. Our study results showed that DoseAware dosimeter suitable for continuous mode and works properly with the pulse width larger than 100 ms. DoseAware are suitable for gamma rays.
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