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Comparison of the dosimetric response of 4-element BeOSL and TLD-100 passive personal dosimeters
Abstracts / Physica Medica 32 (2016) 274–283
RADIATION RISK OF CANCER FROM MEDICAL IMAGING IN END STAGE KIDNEY DISEASE PATIENTS: ITALIAN NATIONWIDE SURVEY Luca Vigna a,*, Domenico Lizio a, Marco Brambilla a, Andreana De Mauri b, Carmine Zoccali c, Maurizio Postorino d a
University Hospital of Novara, Medical Physics Dept., Novara, Italy University Hospital of Novara, Nephrology Dept., Novara, Italy c National Research Council, Clinical Physiology Institute, Reggio Calabria, Italy d Azienda Ospedaliera Reggio Calabria, Nephrology, Reggio Calabria, Italy ⇑ Corresponding author. b
Purpose. End Stage Kidney Disease patients are exposed to ionizing radiation during imaging studies. The variability in diagnostic imaging policies and the accompanying risk across Renal Units are unknown. We studied this variability at centre level and quantified the associated risks at patient level, by estimating the organ doses (HT) and the Risk of exposure-induced cancer death (%) (REID). Materials and methods. Fourteen nephrology departments enrolled 739 patients on hemodialysis (HD) and 486 kidney transplant patients (KTP), recording the details of the radiological procedures performed over one year. HT were derived using Montecarlo based simulation software for conventional diagnostic radiology procedures and for Computed Tomography. HT were derived using tabulated conversion factors for cardiac interventional radiology and nuclear medicine procedures. Results. The average REID was 0.047 ± 0.12 % and the corresponding 5-years cancer risk attributable to ionizing radiation exposure was 1 every 424 patients. The median REID was 0.009% and the 3rd quartile was 0.03%. The average REID was significantly higher in HD than in KTP (0.06 ± 0.13 i.e. 1:333 patients for 5-years vs 0.03 ± 0.09 i.e. 1:666 patients for 5-years; p < 0.001). The variation of average REID among participating centres was highly significant (F = 3.23; p < 0.001) ranging from a minimum of 0.009% to a maximum of 0.09%. Conclusion. The excess cancer risk attributable to medical exposure is highly variable among centres (a tenfold variation), suggesting that protocols of individual patient’s follow up with medical imaging are not standardized. On average, KTP have a lower exposure than HD patients (a twofold variation). Disclosure. None to declare. http://dx.doi.org/10.1016/j.ejmp.2016.07.620
COMPARISON OF THE DOSIMETRIC RESPONSE OF 4-ELEMENT BEOSL AND TLD-100 PASSIVE PERSONAL DOSIMETERS L. Oliver a,b,*, C. Candela a, J.D. Palma a, M.C. Pujades a, A. Soriano a, J. Alabau a, J. Martínez a, V. Mestre a, J.C. Ruiz a, J. Vilar a, N. Llorca a a
National Dosimetry Centre (CND), Instituto de Gestión Sanitaria, Valencia, Spain b Fundación Instituto Valenciano de Oncología (IVO), Valencia, Spain ⇑ Corresponding author. Introduction. Thermoluminescent dosimeters (TLD-100, ThermoFisher-Scientific, USA) and optically stimulated dosimeters based on beryllium oxide (BeOSL, Dosimetrics GmbH, Germany) are passive personal dosimeters. Purpose. The aims of this study were to verify that the 4-element version of both systems satisfy the IEC-62387 dosimetric requirements, and to compare them. Materials and methods. The TLDs tested were those provided by the National Dosimetry Centre (CND), with a home-made dose calcu-
279
lation algorithm, whereas BeOSLs were as distributed by Dosimetrics. The tests performed were: coefficient of variation, nonlinearity, photon angular and energy dependency, reusability and time dependency, as well as detection threshold and energy estimation accuracy. Results. Both systems satisfy the IEC-62387 requirements for the tests described above. Among the advantages of BeOSLs, these have lower energy dependency (Hp(10) accuracy is better than 11% between 16.1 keV and 662 keV) and can be read more than once with good accuracy when re-reading correction is applied (<3% variation beyond 1 mSv between at least 5 consecutive re-readings). Also, each dose value provided is the average of 5 measurements, with a consistency check. However, the CND dose algorithm for TLDs provides more accurate energy estimations, which are used to correct their higher energy dependency. In addition, TLD readers provide glow curves that can be used to identify misreading of any of the 4 elements. Conclusion. The TLDs and BeOSLs tested satisfy the dosimetric requirements to be used as personal dosimeters. The choice between one of them might depend on the importance given to the different criteria studied. http://dx.doi.org/10.1016/j.ejmp.2016.07.621
IMPLEMENTATION OF THE EFOMP PROTOCOL FOR QUALITY CONTROL IN DIGITAL MAMMOGRAPHY IN A MULTI-HOSPITAL/ VENDOR CONTEXT A.Savini a,*, F. Bartolucci a, C. Fidanza a, F. Rosica a, F. Capone b, G. Orlandi a a
Medical Physics Department, AUSL4, Teramo, Italy Radiology Department, AUSL4, Teramo, Italy ⇑ Corresponding author. b
Introduction. The European Federation of Organisations in Medical Physics (EFOMP) has recently released a protocol for quality control (QC) in digital mammography with the intent of harmonizing and simplifying the QC procedures across the European countries. Purpose. The aim of this work was to report our experience regarding the implementation of the EFOMP protocol for QC in digital mammography in a multi-hospital/vendor context. Materials and methods. QC tests suggested by the EFOMP protocol were merged with mandatory tests by national (Italian) regulations in order to build a local QC protocol. The protocol was applied to one DR and three CR mammography systems developed by different vendors. Time needed for routine QCs was measured. A fast weekly test was implemented to assess the long term reproducibility of relevant quantities (dose and SNR). Results. By employing one physicist and one technologist, the time needed for routine QC was: 4.5 h ± 0.5 h (annual tests), 2.5 h ± 0.5 h (semiannual tests), 0.2 h ± 0.1 h (weekly tests). For weekly tests, coefficients of variation of dose and SNR were below 6.0% (four-months period evaluated). By applying the developed protocol, two major and five minor anomalies were identified and corrected. Conclusions. The EFOMP protocol could be adapted to local (Italian) regulations with minor modifications. Flexibility and simplification of routine QCs were advantageous in a busy multi-hospital/ vendor context. Disclosure. None. http://dx.doi.org/10.1016/j.ejmp.2016.07.622
RADIATION RISK OF CANCER FROM MEDICAL IMAGING IN END STAGE KIDNEY DISEASE PATIENTS: ITALIAN NATIONWIDE SURVEY Luca Vigna a,*, Domenico Lizio a, Marco Brambilla a, Andreana De Mauri b, Carmine Zoccali c, Maurizio Postorino d a
University Hospital of Novara, Medical Physics Dept., Novara, Italy University Hospital of Novara, Nephrology Dept., Novara, Italy c National Research Council, Clinical Physiology Institute, Reggio Calabria, Italy d Azienda Ospedaliera Reggio Calabria, Nephrology, Reggio Calabria, Italy ⇑ Corresponding author. b
Purpose. End Stage Kidney Disease patients are exposed to ionizing radiation during imaging studies. The variability in diagnostic imaging policies and the accompanying risk across Renal Units are unknown. We studied this variability at centre level and quantified the associated risks at patient level, by estimating the organ doses (HT) and the Risk of exposure-induced cancer death (%) (REID). Materials and methods. Fourteen nephrology departments enrolled 739 patients on hemodialysis (HD) and 486 kidney transplant patients (KTP), recording the details of the radiological procedures performed over one year. HT were derived using Montecarlo based simulation software for conventional diagnostic radiology procedures and for Computed Tomography. HT were derived using tabulated conversion factors for cardiac interventional radiology and nuclear medicine procedures. Results. The average REID was 0.047 ± 0.12 % and the corresponding 5-years cancer risk attributable to ionizing radiation exposure was 1 every 424 patients. The median REID was 0.009% and the 3rd quartile was 0.03%. The average REID was significantly higher in HD than in KTP (0.06 ± 0.13 i.e. 1:333 patients for 5-years vs 0.03 ± 0.09 i.e. 1:666 patients for 5-years; p < 0.001). The variation of average REID among participating centres was highly significant (F = 3.23; p < 0.001) ranging from a minimum of 0.009% to a maximum of 0.09%. Conclusion. The excess cancer risk attributable to medical exposure is highly variable among centres (a tenfold variation), suggesting that protocols of individual patient’s follow up with medical imaging are not standardized. On average, KTP have a lower exposure than HD patients (a twofold variation). Disclosure. None to declare. http://dx.doi.org/10.1016/j.ejmp.2016.07.620
COMPARISON OF THE DOSIMETRIC RESPONSE OF 4-ELEMENT BEOSL AND TLD-100 PASSIVE PERSONAL DOSIMETERS L. Oliver a,b,*, C. Candela a, J.D. Palma a, M.C. Pujades a, A. Soriano a, J. Alabau a, J. Martínez a, V. Mestre a, J.C. Ruiz a, J. Vilar a, N. Llorca a a
National Dosimetry Centre (CND), Instituto de Gestión Sanitaria, Valencia, Spain b Fundación Instituto Valenciano de Oncología (IVO), Valencia, Spain ⇑ Corresponding author. Introduction. Thermoluminescent dosimeters (TLD-100, ThermoFisher-Scientific, USA) and optically stimulated dosimeters based on beryllium oxide (BeOSL, Dosimetrics GmbH, Germany) are passive personal dosimeters. Purpose. The aims of this study were to verify that the 4-element version of both systems satisfy the IEC-62387 dosimetric requirements, and to compare them. Materials and methods. The TLDs tested were those provided by the National Dosimetry Centre (CND), with a home-made dose calcu-
279
lation algorithm, whereas BeOSLs were as distributed by Dosimetrics. The tests performed were: coefficient of variation, nonlinearity, photon angular and energy dependency, reusability and time dependency, as well as detection threshold and energy estimation accuracy. Results. Both systems satisfy the IEC-62387 requirements for the tests described above. Among the advantages of BeOSLs, these have lower energy dependency (Hp(10) accuracy is better than 11% between 16.1 keV and 662 keV) and can be read more than once with good accuracy when re-reading correction is applied (<3% variation beyond 1 mSv between at least 5 consecutive re-readings). Also, each dose value provided is the average of 5 measurements, with a consistency check. However, the CND dose algorithm for TLDs provides more accurate energy estimations, which are used to correct their higher energy dependency. In addition, TLD readers provide glow curves that can be used to identify misreading of any of the 4 elements. Conclusion. The TLDs and BeOSLs tested satisfy the dosimetric requirements to be used as personal dosimeters. The choice between one of them might depend on the importance given to the different criteria studied. http://dx.doi.org/10.1016/j.ejmp.2016.07.621
IMPLEMENTATION OF THE EFOMP PROTOCOL FOR QUALITY CONTROL IN DIGITAL MAMMOGRAPHY IN A MULTI-HOSPITAL/ VENDOR CONTEXT A.Savini a,*, F. Bartolucci a, C. Fidanza a, F. Rosica a, F. Capone b, G. Orlandi a a
Medical Physics Department, AUSL4, Teramo, Italy Radiology Department, AUSL4, Teramo, Italy ⇑ Corresponding author. b
Introduction. The European Federation of Organisations in Medical Physics (EFOMP) has recently released a protocol for quality control (QC) in digital mammography with the intent of harmonizing and simplifying the QC procedures across the European countries. Purpose. The aim of this work was to report our experience regarding the implementation of the EFOMP protocol for QC in digital mammography in a multi-hospital/vendor context. Materials and methods. QC tests suggested by the EFOMP protocol were merged with mandatory tests by national (Italian) regulations in order to build a local QC protocol. The protocol was applied to one DR and three CR mammography systems developed by different vendors. Time needed for routine QCs was measured. A fast weekly test was implemented to assess the long term reproducibility of relevant quantities (dose and SNR). Results. By employing one physicist and one technologist, the time needed for routine QC was: 4.5 h ± 0.5 h (annual tests), 2.5 h ± 0.5 h (semiannual tests), 0.2 h ± 0.1 h (weekly tests). For weekly tests, coefficients of variation of dose and SNR were below 6.0% (four-months period evaluated). By applying the developed protocol, two major and five minor anomalies were identified and corrected. Conclusions. The EFOMP protocol could be adapted to local (Italian) regulations with minor modifications. Flexibility and simplification of routine QCs were advantageous in a busy multi-hospital/ vendor context. Disclosure. None. http://dx.doi.org/10.1016/j.ejmp.2016.07.622