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Dosimetric validation and comparison of a novel electronic dosimetric system for nuclear medicine radiation protection
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Abstracts/Physica Medica 32 (2016) e97–e115
a defined volume at a sequence of time points using QI, (III) integration of the time sequence of measured activity values, (IV) calculation of the absorbed dose from the activity–time integral. Each link in this chain may involve methods and procedures for which there is as yet no harmonized approach. Conclusions: An agreed dosimetry protocol is needed to raise MRT treatments to an acceptable level. Standardization and harmonization of nuclear imaging procedures for QI is the first step toward the development of a dosimetry protocol for MRT. The aim of the MetroMRT project was to provide a standardized methodology for calculating of internal dose quantities and associated uncertainties. In the present paper the steps taken toward the development of an international protocol are presented, along with the major results achieved.
of view (FOV), system spatial resolution and system sensitivity were performed by using a capillary (0.85 mm inner diameter) filled with 7400 kBq 99mTcO4- (140 keV) and a sealed gamma-emitting 241Am source (60 keV) with activity of 37 MBq. The detector is operated at a single low-energy threshold of about 5 keV. Results: At an FOV of 50 × 50 mm2: the background-subtracted sensitivity is 0.086 cps/kBq at 140 keV (w/1.9 mm pinhole) and the system spatial resolution is 7.8 mm FWHM; at 60 keV, the sensitivity is 0.0025 cps/kBq and the system spatial resolution is 4.2 mm FWHM (w/0.78 mm pinhole). Larger sensitivity and spatial resolution were estimated with the use of the coded aperture mask. Conclusion: The laboratory performance suggests the possibility to start a clinical trial to evaluate the performance of MediPROBE for gamma-ray nuclear imaging.
http://dx.doi.org/10.1016/j.ejmp.2016.01.358 http://dx.doi.org/10.1016/j.ejmp.2016.01.360 C.353 DOSIMETRIC VALIDATION AND COMPARISON OF A NOVEL ELECTRONIC DOSIMETRIC SYSTEM FOR NUCLEAR MEDICINE RADIATION PROTECTION A. Daniele *,a, E. Nicolai a, N. Franza b, A. Tonnetti b. a IRCCS SDN, Napoli, Italy; b DOSIMETRICA, Nocera Inferiore (NA), Italy Purpose: A growing use of diagnostic medical examination using ionizing radiation is observed but the risk associated for the operators who attend them in this procedures is not always clear and is necessary a dosimetric instrumentation for operators who really are subject to continuous exposure of nuclear medicine radiations. The purpose of this work is to evaluate the dosimetric property of a novel electronic pocket dosimeter by comparison with commercial dosimetric devices and to compare it with the TLD dosimeter in the clinical routine. Methods and Materials: The dosimetric device is an electronic semiconductor pocket dosimeter (Aloka, Hitachi) that allows to check at any time the accumulated amount of radiation exposure. The Energy threshold of the device is of 40 keV with a measurement dose ranging from 1 μSv to 10 Sv. The measurement has been performed in the NM department of the Diagnostics and Nuclear Research Institute SDN in Naples. The dosimetric validation of the dosimeter is assessed by an intercomparison with a camera and a spectroscope in terms of dose and dose rate and 2 months study for the comparison of the pocket dosimeter and a commercial TLD. Results: A very good agreement between the electronic dosimeter, the camera and the spectroscope was found. A linear fit for different activity dose and the measured dose has been reported. The same linear fit with an R2 equal to 1 is found in the comparison between the pocket dosimeter and the TLD dosimeter. Discussion: The accuracy of the electronic dosimeter has been found comparable with that of calibrated reference instruments, with a negligible difference within 5%. Different measures of absorbed dose and dose rate for different activity source have shown a good linear fit. The comparison with the TLD dosimeter has established that the electronic pocket dosimeter is a good candidate to be used in the clinical routine in the Nuclear Medicine department for the operative radiation protection. http://dx.doi.org/10.1016/j.ejmp.2016.01.359 C.354 PERFORMANCE OF MEDIPROBE COMPACT GAMMA CAMERA F. Di Lillo * ,a,b , V. Corvino a , A. Sarno a,b , G. Mettivier a,b , P. Russo a,b . a Dipartimento di Fisica, Università di Napoli Federico II, Napoli, Italy; b INFN Sezione di Napoli, Napoli, Italy Introduction: The aim of this work is to assess the performance of a prototype compact gamma camera (MediPROBE) based on a semiconductor hybrid pixel detector. This probe could be adopted for various tasks as preoperative sentinel lymph node localization, breast imaging with 99Tcsestamibi and thyroid imaging with iodine radioisotopes. Material and Methods: The hybrid detector is an assembly of a 1-mm thick CdTe detector (sensitive area 14.08 × 14.08 mm2) electrically connected pixelby-pixel to a photon-counting CMOS ASIC of the Medipix2 series (256 × 256 square pixels, 55-μm pitch). MediPROBE is equipped with a set of three interchangeable knife-edge pinhole collimators (hole aperture of 0.78 mm, 1 mm, and 1.9 mm) and with a coded aperture mask. Measurement of field
C.355 ABSOLUTE MEASUREMENT IN SITU OF THE 90Y ACTIVITY IN LIQUID SOLUTION BY TDCR METHOD AND CALIBRATION OF AN IONIZATION CHAMBER S. Donatiello *,a, M. Capogni b, P. De Felice b, V. Cannatà a, M. D’Arienzo b, L. Strigari c, M. Tapner d. a Enterprise Risk Management/Medical Physics, Bambino Gesù Children’s Hospital, IRCCS, Rome, Italy; b ENEA National Institute of Ionizing Radiation Metrology (INMRI) Casaccia, Rome, Italy; c National Cancer Institute Regina Elena, Rome, Italy; d Sirtex, Sydney, NSW, Australia Aim: One of the main problems in molecular radiation therapy is the accurate determination of the activity of a radiopharmaceutical to be administered to a patient for the cancer treatment. Usually commerciallyavailable radionuclide calibrators, based on a re-entrant 4pi ionization chamber (IC), are used for this scope. These devices require in many cases a calibration directly on site due to the short half-life of the radionuclides, typically used in nuclear medicine (NM), measured in them. In this work the activity measurements directly in situ of a pure-beta shortlived emitter of interest of NM, as the 90Y, are presented. Materials and Methods: A portable detector based on the ENEA-INMRI Triple-to-Double Coincidence Ratio (TDCR) counter, equipped with the CAEN Desktop DT5720B digitizer, was used at the Laboratory of Medical Physics and Expert Systems IFO in Rome. The counter, made by three square Hamamatsu photomultipliers arranged in a 120 degree planar geometry, was used for direct activity measurements of a 90Y liquid solution, sent by Sirtex to IFO, and to calibrate the IFO IC to 90Y. From the master solution two lowactivity samples were prepared in 20 mL glass vials containing radioactive material in solution with 10 mL of Ultima Gold liquid scintillator; a highactivity sample was also prepared ready-to-measure in the IFO IC. Results: The experimental data showed a good agreement between the activity of the two samples directly measured on site by the TDCR; this allowed the calibration of the IFO IC for 90Y in liquid solution with an uncertainty by far within the limit of ±10% established by the European Pharmacopoeia. Conclusions: A new method based on a portable TDCR device was tested for direct activity measurements on site of a short-lived pure-beta emitter used in NM. The IC at an NM site, as well as IFO, was then calibrated with low uncertainty by using the previous standardized solution. This work was carried out in the frame of the EMRP MetroMRT project. http://dx.doi.org/10.1016/j.ejmp.2016.01.361
C.356 A NOVEL RADIOGUIDED SURGERY TECHNIQUE EXPLOITING BETA – DECAY R. Donnarumma * ,a,b , V. Bocci a,b,c , E. Capparella a , F. Collamati a,b , M. Cremonesi d, M.E. Ferrari d, F. Fioroni e, C.M. Grana d, G. Ioannidis a, M. Iori e, G. Limiti a,f , C. Mancini Terracciano a,b , M. Marafini b , S. Morganti a,b , A. Russomando a,b,c, E. Solfaroli Camilloci a,b, M. Toppi g, G. Traini a, A. Versari e, R. Faccini a,b. a Sapienza Universita di Roma, Roma, Italy; b INFN Sezione di Roma, Roma, Italy; c Istituto Italiano di Tecnologia, Roma, Italy; d Istituto Europeo di Oncologia, Milano, Italy; e IRCCS – ASMN, Reggio Emilia, Italy; f Istituto Superiore di Sanità, Roma, Italy; g Laboratori Nazionali di Frascati dell’INFN, Frascati, Italy
Abstracts/Physica Medica 32 (2016) e97–e115
a defined volume at a sequence of time points using QI, (III) integration of the time sequence of measured activity values, (IV) calculation of the absorbed dose from the activity–time integral. Each link in this chain may involve methods and procedures for which there is as yet no harmonized approach. Conclusions: An agreed dosimetry protocol is needed to raise MRT treatments to an acceptable level. Standardization and harmonization of nuclear imaging procedures for QI is the first step toward the development of a dosimetry protocol for MRT. The aim of the MetroMRT project was to provide a standardized methodology for calculating of internal dose quantities and associated uncertainties. In the present paper the steps taken toward the development of an international protocol are presented, along with the major results achieved.
of view (FOV), system spatial resolution and system sensitivity were performed by using a capillary (0.85 mm inner diameter) filled with 7400 kBq 99mTcO4- (140 keV) and a sealed gamma-emitting 241Am source (60 keV) with activity of 37 MBq. The detector is operated at a single low-energy threshold of about 5 keV. Results: At an FOV of 50 × 50 mm2: the background-subtracted sensitivity is 0.086 cps/kBq at 140 keV (w/1.9 mm pinhole) and the system spatial resolution is 7.8 mm FWHM; at 60 keV, the sensitivity is 0.0025 cps/kBq and the system spatial resolution is 4.2 mm FWHM (w/0.78 mm pinhole). Larger sensitivity and spatial resolution were estimated with the use of the coded aperture mask. Conclusion: The laboratory performance suggests the possibility to start a clinical trial to evaluate the performance of MediPROBE for gamma-ray nuclear imaging.
http://dx.doi.org/10.1016/j.ejmp.2016.01.358 http://dx.doi.org/10.1016/j.ejmp.2016.01.360 C.353 DOSIMETRIC VALIDATION AND COMPARISON OF A NOVEL ELECTRONIC DOSIMETRIC SYSTEM FOR NUCLEAR MEDICINE RADIATION PROTECTION A. Daniele *,a, E. Nicolai a, N. Franza b, A. Tonnetti b. a IRCCS SDN, Napoli, Italy; b DOSIMETRICA, Nocera Inferiore (NA), Italy Purpose: A growing use of diagnostic medical examination using ionizing radiation is observed but the risk associated for the operators who attend them in this procedures is not always clear and is necessary a dosimetric instrumentation for operators who really are subject to continuous exposure of nuclear medicine radiations. The purpose of this work is to evaluate the dosimetric property of a novel electronic pocket dosimeter by comparison with commercial dosimetric devices and to compare it with the TLD dosimeter in the clinical routine. Methods and Materials: The dosimetric device is an electronic semiconductor pocket dosimeter (Aloka, Hitachi) that allows to check at any time the accumulated amount of radiation exposure. The Energy threshold of the device is of 40 keV with a measurement dose ranging from 1 μSv to 10 Sv. The measurement has been performed in the NM department of the Diagnostics and Nuclear Research Institute SDN in Naples. The dosimetric validation of the dosimeter is assessed by an intercomparison with a camera and a spectroscope in terms of dose and dose rate and 2 months study for the comparison of the pocket dosimeter and a commercial TLD. Results: A very good agreement between the electronic dosimeter, the camera and the spectroscope was found. A linear fit for different activity dose and the measured dose has been reported. The same linear fit with an R2 equal to 1 is found in the comparison between the pocket dosimeter and the TLD dosimeter. Discussion: The accuracy of the electronic dosimeter has been found comparable with that of calibrated reference instruments, with a negligible difference within 5%. Different measures of absorbed dose and dose rate for different activity source have shown a good linear fit. The comparison with the TLD dosimeter has established that the electronic pocket dosimeter is a good candidate to be used in the clinical routine in the Nuclear Medicine department for the operative radiation protection. http://dx.doi.org/10.1016/j.ejmp.2016.01.359 C.354 PERFORMANCE OF MEDIPROBE COMPACT GAMMA CAMERA F. Di Lillo * ,a,b , V. Corvino a , A. Sarno a,b , G. Mettivier a,b , P. Russo a,b . a Dipartimento di Fisica, Università di Napoli Federico II, Napoli, Italy; b INFN Sezione di Napoli, Napoli, Italy Introduction: The aim of this work is to assess the performance of a prototype compact gamma camera (MediPROBE) based on a semiconductor hybrid pixel detector. This probe could be adopted for various tasks as preoperative sentinel lymph node localization, breast imaging with 99Tcsestamibi and thyroid imaging with iodine radioisotopes. Material and Methods: The hybrid detector is an assembly of a 1-mm thick CdTe detector (sensitive area 14.08 × 14.08 mm2) electrically connected pixelby-pixel to a photon-counting CMOS ASIC of the Medipix2 series (256 × 256 square pixels, 55-μm pitch). MediPROBE is equipped with a set of three interchangeable knife-edge pinhole collimators (hole aperture of 0.78 mm, 1 mm, and 1.9 mm) and with a coded aperture mask. Measurement of field
C.355 ABSOLUTE MEASUREMENT IN SITU OF THE 90Y ACTIVITY IN LIQUID SOLUTION BY TDCR METHOD AND CALIBRATION OF AN IONIZATION CHAMBER S. Donatiello *,a, M. Capogni b, P. De Felice b, V. Cannatà a, M. D’Arienzo b, L. Strigari c, M. Tapner d. a Enterprise Risk Management/Medical Physics, Bambino Gesù Children’s Hospital, IRCCS, Rome, Italy; b ENEA National Institute of Ionizing Radiation Metrology (INMRI) Casaccia, Rome, Italy; c National Cancer Institute Regina Elena, Rome, Italy; d Sirtex, Sydney, NSW, Australia Aim: One of the main problems in molecular radiation therapy is the accurate determination of the activity of a radiopharmaceutical to be administered to a patient for the cancer treatment. Usually commerciallyavailable radionuclide calibrators, based on a re-entrant 4pi ionization chamber (IC), are used for this scope. These devices require in many cases a calibration directly on site due to the short half-life of the radionuclides, typically used in nuclear medicine (NM), measured in them. In this work the activity measurements directly in situ of a pure-beta shortlived emitter of interest of NM, as the 90Y, are presented. Materials and Methods: A portable detector based on the ENEA-INMRI Triple-to-Double Coincidence Ratio (TDCR) counter, equipped with the CAEN Desktop DT5720B digitizer, was used at the Laboratory of Medical Physics and Expert Systems IFO in Rome. The counter, made by three square Hamamatsu photomultipliers arranged in a 120 degree planar geometry, was used for direct activity measurements of a 90Y liquid solution, sent by Sirtex to IFO, and to calibrate the IFO IC to 90Y. From the master solution two lowactivity samples were prepared in 20 mL glass vials containing radioactive material in solution with 10 mL of Ultima Gold liquid scintillator; a highactivity sample was also prepared ready-to-measure in the IFO IC. Results: The experimental data showed a good agreement between the activity of the two samples directly measured on site by the TDCR; this allowed the calibration of the IFO IC for 90Y in liquid solution with an uncertainty by far within the limit of ±10% established by the European Pharmacopoeia. Conclusions: A new method based on a portable TDCR device was tested for direct activity measurements on site of a short-lived pure-beta emitter used in NM. The IC at an NM site, as well as IFO, was then calibrated with low uncertainty by using the previous standardized solution. This work was carried out in the frame of the EMRP MetroMRT project. http://dx.doi.org/10.1016/j.ejmp.2016.01.361
C.356 A NOVEL RADIOGUIDED SURGERY TECHNIQUE EXPLOITING BETA – DECAY R. Donnarumma * ,a,b , V. Bocci a,b,c , E. Capparella a , F. Collamati a,b , M. Cremonesi d, M.E. Ferrari d, F. Fioroni e, C.M. Grana d, G. Ioannidis a, M. Iori e, G. Limiti a,f , C. Mancini Terracciano a,b , M. Marafini b , S. Morganti a,b , A. Russomando a,b,c, E. Solfaroli Camilloci a,b, M. Toppi g, G. Traini a, A. Versari e, R. Faccini a,b. a Sapienza Universita di Roma, Roma, Italy; b INFN Sezione di Roma, Roma, Italy; c Istituto Italiano di Tecnologia, Roma, Italy; d Istituto Europeo di Oncologia, Milano, Italy; e IRCCS – ASMN, Reggio Emilia, Italy; f Istituto Superiore di Sanità, Roma, Italy; g Laboratori Nazionali di Frascati dell’INFN, Frascati, Italy