Pub Date : 2026-02-06DOI: 10.1016/j.radmeas.2026.107636
Juan C. Mora , Mariella Terán , Helen Khoury , Daniel Molina , Patricia Mora , Nancy Puerta , Leslie Anne Vironneau Janicek , Sebastian Gossio , Denison de Souza-Santos , Omar Garcia , Julieta Rearte , Marina Di Giorgio , V. Correcher
<div><div>This study presents a comprehensive regional assessment of dosimetry capabilities in Latin America and the Caribbean countries (LAC). The study was conducted using surveys coordinated, elaborated and analyzed by the steering committee of the Latin American Network for the Optimization of Occupational Radiation Protection (REPROLAM). All the work was supported by the Technical Cooperation of International Atomic Energy Agency (TC IAEA) through the RLA9088 and RLA9091 regional projects. The investigation covers five different dosimetry fields: external, internal, computational, biological, and retrospective dosimetry. Answers from participants of 16 countries were received: A total of 32 individual monitoring services for external dosimetry, 24 centers for internal dosimetry, 38 researchers for computational dosimetry, 12 biological dosimetry laboratories members of the Latin American Biological Dosimetry Network (LBDNet), and 16 retrospective dosimetry facilities. In the case of external dosimetry, an analysis of the results from 13 countries reveals that thermoluminescent dosimetry (TLD) remains the main technology for external monitoring (79% of services), with a growing adoption of optically stimulated luminescence dosimetry (OSLD) systems. Using both TLD and OSLD, over 160,000 occupationally exposed workers are monitored regionally, predominantly in medical applications (75%). Internal dosimetry services (16 direct, 15 indirect services) focus primarily on thyroid monitoring due to extensive <span><math><mrow><msup><mrow></mrow><mrow><mn>131</mn></mrow></msup><mi>I</mi></mrow></math></span> use in nuclear medicine in the region, but the results showed a lack of homogeneity in calibration and reporting levels. Monte Carlo-based computational dosimetry employs MCNP as the preferred code (25% of users). Biological dosimetry is well-established in the region through the LBDNet, with 21 laboratories capable of performing dicentric chromosome assays for emergency triage. LBDNet demonstrated to be a robust emergency response network. Retrospective dosimetry in the region relies predominantly on luminescence techniques. While dosimetry laboratories and techniques are well established in the region, several gaps have been identified which should be addressed in further approaches. These gaps include insufficient implementation of lens of the eye dosimetry (<span><math><mrow><msub><mrow><mi>H</mi></mrow><mrow><mi>p</mi></mrow></msub><mrow><mo>(</mo><mn>3</mn><mo>)</mo></mrow></mrow></math></span>), limited neutron dosimetry capacity, poor implementation of quality management system (60% of the IMS) and insufficient ISO/IEC 17025 accreditation (70% of those implementing a QMS, i.e. 42% of the total), a lack of standardized internal dosimetry protocols in the different laboratories, and the need for organizing periodic regional intercomparison exercises, which started with the 2023 intercomparison. The results of these surveys provide a baseline
{"title":"A survey of dosimetry capabilities and trends in Latin America and the Caribbean region: Implications for occupational dosimetry","authors":"Juan C. Mora , Mariella Terán , Helen Khoury , Daniel Molina , Patricia Mora , Nancy Puerta , Leslie Anne Vironneau Janicek , Sebastian Gossio , Denison de Souza-Santos , Omar Garcia , Julieta Rearte , Marina Di Giorgio , V. Correcher","doi":"10.1016/j.radmeas.2026.107636","DOIUrl":"10.1016/j.radmeas.2026.107636","url":null,"abstract":"<div><div>This study presents a comprehensive regional assessment of dosimetry capabilities in Latin America and the Caribbean countries (LAC). The study was conducted using surveys coordinated, elaborated and analyzed by the steering committee of the Latin American Network for the Optimization of Occupational Radiation Protection (REPROLAM). All the work was supported by the Technical Cooperation of International Atomic Energy Agency (TC IAEA) through the RLA9088 and RLA9091 regional projects. The investigation covers five different dosimetry fields: external, internal, computational, biological, and retrospective dosimetry. Answers from participants of 16 countries were received: A total of 32 individual monitoring services for external dosimetry, 24 centers for internal dosimetry, 38 researchers for computational dosimetry, 12 biological dosimetry laboratories members of the Latin American Biological Dosimetry Network (LBDNet), and 16 retrospective dosimetry facilities. In the case of external dosimetry, an analysis of the results from 13 countries reveals that thermoluminescent dosimetry (TLD) remains the main technology for external monitoring (79% of services), with a growing adoption of optically stimulated luminescence dosimetry (OSLD) systems. Using both TLD and OSLD, over 160,000 occupationally exposed workers are monitored regionally, predominantly in medical applications (75%). Internal dosimetry services (16 direct, 15 indirect services) focus primarily on thyroid monitoring due to extensive <span><math><mrow><msup><mrow></mrow><mrow><mn>131</mn></mrow></msup><mi>I</mi></mrow></math></span> use in nuclear medicine in the region, but the results showed a lack of homogeneity in calibration and reporting levels. Monte Carlo-based computational dosimetry employs MCNP as the preferred code (25% of users). Biological dosimetry is well-established in the region through the LBDNet, with 21 laboratories capable of performing dicentric chromosome assays for emergency triage. LBDNet demonstrated to be a robust emergency response network. Retrospective dosimetry in the region relies predominantly on luminescence techniques. While dosimetry laboratories and techniques are well established in the region, several gaps have been identified which should be addressed in further approaches. These gaps include insufficient implementation of lens of the eye dosimetry (<span><math><mrow><msub><mrow><mi>H</mi></mrow><mrow><mi>p</mi></mrow></msub><mrow><mo>(</mo><mn>3</mn><mo>)</mo></mrow></mrow></math></span>), limited neutron dosimetry capacity, poor implementation of quality management system (60% of the IMS) and insufficient ISO/IEC 17025 accreditation (70% of those implementing a QMS, i.e. 42% of the total), a lack of standardized internal dosimetry protocols in the different laboratories, and the need for organizing periodic regional intercomparison exercises, which started with the 2023 intercomparison. The results of these surveys provide a baseline","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"193 ","pages":"Article 107636"},"PeriodicalIF":2.2,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-05DOI: 10.1016/j.radmeas.2026.107633
Bao Wang , Xiongjie Zhang , Dongyang Wang , Wenming Dong , Dong Li , Shiliang Liu , Haoran Zhang , Jiangni Liu , Haixian Zhou , Qi Liu , Haitao Wang , Ning Chen , Renbo Wang
Pulse height analysis (PHA) is commonly used in scintillation γ-ray spectroscopy because it is simple and fast. However, in systems utilizing summed outputs from multi-channel silicon photomultiplier (SiPM) arrays, PHA becomes increasingly susceptible to waveform distortions inherent to the summing architecture. Such distortions alter the signal shape and significantly degrade the energy resolution. In this study, we systematically investigate the characteristics and origins of such abnormal signals using a 16-channel SiPM array coupled to a NaI(Tl) scintillator. By analyzing the pulse area-to-height ratio distributions, we show that summing-induced distortions tend to exhibit broadened pulse shapes and deviate significantly from the single-event signal profile. To mitigate this issue, a threshold-based waveform discrimination method is introduced. This method identifies and rejects abnormal pulses based on receiver operating characteristic (ROC) curve optimization, offering practical improvement in spectral performance when PHA must be retained for speed or simplicity. However, waveform correction alone cannot restore distorted signals. To address this limitation, we further explore pulse area analysis (PAA) as an alternative approach that is inherently less sensitive to distortion effects. Our experiments show that PAA improves energy resolution by 24.25% over conventional PHA, reaching 9.40% at 662 keV. These findings highlight the limitations of amplitude-based methods under summed readout architectures and suggest that PAA, when applicable, offers a more robust solution for compact gamma spectroscopy using SiPM arrays. This work provides both theoretical insights and practical strategies for mitigating signal anomalies in modern scintillation detectors.
{"title":"Summing-induced signal distortion mechanisms and suppression methods in SiPM array gamma spectroscopy detectors","authors":"Bao Wang , Xiongjie Zhang , Dongyang Wang , Wenming Dong , Dong Li , Shiliang Liu , Haoran Zhang , Jiangni Liu , Haixian Zhou , Qi Liu , Haitao Wang , Ning Chen , Renbo Wang","doi":"10.1016/j.radmeas.2026.107633","DOIUrl":"10.1016/j.radmeas.2026.107633","url":null,"abstract":"<div><div>Pulse height analysis (PHA) is commonly used in scintillation γ-ray spectroscopy because it is simple and fast. However, in systems utilizing summed outputs from multi-channel silicon photomultiplier (SiPM) arrays, PHA becomes increasingly susceptible to waveform distortions inherent to the summing architecture. Such distortions alter the signal shape and significantly degrade the energy resolution. In this study, we systematically investigate the characteristics and origins of such abnormal signals using a 16-channel SiPM array coupled to a NaI(Tl) scintillator. By analyzing the pulse area-to-height ratio distributions, we show that summing-induced distortions tend to exhibit broadened pulse shapes and deviate significantly from the single-event signal profile. To mitigate this issue, a threshold-based waveform discrimination method is introduced. This method identifies and rejects abnormal pulses based on receiver operating characteristic (ROC) curve optimization, offering practical improvement in spectral performance when PHA must be retained for speed or simplicity. However, waveform correction alone cannot restore distorted signals. To address this limitation, we further explore pulse area analysis (PAA) as an alternative approach that is inherently less sensitive to distortion effects. Our experiments show that PAA improves energy resolution by 24.25% over conventional PHA, reaching 9.40% at 662 keV. These findings highlight the limitations of amplitude-based methods under summed readout architectures and suggest that PAA, when applicable, offers a more robust solution for compact gamma spectroscopy using SiPM arrays. This work provides both theoretical insights and practical strategies for mitigating signal anomalies in modern scintillation detectors.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"193 ","pages":"Article 107633"},"PeriodicalIF":2.2,"publicationDate":"2026-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-03DOI: 10.1016/j.radmeas.2026.107631
Xue Yang , Changran Geng , Lu Han , Feng Tian , Ningxin Dong , Xiaobin Tang
Traditional single-photon emission computed tomography (SPECT) systems exhibit a tradeoff between spatial resolution and sensitivity because of the use of mechanical collimators. To address this issue, this paper proposes a collimator-free SPECT detector design based on a staggered multilayer grid scintillator array, to enable image reconstruction without requiring conventional mechanical collimation. Based on the experimental and simulation results, the system parameters were evaluated and a practical configuration incorporating 25 mm-long elongated scintillators, 6 mm-thick grid layers, and 40 mm layer spacing was established. To preliminarily assess the clinical-scale system performance, a clinical-scale system featuring a 15-detector annular array with a 300 mm rotation radius was simulated to emulate realistic cardiac SPECT imaging conditions. The results demonstrated that the system had a 0.76% detection efficiency on a clinical scale (compared to 0.1% for conventional SPECT), successfully resolving point sources spaced 2 mm apart. The cylinder model imaging results demonstrated that the mean activity recovery coefficient (ARC) of the reconstructed images for each cylinder was between 0.5 and 0.6. This preliminary result validates the feasibility of a collimator-free SPECT system and lays the foundation for further improvements in reconstruction accuracy. The proposed approach offers a potentially viable solution for concurrently enhancing spatial resolution and detection sensitivity in SPECT systems, with promising applications in myocardial perfusion imaging.
{"title":"Design of a collimator-free SPECT system based on multi-layer grid scintillator array","authors":"Xue Yang , Changran Geng , Lu Han , Feng Tian , Ningxin Dong , Xiaobin Tang","doi":"10.1016/j.radmeas.2026.107631","DOIUrl":"10.1016/j.radmeas.2026.107631","url":null,"abstract":"<div><div>Traditional single-photon emission computed tomography (SPECT) systems exhibit a tradeoff between spatial resolution and sensitivity because of the use of mechanical collimators. To address this issue, this paper proposes a collimator-free SPECT detector design based on a staggered multilayer grid scintillator array, to enable image reconstruction without requiring conventional mechanical collimation. Based on the experimental and simulation results, the system parameters were evaluated and a practical configuration incorporating 25 mm-long elongated scintillators, 6 mm-thick grid layers, and 40 mm layer spacing was established. To preliminarily assess the clinical-scale system performance, a clinical-scale system featuring a 15-detector annular array with a 300 mm rotation radius was simulated to emulate realistic cardiac SPECT imaging conditions. The results demonstrated that the system had a 0.76% detection efficiency on a clinical scale (compared to 0.1% for conventional SPECT), successfully resolving point sources spaced 2 mm apart. The cylinder model imaging results demonstrated that the mean activity recovery coefficient (ARC) of the reconstructed images for each cylinder was between 0.5 and 0.6. This preliminary result validates the feasibility of a collimator-free SPECT system and lays the foundation for further improvements in reconstruction accuracy. The proposed approach offers a potentially viable solution for concurrently enhancing spatial resolution and detection sensitivity in SPECT systems, with promising applications in myocardial perfusion imaging.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"193 ","pages":"Article 107631"},"PeriodicalIF":2.2,"publicationDate":"2026-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-24DOI: 10.1016/j.radmeas.2026.107623
I.D. Muñoz , M. Sankowska , A. Kilian , O. Jäkel , P. Bilski
Fluorescent nuclear track detectors (FNTDs) enable measurement of the linear energy transfer (LET) of heavy charged particles. Lithium fluoride (LiF) is widely used in solid-state dosimetry and has been shown to function as an FNTD, with all previous studies employing wide-field microscopy (WM). Compared with WM, confocal microscopy (CM) – while more complex and time-consuming – provides superior image quality, potentially allowing improved ion track visualization and detection. This study aims to establish the feasibility of imaging LiF crystals with CM to visualize ion tracks and measure LET. Single LiF crystals were irradiated with high-energy quasi-monoenergetic 4He-, 12C-, and 16O-ions. Following irradiation, samples underwent thermal treatment to enhance fluorescence intensity and were subsequently imaged with a confocal microscope. Single-ion tracks were reconstructed from the resulting images, and fluorescence intensity was correlated with the LET in water (LETw). The results demonstrate that it is feasible to image single ion tracks in LiF using CM. Detection efficiency reached nearly 100 % for 16O-ions at LETw = 50.4 keV μm−1 and for 12C-ions at (31.8 and 10.6) keV μm−1. Reduced efficiencies (∼50 %) were observed for 16O-ions at 18.9 keV μm−1 and for 12C-ions at 17.9 keV μm−1. For 4He-ions, the efficiency was approximately 30 %. The mean fluorescence track intensity increased with LETw, consistent with previous findings. CM shows potential for LET measurements using LiF-based FNTDs. However, at this stage, no significant improvement was observed for CM compared with WM.
{"title":"Characterization of lithium fluoride fluorescent nuclear track detectors for linear energy transfer measurements in light-ion beams using confocal microscopy","authors":"I.D. Muñoz , M. Sankowska , A. Kilian , O. Jäkel , P. Bilski","doi":"10.1016/j.radmeas.2026.107623","DOIUrl":"10.1016/j.radmeas.2026.107623","url":null,"abstract":"<div><div>Fluorescent nuclear track detectors (FNTDs) enable measurement of the linear energy transfer (LET) of heavy charged particles. Lithium fluoride (LiF) is widely used in solid-state dosimetry and has been shown to function as an FNTD, with all previous studies employing wide-field microscopy (WM). Compared with WM, confocal microscopy (CM) – while more complex and time-consuming – provides superior image quality, potentially allowing improved ion track visualization and detection. This study aims to establish the feasibility of imaging LiF crystals with CM to visualize ion tracks and measure LET. Single LiF crystals were irradiated with high-energy quasi-monoenergetic <sup>4</sup>He-, <sup>12</sup>C-, and <sup>16</sup>O-ions. Following irradiation, samples underwent thermal treatment to enhance fluorescence intensity and were subsequently imaged with a confocal microscope. Single-ion tracks were reconstructed from the resulting images, and fluorescence intensity was correlated with the LET in water (LET<sub>w</sub>). The results demonstrate that it is feasible to image single ion tracks in LiF using CM. Detection efficiency reached nearly 100 % for <sup>16</sup>O-ions at LET<sub>w</sub> = 50.4 keV μm<sup>−1</sup> and for <sup>12</sup>C-ions at (31.8 and 10.6) keV μm<sup>−1</sup>. Reduced efficiencies (∼50 %) were observed for <sup>16</sup>O-ions at 18.9 keV μm<sup>−1</sup> and for <sup>12</sup>C-ions at 17.9 keV μm<sup>−1</sup>. For <sup>4</sup>He-ions, the efficiency was approximately 30 %. The mean fluorescence track intensity increased with LET<sub>w</sub>, consistent with previous findings. CM shows potential for LET measurements using LiF-based FNTDs. However, at this stage, no significant improvement was observed for CM compared with WM.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"192 ","pages":"Article 107623"},"PeriodicalIF":2.2,"publicationDate":"2026-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146078831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-16DOI: 10.1016/j.radmeas.2026.107622
Molham M. Eyadeh , Khalid A. Rabaeh , Dua'a I. Bani Hamdan , Ali M. Almomani
In this work, the influence of glucose on the dose sensitivity of N-vinyl caprolactam based gel dosimeters (NVCL) is studied. Moreover, the radiation properties of the NVCL-glucose gel dosimeters such as temperature dependence, dose rate and energy dependence and temporal stability were investigated. The improved NVCL-glucose polymers were exposed to megavoltage photon beams from a medical linear accelerator at doses up to 20 Gy. The exposures were carried out at photon energies of 6–15 MV, dose rates between 50 and 500 cGy/min, and temperatures ranging from 10 °C to 30 °C. The transverse relaxation rate (R2) of the gel samples was measured using a time-domain NMR relaxometer with a magnetic field strength of 0.5 T. The R2-dose response was found to be linear up to a radiation dose of 10 Gy, where the dose sensitivity of the improved polymers exhibited a significant enhancement, achieving 0.37 s−1 Gy−1, which is twice the R2-dose sensitivity of previous NVCL systems. Additionally, it was observed that the NVCL-glucose polymers were independent of dose rate and radiation energy. A decrease in R2 dose sensitivity was observed with increasing scanning temperature. The optimized NVCL–glucose formulation remained stable for at least 7 days after irradiation, with no significant change in the R2 dose response over this period. These findings highlight the potential of NVCL-glucose dosimeters for practical application in MRI/NMR based 3-D dose verification.
{"title":"Optimizing the feasibility of N-Vinyl caprolactam polymer gel dosimeter using saccharide sensitizer for medical dosimetry","authors":"Molham M. Eyadeh , Khalid A. Rabaeh , Dua'a I. Bani Hamdan , Ali M. Almomani","doi":"10.1016/j.radmeas.2026.107622","DOIUrl":"10.1016/j.radmeas.2026.107622","url":null,"abstract":"<div><div>In this work, the influence of glucose on the dose sensitivity of N-vinyl caprolactam based gel dosimeters (NVCL) is studied. Moreover, the radiation properties of the NVCL-glucose gel dosimeters such as temperature dependence, dose rate and energy dependence and temporal stability were investigated. The improved NVCL-glucose polymers were exposed to megavoltage photon beams from a medical linear accelerator at doses up to 20 Gy. The exposures were carried out at photon energies of 6–15 MV, dose rates between 50 and 500 cGy/min, and temperatures ranging from 10 °C to 30 °C. The transverse relaxation rate (R<sub>2</sub>) of the gel samples was measured using a time-domain NMR relaxometer with a magnetic field strength of 0.5 T. The R<sub>2</sub>-dose response was found to be linear up to a radiation dose of 10 Gy, where the dose sensitivity of the improved polymers exhibited a significant enhancement, achieving 0.37 s<sup>−1</sup> Gy<sup>−1</sup>, which is twice the R<sub>2</sub>-dose sensitivity of previous NVCL systems. Additionally, it was observed that the NVCL-glucose polymers were independent of dose rate and radiation energy. A decrease in R<sub>2</sub> dose sensitivity was observed with increasing scanning temperature. The optimized NVCL–glucose formulation remained stable for at least 7 days after irradiation, with no significant change in the R<sub>2</sub> dose response over this period. These findings highlight the potential of NVCL-glucose dosimeters for practical application in MRI/NMR based 3-D dose verification.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"192 ","pages":"Article 107622"},"PeriodicalIF":2.2,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146039055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-16DOI: 10.1016/j.radmeas.2026.107621
Isaías Petronis , Denise Y. Nersissian , Francisco S. Cancio , Nancy K. Umisedo , Elisabeth M. Yoshimura
Interventional radiology (IR) procedures are the key source of radiation exposure for healthcare workers. Personal dosimetry is essential to ensure that dose limits are respected and radiation protection is maintained. This study aimed to estimate the average radiation dose received by the healthcare team during the most common IR procedure at a university hospital in São Paulo,Brasil. Cumulative personal dose equivalent, Hp(10), was measured outside the lead apron using thermoluminescent dosimetry (TL) in 57 percutaneous transhepatic biliary cholangiography procedures, divided into biliary drain insertions and biliary drain replacement. Three interventional radiologists participate in each procedure, with distinct roles and positions around the patient. The effective dose per procedure for the three roles of the interventional radiologists were estimated. For the primary interventional radiologist, the values were (54 ± 2) μSv and (32 ± 1) μSv in primary drain insertion and drain replacement, respectively. Additionally, as patient dose indicator, the kerma-area product medians were estimated as 34.3 Gy cm2 and 13.4 Gy cm2 in primary drain insertions and drain replacements, respectively. Under controlled equipment settings, which simulates clinical procedures with acrylic slabs, TL readings showed strong linear correlations with measurements from an ionization chamber (R2 = 0.979) and with the equipment dose indicator. The expected relationship between patient and staff doses was confirmed, in both clinical procedures and controlled settings. Finally, based on the results, recommendations were made regarding radiation protection at this facility, aiming to reduce both patient and staff exposure during this procedure.
{"title":"Radiation exposure assessment in interventional radiology: Staff personal dosimetry and radiation protection in percutaneous transhepatic cholangiography","authors":"Isaías Petronis , Denise Y. Nersissian , Francisco S. Cancio , Nancy K. Umisedo , Elisabeth M. Yoshimura","doi":"10.1016/j.radmeas.2026.107621","DOIUrl":"10.1016/j.radmeas.2026.107621","url":null,"abstract":"<div><div>Interventional radiology (IR) procedures are the key source of radiation exposure for healthcare workers. Personal dosimetry is essential to ensure that dose limits are respected and radiation protection is maintained. This study aimed to estimate the average radiation dose received by the healthcare team during the most common IR procedure at a university hospital in <em>São Paulo,</em> <em>Bra</em><em>s</em><em>il</em>. Cumulative personal dose equivalent, <em>H</em><sub>p</sub>(10), was measured outside the lead apron using thermoluminescent dosimetry (TL) in 57 percutaneous transhepatic biliary cholangiography procedures, divided into biliary drain insertions and biliary drain replacement. Three interventional radiologists participate in each procedure, with distinct roles and positions around the patient. The effective dose per procedure for the three roles of the interventional radiologists were estimated. For the primary interventional radiologist, the values were (54 ± 2) μSv and (32 ± 1) μSv in primary drain insertion and drain replacement, respectively. Additionally, as patient dose indicator, the kerma-area product medians were estimated as 34.3 Gy cm<sup>2</sup> and 13.4 Gy cm<sup>2</sup> in primary drain insertions and drain replacements, respectively. Under controlled equipment settings, which simulates clinical procedures with acrylic slabs, TL readings showed strong linear correlations with measurements from an ionization chamber (R<sup>2</sup> = 0.979) and with the equipment dose indicator. The expected relationship between patient and staff doses was confirmed, in both clinical procedures and controlled settings. Finally, based on the results, recommendations were made regarding radiation protection at this facility, aiming to reduce both patient and staff exposure during this procedure.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"192 ","pages":"Article 107621"},"PeriodicalIF":2.2,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-15DOI: 10.1016/j.radmeas.2026.107620
Yufan Liu, Kexin Wang, Wenjie Xu, Jialu Feng, Tao Ao, Lidan Lv, Qingzhi Zhou, Zhengzhong He
The study of the deposition behavior of progeny is crucial for the assessment of public and occupational radiation doses and for controlling progeny concentration in a thoron chamber. To address the difficulty of maintaining stable environmental conditions over long durations when studying deposition velocity variations, a rapid and accurate method for the deposition velocity measurement of progeny is proposed in this study, based on a BAS-TR imaging plate (IP), which has advantages of high sensitivity, large detection area and portability. In this research, measurement procedures were optimized based on the analysis of uncertainty, whereby the total time for a single measurement can be limited within 8 h. A dedicated Python program was developed for the automatic processing of IP count data, and key parameters such as IP detection efficiency, IP scanner sensitivity, and IP fading correction were determined through experiments. Comparative experiment was conducted between IP and a calibrated alpha spectroscopy, with results showing good agreement between two method. This method was preliminarily applied on progeny deposition velocity measurement using collection plates of different sizes. Compared to traditional techniques, multi-sample, large-area measurements of deposition velocity can be completed within 8 hours using the proposed method, thereby providing an new efficient approach for the study of the deposition of progeny and other radionuclides.
{"title":"Study on a rapid measurement method for the deposition velocity of 220Rn progeny based on an imaging plate","authors":"Yufan Liu, Kexin Wang, Wenjie Xu, Jialu Feng, Tao Ao, Lidan Lv, Qingzhi Zhou, Zhengzhong He","doi":"10.1016/j.radmeas.2026.107620","DOIUrl":"10.1016/j.radmeas.2026.107620","url":null,"abstract":"<div><div>The study of the deposition behavior of <span><math><mrow><msup><mrow></mrow><mrow><mn>220</mn></mrow></msup><mi>Rn</mi></mrow></math></span> progeny is crucial for the assessment of public and occupational radiation doses and for controlling progeny concentration in a thoron chamber. To address the difficulty of maintaining stable environmental conditions over long durations when studying deposition velocity variations, a rapid and accurate method for the deposition velocity measurement of <span><math><mrow><msup><mrow></mrow><mrow><mn>220</mn></mrow></msup><mi>Rn</mi></mrow></math></span> progeny is proposed in this study, based on a BAS-TR imaging plate (IP), which has advantages of high sensitivity, large detection area and portability. In this research, measurement procedures were optimized based on the analysis of uncertainty, whereby the total time for a single measurement can be limited within 8 h. A dedicated Python program was developed for the automatic processing of IP count data, and key parameters such as IP detection efficiency, IP scanner sensitivity, and IP fading correction were determined through experiments. Comparative experiment was conducted between IP and a calibrated alpha spectroscopy, with results showing good agreement between two method. This method was preliminarily applied on <span><math><mrow><msup><mrow></mrow><mrow><mn>220</mn></mrow></msup><mi>Rn</mi></mrow></math></span> progeny deposition velocity measurement using collection plates of different sizes. Compared to traditional techniques, multi-sample, large-area measurements of deposition velocity can be completed within 8 hours using the proposed method, thereby providing an new efficient approach for the study of the deposition of <span><math><mrow><msup><mrow></mrow><mrow><mn>220</mn></mrow></msup><mi>Rn</mi></mrow></math></span> progeny and other radionuclides.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"192 ","pages":"Article 107620"},"PeriodicalIF":2.2,"publicationDate":"2026-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145981056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study depicts how a nationwide remote dosimetry audit (RDA) system in radiotherapy, utilizing radiophotoluminescent dosemeters, was commissioned and validated in Bulgaria. The work outlines the commissioning process of the dosimetry system, presents the organization of the RDA feasibility study, and describes how a preliminary clinical audit was carried out in Bulgaria, with determination of absorbed dose correction factors as an integral part of the commissioning process. After successful commissioning of the RDA system, the dosimetric accuracy of the absorbed dose to water at the reference point under reference conditions was evaluated during both the feasibility study and the clinical audit. Across all investigated photon beam energies (6 MV, 10 MV, 15 MV, 6 MV FFF, and 10 MV FFF), the differences between the stated doses and the RPLD-measured doses ranged from −1.5 % to +4.0 % during the feasibility phase and from −1.5 % to +2.0 % during the first clinical audits, with all deviations remaining well within the ±5 % acceptance tolerance. The findings of the feasibility study and the preliminary clinical results indicate that the proposed RDA methodology is viable for implementation in Bulgarian radiotherapy centers.
{"title":"Commissioning of radiophotoluminescent dosimetry system for radiotherapy dosimetry audits - feasibility and pilot study results in Bulgaria","authors":"Gueorgui Gueorguiev , Tsvetelina Todorova , Bozhidar Vladimirov , Filip Simeonov , Katia Sergieva","doi":"10.1016/j.radmeas.2026.107619","DOIUrl":"10.1016/j.radmeas.2026.107619","url":null,"abstract":"<div><div>This study depicts how a nationwide remote dosimetry audit (RDA) system in radiotherapy, utilizing radiophotoluminescent dosemeters, was commissioned and validated in Bulgaria. The work outlines the commissioning process of the dosimetry system, presents the organization of the RDA feasibility study, and describes how a preliminary clinical audit was carried out in Bulgaria, with determination of absorbed dose correction factors as an integral part of the commissioning process. After successful commissioning of the RDA system, the dosimetric accuracy of the absorbed dose to water at the reference point under reference conditions was evaluated during both the feasibility study and the clinical audit. Across all investigated photon beam energies (6 MV, 10 MV, 15 MV, 6 MV FFF, and 10 MV FFF), the differences between the stated doses and the RPLD-measured doses ranged from −1.5 % to +4.0 % during the feasibility phase and from −1.5 % to +2.0 % during the first clinical audits, with all deviations remaining well within the ±5 % acceptance tolerance. The findings of the feasibility study and the preliminary clinical results indicate that the proposed RDA methodology is viable for implementation in Bulgarian radiotherapy centers.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"192 ","pages":"Article 107619"},"PeriodicalIF":2.2,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145980461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-13DOI: 10.1016/j.radmeas.2026.107617
J.A. Winzar, G.A.T. Duller, H.M. Roberts
For luminescence research, samples are often heated prior to and/or during measurement to measure the thermoluminescence (TL) signal or to remove charge from shallow traps. The reproducibility and repeatability of luminescence measurements will be influenced by how consistently and uniformly the samples are heated, both within a single aliquot and between different readers or sample positions. While the effects of temperature lag during heating have been intensively studied, the spatial uniformity of temperature across samples has received less attention.
This study presents spatially-resolved measurements of the temperature of the heating strip, a steel cup and an aluminium single grain disc in a Risø TL/OSL DA20 reader. Temperature is calculated using black body emissions from the three materials, detected with an Electron Multiplying Charge Coupled Device (EMCCD). The results show that temperature is not spatially uniform across any of the three materials, although the degree of variation differs between them. The largest temperature variation is observed across the steel cup (∼18 % at a temperature of 500 °C), followed by the heating strip (∼8 % at a temperature of 500 °C), and then the single grain disc (∼2 % at a temperature of 250 °C). The steel cup also has greater anisotropy in temperature compared to the single grain disc. This study suggests that spatial variation in temperature can be minimised by using sample holders made of materials with high thermal conductivity (e.g. aluminium or silver), and that the impact of thermal variation can be reduced by restricting samples to the central portion of a sample holder (e.g. the central 2 mm of a sample holder (i.e. ‘small aliquots’)).
{"title":"Uniformity of heating across sample holders during luminescence measurements","authors":"J.A. Winzar, G.A.T. Duller, H.M. Roberts","doi":"10.1016/j.radmeas.2026.107617","DOIUrl":"10.1016/j.radmeas.2026.107617","url":null,"abstract":"<div><div>For luminescence research, samples are often heated prior to and/or during measurement to measure the thermoluminescence (TL) signal or to remove charge from shallow traps. The reproducibility and repeatability of luminescence measurements will be influenced by how consistently and uniformly the samples are heated, both within a single aliquot and between different readers or sample positions. While the effects of temperature lag during heating have been intensively studied, the spatial uniformity of temperature across samples has received less attention.</div><div>This study presents spatially-resolved measurements of the temperature of the heating strip, a steel cup and an aluminium single grain disc in a Risø TL/OSL DA20 reader. Temperature is calculated using black body emissions from the three materials, detected with an Electron Multiplying Charge Coupled Device (EMCCD). The results show that temperature is not spatially uniform across any of the three materials, although the degree of variation differs between them. The largest temperature variation is observed across the steel cup (∼18 % at a temperature of 500 °C), followed by the heating strip (∼8 % at a temperature of 500 °C), and then the single grain disc (∼2 % at a temperature of 250 °C). The steel cup also has greater anisotropy in temperature compared to the single grain disc. This study suggests that spatial variation in temperature can be minimised by using sample holders made of materials with high thermal conductivity (e.g. aluminium or silver), and that the impact of thermal variation can be reduced by restricting samples to the central portion of a sample holder (e.g. the central 2 mm of a sample holder (i.e. ‘small aliquots’)).</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"192 ","pages":"Article 107617"},"PeriodicalIF":2.2,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145981057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We have developed a new method using a selective plastic scintillation resin (PSresin) based on Aliquat-336 for analysing 210Po in water samples. The PSresin effectively isolates 210Po while removing main interferences such as 210Pb and 210Bi by loading the sample in a HCl 1 mol L−1 medium and rinsing with HCl 1 mol L−1 and 6.25 mol L−1, consecutively. We optimized the rinse volumes and conducted a search for suitable chemical analogues of polonium to be used as tracers throughout the procedure. Zinc and cadmium were identified as the most suitable elements for preconcentration and separation of 210Po on the PSresin. We compared our PSresin method with reference methods (UNE-EN ISO 13161 and IAEA/AQ/12) based on alpha spectrometry by analysing drinking water samples. The results showed that the PSresin method is faster and provides accurate results, although the alpha spectrometry methods achieve lower detection limits.
{"title":"A new method for the determination of 210Po in environmental samples using plastic scintillation resins","authors":"Jordi Rotger , Joana Tent , Hector Bagán , Anna Rigol , Àlex Tarancón","doi":"10.1016/j.radmeas.2026.107618","DOIUrl":"10.1016/j.radmeas.2026.107618","url":null,"abstract":"<div><div>We have developed a new method using a selective plastic scintillation resin (PSresin) based on Aliquat-336 for analysing <sup>210</sup>Po in water samples. The PSresin effectively isolates <sup>210</sup>Po while removing main interferences such as <sup>210</sup>Pb and <sup>210</sup>Bi by loading the sample in a HCl 1 mol L<sup>−1</sup> medium and rinsing with HCl 1 mol L<sup>−1</sup> and 6.25 mol L<sup>−1</sup>, consecutively. We optimized the rinse volumes and conducted a search for suitable chemical analogues of polonium to be used as tracers throughout the procedure. Zinc and cadmium were identified as the most suitable elements for preconcentration and separation of <sup>210</sup>Po on the PSresin. We compared our PSresin method with reference methods (UNE-EN ISO 13161 and IAEA/AQ/12) based on alpha spectrometry by analysing drinking water samples. The results showed that the PSresin method is faster and provides accurate results, although the alpha spectrometry methods achieve lower detection limits.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"192 ","pages":"Article 107618"},"PeriodicalIF":2.2,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145981058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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