@article{MTMT:33095031, title = {Accounting for radiation exposure from previous CT exams while deciding on the next exam: What do referring clinicians think?}, url = {https://m2.mtmt.hu/api/publication/33095031}, author = {Rehani, M.M. and Applegate, K. and Bodzay, Tamás and Heon, Kim C. and Miller, D.L. and Ali, Nassiri M. and Chul, Paeng J. and Srimahachota, S. and Srinivasa, S. and Takenaka, M. and Séra, Teréz Emese and Vassileva, J. and Zhuo, W.}, doi = {10.1016/j.ejrad.2022.110468}, journal-iso = {EUR J RADIOL}, journal = {EUROPEAN JOURNAL OF RADIOLOGY}, volume = {155}, unique-id = {33095031}, issn = {0720-048X}, abstract = {Purpose: To obtain clinicians’ views of the need to account for radiation exposure from previous CT scans and the advisability of a regulatory mechanism to control the number of CT scans for an individual patient. Methods: A convenience survey was conducted by emailing a link to a three-question electronic survey to clinicians in many countries, mostly through radiology and radiation protection contacts. Results: 505 responses were received from 24 countries. 293 respondents (58%) understand that current regulations do not limit the number of CT scans that can be prescribed for a single patient in a year. When asked whether there should be a regulation to limit the number of CT scans that can be prescribed for a single patient in one year, only a small fraction (143, 28%) answered ‘No’, 182 (36%) answered ‘Maybe’ and 166 (33%) answered ‘Yes’. Most respondents (337; 67%) think that radiation risk should form part of the consideration when deciding whether to request a CT exam. A minority (138; 27%) think the decision should be based only on the medical indication for the CT exam. Comparison among the 4 countries (South Korea, Hungary, USA and Canada) with the largest number of respondents indicated wide variations in responses. Conclusions: A majority of the surveyed clinicians consider radiation risk, in addition to clinical factors, when prescribing CT exams. Most respondents are in favor of, or would consider, regulation to control the number of CT scans that could be performed on a patient annually. © 2022 Elsevier B.V.}, keywords = {Adult; Female; Male; ARTICLE; human; Hungary; Canada; physician; major clinical study; controlled study; Diagnostic Imaging; radiation exposure; radiation protection; radiation dose; radiology; prescription; radiation hazard; X-ray computed tomography; South Korea; Cumulative radiation dose; Recurrent CT scans; Referring clinicians and CT exams; Referring physicians survey; Regulation for justification in medical imaging}, year = {2022}, eissn = {1872-7727} } @{MTMT:32771739, title = {Multicentre Studies. Hardware and Software Requirements}, url = {https://m2.mtmt.hu/api/publication/32771739}, author = {Séra, Teréz Emese and Boellaard, Ronald and Kaalep, Andres and Ljungberg, Michael}, booktitle = {Handbook of Nuclear Medicine and Molecular Imaging for Physicists}, doi = {10.1201/9780429489556-27}, unique-id = {32771739}, year = {2022}, pages = {499-514} } @article{MTMT:32759167, title = {Radiation Safety and Accidental Radiation Exposures in Nuclear Medicine}, url = {https://m2.mtmt.hu/api/publication/32759167}, author = {Marengo, M. and Martin, C.J. and Rubow, S. and Séra, Teréz Emese and Amador, Z. and Torres, L.}, doi = {10.1053/j.semnuclmed.2021.11.006}, journal-iso = {SEMIN NUCL MED}, journal = {SEMINARS IN NUCLEAR MEDICINE}, volume = {52}, unique-id = {32759167}, issn = {0001-2998}, abstract = {Medical radiation accidents and unintended events may lead to accidental or unintended medical exposure of patients and exposure of staff or the public. Most unintended exposures in nuclear medicine will lead to a small increase in risk; nevertheless, these require investigation and a clinical and dosimetric assessment. Nuclear medicine staff are exposed to radiation emitted directly by radiopharmaceuticals and by patients after administration of radiopharmaceuticals. This is particularly relevant in PET, due to the penetrating 511 keV γ-rays. Dose constraints should be set for planning the exposure of individuals. Staff body doses of 1-25 µSv/GBq are reported for PET imaging, the largest component being from the injection. The preparation and administration of radiopharmaceuticals can lead to high doses to the hands, challenging dose limits for radionuclides such as 90Y and even 18F. The risks of contamination can be minimized by basic precautions, such as carrying out manipulations in purpose-built facilities, wearing protective clothing, especially gloves, and removing contaminated gloves or any skin contamination as quickly as possible. Airborne contamination is a potential problem when handling radioisotopes of iodine or administering radioaerosols. Manipulating radiopharmaceuticals in laminar air flow cabinets, and appropriate premises ventilation are necessary to improve safety levels. Ensuring patient safety and minimizing the risk of incidents require efficient overall quality management. Critical aspects include: the booking process, particularly if qualified medical supervision is not present; administration of radiopharmaceuticals to patients, with the risk of misadministration or extravasation; management of patients' data and images by information technology systems, considering the possibility of misalignment between patient personal data and clinical information. Prevention of possible mistakes in patient identification or in the management of patients with similar names requires particular attention. Appropriate management of pregnant or breast-feeding patients is another important aspect of radiation safety. In radiopharmacy activities, strict quality assurance should be implemented at all operational levels, in addition to adherence to national and international regulations and guidelines. This includes not only administrative aspects, like checking the request/prescription, patient's data and the details of the requested procedure, but also quantitative tests according to national/international pharmacopoeias, and measuring the dispensed activity with a calibrated activity meter prior to administration. In therapy with radionuclides, skin tissue reactions can occur following extravasation, which can result in localized doses of tens of Grays. Other relevant incidents include confusion of products for patients administered at the same time or malfunction of administration devices. Furthermore, errors in internal radiation dosimetry calculations for treatment planning may lead to under or over-treatment. According to literature, proper instructions are fundamental to keep effective dose to caregivers and family members after patient discharge below the Dose constraints. The IAEA Basic Safety Standards require measures to minimize the likelihood of any unintended or accidental medical exposures and reporting any radiation incident. The relative complexity of nuclear medicine practice presents many possibilities for errors. It is therefore important that all activities are performed according to well established procedures, and that all actions are supported by regular quality assurance/QC procedures. © 2021 Elsevier Inc.}, year = {2022}, eissn = {1558-4623}, pages = {94-113} } @article{MTMT:32436384, title = {Harmonisation of PET/CT contrast recovery performance for brain studies}, url = {https://m2.mtmt.hu/api/publication/32436384}, author = {Verwer, E. E. and Golla, S. S. V. and Kaalep, A. and Lubberink, M. and van Velden, F. H. P. and Bettinardi, V. and Yaqub, M. and Séra, Teréz Emese and Rijnsdorp, S. and Lammertsma, A. A. and Boellaard, R.}, doi = {10.1007/s00259-021-05201-w}, journal-iso = {EUR J NUCL MED MOL I}, journal = {EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING}, volume = {48}, unique-id = {32436384}, issn = {1619-7070}, abstract = {Purpose In order to achieve comparability of image quality, harmonisation of PET system performance is imperative. In this study, prototype harmonisation criteria for PET brain studies were developed.Methods Twelve clinical PET/CT systems (4 GE, 4 Philips, 4 Siemens, including SiPM-based "digital" systems) were used to acquire 30-min PET scans of a Hoffman 3D Brain phantom filled with similar to 33 kBq.mL(-1) [F-18]FDG. Scan data were reconstructed using various reconstruction settings. The images were rigidly coregistered to a template (voxel size 1.17 x 1.17 x 2.00 mm(3)) onto which several volumes of interest (VOIs) were defined. Recovery coefficients (RC) and grey matter to white matter ratios (GMWMr) were derived for eroded (denoted in the text by subscript e) and non-eroded grey (GM) and white (WM) matter VOIs as well as a mid-phantom cold spot (VOIcold) and VOIs from the Hammers atlas. In addition, left-right hemisphere differences and voxel-by-voxel differences compared to a reference image were assessed.Results Systematic differences were observed for reconstructions with and without point-spread-function modelling (PSFON and PSFOFF, respectively). Normalising to image-derived activity, upper and lower limits ensuring image comparability were as follows: for PSFON, RCGMe = [0.97-1.01] and GMWMr(e) = [3.51-3.91] for eroded VOI and RCGM = [0.78-0.83] and GMWMr = [1.77-2.06] for non-eroded VOI, and for PSFOFF, RCGMe = [0.92-0.99] and GMWMr(e) = [3.14-3.68] for eroded VOI and RCGM = [0.75-0.81] and GMWMr = [1.72-1.95] for non-eroded VOI.Conclusions To achieve inter-scanner comparability, we propose selecting reconstruction settings based on RCGMe and GMWMr(e) as specified in "Results". These proposed standards should be tested prospectively to validate and/or refine the harmonisation criteria.}, keywords = {Brain; PET; neuroimaging; image quality; standardisation; harmonisation}, year = {2021}, eissn = {1619-7089}, pages = {2856-2870} } @article{MTMT:32759159, title = {Updating PET/CT performance standards and PET/CT interpretation criteria should go hand in hand}, url = {https://m2.mtmt.hu/api/publication/32759159}, author = {Boellaard, Ronald and Séra, Teréz Emese and Kaalep, Andres and Hoekstra, Otto S. and Barrington, Sally F. and Zijlstra, Josee M.}, doi = {10.1186/s13550-019-0565-y}, journal-iso = {EJNMMI RES}, journal = {EJNMMI RESEARCH}, volume = {9}, unique-id = {32759159}, issn = {2191-219X}, abstract = {This letter aims at explaining that adjusting the performance of PET/CT systems to a new standard also requires updating of interpretation criteria. Simply changing one aspect of the imaging procedure, i.e., PET/CT performance and image quality, and not adapting interpretation criteria will result in an increase of false positive (or negative) reads.}, year = {2019}, eissn = {2191-219X}, orcid-numbers = {Barrington, Sally F./0000-0002-2516-5288} } @article{MTMT:32759158, title = {Multicentre quantitative 68 Ga PET/CT performance harmonisation}, url = {https://m2.mtmt.hu/api/publication/32759158}, author = {Huizing, Daphne M. V. and Koopman, Danielle and van, Dalen Jorn A. and Gotthardt, Martin and Boellaard, Ronald and Séra, Teréz Emese and Sinaasappel, Michiel and Stokkel, Marcel P. M. and de, Wit-van der Veen Berlinda J.}, doi = {10.1186/s40658-019-0253-z}, journal-iso = {EJNMMI PHYS}, journal = {EJNMMI PHYSICS}, volume = {6}, unique-id = {32759158}, issn = {2197-7364}, abstract = {Purpose Performance standards for quantitative F-18-FDG PET/CT studies are provided by the EANM Research Ltd. (EARL) to enable comparability of quantitative PET in multicentre studies. Yet, such specifications are not available for Ga-68. Therefore, our aim was to evaluate Ga-68-PET/CT quantification variability in a multicentre setting. Methods A survey across Dutch hospitals was performed to evaluate differences in clinical Ga-68 PET/CT study protocols. Ga-68 and F-18 phantom acquisitions were performed by 8 centres with 13 different PET/CT systems according to EARL protocol. The cylindrical phantom and NEMA image quality (IQ) phantom were used to assess image noise and to identify recovery coefficients (RCs) for quantitative analysis. Both phantoms were used to evaluate cross-calibration between the PET/CT system and local dose calibrator. Results The survey across Dutch hospitals showed a large variation in clinical Ga-68 PET/CT acquisition and reconstruction protocols. Ga-68 PET/CT image noise was below 10%. Cross-calibration was within 10% deviation, except for one system to overestimate F-18 and two systems to underestimate the Ga-68 activity concentration. RC-curves for F-18 and Ga-68 were within and on the lower limit of current EARL standards, respectively. After correction for local Ga-68/F-18 cross-calibration, mean Ga-68 performance was 5% below mean EARL performance specifications. Conclusions Ga-68 PET/CT quantification performs on the lower limits of the current EARL RC standards for F-18. Correction for local Ga-68/F-18 cross-calibration mismatch is advised, while maintaining the EARL reconstruction protocol thereby avoiding multiple EARL protocols.}, keywords = {QUANTIFICATION; CT; image quality; (68)Gallium PET}, year = {2019}, eissn = {2197-7364} } @article{MTMT:32759157, title = {Quantitative implications of the updated EARL 2019 PET-CT performance standards}, url = {https://m2.mtmt.hu/api/publication/32759157}, author = {Kaalep, Andres and Burggraaff, Coreline N. and Pieplenbosch, Simone and Verwer, Eline E. and Séra, Teréz Emese and Zijlstra, Josee and Hoekstra, Otto S. and Oprea-Lager, Daniela E. and Boellaard, Ronald}, doi = {10.1186/s40658-019-0257-8}, journal-iso = {EJNMMI PHYS}, journal = {EJNMMI PHYSICS}, volume = {6}, unique-id = {32759157}, issn = {2197-7364}, abstract = {Purpose Recently, updated EARL specifications (EARL2) have been developed and announced. This study aims at investigating the impact of the EARL2 specifications on the quantitative reads of clinical PET-CT studies and testing a method to enable the use of the EARL2 standards whilst still generating quantitative reads compliant with current EARL standards (EARL1). Methods Thirteen non-small cell lung cancer (NSCLC) and seventeen lymphoma PET-CT studies were used to derive four image datasets-the first dataset complying with EARL1 specifications and the second reconstructed using parameters as described in EARL2. For the third (EARL2F6) and fourth (EARL2F7) dataset in EARL2, respectively, 6 mm and 7 mm Gaussian post-filtering was applied. We compared the results of quantitative metrics (MATV, SUVmax, SUVpeak, SUVmean, TLG, and tumor-to-liver and tumor-to-blood pool ratios) obtained with these 4 datasets in 55 suspected malignant lesions using three commonly used segmentation/volume of interest (VOI) methods (MAX41, A50P, SUV4). Results We found that with EARL2 MAX41 VOI method, MATV decreases by 22%, TLG remains unchanged and SUV values increase by 23-30% depending on the specific metric used. The EARL2F7 dataset produced quantitative metrics best aligning with EARL1, with no significant differences between most of the datasets (p>0.05). Different VOI methods performed similarly with regard to SUV metrics but differences in MATV as well as TLG were observed. No significant difference between NSCLC and lymphoma cancer types was observed. Conclusions Application of EARL2 standards can result in higher SUVs, reduced MATV and slightly changed TLG values relative to EARL1. Applying a Gaussian filter to PET images reconstructed using EARL2 parameters successfully yielded EARL1 compliant data.}, keywords = {PET; CANCER; PERFORMANCE; QUANTIFICATION; CT; CLINICAL-TRIALS; IMAGE-RECONSTRUCTION; F-18-FDG PET/CT; FDG-PET/CT; harmonisation; EARL accreditation}, year = {2019}, eissn = {2197-7364}, orcid-numbers = {Burggraaff, Coreline N./0000-0001-5863-6528} } @article{MTMT:32759163, title = {EANM/EARL FDG-PET/CT accreditation - summary results from the first 200 accredited imaging systems}, url = {https://m2.mtmt.hu/api/publication/32759163}, author = {Kaalep, Andres and Séra, Teréz Emese and Oyen, Wim and Krause, Bernd J. and Chiti, Arturo and Liu, Yan and Boellaard, Ronald}, doi = {10.1007/s00259-017-3853-7}, journal-iso = {EUR J NUCL MED MOL I}, journal = {EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING}, volume = {45}, unique-id = {32759163}, issn = {1619-7070}, abstract = {Purpose From 2010 until July 2016, the EANM Research Ltd. (EARL) FDG-PET/CT accreditation program has collected over 2500 phantom datasets from approximately 200 systems and 150 imaging sites worldwide. The objective of this study is to report the findings and impact of the accreditation program on the participating PET/CT systems. Methods To obtain and maintain EARL accredited status, sites were required to complete and submit two phantom scans - calibration quality control (CalQC), using a uniform cylindrical phantom and image quality control (IQQC), using a NEMA NU2-2007 body phantom. Average volumetric SUV bias and SUV recovery coefficients (RC) were calculated and the data evaluated on the basis of quality control (QC) type, approval status, PET/CT system manufacturer and submission order. Results SUV bias in 5% (n = 96) of all CalQC submissions (n = 1816) exceeded 10%. After corrective actions following EARL feedback, sites achieved 100% compliance within EARL specifications. 30% (n = 1381) of SUVmean and 23% (n = 1095) of SUVmax sphere recoveries from IQQC submissions failed to meet EARL accreditation criteria while after accreditation, failure rate decreased to 12% (n = 360) and 9% (n = 254), respectively. Most systems demonstrated longitudinal SUV bias reproducibility within +/- 5%, while RC values remained stable and generally within +/- 10% for the four largest and +/- 20% for the two smallest spheres. Conclusions Regardless of manufacturer or model, all investigated systems are able to comply with the EARL specifications. Within the EARL accreditation program, gross PET/CT calibration errors are successfully identified and longitudinal variability in PET/CT performances reduced. The program demonstrates that a harmonising accreditation procedure is feasible and achievable.}, keywords = {VALIDATION; PERFORMANCE; QUANTIFICATION; PET/CT; CELL LUNG-CANCER; POSITRON-EMISSION-TOMOGRAPHY; RECOMMENDATIONS; F-18-FDG PET; harmonisation; MULTICENTER TRIALS}, year = {2018}, eissn = {1619-7089}, pages = {412-422}, orcid-numbers = {Chiti, Arturo/0000-0002-5806-1856; Boellaard, Ronald/0000-0002-0313-5686} } @article{MTMT:32759162, title = {Feasibility of brain PET/CT harmonization - a multicenter, multivendor pilot study}, url = {https://m2.mtmt.hu/api/publication/32759162}, author = {Boellaard, Ronald and Golla, Sandeep and Kaleep, Andres and Lubberink, Mark and Van, Velden Floris and Bettinardi, Valentino and Yaqub, Maqsood and Séra, Teréz Emese and Rijnsdorp, Sjoerd and Lammertsma, Adriaan}, journal-iso = {J NUCL MED}, journal = {JOURNAL OF NUCLEAR MEDICINE}, volume = {59}, unique-id = {32759162}, issn = {0161-5505}, year = {2018}, eissn = {1535-5667} } @article{MTMT:32759161, title = {Feasibility of state of the art PET/CT systems performance harmonisation}, url = {https://m2.mtmt.hu/api/publication/32759161}, author = {Kaalep, Andres and Séra, Teréz Emese and Rijnsdorp, Sjoerd and Yaqub, Maqsood and Talsma, Anne and Lodge, Martin A. and Boellaard, Ronald}, doi = {10.1007/s00259-018-3977-4}, journal-iso = {EUR J NUCL MED MOL I}, journal = {EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING}, volume = {45}, unique-id = {32759161}, issn = {1619-7070}, abstract = {Purpose The objective of this study was to explore the feasibility of harmonising performance for PET/CT systems equipped with time-of-flight (ToF) and resolution modelling/point spread function (PSF) technologies. A second aim was producing a working prototype of new harmonising criteria with higher contrast recoveries than current EARL standards using various SUV metrics. Methods Four PET/CT systems with both ToF and PSF capabilities from three major vendors were used to acquire and reconstruct images of the NEMA NU2-2007 body phantom filled conforming EANM EARL guidelines. A total of 15 reconstruction parameter sets of varying pixel size, post filtering and reconstruction type, with three different acquisition durations were used to compare the quantitative performance of the systems. A target range for recovery curves was established such that it would accommodate the highest matching recoveries from all investigated systems. These updated criteria were validated on 18 additional scanners from 16 sites in order to demonstrate the scanners' ability to meet the new target range. Results Each of the four systems was found to be capable of producing harmonising reconstructions with similar recovery curves. The five reconstruction parameter sets producing harmonising results significantly increased SUVmean (25%) and SUVmax (26%) contrast recoveries compared with current EARL specifications. Additional prospective validation performed on 18 scanners from 16 EARL accredited sites demonstrated the feasibility of updated harmonising specifications. SUVpeak was found to significantly reduce the variability in quantitative results while producing lower recoveries in smaller (<= 17 mm diameter) sphere sizes. Conclusions Harmonising PET/CT systems with ToF and PSF technologies from different vendors was found to be feasible. The harmonisation of such systems would require an update to the current multicentre accreditation program EARL in order to accommodate higher recoveries. SUVpeak should be further investigated as a noise resistant alternative quantitative metric to SUVmax.}, keywords = {PERFORMANCE; QUANTIFICATION; PET/CT; CELL LUNG-CANCER; POSITRON-EMISSION-TOMOGRAPHY; CLINICAL-TRIALS; RESPONSE ASSESSMENT; FDG-PET; F-18-FDG PET; Standardized uptake value; harmonisation; MULTICENTER TRIALS; ROI DEFINITION}, year = {2018}, eissn = {1619-7089}, pages = {1344-1361}, orcid-numbers = {Boellaard, Ronald/0000-0002-0313-5686} }