Quality Control In Nuclear Medicine Research Articles

The status of nuclear medicine in China: the first official national survey.

The National Nuclear Medicine Quality Control Center of China conducted the first official survey to investigate the nationwide situation of nuclear medicine in 2020. The survey aimed to unveil the current nuclear medicine situation and its quality control in China. The web-based survey was conducted and the data was collected via the National Clinical Improvement System (NCIS) of China from 1st April to 31st May 2021. A total of 808 institutes across 30 provinces responded to the national survey. For human resources, there are 4460 physicians, 3077 technologists, 339 physicists, and 309 radiochemists. There are 887 single-photon imaging instruments, including 823 SPECT or SPECT/CT, and 365 PET instruments including 314 PET/CT. Six hundred twenty-four institutes perform SPECT examinations and 319 institutes perform PET examinations. 60% of SPECT scans are bone scintigraphy. A total of 97% of PET scans use an [18F]F-FDG tracer. Furthermore, 587 institutes provide radionuclide therapy services but only 280 institutes have admission rooms. The top three radionuclide therapies are [131I] therapy of hyperthyroidism with 546 institutes, [89Sr] therapy of bone metastasis with 400 institutes, and [131I] therapy of differentiated thyroid cancer with 286 institutes. Finally, for the frequency of equipment quality control per year, there are about 67 times self-test within the department for SPECT instruments and 111 times for PET instruments on average in each province. There are about three failures of SPECT and five failures of PET on average per year in each province. There are 408 institutes (of 624 SPECT institutes) performing quality control of SPECT radiopharmaceuticals, 216 (of 319) for PET radiopharmaceuticals, and 373 (of 587) for radionuclide therapy. These results of the first official survey towards current status of nuclear medicine in China are the foundation for the establishment of the quality control management system.

Evaluation of TlBr semiconductor detector in gamma camera imaging: Monte Carlo simulation study

Among the detector materials available at room temperature, thallium bromide (TlBr), which has a relatively high atomic number and density, is widely used for gamma camera imaging. This study aimed to verify the usefulness of TlBr through quantitative evaluation by modeling detectors of various compound types using Monte Carlo simulations. The Geant4 application for tomographic emission was used for simulation, and detectors based on cadmium zinc telluride and cadmium telluride materials were selected as a comparison group. A pixel-matched parallel-hole collimator with proven excellent performance was modeled, and phantoms used for quality control in nuclear medicine were used. The signal-to-noise ratio (SNR), contrast to noise ratio (CNR), sensitivity, and full width at half maximum (FWHM) were used for quantitative analysis to evaluate the image quality. The SNR, CNR, sensitivity, and FWHM for the TlBr detector material were approximately 1.05, 1.04, 1.41, and 1.02 times, respectively, higher than those of the other detector materials. The SNR, CNR and sensitivity increased with increasing detector thickness, but the spatial resolution in terms of FWHM decreased. Thus, we demonstrated the feasibility and possibility of using the TlBr detector material in comparison with commercial detector materials.

Chinese expert consensus on selective internal radiation therapy with yttrium-90 for primary and metastatic hepatocellular carcinoma

Liver malignant tumors are one of the most common causes of cancer-related deaths in China. Selective internal yttrium-90 radioembolization therapy ((90)Y-SIRT) is a kind of promising local minimally invasive method, and its effectiveness and safety has been confirmed in clinical application over the past two decades. Moreover, it has been approved by the U.S. National Comprehensive Cancer Network and other international guidelines for the topical treatment of patients with liver malignancies. Taking into account the complexity of the (90)Y-SIRT and the need for multidisciplinary collaboration to improve the safety and success rate of treatment, the Nuclear Medicine Expert Committee of the Chinese society of Clinical Oncology, along with Beijing Nuclear Medicine Quality Control and Improvement Center invited experts from surgical oncology, interventional medicine, nuclear medicine, and other related fields to discuss and form a consensus on the clinical diagnosis, treatment and management, which mainly included definition, indications and contraindications, treatment procedures, postoperative follow-up, adverse reactions and complications, radiation safety management, etc. Herein, we provide the reference guidance to establish (90)Y-SIRT standardized management and treatment system various units for relevant practitioners.

Deep Learning Application of Gamma Camera Quality Control in Nuclear Medicine

Deep Learning Application of Gamma Camera Quality Control in Nuclear Medicine

Automated quality control in nuclear medicine using the structured noise index.

PurposeDaily flood‐field uniformity evaluation serves as the central element of nuclear medicine (NM) quality control (QC) programs. Uniformity images are traditionally analyzed using pixel value‐based metrics, that is, integral uniformity (IU), which often fail to capture subtle structure and patterns caused by changes in gamma camera performance, requiring visual inspections which are subjective and time demanding. The goal of this project was to implement an advanced QC metrology for NM to effectively identify nonuniformity issues, and report issues in a timely manner for efficient correction prior to clinical use. The project involved the implementation of the program over a 2‐year period at a multisite major medical institution.MethodsUsing a previously developed quantitative uniformity analysis metric, the structured noise index (SNI) [Nelson et al. (2014), \ extit{J Nucl Med.}, \ extbf{55}:169—174], an automated QC process was developed to analyze, archive, and report on daily NM QC uniformity images. Clinical implementation of the newly developed program ran in parallel with the manufacturer’s reported IU‐based QC program. The effectiveness of the SNI program was evaluated over a 21‐month period using sensitivity and coefficient of variation statistics.ResultsA total of 7365 uniformity QC images were analyzed. Lower level SNI alerts were generated in 12.5% of images and upper level alerts in 1.7%. Intervention due to image quality issues occurred on 26 instances; the SNI metric identified 24, while the IU metric identified eight. The SNI metric reported five upper level alerts where no clinical engineering intervention was deemed necessary.ConclusionAn SNI‐based QC program provides a robust quantification of the performance of gamma camera uniformity. It operates seamlessly across a fleet of multiple camera models and, additionally, provides effective workflow among the clinical staff. The reliability of this process could eliminate the need for visual inspection of each image, saving valuable time, while enabling quantitative analysis of inter‐ and intrasystem performance.

Hybrid installations for multimodal PET/SPECT/CT visualization in Ukraine and quality control in nuclear medicine

P.L. Shupyk National University of Health of Ukraine, Kyiv, Ukraine SI "O.O. Shalimov National Institute of Surgery and Transplantology of the NAMS of Ukraine", Kiev, Ukraine The article considers the prospects of using hybrid imaging methods (PET/SPECT/CT) and quality control in nuclear medicine. The quality control system is a comprehensive measure that involves the creation and implementation of quality guidelines, quality control programs, instructions and protocols for checking control parameters. A quality control audit is a measure that allows you to verify the proper functioning of the department, identify and eliminate errors and improve the quality of patient care. All technical parameters of the devices should be checked according to standardized protocols to ensure reproduction and comparability of results. The availability of additional equipment for inspections of control parameters must be provided in advance, as well as a set of actions aimed at maintaining the quality of equipment and its timely update in order to meet modern requirements. Due to the integration of SPECT, PET and CT modules, the multimodal system is used for use in various fields of clinical medicine, in particular in oncology, cardiology, endocrinology and neurology. The comprehensive implementation of a quality management system for diagnostic tests, as an end result, allows to increase the effectiveness of these tests (not only in nuclear medicine) and to guarantee "trust" in these methods. Key words: hybrid imaging, nuclear medicine, positron emission tomography, single-photon emission computed tomography, quality control.

Medical Image Processing Server applied to Quality Control of Nuclear Medicine.

This paper is framed within the area of medical image processing and aims to present the process of installation, configuration and implementation of a processing server of medical images (MIPS) in the Fundación Escuela de Medicina Nuclear located in Mendoza, Argentina (FUESMEN). It has been developed in the Gabinete de Tecnologia Médica (GA.TE.ME), Facultad de Ingeniería-Universidad Nacional de San Juan. MIPS is a software that using the DICOM standard, can receive medical imaging studies of different modalities or viewing stations, then it executes algorithms and finally returns the results to other devices. To achieve the objectives previously mentioned, preliminary tests were conducted in the laboratory. More over, tools were remotely installed in clinical enviroment. The appropiate protocols for setting up and using them in different services were established once defined those suitable algorithms. Finally, it’s important to focus on the implementation and training that is provided in FUESMEN, using nuclear medicine quality control processes. Results on implementation are exposed in this work.

Dose Calibrator Linearity Testing: Radioisotope (99m)Tc or (18)F? An Alternative for Reducing Costs in Nuclear Medicine Quality Control.

Dose calibrator linearity testing is indispensable for evaluating the capacity of this equipment in measuring radioisotope activities at different magnitudes, a fundamental aspect of the daily routine of a nuclear medicine department, and with an impact on patient exposure. The main aims of this study were to evaluate the feasibility of substituting the radioisotope Fluorine-18 (18F) with Technetium-99m (99mTc) in this test, and to indicate it with the lowest operational cost. The test was applied with sources of 99mTc (62 GBq) and 18F (12 GBq), the activities of which were measured at different times, with the equipment preadjusted to measuring sources of 99mTc, 18F, Gallium-67 (67Ga), and Iodine-131 (131I). Over time, the average deviation between measured and expected activities from 99mTc and 18F were, respectively, 0.56 (±1.79)% and 0.92 (±1.19)%. The average ratios for 99mTc source experimental activity, when measured with the equipment adjusted for measuring 18F, 67Ga, and 131I sources, in real values, were, respectively, 3.42 (±0.06), 1.45 (±0.03), and 1.13 (±0.02), and those for the 18F source experimental activity, measured through adjustments of 99mTc, 67Ga, and 131I, were, respectively, 0.295 (±0.004), 0.335 (±0.007), and 0.426 (±0.006). The adjustment of a simple exponential function for describing 99mTc and 18F experimental activities facilitated the calculation of the physical half-lives of the radioisotopes, with a difference of about 1% in relation to the values described in the literature. Linearity test results, when using 99mTc, through being compatible with those acquired with 18F, imply the possibility of using both radioisotopes during linearity testing. Nevertheless, this information, along with the high potential of exposure and the high cost of 18F, implies that 99mTc should preferably be employed for linearity testing in clinics that normally use 18F, without the risk of prejudicing either the procedure itself or the guarantee of a high-quality nuclear medicine service.

SU-C-9A-02: Structured Noise Index as An Automated Quality Control for Nuclear Medicine: A Two Year Experience

Purpose: Flood-field uniformity evaluation is an essential element in the assessment of nuclear medicine (NM) gamma cameras. It serves as the central element of the quality control (QC) program, acquired and analyzed on a daily basis prior to clinical imaging. Uniformity images are traditionally analyzed using pixel value-based metrics which often fail to capture subtle structure and patterns caused by changes in gamma camera performance requiring additional visual inspection which is subjective and time demanding. The goal of this project was to develop and implement a robust QC metrology for NM that is effective in identifying non-uniformity issues, reporting issues in a timely manner for efficient correction prior to clinical involvement, all incorporated into an automated effortless workflow, and to characterize the program over a two year period. Methods: A new quantitative uniformity analysis metric was developed based on 2D noise power spectrum metrology and confirmed based on expert observer visual analysis. The metric, termed Structured Noise Index (SNI) was then integrated into an automated program to analyze, archive, and report on daily NM QC uniformity images. The effectiveness of the program was evaluated over a period of 2 years. Results: The SNI metric successfully identified visually apparent non-uniformities overlooked by the pixel valuebased analysis methods. Implementation of the program has resulted in nonuniformity identification in about 12% of daily flood images. In addition, due to the vigilance of staff response, the percentage of days exceeding trigger value shows a decline over time. Conclusion: The SNI provides a robust quantification of the NM performance of gamma camera uniformity. It operates seamlessly across a fleet of multiple camera models. The automated process provides effective workflow within the NM spectra between physicist, technologist, and clinical engineer. The reliability of this process has made it the preferred platform for NM uniformity analysis.

SU-D-217A-03: Nuclear Medicine Uniformity Assessment Using 2D Noise Power Spectrum.

Nuclear medicine quality control programs require daily evaluation for the presence of potential non-uniformities by commonly utilizing a traditional pixel value-based assessment (Integral CFOVUniformity). While this method effectively captures regional non- uniformities in the image, it does not adequately reflect subtle periodic structures that are visually apparent and clinically unacceptable, therefore requiring the need for additional visual inspection of the image. The goal of this project was to develop a new uniformity assessment metric by targetingstructural patterns and more closely correlating with visual inspection. The new quantitative uniformity assessment metric is based on the 2D Noise Power Spectrum (NPS). A full 2D NPS was performed on each image. The NPS was thresholded to remove quantum noise and further filtered by the visual response function. A score, the Structure Noise Index (SNI), was then applied to each based on the average magnitude of the structured noise in the processed image. To verify the validity of the new metric, 50 daily uniformity images with varying degrees of visual structured and non-structured non-uniformity were scored by 5 expert nuclear medicine physicists. The correlation between the visual score and SNI were assessed. The Integral CFOV was also compared against the visual score. Our new SNI assessment metric compared to the Integral CFOV showed in increase in sensitivity from 67% to 100% in correctly identifying structured non-uniformities. The overall positive predictive value also increased from 55% to 72%. Our new uniformity metric correlates much more closely with visual assessment of structured non- uniform NM images than the traditional pixel-based method. Using this new metric in conjunction with the traditional pixel value-based assessment will allow a more accurate quantitative assessment of nuclear medicineuniformity.

Calibration of activity readings from radiopharmaceuticals with impurities

Accurately determining the amount of a radionuclide actually administered to a patient is an important aspect of quality control in nuclear medicine. In this study, in order to accurately assess the “apparent” radioactivities of radionuclides with impurities by a dose calibrator, two methods, (1) curve fitting, and (2) relative sensitivities calculation, have been employed to determine the parameter, M (relative response). From the comparisons between the measurement and re-calculated radioactivity using the M values, each method was found to have its own advantage and disadvantage, depending upon the fraction ratio of the impurity as well as the energy level of the impurity’s photons. This study might be helpful for improving the assessment of radiopharmaceuticals’ “true” activity and its “apparent” activity measured by a dose calibrator.

Aceitabilidade de um futuro banco de objetos simuladores para controle de qualidade em medicina nuclear

OBJETIVO: O objetivo deste trabalho foi verificar a aceitabilidade para a implantação no Brasil de um banco de objetos simuladores nacional, ou bancos regionais, para uso compartilhado desses objetos em atividades de controle de qualidade nos serviços de medicina nuclear. MATERIAIS E MÉTODOS: Foram analisadas as respostas dadas em um questionário que foi enviado a supervisores de radioproteção e físicos médicos de serviços de medicina nuclear do Brasil. Inicialmente, o questionário foi validado por profissionais da cidade de Aracaju, SE, que está localizada no Nordeste. De acordo com as regiões geográficas brasileiras, fizeram parte da amostra investigada: o Nordeste, com respostas de profissionais de 13 serviços de medicina nuclear; o Norte, com 2 profissionais; o Sul, com 7 profissionais; o Sudeste, com 43 profissionais; e o Centro-Oeste, com 2 profissionais. RESULTADOS: Segundo os dados analisados, 82% dos entrevistados consideram que a implantação de um banco de simuladores seria uma alternativa apropriada para o aprimoramento do controle de qualidade em medicina nuclear. O interesse em compartilhar com o banco foi de 87%. CONCLUSÃO: Os resultados mostraram que há motivação para o compartilhamento de objetos simuladores, ou seja, para o uso desses objetos de forma socializada.

Liver phantom for quality control and training in nuclear medicine

Abstract In nuclear medicine, liver scintigraphy aims to verify organ function based on the radionuclide concentration in the liver and bile flow and is also used to detect tumors. Therefore it is necessary to perform quality control tests in the gamma camera before running the exam to prevent false results. Quality control tests of the gamma camera should thus be performed before running the exam to prevent false results. Such tests generally use radioactive material inside phantoms for evaluation of gamma camera parameters in quality control procedures. Phantoms can also be useful for training doctors and technicians in nuclear medicine procedures. The phantom proposed here has artifacts that simulate nodules; it may take on different quantities, locations and sizes and it may also be mounted without the introduction of nodules. Thus, its images may show hot or cold nodules or no nodules. The phantom consists of acrylic plates hollowed out in the centre, with the geometry of an adult liver. Images for analyses of simulated liver scintigraphy were obtained with the detector device at 5 cm from the anterior surface of the phantom. These simulations showed that this object is suitable for quality control in nuclear medicine because it was possible to visualize artifacts larger than 7.9 mm using a 256×256 matrix and 1000 kcpm. The phantom constructed in this work will also be useful for training practitioners and technicians in order to prevent patients from repeat testing caused by error during examinations.

Mise en œuvre du contrôle de qualité en médecine nucléaire

Like in many nuclear medicine centers, the AFSSAPS decision of November 25, 2008, has slightly changed our habits. The centers with medical physicist already made most of these controls, and this concept was not new for them. But what about the other centers? Sometimes, measures were made as expected, other times the manufacturers were expected to do them during the maintenance time, often nothing was formalized, and even in some cases nothing was done. Our experience in quality control in nuclear medicine is relatively recent, but we find interesting to raise some issues, including the duration for all these controls, the possible delegations, the means necessary to build them and difficulties in applying these controls.

Technetium-99m Pharmaceuticals: Preparation and Quality Control in Nuclear Medicine

I. Zolle, ed. New York, NY: Springer, 2007, 345 pages, $169 Written by a panel of 21 experts in the field and edited by Ilse Zolle, this hardbound volume is the current authoritative desk reference for those working with 99mTc-labeled radiopharmaceuticals. The 11 chapters of part 1 provide

Patient-related pitfalls and artifacts in nuclear medicine imaging

Quality control in nuclear medicine is all important. This applies not only to preparation of the patient and acquisition of the image, but also to interpretation of the study. Although it may seem self-evident, it is important to remain aware of artifacts that are directly related to the patient and need special consideration. Furthermore, at times the distinction between normal variants and artifacts can be difficult. Commonly encountered patient-related artifacts include artifacts caused by attenuation, contamination artifacts, and artifacts caused by intravenous lines, tubes, and catheters. Less commonly, artifacts arise because of the use of multiple isotopes, the presence of fistulas or surgically altered anatomy, and pharmaceuticals and other substances interfering with expected radiopharmaceutical uptake and distribution. The diagnostic accuracy of nuclear medicine reporting can be improved by awareness of these patient-related artifacts. Both awareness and experience are also important when it comes to detecting and identifying normal (and abnormal) variants.

Quality Control of Nuclear Medicine Instruments in Argentina

A teaching and supportive programme on quality control (QC) has been going on since 1980 in Argentina. Only 11% of the laboratories had their own QC programme at the beginning; implementation of QC programmes in the other laboratories was necessary. In 1988 a programme on QC in nuclear medicine (NM) to make the staff aware that QC is necessary had been carried out in 82% of the laboratories. After a first round, only 20% of the laboratories had implemented QC programmes. After multistage visits, 66% applied the programme successfully. This demonstrated the need for a teaching physicist. External QC was also carried out performing unknown-sample surveys. Ranking the NM units in three categories according to phantom lesion detectability, only 20% were considered acceptable, 47% unacceptable, while the rest needed further maintenance and QC. A legal support is necessary to urge the NM staff to perform QC.

Quality Control of Nuclear Medicine Instruments in Argentina

A teaching and supportive programme on quality control (QC) has been going on since 1980 in Argentina. Only 11% of the laboratories had their own QC programme at the beginning; implementation of QC programmes in the other laboratories was necessary. In 1988 a programme on QC in nuclear medicine (NM) to make the staff aware that QC is necessary had been carried out in 82% of the laboratories. After a first round, only 20% of the laboratories had implemented QC programmes. After multistage visits, 66% applied the programme successfully. This demonstrated the need for a teaching physicist. External QC was also carried out performing unknown-sample surveys. Ranking the NM units in three categories according to phantom lesion detectability, only 20% were considered acceptable, 47% unacceptable, while the rest needed further maintenance and QC. A legal support is necessary to urge the NM staff to perform QC.

Book review

This report will be of interest to all nuclear medicine and physics staff who use gamma cameras and associated computer systems. It has been written by a group of experts in the field of nuclear medicine quality control, namely the Radionuclide Topic Group of the Institute of Physical Sciences in Medicine, and replaces the Hospital Physicists Association's earlier report (TGR27) on the theory, specification and testing of Anger type gamma cameras, published in 1978.

Phantoms for External Quality Control in Nuclear Medicine by Blind Evaluation

Low contrast phantoms for nuclear medicine external quality control have been used over the past fifteen years by the College of American Pathologists, the World Health Organisation, the International Atomic Energy Agency, and the Comisión Nacional de Energia Atómica. Their applications, experimental designs and methods of analysis were evaluated. Requirements for new phantom construction and measurements are proposed.