Fatores associados a anormalidades na cintilografia de perfusão miocárdica de pacientes diabéticos / Factors associated with abnormalities on myocardial perfusion scintigraphy in diabetic patients

O diabetes melito é o maior fator de risco para doença arterial coronariana. Além da longa duração de diabetes, outros fatores, como presença de doença arterial periférica e tabagismo são fortes preditores para anormalidades na cintilografia de perfusão do miocárdio. O objetivo deste estudo foi avaliar o impacto dos fatores de risco de pacientes diabéticos nos resultados da cintilografia de perfusão do miocárdio e comparar com os resultados de pacientes não diabéticos em uma clínica de medicina nuclear. Foi realizado um estudo transversal retrospectivo por meio da análise de prontuários de pacientes que realizaram cintilografia miocárdica no período de 2010 a 2019. Foram avaliados 34.736 prontuários. Analisando a fase de estresse da cintilografia de perfusão do miocárdio, os portadores de diabetes melito precisaram receber estímulo farmacológico duas vezes mais que os não diabéticos para sua realização. Também foram avaliados fatores que tivessem impacto negativo no resultado da cintilografia de perfusão do miocárdio, e foi visto que o diabetes melito (33,6%), a insulinoterapia (18,1%), a hipertensão arterial sistêmica (69,9%), a dislipidemia (53%), o sedentarismo (83,1%), o uso de estresse farmacológico (50,6%), a dor torácica típica (8,5%) e a angina limitante durante o teste (1,7%) estiveram associados significativamente (p<0,001) a anormalidades neste exame. (AU)

Diabetes mellitus (DM) is the greatest risk factor for coronary artery disease. In addition to a long duration of diabetes, the presence of peripheral arterial disease and smoking are strong predictors of abnormalities on myocardial perfusion scintigraphy (MPS). This study aimed to assess the impact of risk factors in diabetic patients on MPS results and compare them with those of non-diabetic patients in a nuclear medicine clinic. A retrospective cross-sectional study was performed through the analysis of the medical records of patients who underwent MPS in 2010­2019. A total of 34,736 medical records were evaluated. Analyzing the stress phase of MPS, DM patients required two-fold more pharmacological stimulation than non-diabetic patients for MPS. Factors that negatively impact the MPS results were also evaluated, and DM (33.6%), insulin therapy (18.1%), systemic arterial hypertension (69.9%), dyslipidemia (53%), sedentary lifestyle (83.1%), use of pharmacological stress (50.6%), typical chest pain (8.5%), and limiting angina during the test (1.7%) were significantly associated (p < 0.001) with test abnormalities. (AU)

[Impact of COVID-19 on Nuclear Medicine Procedures in Germany 2020 - Results of a National Survey]. / Auswirkungen von COVID-19 auf nuklearmedizinische Untersuchungen und Therapien im Verlauf von 2020 ­ Ergebnisse einer nationalen Umfrage.

INTRODUCTION: The COVID-19 pandemic imposed an unimaginable challenge to the healthcare systems worldwide. This online survey captured the impact of the COVID-19 pandemic on nuclear medicine services in Germany comparing 2020 to 2019. MATERIALS AND METHODS: A web-based questionnaire was developed to record the 2020 numbers of nuclear medicine procedures and, in particular, the change compared with 2019. The changes in nuclear medicine diagnostics and therapy were queried, as well as the extent to which "Coronavirus SARS-CoV-2" recommendations provided by the DGN were implemented. RESULTS: 91 complete responses were recorded and evaluated. This corresponds to about 20 % of all German nuclear medicine facilities. Nuclear medicine diagnostic tests showed a decrease in scintigraphies for thyroid (15.9 %), bone (8.8 %), lung (7.6 %), sentinel lymph nodes (5.5 %), and myocardium (1.4 %) with small increases in PET/CT examinations (1.2 %) compared with 2019. Among nuclear medicine therapies, reductions were highest for benign indications (benign thyroid 13.3 %, RSO 7.7 %), while changes from 2019 were less pronounced for malignant indications (PRRT: + 2.2 %, PSMA: + 7.4 %, SIRT: -5.9 %, and RJT for thyroid carcinoma -2.4 %). The DGN recommendations for action were fully or partially applied in 90 %. CONCLUSIONS: The initial significant reduction in nuclear medicine procedures in the first three weeks of the COVID-19 pandemic did not continue, but there was no compensation of the previously not performed services. The decrease in diagnostics and therapy procedures of benign diseases was particularly severe.

How COVID-19 pandemic affected cancer progression: Three different scenarios evidenced by PET imaging.

COVID-19 pandemic is having a strong impact on healthcare providers around the world, by refocusing and reducing non-essential medical activities. Nuclear medicine departments among others, have been reorganizing and reprioritizing diagnostic and theragnostic procedures. This reorganizing had a negative impact on the supply of positron emission tomography (PET) services to oncologic patients, whose health was affected. We herein present the PET findings in three different cancer scenarios in which disease course was dramatically affected by the COVID-19 outbreak.

COVID-19 pandemic: Implications for radionuclide therapy in Nuclear Medicine departments.

The global COVID-19 health and economic crisis has forced people to adopt challenging rules of social distancing and self-isolation. Health care staff has been advised to change working routines to keep themselves and their patients safe. Radionuclide therapy has had an increasing role in clinical practice. Most therapeutic radionuclide procedures have applications in oncology. Cancer patients are an especially fragile and vulnerable population with higher risk due to co morbidities and immunosuppression. COVID-19 is another risk that must be considered in treatment planning. Therapeutic, prophylactic, and supportive interventions may require changes for these patients. The most common radionuclide therapies involve patients with differentiated thyroid cancer (DTC) who need radioiodine therapy (RAI), patients with neuroendocrine tumours (NETs) who need peptide receptor radionuclide therapy (PRRT), patients with hepatocellular carcinoma (HCC) who need therapy with radiolabelled microspheres, and patients with prostate cancer and bone metastasis who need radionuclide palliative therapy. If infected, cancer patients could be at a higher risk for serious COVID-19 disease. Treatment decisions for thyroid cancer and NETs are challenging in this environment. Any decision to postpone therapy must be carefully considered, balancing risks and benefits. A risk of worsened prognosis due to delayed or suboptimal cancer treatment must be weighed against the risk of severe COVID-19 illness.

Nuclear Medicine and Oncology in the COVID-19 pandemic era.

The coronavirus disease 2019 (COVID-19) global pandemic poses a significant challenge to the national health systems. Not only China, the first country that experienced the health crisis since last December, but the rest of the world, is facing an unprecedented global health crisis, the most serious crisis in a century, with social and economic impact. However, the most important impact of the new pandemic is the human impact. Till 4th of June 2020, coronavirus SARS-CoV-2, causing COVID-19 disease, has infected more than 65000.000 people and has been responsible for more than 386000 deaths globally. The first priority of public health authorities is to contain and mitigate the spread and infection rate of the coronavirus SARS-CoV-2, distributing the number of infections over time and, if possible, reduce the incidence of the disease (COVID-19) it causes. A critical task for health systems confronted with the spread of the coronavirus is to protect the health of all citizens, so this requires that both diagnosis/testing and appropriate care should be readily available, affordable, and provided in a safe environment. The health care systems of many developed countries failed to demonstrate a satisfactory response to the increased demand for acute care hospital beds, ventilators, emergency services, diagnostics tests, support equipment for their COVID-19 patients, availability of essential medicines, protective equipment for their staff etc. Nuclear Medicine (NM) departments and their staff, in spite of the fact that not being in the front line of the pandemic response, have experienced a dramatic alteration in their daily clinical activity, trying to adapt their clinical routine to the new environment. There are several issued guidance from national and international organizations, trying to help to cope with suspected or verified COVID-19 patients. Patients with cancer are thought to be more susceptible and have higher morbidity and mortality rates from COVID-19 than the general population. In the current article, our aim is to present measures, guidance and thoughts that should be considered for the cancer patients.

Challenges and priorities in skeletal, gastrointestinal, hepatobiliary, genitourinary and lung scintigraphy during the COVID-19 pandemic.

On December 29, 2019, a hospital in the City of Wuhan, Hubei Province, in Central China, admitted four individuals with pneumonia. The hospital reported this occurrence to the local center for disease control (CDC), which lead Wuhan CDC staff to initiate a field investigation with a retrospective search for pneumonia patients. On December 31, 2019, the World Health Organization (WHO) was alerted by the Chinese authorities for several cases of pneumonia of unknown origin in the City of Wuhan. On January 7, 2020, a novel virus was identified as the causative agent, belonging to the Coronaviridae family (Severe Acute Respiratory Syndrome Coronavirus 2, SARS-CoV-2). Within the same month, the virus spread to other provinces of China, as well as a number of neighbouring countries. On February 11, 2020, the WHO announced that the SARS-CoV-2 - caused infection would be called coronavirus disease 2019 (COVID-19). On February 15, 2020, the first death due to COVID-19 in Europe was reported; a Chinese tourist who died in France. The first COVID-19 case was diagnosed in Greece on February 26th. The WHO declared COVID-19 a pandemic on 11 March 2020. On March 12th, movie theaters, gyms and courtrooms were closed in Greece and on March 13th, with 190 confirmed cases and 1 death, malls, cafés, restaurants, bars, beauty parlors, museums and archaeological sites were also closed. So far, COVID-19 pandemic has affected the way people live and work globally, and has resulted in extreme strain on the healthcare systems worldwide. Most of the nuclear medicine studies are performed on an out-patient basis. Therefore, without effective implementation of the required preventive measures, there is a significant risk for viral transmission when visiting nuclear medicine departments, particularly in periods of high community spread.

Nuclear thyroidology in pandemic times: The paradigm shift of COVID-19.

Since its outbreak in Wuhan, China the SARS-CoV-2 has become a public health emergency of international concern, impacting all areas of daily life, including medical care. Although not in the front line nuclear medicine practice should adjust their standard operating procedures. The adaptations and the flexibility that nuclear thyroidology, among other fields of nuclear medicine, should show during the pandemic, must focus not only in minimizing the risk of infection to staff, patients, and family members, but also in controlling the transmission of the virus while continuing to provide health care services which do not jeopardize patients' prognosis and quality of life. Favorable prognosis and indolent symptoms of most cases of thyroid diseases, allows postponements and rescheduling as well as alternative procedures, provided that they are cautiously considered for each case individually. The objective of the current paper is to provide guidance on how diagnostic and therapeutic management of patients with thyroid diseases can be safely and effectively adjusted during pandemic, in nuclear medicine settings.

Non-Oncological PET/CT imaging during SARS-CoV-2 pandemic.

In December 2019 a new ß-CoV, Severe Acute Respiratory Coronavirus- 2 (SARS-CoV-2), has been identified in Wuhan Hubei Province, China. Within a few months it spread rapidly to more than 114 countries and the disease, Coronavirus disease 2019 (COVID-19), was declared pandemic on 11th February 2020 by the World Health Organization (WHO). Until 20 June 2020 8:09 am, 8,465,085 cases of COVID-19 were confirmed globally, with 454,258 deaths. The first incidence in Greece was documented on 26 February 2020 in Thessaloniki and up to 20 June 2020 8:09 am, 3,227 confirmed cases of COVID-19 were reported, with 188 deaths. At the time of writing USA and Brazil, are the countries with the highest disease burden. Governments have imposed a variety of suggestions and restrictions in order to control the spread of the virus, focusing mainly on social distancing, self-isolation, personal hygiene and personal protective equipment (PPE). Greece was one of the countries that implemented early drastic measures thus succeeding in controlling the virus transmission; having a profound economical effect though.

Radiotherapy treatment scheduling considering time window preferences.

External-beam radiotherapy treatments are delivered by a linear accelerator (linac) in a series of high-energy radiation sessions over multiple days. With the increase in the incidence of cancer and the use of radiotherapy (RT), the problem of automatically scheduling RT sessions while satisfying patient preferences regarding the time of their appointments becomes increasingly relevant. While most literature focuses on timeliness of treatments, several Dutch RT centers have expressed their need to include patient preferences when scheduling appointments for irradiation sessions. In this study, we propose a mixed-integer linear programming (MILP) model that solves the problem of scheduling and sequencing RT sessions considering time window preferences given by patients. The MILP model alone is able to solve the problem to optimality, scheduling all sessions within the desired window, in reasonable time for small size instances up to 66 patients and 2 linacs per week. For larger centers, we propose a heuristic method that pre-assigns patients to linacs to decompose the problem in subproblems (clusters of linacs) before using the MILP model to solve the subproblems to optimality in a sequential manner. We test our methodology using real-world data from a large Dutch RT center (8 linacs). Results show that, combining the heuristic with the MILP model, the problem can be solved in reasonable computation time with as few as 2.8% of the sessions being scheduled outside the desired time window.

Herramienta basada en código abierto para el cálculo de blindaje en las instalaciones de Medicina Nuclear / Open Source Based Tool for Shielding Calculation in Nuclear Medicine Installations

Uno de los requerimientos indispensables en el diseño de las instalaciones donde se trabaja con radiación ionizante es la determinación del espesor adecuado de las paredes, pisos, techo y puertas de los locales, que garanticen dosis por debajo de las restricciones establecidas por la autoridad regulatoria. El objetivo del presente trabajo es desarrollar una herramienta interactiva, libre y de código abierto para calcular los blindajes requeridos en una instalación de Medicina Nuclear. En el código, desarrollado en Phyton utilizando el entorno interactivo Jupiter Notebook, se incluyó el análisis tanto para Tomografía por Emisión de Fotón Único como para Tomografía por Emisión de Positrones. La herramienta fue implementada para el cálculo de los blindajes de un departamento de Medicina Nuclear del Centro Internacional de Restauración Neurológica (CIREN). Esta herramienta libre y de código abierto facilita los cálculos de blindaje aumentando la velocidad, lo que contribuye a lograr una optimización de la protección radiológica, pero también puede usarse como herramienta pedagógica(AU)

One of the indispensable requirements in the design of the facilities where ionizing radiation is used is the determination of the adequate thickness of the walls, floors, ceiling and doors of the premises, which guarantee doses below the restrictions established by the regulatory authority. The goal of this work is to develop an interactive, free and open source tool to calculate the shields required in a Nuclear Medicine installation. Analysis for both Single Photon Emission Tomography and Positron Emission Tomography was included in the code, developed in Phyton using the interactive Jupiter Notebook environment. The tool was implemented to calculate the shields of a Nuclear Medicine department of the International Center for Neurological Restoration (CIREN). This free and open source tool facilitates shielding calculations by increasing speed, which contributes to the optimization of radiation protection, but can also be used as a pedagogical tool(AU)

An IAEA survey of radiotherapy practice including quality assurance extent and depth.

Background: The IAEA recommends a quality assurance program in radiotherapy to ensure safe and effective treatments. In this study, radiotherapy departments were surveyed on their current practice including the extent and depth of quality assurance activities.Methods: Radiotherapy departments were voluntarily surveyed in three stages, firstly, in basic facility information, secondly, in quality assurance activities and treatment techniques, and thirdly, in a snapshot of quality assurance, departmental and treatment activities.Results: The IAEA received completed surveys from 381 radiotherapy departments throughout the world with 100 radiotherapy departments completing all three surveys. Dominant patterns were found in linac-based radiotherapy with access to treatment planning systems for 3D-CRT and 3D imaging. Staffing levels for major staff groups were on average in the range recommended by the IAEA. The modal patient workload per EBRT unit was as expected in the range of 21-30 patients per day, however significant instances of high workload (more than 50 patients per day per treatment unit) were reported. Staffing levels were found to correlate with amount of treatment equipment and patient workload. In a self-assessment of quality assurance performance, most radiotherapy departments reported that they would perform at least 60% of the quality assurance activities itemized in the second survey, with particular strength in equipment quality control. In a snapshot survey of quality assurance performance, again equipment quality control practice was well developed, particularly for the treatment equipment.Conclusions: The IAEA surveys provide a snapshot of current radiotherapy practice including quality assurance activities.

Avaliação da metodologia de estimação da atividade em rejeitos sólidos radioativos perfurocortantes gerados em um Serviço de Medicina Nuclear / [Evaluation of the methodology for estimating activity in sharp radioactive solid waste generated in a Nuclear Medicine Service]

A utilização das radiações ionizantes deve trazer um benefício líquido para a sociedade. A medicina nuclear é uma especialidade médica que emprega radiofármacos para o diagnóstico e tratamento de diversas doenças, o que invariavelmente ocasiona a produção de rejeitos radioativos. Rejeitos radioativos são materiais contendo radionuclídeos sem utilização presente ou futura, e a sua liberação no meio ambiente pode causar a exposição da população. A Comissão Nacional de Energia Nuclear (CNEN), através da norma CNEN-NN-8.01 regulamenta os procedimentos para a gerência dos rejeitos radioativos, determinando como os mesmos devem ser descritos e classificados, os procedimentos para a sua coleta e segregação, embalagem, identificação, armazenamento, e os limites para a sua transferência para os serviços de coleta urbana. Como determinado pela CNEN, todos os embalados contendo rejeitos radioativos devem ter a atividade estimada e registrada em sinalização afixada em seu exterior e no inventário de rejeitos radioativos. A determinação ou a estimação da atividade é importante para o cálculo do tempo de armazenagem até a liberação dos rejeitos nos serviços de coleta de lixo hospitalar e urbano. Portanto, são necessários procedimentos práticos para mensurar ou estimar a atividade. A metodologia aplicada pelo Serviço de Medicina Nuclear do Instituto Nacional de Câncer José Alencar Gomes da Silva (SMN/INCA) para estimar a atividade nos coletores de perfurocortantes (rejeitos radioativos) utiliza algumas aproximações físicas, considerando os embalados como fontes pontuais, homogêneas e isotrópicas sem autoabsorção ou espalhamento das radiações. Essas aproximações não são geralmente compatíveis com a realidade, onde os embalados têm volumes consideráveis, com materiais que produzem atenuação e espalhamento das radiações. O objetivo desse trabalho é avaliar a metodologia aplicada pelo SMN/INCA para estimar a atividade nos coletores de perfurocortantes e comparar tais estimativas com a atividade real dos rejeitos radioativos, determinando um possível fator de correção para as mesmas. Foram realizados experimentos de forma a avaliar os procedimentos rotineiramente empregados no SMN/INCA, assumindo que podem existir diferenças significativas com relação a atividade presente nos embalados e aquelas estimadas por tais procedimentos, baseados nas medições obtidas com o uso de monitores de radiação calibrados na grandeza dosimétrica equivalente de dose ambiente - H*(10). Os resultados obtidos monstram que a metodologia empregada para estimar tal atividade dos embalados, contendo rejeitos radioativos perfurocortantes, subestima a atividade real contida nos embalados em até 20%. Essas diferenças são devidas as variações de leituras obtidas com o monitor de radiação Geiger-Müller. Entretanto, tais variações se encontram na faixa de tolerância para tal classe de monitores calibrados em H*(10). Embora existam diferenças entre a atividade real e a estimada, a correção é possível através de um fator de ajuste fixo (k = 1, 2) , que pode ser utilizado de forma a garantir que a metodologia produza resultados compativeis com os requisitos normativos de proteção radiológica definidos pela CNEN.

The use of ionizing radiation must provide net benefits to society. Nuclear medicine is a medical specialty that uses radiopharmaceuticals to diagnosis and treatment for several illnesses, inevitably producing radioactive waste. Radioactive waste is any material containing radionuclides with no present or future use, and your release in the environment can cause radioactivity exposure to the population. The Brazilian National Nuclear Energy Commission (CNEN), through norm CNEN NN-8.01, regulates the procedures for the management of such radioactive waste, determining how to describe and classify, the methods for their collection, segregation, packaging, identification, storage, and the limits to transfer it to urban waste collection services. As ruled by CNEN, all packages containing radioactive waste must have the estimated activity recorded in external labels and on the inventory of radioactive waste. The activity determination or estimation is essential to the calculation of the storage time until the release of such waste in medical or urban waste collecting services. Therefore, practical procedures are necessary to carry out that measurement or estimation. The methodology applied by the Nuclear Medicine Department of the Brazilian National Cancer Institute José de Alencar Gomes da Silva (SMN/INCA) to estimate the activity in the sharp containers (radioactive waste) uses some physical approximations to perform the activity estimation, considering the packages as punctual, homogeneous and isotropic sources with no radiation autoabsorption or scattering. Those approximations have no link to the reality where the packages have considerable volumes with materials that produce radiation attenuation and scattering. This work aims to evaluate the methodology applied by the SMN/INCA to estimate the activity in the sharp containers (radioactive waste) and compare the provided estimates with the actual activity on that waste, providing a correction factor for those estimations. Experiments were carried out to evaluate the procedures employed in the routine of the Service. Assuming that there may be significant differences about the actual activities present in the packages and those estimated by such methodology, based on measurements obtained with the use of radiation monitors calibrated in the dosimetric quantity equivalent of ambient dose - H*(10). The results show that the methodology can underestimate the activity contained in the packages by up to 20%. Those differences are due to the variation on the Geiger-Müller monitor readings. However, the differences are in the tolerance range for those instruments when calibrated on H*(10). Although there are differences between the actual activity and that estimated, the correction is possible with one fixed adjustment factor (k = 1, 2) , allowing the methodology gives results compatible with the regulatory requirements of radiological protection determined by CNEN.

The nuclear medicine therapy care coordination service: a model for radiologist-driven patient-centered care.

We developed a longitudinal care coordination service to proactively deliver high-quality and family-centered care in patients receiving radioiodine therapy for thyroid cancer. In an iterative, multidisciplinary team manner, a pretherapy consultation service, which included scripted interactions, documentation, and checklists for quality control, evolved over time into a robust patient-centered longitudinal care coordination nuclear medicine service. Radiation safety precautions, the rationale for therapy, and management of patient expectations were addressed through the initial consultation, and discharge and posttreatment care were managed during subsequent follow-up. The patient-physician relationship created during longitudinal nuclear medicine therapy care is one tool to help counteract the growing commoditization of radiology. This article describes the process that the nuclear medicine specialists in our department established to enhance radiologist value by providing both exceptional thyroid cancer treatment and continuity of care.

Online stochastic optimization of radiotherapy patient scheduling.

The effective management of a cancer treatment facility for radiation therapy depends mainly on optimizing the use of the linear accelerators. In this project, we schedule patients on these machines taking into account their priority for treatment, the maximum waiting time before the first treatment, and the treatment duration. We collaborate with the Centre Intégré de Cancérologie de Laval to determine the best scheduling policy. Furthermore, we integrate the uncertainty related to the arrival of patients at the center. We develop a hybrid method combining stochastic optimization and online optimization to better meet the needs of central planning. We use information on the future arrivals of patients to provide an accurate picture of the expected utilization of resources. Results based on real data show that our method outperforms the policies typically used in treatment centers.

First experiences with the implementation of the European standard EN 62304 on medical device software for the quality assurance of a radiotherapy unit.

BACKGROUND: According to the latest amendment of the Medical Device Directive standalone software qualifies as a medical device when intended by the manufacturer to be used for medical purposes. In this context, the EN 62304 standard is applicable which defines the life-cycle requirements for the development and maintenance of medical device software. A pilot project was launched to acquire skills in implementing this standard in a hospital-based environment (in-house manufacture). METHODS: The EN 62304 standard outlines minimum requirements for each stage of the software life-cycle, defines the activities and tasks to be performed and scales documentation and testing according to its criticality. The required processes were established for the pre-existent decision-support software FlashDumpComparator (FDC) used during the quality assurance of treatment-relevant beam parameters. As the EN 62304 standard implicates compliance with the EN ISO 14971 standard on the application of risk management to medical devices, a risk analysis was carried out to identify potential hazards and reduce the associated risks to acceptable levels. RESULTS: The EN 62304 standard is difficult to implement without proper tools, thus open-source software was selected and integrated into a dedicated development platform. The control measures yielded by the risk analysis were independently implemented and verified, and a script-based test automation was retrofitted to reduce the associated test effort. After all documents facilitating the traceability of the specified requirements to the corresponding tests and of the control measures to the proof of execution were generated, the FDC was released as an accessory to the HIT facility. CONCLUSIONS: The implementation of the EN 62304 standard was time-consuming, and a learning curve had to be overcome during the first iterations of the associated processes, but many process descriptions and all software tools can be re-utilized in follow-up projects. It has been demonstrated that a standards-compliant development of small and medium-sized medical software can be carried out by a small team with limited resources in a clinical setting. This is of particular relevance as the upcoming revision of the Medical Device Directive is expected to harmonize and tighten the current legal requirements for all European in-house manufacturers.

[Evaluating radiation dose load in medical personnel of radiologic diagnostic departments].

The article deals with materials on radiation hygienic evaluation of radiologic diagnostic departments in various medical institutions of Moscow. The studies covered work of medical staffers in X-ray examination and in contact with short-lived isotope generators. The authors outlined the examination types and stages with maximal radiation danger. Disimetric information obtained during the study helped to calculate values of equivalent, effective doses of radiation for medical personnel and maximal potential doses.

Radiation doses of employees of a Nuclear Medicine Department after implementation of more rigorous radiation protection methods.

The appropriate radiation protection measures applied in departments of nuclear medicine should lead to a reduction in doses received by the employees. During 1991-2007, at the Department of Nuclear Medicine of Pomeranian Medical University (Szczecin, Poland), nurses received on average two-times higher (4.6 mSv) annual doses to the whole body than those received by radiopharmacy technicians. The purpose of this work was to examine whether implementation of changes in the radiation protection protocol will considerably influence the reduction in whole-body doses received by the staff that are the most exposed. A reduction in nurses' exposure by ~63 % took place in 2008-11, whereas the exposure of radiopharmacy technicians grew by no more than 22 % in comparison with that in the period 1991-2007. Proper reorganisation of the work in departments of nuclear medicine can considerably affect dose reduction and bring about equal distribution of the exposure.

Myocardial perfusion imaging laboratory efficiency with the use of regadenoson compared to adenosine and dipyridamole.

OBJECTIVE: Adenosine, dipyridamole, and regadenoson are pharmacologic stress agents used in myocardial perfusion imaging (MPI), to diagnose and monitor coronary artery disease. Clinical studies suggest that regadenoson has pharmacologic properties that simplify the MPI procedure through availability to a wider range of patients and easier administrative requirements. This study assesses the operational advantages and laboratory efficiency associated with the use of regadenoson compared to adenosine and dipyridamole. METHODS: A web-based survey of 141 nuclear medicine technologists working in US-based cardiovascular imaging laboratories from June-July 2009. MAIN OUTCOME MEASURES: Descriptive statistics measured the adenosine, dipyridamole, and regadenoson cohorts. Bivariate analyses compared the overall and staff-specific time to conduct an MPI test. The site-specific sub-groups were defined by hospital vs non-hospital setting, hours of operation, number of SPECT cameras, and number of full-time equivalent staff, including nurses, nuclear technologists, physicians, and nurse practitioners/physician assistants. RESULTS: The total time to conduct an MPI test was shortest with regadenoson 156 (46) min compared to adenosine and dipyridamole 182 (63) and 191 (61) min, respectively. Time from regadenoson administration to the start of the imaging session, including dose calculation and infusion time, was 14.2 min less than adenosine, and 12.0 min less than dipyridamole. The time to manage adverse events was shortest if it occurred with regadenoson compared to adenosine and dipyridamole, with minor exceptions. Due to the nature of survey implementation, possible recall bias may limit the results. Some differences in procedures times may be attributable to differences in laboratories' protocols. CONCLUSIONS: Overall time savings and time savings stratified by operational ability (number of staff, number of SPECT cameras, hours of operation) translate to a more efficient utilization of laboratory resources when using regadenoson compared to adenosine and dipyridamole. Regadenoson is the most efficient pharmacologic stress agent compared to adenosine and dipyridamole.