Norman E. Bolus

Basic Review of Radiation Biology and Terminology

The purpose of this paper is to review basic radiation biology and associated terminology to impart a better understanding of the importance of basic concepts of ionizing radiation interactions with living tissue. As health care workers in a field that utilizes ionizing radiation, nuclear medicine technologists are concerned about the possible acute and chronic effects of occupational radiation exposure. Technologists should have a clear understanding of what they are exposed to and how their safety could be affected. Furthermore, technologists should be knowledgeable about radiation effects so that they can adequately assuage possible patient fears about undergoing a nuclear medicine procedure. After reading this article, the nuclear medicine technologist will be familiar with basic radiation biology concepts; types of interactions of radiation with living tissue, and possible effects from that exposure; theoretic dose–response curves and how they are used in radiation biology; stochastic versus nonstochastic effects of radiation exposure, and what these terms mean in relation to both high- and low-dose radiation exposure; and possible acute and chronic radiation exposure effects.

PET/MRI: The Blended-Modality Choice of the Future?

This article addresses the emerging technology of PET coupled with MRI, or PET/MRI, which could become the technology of choice in the future for many reasons. Some of these reasons will be discussed, along with a historical account of the field of MRI and how this modality has evolved to include many aspects of molecular and functional imaging. After reading this article, nuclear medicine technologists should be able to provide an overview of the history of MRI, discuss PET and how it is mainly used today melded to CT as PET/CT, discuss how MRI is used diagnostically, explain how PET technology and MRI technology are able to function simultaneously together as PET/MRI, discuss some issues concerning who will operate these new units, and discuss the possibility that PET/MRI could be the blended technology of choice in the future.

NCRP report 160 and what it means for medical imaging and nuclear medicine.

The purpose of this paper is to briefly explain report 160 of the National Council on Radiation Protection and Measurement and the significance of the report to medical imaging as a whole and nuclear medicine specifically. The implications of the findings of report 160 have had repercussions and will continue to affect all of ionizing radiation medical imaging. The nuclear medicine community should have an understanding of why and how report 160 is important. After reading this article, the nuclear medicine technologist will be familiar with the main focus of report 160, the significant change that has occurred since the 1980s in the ionizing radiation exposure of people in the United States, the primary background source of ionizing radiation in the United States, the primary medical exposure to ionizing radiation in the United States, trends in nuclear medicine procedures and patient exposure, and a comparison of population doses between 2006 and the early 1980s as outlined in report 160.

Stress Resulting from Change and Restructuring: A Cognitive Approach

Restructuring of the health care system has brought about stress in health care workers who are attempting to adapt to change. Although most stress-reduction approaches utilize affective solutions, this article argues that instituting a new way of thinking is needed for health care workers to survive and thrive under restructuring. There are a number of fallacies of thinking that individuals use in the face of change, including dichotomous thinking and weak-sense critical thinking. Adaptation and survival in todays health care environment requires complex ways of thinking that go beyond an innate resistance to change, shown in this article as dialectical thinking

Radiological Emergency Preparedness: A Survey of Nuclear Medicine Technologists in the United States

Because of the increasing risk of radiological emergencies, public health agencies and first-response organizations are working to increase their capability of responding. Nuclear medicine technologists (NMTs) have expertise in certain areas, such as radiation safety, radiobiology, decontamination, and the use of radiation detection and monitoring equipment, that could be useful during the response to events that involve radiological materials. Methods. To better understand the potential role that NMTs may have in response efforts, a cross-sectional survey was conducted. The survey was sent electronically to the 7,000 members of the Technology Section of the Society of Nuclear Medicine and Molecular Imaging. Eight hundred fifty NMTs responded to the survey, for a response rate of 12.14%. The study queried NMTs across the United States on their knowledge of using radiation detection and monitoring equipment, such as a scintillation γ-cameras, Geiger counters, thyroid probes, well counters, and portal monitors; willingness to participate in response efforts during a nuclear reactor accident, nuclear weapon detonation, or dirty bomb detonation; access to radiation detection and monitoring equipment within their work setting; familiarity with current preparedness guidance and tools provided by the Centers for Disease Control and Prevention and U.S. Department of Health and Human Services; and registration in volunteer initiatives such as the Emergency System for Advance Registration of Volunteer Health Professionals, Metropolitan Medical Response System, and Medical Reserve Corps. Results. Survey results suggest that NMTs are knowledgeable and willing to respond to radiological emergencies, regardless of number of years of work experience. Radiological preparedness training within the last 5 y significantly increases NMTs’ willingness to respond and familiarity with current guidance and tools provided by the Centers for Disease Control and Prevention and Department of Health and Human Services. Respondents reported a low participation level in volunteer programs, and most agreed that continuing education should include radiological emergency preparedness. Conclusion. NMTs should be considered an untapped resource and should be strategically recruited for involvement in radiological emergency preparedness planning and training. NMTs should also consider becoming involved in local volunteer initiatives because they have the knowledge and willingness to provide assistance during a radiological emergency.

A Short Interfering RNA (siRNA) Molecular Beacon for the Detection of Mycobacterial Infection

In latent TB, the ability of Mycobacterium tuberculosis to invade and survive within macrophages of the pulmonary granuloma is attributed to protein products of mammalian cell entry (mce4) operon genes (A-F). These are cholesterol transporters which facilitate the transport of host lipids into the mycobacterium allowing long term survival during chronic infection. Currently, there are no rapid and reliable tests for the detection of latent TB. Therefore, because there is a lack of reliable and efficient tests for the diagnosis of latent TB, we tested the hypothesis that mycobacterial infection can be detected using mce4 siRNA molecular beacons against mce4 mRNAs. Because our work showed that the mce4A gene of the mce4 operon conferred infectivity to host E. coli, a siRNA molecular beacon was designed against a region of the mce4A mRNA that is highly homologous in Mycobacterium tuberculosis and Mycobacterium smegmatis. This molecular beacon has a hairpin structure with a stem, 5 nucleotides on either end that are complementary to each other, and a loop which contains 20 nucleotides that are complementary to a region of the target mRNA. Conjugated to the 5’ and 3’ ends of the molecular beacon are the fluorophore TYE 665 and quencher Iowa Black RQ-SP. In the absence of the target mRNA the hairpin structure will predominate and fluorescence will be quenched while in the presence of the target mRNA fluorescence will be induced. Our study shows that the siRNA molecular beacon detects its target in M. smegmatis and in macrophages infected with M. smegmatis and offers a potential test for detection of mycobacterial infection.

Review of common occupational hazards and safety concerns for nuclear medicine technologists.

The purpose of this article is to address common occupational hazards and safety concerns of nuclear medicine technologists. There are many possible occupational hazards, but this review is intended to concentrate on common hazards and safety concerns. These include radiation safety issues and concerns about the possibility of developing latent diseases, such as eye cataracts or cancer; pregnant workers and radiation safety issues; biohazard concerns associated with patient body fluids; possible low-back pain from moving heavy equipment and performing patient transfers; and possible repetitive trauma disorders, such as carpal tunnel syndrome, from computer work. Suggestions are made regarding how to identify potential hazards and avoid them. After reading this article, nuclear medicine technologists should be able to explain the importance of the as-low-as-reasonably-achievable concept, discuss the possible effects of ionizing radiation on the adult and the developing fetus, list several basic principles to avoid injury to the back, list and describe the more common repetitive trauma disorders or injuries and how to avoid them, and list and describe the biohazard safety issues that nuclear medicine technologists face and how to develop policy to minimize exposure risk.

Historical Patterns in the Types of Procedures Performed and Radiation Safety Practices Used in Nuclear Medicine From 1945-2009.

AbstractThe authors evaluated historical patterns in the types of procedures performed in diagnostic and therapeutic nuclear medicine and the associated radiation safety practices used from 1945–2009 in a sample of U.S. radiologic technologists. In 2013–2014, 4,406 participants from the U.S. Radiologic Technologists (USRT) Study who previously reported working with medical radionuclides completed a detailed survey inquiring about the performance of 23 diagnostic and therapeutic radionuclide procedures and the use of radiation safety practices when performing radionuclide procedure-related tasks during five time periods: 1945–1964, 1965–1979, 1980–1989, 1990–1999, and 2000–2009. An overall increase in the proportion of technologists who performed specific diagnostic or therapeutic procedures was observed across the five time periods. Between 1945–1964 and 2000–2009, the median frequency of diagnostic procedures performed substantially increased (from 5 wk−1 to 30 wk−1), attributable mainly to an increasing frequency of cardiac and non-brain PET scans, while the median frequency of therapeutic procedures performed modestly decreased (from 4 mo−1 to 3 mo−1). Also a notable increase was observed in the use of most radiation safety practices from 1945–1964 to 2000–2009 (e.g., use of lead-shielded vials during diagnostic radiopharmaceutical preparation increased from 56 to 96%), although lead apron use dramatically decreased (e.g., during diagnostic imaging procedures, from 81 to 7%). These data describe historical practices in nuclear medicine and can be used to support studies of health risks for nuclear medicine technologists.

O10-4 Ionizing radiation exposure and risks of cancer and circulatory disease in technologists performing nuclear medicine procedures

The number of nuclear medicine procedures performed has increased substantially over the past several decades, resulting in potentially greater radiation exposure to the technologists who perform them. However, there have been no epidemiologic studies of cancer or other serious health effects in these workers. Using data from the U.S. Radiologic Technologists (USRT) Study (1994–1998), we prospectively examined risks of cancer and circulatory disease (incidence through 2005 and mortality through 2008) associated with reported performance of nuclear medicine and brachytherapy procedures. Although risks for most outcomes examined were not elevated, we observed increased risks for squamous cell carcinoma of the skin (HR = 1.29, 95% CI: 1.01–1.66) with ever performing diagnostic radionuclide procedures, for myocardial infarction incidence (HR = 1.37, 95% CI: 1.10–1.70), all-cause mortality (HR = 1.10, 95% CI: 1.00–1.20) and all-cancer mortality (HR = 1.20, 95% CI: 1.01–1.43) with ever performing brachytherapy; also mortality from all causes (HR = 1.14, 95% CI: 1.01–1.30), breast cancer (HR = 2.68, 95% CI: 1.10–6.51), and myocardial infarction (HR = 1.76, 95% CI: 1.02–3.04) were associated with ever performing other radionuclide therapy procedures; higher risks were also observed with greater frequency of performing these procedures before 1980. For a sample of 4,406 technologists in USRT who completed a detailed work history survey in 2013–14, we described trends over the past six decades in nuclear medicine work history practices. We found that the frequency of most diagnostic nuclear medicine procedures performed by technologists increased over time, particularly for cardiac and positron emission tomography (PET) scans, while the frequency of therapeutic procedures performed remained stable. Although adherence to most radiation protection practices increased, lead apron use sharply declined. Estimation of organ-specific occupational radiation doses for individual technologists using these data (in progress) will be used in comprehensive retrospective and prospective investigations of radiogenic cancer and other serious disease risks. A study evaluating nuclear medicine work history practices and associated doses in a sample of U.S. technologists who are more recently trained and primarily certified in nuclear medicine technology is currently underway.

Survey on the Use of Nuclear Renal Imaging in the United States

Throughout the years, the role of nuclear medicine departments in the care of renal patients has changed as a result of technologic advancements and other factors. This study evaluated the current role of nuclear renal imaging. Methods: A survey was generated with questions about patient populations, the clinical indications most often seen, radiopharmaceutical use, measurement techniques, the average number of scans completed, and medical center/transplant team affiliations. The survey was sent to recipients on a mailing list acquired from the Nuclear Medicine Technology Certification Board. Results: Most of the responses came from departments in the southeastern United States. Most of the patient population is suburban. Nephrologists are the most common referring physicians for renal imaging. Most departments complete fewer than 10 renograms per month, and most departments use 99mTc-mercaptoacetyltriglycine as the radiopharmaceutical of choice. A camera-based measurement technique is used most often. Most departments report being affiliated with a medical center, but only about half of those medical centers perform renal transplantation. The most commonly seen clinical indication for renal imaging is renal obstruction, whereas the least commonly seen is urine leakage. Conclusion: These results provide a better understanding of the current role of nuclear medicine in the care of renal patients and how this role has changed over the years.