NCRP Commentary Research Articles

NCRP commentary no. 33—recommendations for stratification of equipment use and radiation safety training for fluoroscopy

National Council on Radiation Protection and Measurements Commentary No. 33 ‘Recommendations for Stratification of Equipment Use and Radiation Safety Training for Fluoroscopy’ defines an evidence-based, radiation risk classification for fluoroscopically guided procedures (FGPs), provides radiation-related recommendations for the types of fluoroscopes suitable for each class of procedure, and indicates the extent and content of training that ought to be provided to different categories of facility staff who might enter a room where fluoroscopy is or may be performed. For FGP, radiation risk is defined by the type and likelihood of radiation hazards that could be incurred by a patient undergoing a FGP. The Commentary also defines six training groups of facility staff based on their role in the fluoroscopy room. The training groups are based on a combination of job descriptions and the procedures in which these individuals might be involved. The Commentary recommends the extent and content of training that should be provided to each of these training groups. It also provides recommendations on training formats, training frequency, and methods for demonstrating that the learner has acquired the necessary knowledge.

Methods of improving brain dose estimates for internally deposited radionuclides * * This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the US Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or

The US National Council on Radiation Protection and Measurements (NCRP) convened Scientific Committee 6–12 (SC 6–12) to examine methods for improving dose estimates for brain tissue for internally deposited radionuclides, with emphasis on alpha emitters. This Memorandum summarises the main findings of SC 6–12 described in the recently published NCRP Commentary No. 31, ‘Development of Kinetic and Anatomical Models for Brain Dosimetry for Internally Deposited Radionuclides’. The Commentary examines the extent to which dose estimates for the brain could be improved through increased realism in the biokinetic and dosimetric models currently used in radiation protection and epidemiology. A limitation of most of the current element-specific systemic biokinetic models is the absence of brain as an explicitly identified source region with its unique rate(s) of exchange of the element with blood. The brain is usually included in a large source region called Other that contains all tissues not considered major repositories for the element. In effect, all tissues in Other are assigned a common set of exchange rates with blood. A limitation of current dosimetric models for internal emitters is that activity in the brain is treated as a well-mixed pool, although more sophisticated models allowing consideration of different activity concentrations in different regions of the brain have been proposed. Case studies for 18 internal emitters indicate that brain dose estimates using current dosimetric models may change substantially (by a factor of 5 or more), or may change only modestly, by addition of a sub-model of the brain in the biokinetic model, with transfer rates based on results of published biokinetic studies and autopsy data for the element of interest. As a starting place for improving brain dose estimates, development of biokinetic models with explicit sub-models of the brain (when sufficient biokinetic data are available) is underway for radionuclides frequently encountered in radiation epidemiology. A longer-term goal is development of coordinated biokinetic and dosimetric models that address the distribution of major radioelements among radiosensitive brain tissues.

Using personal monitoring data to derive organ doses for medical radiation workers in the Million Person Study—considerations regarding NCRP Commentary no. 30

The study of low dose and low-dose rate exposure is of central importance in understanding the possible range of health effects from prolonged exposures to radiation. The One Million Person Study of Radiation Workers and Veterans (MPS) of low-dose health effects was designed to evaluate radiation risks among healthy American workers and veterans. The MPS is evaluating low-dose and dose-rate effects, intakes of radioactive elements, cancer and non-cancer outcomes, as well as differences in risks between women and men. Medical radiation workers make up a large group of individuals occupationally exposed to low doses of radiation from external x-ray/gamma exposures. For the MPS, about 100 000 United States medical radiation workers have been selected for study. The approach to the complex dosimetry circumstances for such workers over three to four decades of occupation were initially and broadly described in National Council on Radiation Protection and Measurements (NCRP) Report No. 178. NCRP Commentary No. 30 provides more detail and describes an optimum approach for using personal monitoring data to estimate lung and other organ doses applicable to the cohort and provides specific precautions/considerations applicable to the dosimetry of medical radiation worker organ doses for use in epidemiologic studies. The use of protective aprons creates dosimetric complexity. It is recommended that dose values from dosimeters worn over a protective apron be reduced by a factor of 20 for estimating mean organ doses to tissues located in the torso and that 15% of the marrow should be assumed to remain unshielded for exposure scenarios when aprons are worn. Conversion coefficients relating personal dose equivalent, H p(10) in mSv, to mean absorbed doses to organs and tissues, D T in mGy, for females and males for six exposure scenarios have been determined and presented for use in the MPS. This Memorandum summarises several key points in NCRP Commentary No. 30.

Recent Epidemiologic Studies and the Linear No-Threshold Model For Radiation Protection-Considerations Regarding NCRP Commentary 27.

National Council on Radiation Protection and Measurements Commentary 27 examines recent epidemiologic data primarily from low-dose or low dose-rate studies of low linear-energy-transfer radiation and cancer to assess whether they support the linear no-threshold model as used in radiation protection. The commentary provides a critical review of low-dose or low dose-rate studies, most published within the last 10 y, that are applicable to current occupational, environmental, and medical radiation exposures. The strengths and weaknesses of the epidemiologic methods, dosimetry assessments, and statistical modeling of 29 epidemiologic studies of total solid cancer, leukemia, breast cancer, and thyroid cancer, as well as heritable effects and a few nonmalignant conditions, were evaluated. An appraisal of the degree to which the low-dose or low dose-rate studies supported a linear no-threshold model for radiation protection or on the contrary, demonstrated sufficient evidence that the linear no-threshold model is inappropriate for the purposes of radiation protection was also included. The review found that many, though not all, studies of solid cancer supported the continued use of the linear no-threshold model in radiation protection. Evaluations of the principal studies of leukemia and low-dose or low dose-rate radiation exposure also lent support for the linear no-threshold model as used in protection. Ischemic heart disease, a major type of cardiovascular disease, was examined briefly, but the results of recent studies were considered too weak or inconsistent to allow firm conclusions regarding support of the linear no-threshold model. It is acknowledged that the possible risks from very low doses of low linear-energy-transfer radiation are small and uncertain and that it may never be possible to prove or disprove the validity of the linear no-threshold assumption by epidemiologic means. Nonetheless, the preponderance of recent epidemiologic data on solid cancer is supportive of the continued use of the linear no-threshold model for the purposes of radiation protection. This conclusion is in accord with judgments by other national and international scientific committees, based on somewhat older data. Currently, no alternative dose-response relationship appears more pragmatic or prudent for radiation protection purposes than the linear no-threshold model.

Implications of recent epidemiologic studies for the linear nonthreshold model and radiation protection

The recently published NCRP Commentary No. 27 evaluated the new information from epidemiologic studies as to their degree of support for applying the linear nonthreshold (LNT) model of carcinogenic effects for radiation protection purposes (NCRP 2018 Implications of Recent Epidemiologic Studies for the Linear Nonthreshold Model and Radiation Protection, Commentary No. 27 (Bethesda, MD: National Council on Radiation Protection and Measurements)). The aim was to determine whether recent epidemiologic studies of low-LET radiation, particularly those at low doses and/or low dose rates (LD/LDR), broadly support the LNT model of carcinogenic risk or, on the contrary, demonstrate sufficient evidence that the LNT model is inappropriate for the purposes of radiation protection. An updated review was needed because a considerable number of reports of radiation epidemiologic studies based on new or updated data have been published since other major reviews were conducted by national and international scientific committees. The Commentary provides a critical review of the LD/LDR studies that are most directly applicable to current occupational, environmental and medical radiation exposure circumstances. This Memorandum summarises several of the more important LD/LDR studies that incorporate radiation dose responses for solid cancer and leukemia that were reviewed in Commentary No. 27. In addition, an overview is provided of radiation studies of breast and thyroid cancers, and cancer after childhood exposures. Non-cancers are briefly touched upon such as ischemic heart disease, cataracts, and heritable genetic effects. To assess the applicability and utility of the LNT model for radiation protection, the Commentary evaluated 29 epidemiologic studies or groups of studies, primarily of total solid cancer, in terms of strengths and weaknesses in their epidemiologic methods, dosimetry approaches, and statistical modelling, and the degree to which they supported a LNT model for continued use in radiation protection. Recommendations for how to make epidemiologic radiation studies more informative are outlined. The NCRP Committee recognises that the risks from LD/LDR exposures are small and uncertain. The Committee judged that the available epidemiologic data were broadly supportive of the LNT model and that at this time no alternative dose-response relationship appears more pragmatic or prudent for radiation protection purposes.

Outline of NCRP Commentary No. 27 “Implications of Recent Epidemiologic Studies for the Linear Nonthreshold Model and Radiation Protection”

Outline of NCRP Commentary No. 27 “Implications of Recent Epidemiologic Studies for the Linear Nonthreshold Model and Radiation Protection”

NCRP Commentary No. 26「眼の水晶体に対する放射線線量限度に関するガイダンス」の概要

NCRP Commentary No. 26「眼の水晶体に対する放射線線量限度に関するガイダンス」の概要

NCRP Commentary No. 20: Radiation Protection and Measurement Issues Related to Cargo Scanning with Accelerator-Produced High-Energy X-Rays

Fermilab; P.O. Box 500; Batavia, IL 60510; [email protected] (The opinions expressed in this section are those of the authors and do not represent the official opinion or position of the Journal, the Health Physics Society, or the authors’ institutions.)

Radiation protection and measurement issues related to cargo scanning with accelerator-produced high-energy X rays, NCRP Commentary No. 20

Having spent roughly the first third of his health physics career on the Norfolk, VA waterfront area, the reviewer was excited to see the NCRP Commentary 20, 'Radiation Protection and Measurements Issues Related to Cargo Scanning with Accelerator Technology'. It signals the advent of the Cargo Advanced Automated Radiography System (CAARS). The waterfront is a border that challenges physical security programs and technology. As Commentary 20 provides in the introduction, waterfront cargo terminals and land border crossings together represent over 300 ports of entry in the USA. Every year, the USA receives over 10 million cargo containers from commercial shipping and a roughly equal amount from land border crossings. While rapidly processing containerized cargo, CAARS will be able to detect small quantities of high atomic number radioactive materials and dense shielding materials used for radioactive gamma ray sources and even illicit human cargo - important concerns for homeland security. It will also be able to detect other contraband such as explosives, weapons and drugs. Section 1 of the Commentary presents an executive summary with NCRP's radiation dose management recommendations and related operational recommendations for effective implementation of CAARS technology in the current regulatory environment.

Book Reviews

Book reviewed in this article: Childhood Tuberculosis By BJ Cremin, DH Jamieson Atlas of Neuroradiology By Stephen J Willing. Pocket Atlas of MRI Musculoskeletal Anatomy By Thomas H Berquist. Magnetic Resonance Imaging of the Brain and Spine, 2nd edn Edited by Scott W Atlas. Tuberculosis, 2nd edn Edited by WN Rom and S Garay. An introduction to efficacy in diagnostic radiology and nuclear medicine (Justification of medical radiation exposure): NCRP Commentary No. 13 By WN Rom and S Garay. Essentials of Radiology By Fred A Mettler Jr. Published by WB Saunders Co.

An Introduction to Efficacy in Diagnostic Radiology and Nuclear Medicine (Justification of Medical Radiation Exposure)-NCRP Commentary No. 13

An Introduction to Efficacy in Diagnostic Radiology and Nuclear Medicine (Justification of Medical Radiation Exposure)-NCRP Commentary No. 13

NCRP Commentary No. 13: An Introduction to Efficacy in Diagnostic Radiology and Nuclear Medicine (Justification of Medical Radiation Exposure)

NCRP Commentary No. 13: An Introduction to Efficacy in Diagnostic Radiology and Nuclear Medicine (Justification of Medical Radiation Exposure)

Book Reviews

Book reviewed in this article:Introduction to Obstetrics and Gynaecology. Edited by Cynthia Farquahar and Murray Jamieson. Published by National Women's Hospital, Auckland.Management of Common Problems in Obstetrics and Gynecology. Edited by D. R. Mishell, Jr. and P. F. Brenner.High Risk Pregnancy ‐ Management Options. Edited by D. K. James, P. J. Steer, C. P. Weiner and B. Gonik.Handbook of Critical Care Obstetrics. Edited by Steven L. Clark, David B. Cotton, Gary D. V. Hankins and Jeffrey P. Pheian.Magnetic Resonance Imaging in Obstetrics & Gynaecology. Martin C. Powell, Brian S. Worthington and E. Malcolm Symonds.MRI of the Female Pelvis. Kaori Togashi. Igaku‐Shoin Ltd, Tokyo.The Endometrium ‐ A Clinico‐Pataologic Approach. Ed. Debra S. Heller. Igaku‐Shoin, New York‐Tokyo.Cytopathology of the Endometrium. Liang‐Cheo Tao, MD, FRACOG. Raven Press, New York.Handbook of Placental Pathology. Vijay V. Joshi, Butterworth‐Heineman, Australia.Laboratory Testing in Ob/Gyn. Gerald D. Willett. Blackwell.Considerations Regarding the Unintended Radiation Exposure of the Embryo, Fetus or Nursing Child. NCRP Commentary No. 9. National Council on Radiation Protection and Measurements, U.S.A.Development Toxicology. Edited by Carole A. Kimmel and Judy Buelke‐Sam. Raven Press, New York.Psychological Aspects of Women's Health Cart Donna E. Stewart, Nada L. Stotland Eds. American Psychiatric Press, Washington.Postnatal Depression: Towards a Research Agenda for Human Services and Health. Edited by Jan Carter.Contraceptive Method Mix ‐ Guidelines for Policy and Service Delivery. World Health Organization, Geneva.Manual of Pelvic Surgery. Edited by Maurice J. Webb. Springer‐Verlag Publications, Berlin.Complications in Gj naecologk Surgery. Prevention, Recognition and Management. James W. Orr and Hugh M. CunninghamThe Management of Adnexal Cysts. Edited by Professor M Abruhat. Biackwell Scientific Publications.What an Abnormal Pap Smear Means ‐ Living for Tomorrow series. Margaret Wilson. Hill of Content Publishing Co, Melbourne.

Review of NCRP Commentary

Review of NCRP Commentary

Considerations regarding the Unintended Radiation Exposure of the Embryo, Fetus or Nursing Child. NCRP Commentary No. 9

Considerations regarding the Unintended Radiation Exposure of the Embryo, Fetus or Nursing Child. NCRP Commentary No. 9

Guidelines for the Release of Waste Water from Nuclear Facilities with Special Reference to the Public Health Significance of the Proposed Release of Treated Waste Waters at Three Mile Island. NCRP Commentary No. 4. 22 pages. Bethesda: National Council on Radiation Protection and Measurements. ISBN 0 913392 88 X.

Guidelines for the Release of Waste Water from Nuclear Facilities with Special Reference to the Public Health Significance of the Proposed Release of Treated Waste Waters at Three Mile Island. NCRP Commentary No. 4. 22 pages. Bethesda: National Council on Radiation Protection and Measurements. ISBN 0 913392 88 X. - Volume 111 Issue 1