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,Hp(10) in mSv, to mean absorbed doses to organs and tissues,DTin 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.

Public Health Efforts Can Impact Adoption of Current Susceptibility Breakpoints, but Closer Attention from Regulatory Bodies Is Needed.

Microbiological testing, including interpretation of antimicrobial susceptibility testing results using current breakpoints, is crucial for clinical care and infection control. Continued use of obsolete Enterobacteriaceae carbapenem breakpoints is common in clinical laboratories. The purposes of this study were (i) to determine why laboratories failed to update breakpoints and (ii) to provide support for breakpoint updates. The Los Angeles County Department of Public Health conducted a 1-year outreach program for 41 hospitals in Los Angeles County that had reported, in a prior survey of California laboratories, using obsolete Enterobacteriaceae carbapenem breakpoints. In-person interviews with hospital stakeholders and customized expert guidance and resources were provided to aid laboratories in updating breakpoints, including support from technical representatives from antimicrobial susceptibility testing device manufacturers. Forty-one hospitals were targeted, 7 of which had updated breakpoints since the prior survey. Of the 34 remaining hospitals, 27 (79%) assumed that their instruments applied current breakpoints, 17 (50%) were uncertain how to change breakpoints, and 10 (29%) lacked resources to perform a validation study for off-label use of the breakpoints on their systems. Only 7 hospitals (21%) were familiar with the FDA/CDC Antibiotic Resistance Isolate Bank. All hospitals launched a breakpoint update process; 16 (47%) successfully updated breakpoints, 12 (35%) received isolates from the CDC in order to validate breakpoints on their systems, and 6 (18%) were planning to update within 1 year. The public health intervention was moderately successful in identifying and overcoming barriers to updating Enterobacteriaceae carbapenem breakpoints in Los Angeles hospitals. However, the majority of targeted hospitals continued to use obsolete breakpoints despite 1 year of effort. These findings have important implications for the quality of patient care and patient safety. Other public health jurisdictions may want to utilize similar resources to bridge the patient safety gap, while manufacturers, the FDA, and others determine how best to address this growing public health issue.

HIV and viral hepatitis co-infection in New York City, 2000-2010: prevalence and case characteristics.

Using surveillance data, we describe the prevalence and characteristics of individuals in New York City (NYC) co-infected with human immunodeficiency virus (HIV) and hepatitis B virus (HBV) and/or hepatitis C virus (HCV). Surveillance databases including persons reported to the NYC Department of Health and Mental Hygiene with HIV, HBV, and HCV by 31 December 2010 and not known to be dead as of 1 January 2000, were matched with 2000-2011 vital statistics mortality data. Of 140 606 persons reported with HIV, 4% were co-infected with HBV only, 15% were co-infected with HCV only, and 1% were co-infected with HBV and HCV. In all groups, 70-80% were male. The most common race/ethnicity and HIV transmission risk groups were non-Hispanic blacks and men who have sex with men (MSM) for HIV/HBV infection, and non-Hispanic blacks, Hispanics, and injection drug users for HIV/HCV and HIV/HBV/HCV infections. The overall age-adjusted 2000-2011 mortality was higher in co-infected than HIV mono-infected individuals. Use of population-based surveillance data provided a comprehensive characterization of HIV co-infection with HBV and HCV. Our findings emphasize the importance of targeting HIV and viral hepatitis testing and prevention efforts to populations at risk for co-infection, and of integrating HIV and viral hepatitis care and testing services.

Estimating the prevalence of hepatitis C infection in New York City using surveillance data.

Hepatitis C virus is the most common chronic blood-borne infection in the USA. Based on results of a serosurvey, national prevalence is estimated to be 1·3% or 3·2 million people. Sub-national estimates are not available for most jurisdictions. Hepatitis C surveillance data was adjusted for death, out-migration, under-diagnosis, and undetectable blood RNA, to estimate prevalence in New York City (NYC). The prevalence of hepatitis C infection in adults aged ⩾20 years in NYC is 2·37% (range 1·53-4·90%) or 146 500 cases of hepatitis C. This analysis presents a mechanism for generating prevalence estimates using local surveillance data accounting for biases and difficulty in accessing hard to reach populations. As the cohort of patients with hepatitis C age and require additional medical care, local public health officials will need a method to generate prevalence estimates to allocate resources. This approach can serve as a guideline for generating local estimates using surveillance data that is less resource prohibitive.

Neuroimaging correlates of language network impairment and reorganization in temporal lobe epilepsy.

Advanced, noninvasive imaging has revolutionized our understanding of language networks in the brain and is reshaping our approach to the presurgical evaluation of patients with epilepsy. Functional magnetic resonance imaging (fMRI) has had the greatest impact, unveiling the complexity of language organization and reorganization in patients with epilepsy both pre- and postoperatively, while volumetric MRI and diffusion tensor imaging have led to a greater appreciation of structural and microstructural correlates of language dysfunction in different epilepsy syndromes. In this article, we review recent literature describing how unimodal and multimodal imaging has advanced our knowledge of language networks and their plasticity in epilepsy, with a focus on the most frequently studied epilepsy syndrome in adults, temporal lobe epilepsy (TLE). We also describe how new analytic techniques (i.e., graph theory) are leading to a refined characterization of abnormal brain connectivity, and how subject-specific imaging profiles combined with clinical data may enhance the prediction of both seizure and language outcomes following surgical interventions.

A pilot study exploring the possibility of establishing guidance levels in x-ray directed interventional procedures.

This article summarizes the dosimetric results of an International Atomic Energy Agency coordinated research program to investigate the feasibility of adopting guidance levels for invasive coronary artery procedures. The main study collected clinical data from hospitals located in five countries. A total of 2265 coronary angiograms (CA) and 1844 percutaneous coronary interventions (PCI) were analyzed. Substudies evaluated the dosimetric performance of 14 fluoroscopes, skin dose maps obtained using film, the quality of CA procedures, and the complexity of PCI procedures. Kerma-area product (PKA) guidance levels of 50 and 125 Gy cm2 are suggested for CA and PCI procedures. These levels should be adjusted for the complexity of the procedures performed in a given institution.

Epiglottitis in the adult patient.

Epiglottitis is an acute disease, which was predominantly caused by Haemophilus influenzae type b in the pre-vaccination era. In the vaccination era, with waning vigilance, adults remain at risk for acute epiglottitis according to recent Dutch incidence rates. There is more diversity in the cause of epiglottitis in adults. We describe three patients who presented to the emergency ward of a regional teaching hospital with severe epiglottitis. All three patients had stridor at presentation indicating a compromised airway. Emergency intubation was attempted, but two patients required a tracheotomy and one patient died. Patients received fibreoptic nasal intubation, systemic dexamethasone and antibiotics. Stridor is an important acute sign of upper airway obstruction, which requires vigilance for epiglottitis, regardless of the patient's age. Fibreoptic nasal intubation should preferentially be attempted with the possibility of immediate surgical airway on hand. Timely diagnosis and treatment usually results in a complete recovery. In adults, severe acute epiglottitis and stridor can justify early intubation.

The International Atomic Energy Agency action plan on radiation protection of patients and staff in interventional procedures: Achieving change in practice.

INTRODUCTION: The International Atomic Energy Agency (IAEA) organized the 3rd international conference on radiation protection (RP) of patients in December 2017. This paper presents the conclusions on the interventional procedures (IP) session. MATERIAL AND METHODS: The IAEA conference was conducted as a series of plenary sessions followed by various thematic sessions. "Radiation protection of patients and staff in interventional procedures" session keynote speakers presented information on: 1) Risk management of skin injuries, 2) Occupational radiation risks and 3) RP for paediatric patients. Then, a summary of the session-related papers was presented by a rapporteur, followed by an open question-and-answer discussion. RESULTS: Sixty-seven percent (67%) of papers came from Europe. Forty-four percent (44%) were patient studies, 44% were occupational and 12% were combined studies. Occupational studies were mostly on eye lens dosimetry. The rest were on scattered radiation measurements and dose tracking. The majority of patient studies related to patient exposure with only one study on paediatric patients. Automatic patient dose reporting is considered as a first step for dose optimization. Despite efforts, paediatric IP radiation dose data are still scarce. The keynote speakers outlined recent achievements but also challenges in the field. Forecasting technology, task-specific targeted education from educators familiar with the clinical situation, more accurate estimation of lens doses and improved identification of high-risk professional groups are some of the areas they focused on. CONCLUSIONS: Manufacturers play an important role in making patients safer. Low dose technologies are still expensive and manufacturers should make these affordable in less resourced countries. Automatic patient dose reporting and real-time skin dose map are important for dose optimization. Clinical audit and better QA processes together with more studies on the impact of lens opacities in clinical practice and on paediatric patients are needed.

On the use of DICOM cine header information for optimisation: results from the 2002 European DIMOND cardiology survey.

The paper explores the level of information contained within the DICOM header in images from various cardiology systems. Data were obtained in the European DIMOND survey on image quality (Italy, Ireland, Belgium, Greece and Spain). Images from five standard diagnostic cardiology procedures carried out in six European hospitals have been analysed. DICOM header information was extracted to a database in order to analyse how it could help in the optimisation of the procedures. The level of data contained in the headers differs widely between cardiology systems. None of the X-ray systems in the 2002 survey archives the dosimetric data in the DICOM header. The mean number of runs per procedure ranges between 7.5 and 15.4 and the mean number of frames per procedure between 575 and 1417. Differences in kVp, mA, pulse time, distances and C-arm angulations are substantial and suggest that there exists a wide range for optimisation.

Optimizing radiologic costs in the DRG environment.

Previously developed consensus algorithms expressing a suggested radiologic workup for the diagnostic related groups (DRGs) specified by the prospective reimbursement policy have proven to be useful tools for investigating radiologic decision making and the resulting economic implications. The mathematical equations for determining diagnostic and therapeutic costs for two alternative algorithms for suspected acute cholecystitis are formulated. Illustrative examples and graphic displays are given regarding how such algorithms and equations are useful in finding answers to questions about the appropriate diagnostic workup, time, and cost. Exploration of the effect of different parameter values on the choice of the appropriate algorithm is illustrated.

Randomized trial of the immunogenicity of fractional dose regimens of PRP-T Haemophilus influenzae type b conjugate vaccine.

To assess the immunogenicity of more economical regimens of Haemophilus influenzae type b (Hib) conjugate vaccine, a randomized trial of fractional doses of polyribosylribitol phosphate-tetanus toxoid (PRP-T) Hib vaccine was undertaken in the Dominican Republic. Six hundred children were assigned to one of six regimens with PRP-T vaccine: full-dose, half-dose, and one-third-dose of Hib vaccine given separately or combined with diphtheria, tetanus, and pertussis (DTP) vaccine at ages 2, 4, and 6 months. Regimens that elicited antibody levels > 1.0 microg/mL in >70% of children and < or = 0.15 microg/mL in > 90% of children were considered acceptable. At 1 month post Dose 3, all regimens met the criteria for acceptable response. Among those who received Hib as a separate injection, geometric mean concentrations of anti-PRP bodies (GMCs) at age 1 month post Dose 3 were 11.2, 11.9, and 16.3 in the full, half, and one-third dose groups, respectively. Among those who received Hib and DTP combined, the GMCs were 6.4, 5.2, and 5.7 in the full-, half-, and one-third-dose groups respectively.

Megavoltage portal films using computed radiographic imaging with photostimulable phosphors.

Conventional portal films taken with high-energy x rays are severely impaired by poor image quality, and many attempts have been made to overcome this problem. A new technology, computed radiographic imaging, has been investigated as a means of producing images taken with 6-and 10-MV x rays. The computed radiographic imaging (CRI) system is based on the principle of laser-stimulated luminescence induced in an image receptor plate exposed to ionizing radiation, and direct conversion of the light into digital form. Image processing using contrast enhancement and unsharp masking yields images at least as good as the best portal films obtainable with conventional commercial radiotherapy cassettes. Additionally, CRI offers advantages of reduced image size and digital storage. The system is capable of producing normal film densities over an extremely wide range of exposure.

Digital imaging of the chest.

The development of effective methods for producing digital chest radiographs is essential if the totally digital radiology department of the future is to evolve. Digital radiography of the chest is now possible with a variety of techniques. The most promising approach currently in clinical use involves the use of large-area detectors composed of photostimulable phosphors read with a laser to produce high-quality digital chest images. Image processing to modify contrast and latitude of the image display as well as enhancement of selected spatial frequencies and energy subtraction is possible with digital chest radiography. The wide exposure latitude of digital image receptors may allow useful images to be obtained with significantly smaller exposure doses than those required in conventional techniques and may also be used to compensate for inadvertent overexposure, eliminating the need for repeat examinations because of errors in exposure technique. Limitations of many current systems result from inadequate resolution provided by CRT display monitors. The production of hard copy images by laser printer on small format film overcomes this problem, allowing application of digital techniques for chest radiology to be incorporated into clinical practice with images comparable in spatial resolution to those of film-screen systems.

Personnel exposure during gamma endovascular brachytherapy.

PURPOSE: The use of 192Ir brachytherapy for the treatment of in-stent restenosis of the coronary arteries has shown promising clinical results. This paper investigates the radiation exposure of catheterization laboratory staff associated with the performance of this procedure. METHODS AND MATERIALS: Cath lab staff were monitored using personal monitors (shielded against fluoroscopic x-rays) during the performance of eleven cases using nominal 10 GBq 192Ir sources. Staff positions in the lab were simultaneously tracked by video cameras. Direct measurements were also made using a survey meter. Treatments were administered in a conventional cardiac-catheterization-laboratory. RESULTS: The dosimeter readings were analyzed in combination with the radiation survey and time motion survey. Brachytherapy procedural times for the cardiologist, oncologist, physicist, and angiographic assistants were, respectively, 26 +/- 24, 401 +/- 132, 486 +/- 148, and 7 +/- 13 s per case (mean +/- standard deviation). Readings of the personnel monitors were low. Credible upper limits of the respective doses are estimated to be less than 10, 10, 7, and 5 microSv per procedure. Auxiliary shields reduced the dose to individuals located outside of the catheterization laboratory to less than 0.5 microSv per procedure. CONCLUSIONS: The average radiation dose received by laboratory personnel during a representative 192Ir endocoronary brachytherapy procedure is estimated to be less than 0.1% of the NCRP recommended annual radiation worker's Maximum Permissible Dose (1% of the general public's MPD). This level is justifiable as long as the use of 192Ir benefits patients by producing an improved clinical outcome relative to the use of a less penetrating radionuclide or the application of alternative therapies. Further optimization of the delivery procedure is expected to reduce staff dose.

A new tool for benchmarking cardiovascular fluoroscopes.

This paper reports the status of a new cardiovascular fluoroscopy benchmarking phantom. A joint working group of the Society for Cardiac Angiography and Interventions (SCAI) and the National Electrical Manufacturers Association (NEMA) developed the phantom. The device has been adopted as NEMA standard XR 21-2000, 'Characteristics of and Test Procedures for a Phantom to Benchmark Cardiac Fluoroscopic and Photographic Performance' in August 2000. The test ensemble includes imaging-field geometry, spatial resolution, low-contrast iodine detectability, working thickness range, motion unsharpness, and phantom entrance dose. The phantom tests systems under conditions simulating normal clinical use for fluoroscopically guided invasive and interventional procedures. Test procedures rely on trained human observers.

Stray radiation in the cardiac catheterisation laboratory.

Staff radiation risk is related to the radiation field in which individuals work. Traditional protective measures focus on reducing stochastic risk. However, deterministic injury to the operator's hands cannot always be ignored. The stray radiation field is almost totally attributable to scatter from the patient. Its relative intensity is greatest near the entry port of the useful beam into the patient. The entry port moves during the procedure as the operator selects various required projections. Therefore, the relative exposure rate at any particular location in the laboratory changes with the clinical projection. The absolute scatter intensity is also dependent on the size and strength of the useful beam. Operators may put their hands near or in the useful beam. Leaded surgical gloves provide some overall finger protection for scatter fields. However, because of automatic dose rate controls, these gloves often increase risk when the operator's hands are seen on the image monitor.

Topometric, roentgenologic, laboratory and clinical criteria of tumor regression in conservative management of prostatic carcinoma.

The assessment of prostatic carcinoma management results requires a complex approach. It is necessary to consider the objective criteria of tumor regression in the primary tumor and metastases to soft tissue, bone as well as indirect signs of tumor process (levels of acid and alkaline phosphatases). Subjective response cannot be assessed accurately. Reliable criteria in prostatic cancer management are: (1) objective regression by 50% or more decrease in all measurable lesions and unequivocal improvement in evaluable but non-measurable lesions with no new lesions developing; (2) Ultrasonotomography is a fine method of objective response assessment in the primary tumor and metastases; (3) Duration of response is the important criteria of tumor regression in conservative management of prostatic carcinoma.

Establishment of trigger levels to steer the follow-up of radiation effects in patients undergoing fluoroscopically-guided interventional procedures in Belgium.

The accumulated dose to the skin of the patient during fluoroscopically-guided procedures can exceed the thresholds for tissue reactions. In practice, interventionalists have no direct information about the local procedure-related skin doses in their patient, causing suboptimal or delayed treatment. In current study, the accumulated Kerma-Area-Product (KAP) values were registered, as well as the reference air kerma (Ka,r) values, if available, for almost 200 cases undergoing seven different procedures. A sheet filled with 50 thermoluminescent dosemeters was wrapped around each patient to measure the peak skin dose. In a significant part of the Transjugular Intrahepatic Portosystemic Shunt (TIPSS) procedures, chemo-embolizations of the liver and cerebral embolizations, the threshold values for deterministic skin damage (2 Gy) were attained. Trigger values in terms of KAP, corresponding to a peak skin dose of 2 Gy, were determined. In general, our results comply reasonably well with the values proposed in the NCRP 168 report, with a KAP value of 425 Gy cm² and a Ka,r value of 3 Gy, corresponding to a peak skin dose of 3 Gy. Only for the TIPSS procedure a considerably lower value of 2 Gy was obtained at the published Ka,r and for the RF ablations we obtained a considerably lower value of 250 Gy cm² in terms of KAP.

On the acceptability of fluoroscopic systems for clinical use.

The proposed European commission report radiation protection 162 (EC RP 162) provides a set of tests and reference criteria that reflect European Union requirements for the acceptability of fluoroscopy X-ray systems. The report updates and expands on the current criteria established in report radiation protection (RP) 91 (1997). There is no universally accepted set of test methods due to differing national regulations and professional opinions. This paper provides a sample of such differences in the context of the proposed RP 162 criteria. A review of some fundamental fluoroscopic tests from both an Irish European Union and a US perspective is presented. The criteria proposed in EC RP 162 provide sufficient information about basic acceptability of interventional fluoroscopes and ideally, evaluations should be extended further to include specific clinical requirements.

Criteria and suspension levels in diagnostic radiology.

The EC (European Council) Directive on radiation protection of patients requires that criteria for acceptability of equipment in diagnostic radiology, nuclear medicine and radiotherapy be established throughout the member states. This study reviews the background to this requirement and to its implementation in practice. It notes and considers parallel requirements in the EC medical devices directive and International Electrotechnical Commission standards that it is also important to consider and that both sets of requirements should ideally be harmonised due to the global nature of the equipment industry. The study further reviews the types of criteria that can be well applied for the above purposes, and defines qualitative criteria and suspension levels suitable for application. Both are defined and relationships with other acceptance processes are considered (including acceptance testing at the time of purchase, commissioning and the issue of second-hand equipment). Suspension levels are divided into four types, A, B, C and D, depending on the quality of evidence and consensus they are based on. Exceptional situations involving, for example, new or rapidly evolving technology are also considered. The publication and paper focuses on the role of the holder of the equipment and related staff, particularly the medical physics expert and the practitioner. Advice on how the criteria should be created and implemented is provided for these groups and how this might be coordinated with the supplier. Additional advice on the role of the regulator is provided.