Screening for Lung Cancer: CHEST Guideline and Expert Panel Report.

BACKGROUND: Low-dose chest CT screening for lung cancer has become a standard of care in the United States, in large part because of the results of the National Lung Screening Trial (NLST). Additional evidence supporting the net benefit of low-dose chest CT screening for lung cancer, and increased experience in minimizing the potential harms, has accumulated since the prior iteration of these guidelines. Here, we update the evidence base for the benefit, harms, and implementation of low-dose chest CT screening. We use the updated evidence base to provide recommendations where the evidence allows, and statements based on experience and expert consensus where it does not. METHODS: Approved panelists reviewed previously developed key questions using the Population, Intervention, Comparator, Outcome format to address the benefit and harms of low-dose CT screening, and key areas of program implementation. A systematic literature review was conducted using MEDLINE via PubMed, Embase, and the Cochrane Library on a quarterly basis since the time of the previous guideline publication. Reference lists from relevant retrievals were searched, and additional papers were added. Retrieved references were reviewed for relevance by two panel members. The quality of the evidence was assessed for each critical or important outcome of interest using the Grading of Recommendations, Assessment, Development, and Evaluation approach. Meta-analyses were performed when enough evidence was available. Important clinical questions were addressed based on the evidence developed from the systematic literature review. Graded recommendations and ungraded statements were drafted, voted on, and revised until consensus was reached. RESULTS: The systematic literature review identified 75 additional studies that informed the response to the 12 key questions that were developed. Additional clinical questions were addressed resulting in seven graded recommendations and nine ungraded consensus statements. CONCLUSIONS: Evidence suggests that low-dose CT screening for lung cancer can result in a favorable balance of benefit and harms. The selection of screen-eligible individuals, the quality of imaging and image interpretation, the management of screen-detected findings, and the effectiveness of smoking cessation interventions can impact this balance.

Radiation Reduction Strategies in Pediatric Orthopaedics.

INTRODUCTION: Pediatric orthopaedic patients have the potential for significant radiation exposure from the use of imaging studies, such as computed tomography and bone scintigraphy. With the potential for long-term treatment, such as is required for scoliosis or osteogenesis imperfecta, patients are at even greater risk of radiation-induced carcinogenesis. DISCUSSION: Although an association between radiation and cancer risk is evident, causation is difficult to prove because comorbidities or genetic predispositions may play a role in the higher baseline rates of malignancy later in life. Efforts have been made over the years to reduce exposure using more modern imaging techniques and simple radiation reduction strategies. Educational efforts and clinical practice guidelines are decreasing the rate of computed tomography scan use in pediatrics. Although considerable work is being done on the development of radiation-free imaging modalities, imaging that uses ionizing radiation will, in the near term, be necessary in specific circumstances to provide optimal care to pediatric orthopaedic patients. CONCLUSION: Knowledge of the ionizing radiation exposure associated with commonly used tests as well as radiation-reduction strategies is essential for the optimal and safe care of pediatric orthopaedic patients.

Patient-reported Outcomes and Late Toxicity After Postprostatectomy Intensity-modulated Radiation Therapy.

BACKGROUND: Limited long-term data characterize patient-reported quality of life (QOL) following postprostatectomy intensity-modulated radiation therapy (PPRT), and predictors of decline are poorly defined. OBJECTIVE: To identify modifiable dosimetric and clinical risk factors impacting QOL and late toxicity following PPRT. DESIGN, SETTING, AND PARTICIPANTS: A prospective cohort study of consecutive men with prostate cancer who received PPRT between 2007 and 2015 at a single academic institution. INTERVENTION: Patients were prospectively evaluated using the Expanded Prostate Cancer Index Composite (EPIC-26) QOL instrument. Radiation Therapy Oncology Group/Common Toxicity Criteria for Adverse Events toxicity grades were assigned at every follow-up visit. Treatment was delivered to the prostate bed (median 68Gy)±pelvic lymphatics (65%, median 50.4Gy) with daily image guidance. Androgen deprivation therapy was concomitantly administered to 132 (66%) men for a median of 4mo. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Changes were deemed relevant if they exceeded the minimally clinically important difference (MCID), as calculated by a distribution-based method. Generalized estimating equation models and Cox regression were used for QOL and late toxicity univariate and multivariable analysis. RESULTS AND LIMITATIONS: Overall, 199 men were identified with a median follow-up of 33mo. Overall urinary function (UF), bowel function (BF), sexual function (SF), and urinary irritation/obstruction (UI/UO) scores were never lower than the MCID. Between 8% and 18% of men experienced a small multidomain (1× MCID) decline, and 0-8% experienced a moderate multidomain decline (2× MCID) at a given time point up to 84mo after PPRT. The rates of freedom from grade 2 or higher (Gr2+) genitourinary (GU) and gastrointestinal (GI) toxicity were 94% and 95%, respectively, at 4yr. Factors associated with worse QOL or toxicity included longer time to PPRT (UC and UF), higher BMI (UF, BF, and late GI toxicity), older age (BF, SF, and late GU toxicity); hormone therapy (SF), total dose (late GI toxicity), tobacco history (BF), and higher bladder V70Gy (UC, UF, and late GU toxicity). CONCLUSIONS: Long-term QOL and late toxicity are favorable following postprostatectomy radiation therapy. Identifiable clinical and dosimetric risk factors may guide decision making to optimize urinary, sexual, and bowel function. PATIENT SUMMARY: The following study provides a detailed report of favorable patient-reported quality of life and late side-effect profiles of radiation therapy following surgery for localized prostate cancer. Our findings provide patients guidance on what symptoms to expect if they are planning to undergo radiation therapy in this setting. It also allows physicians to counsel patients appropriately, and modify certain clinical and radiation-related risk factors to optimize quality of life.

Behaviour and knowledge skill levels of orthopedic surgeons about radiation safety and fluoroscopy use: A survey analysis.

OBJECTIVE: The aim of this study was to evaluate the behaviour and knowledge skill levels of Turkish orthopedic surgeons about fluoroscopy usage and radiation safety. METHODS: The questionnaire, consisting of nineteen questions, was sent to orthopaedic surgeons and requested by a total of 323 surgeons online. The questions were about personal information, training and behaviours related to radiation and fluoroscopy usage, and the use of protective equipment. RESULTS: A total of 277 individuals completed the questionnaire. The answers of 180 surgeons whose working duration was more than 1 year and also who participated in at least one fluoroscopy requiring operation per week, were analysed. 22 (12%) participants answered that they were trained on fluoroscopy usage. Sixty people (33.3%) reported that they did not use any protective equipment regularly. The most commonly used protection methods were lead aprons 123 (68.3%). Thyroid protectors were used by 92 participants (52.1%). There was no significant difference between the groups when comparing the use of protective equipment according to the academic title. Only 19 (10.6%) of the surgeons noted that they used dosimeter regularly, and 15 (83.3%) of them reported that they controlled their dosimeters. CONCLUSION: In this study, Orthopedic surgeons were found not to be adequately trained about use and risks of fluoroscopy and also not to be equipped about methods for preventing radiation damage.

Chest CT Scan at Radiation Dose of a Posteroanterior and Lateral Chest Radiograph Series: A Proof of Principle in Lymphangioleiomyomatosis.

BACKGROUND: Given the rising utilization of medical imaging and the risks of radiation, there is increased interest in reducing radiation exposure. The objective of this study was to evaluate, as a proof of principle, CT scans performed at radiation doses equivalent to that of a posteroanterior and lateral chest radiograph series in the cystic lung disease lymphangioleiomyomatosis (LAM). METHODS: From November 2016 to May 2018, 105 consecutive subjects with LAM received chest CT scans at standard and ultra-low radiation doses. Standard and ultra-low-dose images, respectively, were reconstructed with routine iterative and newer model-based iterative reconstruction. LAM severity can be quantified as cyst score (percentage of lung occupied by cysts), an ideal benchmark for validating CT scans performed at a reduced dose compared with a standard dose. Cyst scores were quantified using semi-automated software and evaluated by linear correlation and Bland-Altman analysis. RESULTS: Overall, ultra-low-dose CT scans represented a 96% dose reduction, with a median dose equivalent to 1 vs 22 posteroanterior and lateral chest radiograph series (0.14 mSv; 5th-95th percentile, 0.10-0.20 vs standard dose 3.4 mSv; 5th-95th percentile, 1.5-7.4; P < .0001). The mean difference in cyst scores between ultra-low- and standard-dose CT scans was 1.1% ± 2.0%, with a relative difference in cyst score of 11%. Linear correlation coefficient was excellent at 0.97 (P < .0001). CONCLUSIONS: In LAM chest CT scan at substantial radiation reduction to doses equivalent to that of a posteroanterior and lateral chest radiograph series provides cyst score quantification similar to that of standard-dose CT scan. TRIAL REGISTRY: ClinicalTrials.gov; Nos.: NCT00001465 and NCT00001532; URL: www.clinicaltrials.gov.

SUSTAINABLE MEDICAL PREPAREDNESS AND RESPONSE SYSTEM FOR RADIATION EMERGENCIES IN THE REPUBLIC OF KOREA.

This paper provides information about the medical preparedness and response system for radiation emergencies in Republic of Korea. The National Radiation Emergency Medical Center (NREMC) oversees medical affairs in the Korean radiological disaster prevention system since its establishment in 2002. It has dedicated itself to set up a nationwide radiation emergency medicine network with 24 designated radiation emergency hospitals. NREMC, as one division under the Korea Institute of Radiological And Medical Sciences (KIRAMS), provides efficient medical care to patients suspected with radiation exposure by collaborating with professional medical staffs in Korea Cancer Center Hospital (KCCH). For prompt response to radiation accidents, NREMC has offered specialized trainings for medical staffs and first responders. It has also operated the 24-h on-call system to consult public concerns of radiation exposure, which can be switched into an emergency mode upon receiving accident reports. In addition, NREMC has conducted dose assessments of radiation exposure with high level of accuracy and implemented R&D programs for radiation injury therapeutics and low-dose radiation risks evaluation in daily life. NREMC supports global initiatives for strengthening medical preparedness and response for radiation emergencies with international organizations.

PUBLIC HEALTH ENGLAND-CENTRE FOR RADIATION, CHEMICAL AND ENVIRONMENTAL HAZARDS (PHE-CRCE) EXTERNAL EXPERT EXPERIENCE IN THE JOINT EXTERNAL EVALUATION (JEE) MISSION FOR THE RADIATION EMERGENCIES TECHNICAL AREA.

From August 2016 to June 2017, the Public Health England-Centre for Radiation Chemical and Environmental Hazards (PHE-CRCE), collaborating centre of the WHO, through its Radiation Hazards and Emergencies Department Emergency Response Group has successfully supported five WHO Joint External Evaluation (JEE) missions in the Eastern Mediterranean (Jordan, Bahrain and Tunisia) and African (Kenya, Mali) regions. The JEE tool is the main document used by both internal and external expert teams as a shared methodology to assess a country's capability in term of preparedness and response to public health threats under the International Health Regulation. This is done by evaluating different indicators. 'Radiation emergencies' is one of the 19 technical fields evaluated by the JEE tool and is composed of two indicators. Each indicator is scored on a 1-5 scale, 1 being the lowest (no capability) and 5 being the highest (sustainable capability). These five countries assessed by radiation experts from PHE, for their preparedness towards radio-nuclear emergencies, were scored between 1 and 3 against the JEE tool, with sometimes similarities in the gaps identified. Points of progress and course of actions were decided for each country.

US CENTERS FOR DISEASE CONTROL AND PREVENTION EXPERIENCE IN THE JOINT EXTERNAL EVALUATION PROCESS-RADIATION EMERGENCIES TECHNICAL AREA.

In 2015-16, the US Department of Health and Human Services led 23 US Government (USG) agencies including the Centers for Disease Control and Prevention (CDC), and more than 120 subject matter experts in conducting an in-depth review of the US core public health capacities and evaluation of the country's compliance with the International Health Regulations using the Joint External Evaluation (JEE) methodology. This two-part process began with a detailed 'self-assessment' followed by a comprehensive independent, external evaluation conducted by 15 foreign assessors. In the Radiation Emergencies Technical Area, on a scale from 1-lowest to 5-highest, the assessors concurred with the USG self-assessed score of 3 in both of the relevant indicators. The report identified five priority actions recommended to improve the USG capacity to handle large-scale radiation emergencies. CDC is working to implement a post-JEE roadmap to address these priority actions in partnership with national and international partners.

[Experience With Different Single-Stage Selective Arterial Catheterization Procedures During X-Ray Endovascular Interventions to Reduce a Radiation Dose for Patients].

Objective: To evaluate the impact of single-stage selective arterial catheterizations during X-ray endovascular interventions to reduce obtained radiation doses in the treatment of patients. Material and Methods: X-ray endovascular interventions were carried out in the operating room equipped with a flat detector digital angiography system (Axiom Artis dTA, Siemens Medical System). The impact of single-stage selective arterial catheterization procedures was analyzed during endovascular interventions for coronary heart disease and uterine myomas on the time course of changes in the collective effective radiation doses for patients in the period 2013 to 2015. Results: Analysis of the findings showed that single-stage selective coronary angiography using a universal (multipurpose) radial coronary catheter and single-stage X-ray endovascular uterine artery embolization techniques could reduce collective effective doses for patients from 5.86 persons-Sv in 2013 to 1.6 persons-Sv in 2015. Conclusion: Different single-stage selective catheterization procedures used during endovascular interventions into the coronary and uterine arteries can reduce radiation doses for patients.

[Comparison of a Radiation Dose During Standard Digital Radiography, Tomosynthesis, and Multislice Spiral Computed Tomography in an Experimental Study of Pediatric Anthropomorphic Phantom].

Objective: To compare a radiation dose obtained during standard digital radiography, tomosynthesis, and multislice spiral computed tomography (MSCT). Material and Methods: Life-size full body pediatric anthropomorphic mannequin phantom was examined with a Fujifilm FDR Ac Selerate 200 X-ray diagnostic apparatus and a Toshiba Aquilion Prime 64 computed scanner using the Piranha dosimetry equipment, as well as Gammex planar target, for comparison of the resolution of the apparatus. The effective radiation doses were calculated for different anatomical regions with the formulas specified in the methodical instructions, using the coefficients K and Kd. Results: The tables and graphs comparing the radiation dose when using different radiation diagnostic techniques were presented. The resolution of standard digital radiography versus that of tomosynthesis was analyzed. Fluctuations of the doses obtained were associated with the difference in the volume of irradiated tissue and in the presence of the doses in the irradiated volume of organs with high radiosensitivity. Optimal physical and technical parameters of photography were proposed, which could reduce a dose load on the patient, without significantly losing the quality of films. Conclusion: The effective doses of tomosynthesis were significantly higher than those of standard digital radiography (p < 0.05) while those of (MSCT) were above those of both X-ray and tomosynthesis, and the resolution of the latter was slightly lower.

Radiation Exposure and Contrast Agent Reduction During Transcatheter Aortic Valve Implantation: An Ongoing Experience.

OBJECTIVES: To determine the patient radiation exposure and contrast agent variation during transcatheter aortic valve implantation (TAVI) procedures resulting from technological improvements. METHODS: TAVI procedures from January 2008 to July 2015 were analyzed in three different time periods: 1st period, when the angiography was equipped with an image intensifier technology; 2nd period, starting with the installation of a new angiography system with flat-panel detector (FPD) technology; and 3rd period, starting with the systematic use of preprocedural multidetector computed tomography (MDCT) to individualize optimal fluoroscopic projections for the aortic prosthesis implantation. RESULTS: Significant differences were found in contrast volume (198 ± 99 mL vs 139 ± 74 mL; P<.001), kerma area product (211 ± 135 Gy•cm² vs 147 ± 120 Gy•cm²; P<.001) and effective dose (42 ± 27 mSv vs 29 ± 24 mSv; P<.001) between the 1st and 2nd periods, respectively. The reduction continued between the 2nd and 3rd periods for contrast volume (139 ± 74 mL vs 110 ± 61 mL; P<.001), kerma area product (147 ± 120 Gy•cm² vs 111 ± 69 Gy•cm²; P<.001), and effective dose (29 ± 24 mSv vs 22 ± 11 mSv; P<.001), respectively. CONCLUSIONS: The present study suggests that the appropriate use of FPD technology and preprocedural MDCT to individualize fluoroscopic implant projections for TAVI temporally reduced the amount of radiation and contrast agent administered over time.

Overview of radiation dose to patients from medical X-ray examinations in Nigeria.

OBJECTIVES: Medical Imaging accounts for the largest radiation exposure of population from artificial sources of radiation. The radiation dose rcceivedby patients from iedicail x-ray examinations in Nigeria has shown large variations within and among diagnostic centers for similar examinations. This could be traced to lack of imaging protocols and on avalability of local/national diagnostic reference, levels. Hence, the need to assess the trend of radiation doseto patients from radiological practice in Nigeria. Methocls:Entrance surface doses(ESDs) reported by, Nigerian authors for common x-ray examinations from 2000 - 2014 were extracted from articles published in peer reviewed journals, analyzed and compared with ifiternationally recommended Diagnostic Reference Levels (DkLs). RESULTS: Among x-ray examinations, skull accounted for 32% followed by chest (22%), lumbar spine (13%), abdomen (12%), pelvis (8%), extremitics(8%), thorax and cervical spine(5%). The range of mean ESDs reported for various projections of x-ray examination are chest (2.28 - 3.70 mGy); Abdomen (4.42 - 7.22 mGy); Skull (3.81 - 5.19 mGy); Pelvis (5.93 mGy); Lumbar spine (5.73 - 10.98 mGy); Thorax (0.96 - 1.85 mGy); Cervical spine (1.45 - 1.49mGy) and Extremitics (0.31 -0.49 mGy). In this study, it was found that the mean ESDs received by patients from chest, skull and pelvis ex'aminations were higher than the published DRLs for similar x-ray examinations. CONCLUSION: The results of this study showed that to harmonize radiation protection of patients and improve radiological practice in Nigeria there is need for development of comprehensive national diagnostic reference levels.

A Radiation Dose Reduction Technology to Improve Patient Safety During Cardiac Catheterization Interventions.

OBJECTIVES: A novel radiation dose reduction technology was evaluated in a cardiac catheterization laboratory during routine clinical care to determine if it could reduce radiation dose to patients undergoing coronary angiography and percutaneous coronary intervention. These results were compared to patients undergoing similar procedures in a cardiac catheterization laboratory without this technology. BACKGROUND: There is a safety priority in clinical care to reduce X-ray radiation dose to patients in order to lower the risk of deterministic and stochastic effects. Dose reduction technologies must be verified in clinical settings to prove if they reduce X-ray radiation dose and to what extent. METHODS: Radiation dose data and procedure characteristics of 268 consecutive patients were collected and analyzed from a cardiac catheterization laboratory with dose reduction technology installed (referred to as Lab A, n = 135) and from a cardiac catheterization laboratory without this technology (referred as Lab B, n = 133). RESULTS: For diagnostic procedures, the median total dose-area product in Lab A was reduced by 46% (P < 0.0001) compared to Lab B, with no differences in terms of body mass index (P = 0.180), total fluoroscopy times (P = 1), number of acquired images (P = 0.920), and contrast medium (P = 0.660). For interventional procedures, the median total dose-area product in Lab A was reduced by 34% (P = 0.015) compared to Lab B, with no differences in terms of body mass index (P = 0.665), total fluoroscopy times (P = 0.765), number of acquired images (P = 0.923), and contrast medium (P = 0.969). CONCLUSIONS: This new dose reduction technology significantly reduces X-ray radiation dose without affecting fluoroscopy time, number of images, and contrast medium used during diagnostic and interventional coronary procedures.

A systems approach to evaluating ionizing radiation: six focus areas to improve quality, efficiency, and patient safety.

Ionizing radiation is an essential component of the care process. However, providers and patients may not be fully aware of the risks involved, the level of ionizing radiation delivered with various procedures, or the potential for harm through incidental overexposure or cumulative dose. Recent high-profile incidents demonstrating the devastating short-term consequences of radiation overexposure have drawn attention to these risks, but applicable solutions are lacking. Although various recommendations and guidelines have been proposed, organizational variability challenges providers to identify their own practical solutions. To identify potential failure modes and develop solutions to preserve patient safety within a large, national healthcare system, we assembled a multidisciplinary team to conduct a comprehensive analysis of practices surrounding the delivery of ionizing radiation. Workgroups were developed to analyze existing culture, processes, and technology to identify deficiencies and propose solutions. Six focus areas were identified: competency and certification; equipment; monitoring and auditing; education; clinical pathways; and communication and marketing. This manuscript summarizes this comprehensive, multidisciplinary, and systemic analysis of risk and provides examples to illustrate how these focus areas can be used to improve the use of ionizing radiation. The proposed solutions, once fully implemented, may advance patient safety and care.

Radiographic Follow-up of DDH in Infants: Are X-rays Necessary After a Normalized Ultrasound?

BACKGROUND: Concerns about radiation exposure have created a controversy over long-term radiographic follow-up of developmental dysplasia of the hip (DDH) in infants who achieve normal clinical and ultrasonographic examinations. The purpose of this study was to assess the importance of continued radiographic monitoring by contrasting the incidence of residual radiographic dysplasia to the risks of radiation exposure. METHODS: We reviewed a consecutive series of infants with idiopathic DDH presenting to our institution over 4 years. Infants with "normalized DDH" had achieved a stable clinical examination with an ultrasound revealing no signs of either hip instability or acetabular dysplasia. We excluded infants with persistently abnormal ultrasonographic indices, clinical examinations, or both by 6 months of age, including those requiring surgical reduction. Anteroposterior pelvic radiographs at approximately 6 and 12 months of age were then evaluated for evidence of residual radiographic acetabular dysplasia. Radiation effective dose was calculated using PCXMC software. RESULTS: We identified 115 infants with DDH who had achieved both normal ultrasonographic and clinical examinations at 3.1±1.1 months of age. At the age of 6.6±0.8 months, 17% of all infants demonstrated radiographic signs of acetabular dysplasia. Of infants left untreated (n=106), 33% had dysplasia on subsequent radiographs at 12.5±1.2 months of age. No significant differences were evident in either the 6- or 12-month rates of dysplasia between infants successfully treated with a Pavlik harness and infants normalizing without treatment but with a history of risk factors (P>0.05). The radiation effective dose was <0.01 mSv for the combined 6- and 12-month single-view anteroposterior radiographs of the pelvis. CONCLUSIONS: The notable incidences of radiographic dysplasia after previous DDH normalization in our study cohort appear to outweigh the risks of radiation exposure. Our findings may warrant radiographic follow-up in this population of infants through at least walking age to allow timely diagnosis and early intervention of residual acetabular dysplasia. LEVEL OF EVIDENCE: Level IV-retrospective case series.

[Prospects of systemic radioecology in solving innovative tasks of nuclear power engineering].

A need of systemic radioecological studies in the strategy developed by the atomic industry in Russia in the XXI century has been justified. The priorities in the radioecology of nuclear power engineering of natural safety associated with the development of the radiation-migration equivalence concept, comparative evaluation of innovative nuclear technologies and forecasting methods of various emergencies have been identified. Also described is an algorithm for the integrated solution of these tasks that includes elaboration of methodological approaches, methods and software allowing dose burdens to humans and biota to be estimated. The rationale of using radioecological risks for the analysis of uncertainties in the environmental contamination impacts,at different stages of the existing and innovative nuclear fuel cycles is shown.

[Thyroid cancer: lessons of chernobyl and prognosis for Fukushima].

Results of epidemiological studies of thyroid cancer incidence in Russia following the Chernobyl accident are presented in the article. Child population in territories contaminated with radionuclides who got thyroid dose from incorporated (131)I above 100-150 mGy, should be referred to a group at radiation risk. Prognostic estimates of increase in thyroid cancer incidence among the population living in close vicinity of the Fukushima Daiichi NPP were made with account for the Chernobyl data and recommendations of the International Commission on Radiological Protection.