Radiation Exposure Levels Research Articles

Prostatic artery embolization using three-dimensional cone-beam computed tomography

PurposeThe purpose of this study was to report the use of three-dimensional (3D) cone-beam computed tomography (CBCT) for prostatic artery embolization (PAE) in patients with benign prostatic hypertrophy (BPH). Materials and methodsTwenty-three consecutive men who underwent PAE using 3D CBCT from June 2016 to September 2018, were retrospectively included in this observational single-center study. There were 23 men with a mean age of 73±12 (SD) years (range: 52–94years) with moderate to severe lower urinary tract symptoms (mean international prostate symptom score, 21±5.7 [SD]; range: 9–30) due to BPH (mean prostate weight, 100g±63 [SD]; range: 30–250g). PAEs were analyzed with respect to procedure time, fluoroscopy time, technical success, complications and dosimetric indices. ResultsThe mean catheterization time of the prostatic artery from the internal iliac artery was 17.3±12.5 (SD) min (range: 8–57min) on the right side and 23.6±14.9 (SD) min (range: 6–54min) on the left side. A technical success was achieved in 21 patients (21/23; 91%). PAE was bilateral in 14 patients (14/21; 66%) and unilateral in 7 patients (7/21; 33%). No occurrence of non-target embolization was reported. The mean dose area product was 146.7±47.9 (SD) Gy.cm2 (range: 54–254Gy.cm2) and mean cumulative air kerma was 771.4±333.3 (SD) mGy; range: 280–1560 mGy. The mean fluoroscopy time was 42.3±23.1 (SD) min (range: 19.4–118.2min). Conclusion3D CBCT is a useful tool to identify the prostatic arteries and facilitates catheterization of prostatic arteries with an acceptable level of radiation exposure.

Dual-Color Plasmonic Nanosensor for Radiation Dosimetry.

Radiation dosimeters are critical for accurately assessing the levels of radiation exposure of tumor sites and surrounding tissues and for optimizing therapeutic interventions as well as for monitoring environmental exposure. To fill the need for a simple, user-friendly, and inexpensive dosimeter, we designed an innovative colorimetric nanosensor-based assay for detecting ionizing radiation. We show that hydroxyl radicals generated by ionizing radiation can be used to etch gold nanorods (AuNRs) and silver nanoprisms (AgNPRs), yielding reproducible color changes for radiation dose detection in the range of 50-2000 rad, broad enough to cover doses used in hyperfractionated, conventional, and hypofractionated radiotherapy. This range of doses detected by this assay correlates with radiation-induced DNA damage response in mammalian cells. Furthermore, this AuNR- and AgNPR-based sensing platform has been established in a paper format that can be readily adopted for a wide range of applications and translation.

Radiation exposure per thrombectomy attempt in modern endovascular stroke treatment in the anterior circulation

ObjectiveTo quantify radiation exposure (RE) of endovascular stroke treatment (EST) in the anterior circulation per thrombectomy attempt and determine causes for interventions associated with high RE.MethodsA retrospective single-center study of an institutional review board−approved stroke database of patients receiving EST for large vessel occlusions in the anterior circulation between January 2013 and April 2018 to evaluate reference levels (RL) per thrombectomy attempt. ESTs with RE above the RL were analyzed to determine causes for high RE.ResultsOverall, n = 544 patients (occlusion location, M1 and M2 segments of the middle cerebral artery 53.5% and 27.2%, carotid artery 17.6%; successful recanalization rate 85.7%) were analyzed. In the overall population, DAP (in Gy cm2, median (IQR)) was 113.7 (68.9–181.7) with a median fluoroscopy time of 31 min (IQR, 17–53) and a median of 2 (IQR, 1–4) thrombectomy attempts. RE increased significantly with every thrombectomy attempt (DAP1, 68.7 (51.2–106.8); DAP2, 106.4 (84.8–115.6); p value1vs2, < 0.001; DAP3, 130.2 (89.1–183.6); p value2vs3, 0.044; DAP4, 169.9 (128.4–224.1); p value3vs4, 0.001; and DAP5, 227.6 (146.3–294.6); p value4vs5, 0.019). Procedures exceeding the 90th percentile of the attempt-dependent radiation exposure level were associated with procedural complications (n = 17/52, 29.8%) or a difficult vascular access (n = 8/52, 14%).ConclusionsRadiation exposure in endovascular stroke treatment is depending on the number of thrombectomy attempts. Radiation exposure doubles when three attempts and triples when five attempts are necessary compared with single-maneuver interventions. Procedural complications and difficult vascular access were associated with a high radiation exposure in this collective.Key Points• Radiation exposure of endovascular stroke treatment (EST) is dependent on the number of thrombectomy attempts.• Reference levels as means for quality control in hospitals performing endovascular stroke treatment should be defined by the number of thrombectomy attempts—we suggest 107 Gy cm2, 156 Gy cm2, 184 Gy cm2, 244 Gy cm2, and 295 Gy cm2for 1 to 5 maneuvers, respectively, for EST of the anterior circulation• Cases with high rates of radiation exposure are associated with periprocedural complications and difficult anatomical access as a probable cause for a high radiation exposure.

Comparison of Radiation Exposure Among 3 Different Endoscopic Diskectomy Techniques for Lumbar Disk Herniation

Lumbar disk herniation can be successfully treated by lumbar endoscopic spinal procedures. However, one of the most important disadvantages of the endoscopic methods used is radiation exposure. There are multiple endoscopic spinal procedures and this study aims to compare unilateral biportal endoscopic diskectomy (UBED), percutaneous endoscopic lumbar diskectomy (PELD), and microendoscopic diskectomy (MED) methods in terms of radiation exposure. A total of 75 people were included in this prospective and multicenter study. The demographic characteristics, operating times (minutes), levels of surgery, lumbar disk herniation types, radiation exposures (dose area product [DAP]), and fluoroscopy times (seconds) of the groups were compared. Mean DAP values were 1.39 Gy·cm2 in the UBED group, 2.46 Gy·cm2 in the PELD group, and 1.01 Gy·cm2 in the MED group. The UBED group had no statistically significant difference with the MED and PELD groups in terms of DAP (P= 0.281 and P= 0.058, respectively), whereas the PELD group had statistically significantly higher DAP values than the MED group (P=0.016). The maximum mean duration of fluoroscopy usage time was 34.9 seconds in the PELD group, 19.3 seconds in the UBED group, and 4.6 seconds in the MED group. The differences between the groups were significant (P ≤ 0.001). The more the level of invasiveness is reduced in spinal surgery, the greater the exposure to radiation. In this study, the groups are listed as PELD >UBED > MED according to the duration and level of radiation exposure.

Assessment of Radiation Exposure Level from Some Scrap Metal Dumpsites in Nasarawa State, Nigeria

In this study, the radiation exposure rate emanating from the scrap metals dumpsite was assessed using an Interceptor Spectroscopic personal radiation detector (SPRD). Sixteen (16) scrap metal dumpsites were selected at random across four Local Government Areas (Nasarawa, Lafia, Akwanga, and Keffi) of Nasarawa State, Nigeria. The gamma activity level in µrem/hr on three (3) randomly selected points on each of the scrap metal dumpsites was determined. A reading was taken on point 100 m away from each of the scrap metal dumpsite. Results show that the highest annual effective dose equivalent was observed in Akwanga (AKW4) scrap metal dumpsite with an annual effective dose equivalent of 0.2167 mSv/yr. The scrap metal dumpsite with the lowest annual effective dose equivalent was observed in Lafia (LAF3) and (LAF4) with an annual effective dose equivalent of 0.0613 mSv/yr. The excess lifetime cancer risk of 0.7585 × 10-3 was the highest value recorded in AKW4, while the lowest value was found to be 0.2146 × 10-3 in LAF3 and LAF4. The control radiation exposure level, 100 m from scrap metal dumpsites, shows the value of gamma activity level and annual effective dose equivalent obtained is ranged between 13 µrem/hr and 0.1594 mSv/yr respectively on location KEF1 to 3 µrem/hr and 0.0368 mSv/yr on locations LAF2 and LAF3 respectively. The annual effective dose equivalent values obtained were below the ICRP dose limit of 1 mSv/yr, indicating that, the environments around these scrap metal dumpsites are safe. The excess lifetime cancer risk value (ELCR) obtained in some locations is higher than the world average value of 0.29 × 10-3. Therefore, we recommend that scavengers, workers at the scrap dumpsites are to minimise the period of their stay within the dumpsites, and also the residential homes are to maintain a distance of 500 meters around the scrap metal dumpsites so as to minimise the risk of developing any health problem relating to cancer in future.

Image quality of a portable X-ray device (Nomad Pro 2) compared to a wall-mounted device in intraoral radiography

ObjectivesThe aim of this study was to determine whether a handheld (HH) X-ray device (Nomad Pro 2) is capable of producing equivalent or even superior X-ray image quality in comparison to a wall-mounted (WM) dental X-ray unit (Heliodent Plus) on the basis of objectifiable image quality parameters.MethodsAnatomical, radiological and biological dental X-ray image quality parameters of a handheld dental X-ray device (Nomad Pro 2, Kavo Kerr, Biberach, Germany) were compared to a standard wall-mounted dental X-ray unit (Heliodent Plus, Sirona Dental Systems, Bensheim, Germany) using a maxillofacial phantom. In addition, the effect of different operators (dentists, dental students, dental assistants) on the dental X-ray image quality was measured.ResultsHH and WM devices showed comparable image quality for anterior teeth, premolars, molars and bitewing images. During the two-month investigational period, the radiation exposure level for the operator of the Nomad Pro 2 was 0.1 mSv for 203 images. Dentists as the highest trained personnel enrolled in the study achieved better image quality with the Nomad Pro 2 as compared to dental students and dental assistants, especially in the molar region.ConclusionsA HH device delivers a comparable image quality to a WM device. In addition, there seem to be short learning curves with regard to image acquisition when using a handheld device, which is further minimised by the previous training of the operating personnel. HH dental X-ray devices, such as the Nomad Pro 2 are a promising adjunct for dental radiology in cases where WM units are of limited practicability.

Awareness of hazards of diagnostic use of radiation during pregnancy among women in Al-Madinah, KSA

Imaging of pregnant women presents a unique challenge to radiologists because of the concern about the radiation risk to the conceptus. To assess awareness of radiation hazards during pregnancy among females in Al-Madinah. A cross-sectional survey questionnaire study was conducted on married and non-married adult females who lives in Al-Madinah. This study included 403 female participants; their age ranged from 16-64 years. 128 participants were health field staff. 201 of participants claimed that they experienced an education regarding radiation hazards during pregnancy. 262 participants chose the 1st trimester as the riskiest time to radiation exposure during pregnancy. Ultrasound was the highest choice (268 times) between participants as the safest imaging modality during pregnancy. 61 answered yes there is a safe level of radiation exposure for a pregnant, during pregnancy and 40% of them chose the answer that cardiac catheterization can be done during pregnancy. Efforts should be done to increase the public orientation about the radiation risks and the safest imaging modalities that can be used during pregnancy. Furthermore, efforts should also be directed to increase the orientation of health working-staff with the safe levels of radiation during pregnancy.

Radiation protection knowledge and practices in interventional cardiologists practicing in Africa: a cross sectional survey

We conducted a survey of doctors working in the cardiac catheterisation laboratories in Africa on their knowledge, attitude and practice with respect to radiation protection. Of seventy-two respondents contacted, 61 (84.7%) completed the questionnaire. Twenty-eight, (45.9%) were younger than 45 years. Thirty-seven, (60.6%) had less than 10 years of experience in the laboratory. Only 28 (45.9%) had undertaken radiation protection training. Fifty-eight, (95.1%) consistently used lead aprons. Forty-seven, (77%) reported consistently using thyroid shields. Ten (16.4%) consistently used radiation protection eyeglasses, whilst 36 (59%) never used them. Thermoluminescent Dosimeter badges were consistently used in 23 (37.7%). Forty-two, (68.9%) reported having ceiling mounted lead/acrylic shields. Level of radiation exposure in the most recent one year was ≤2 mSv in 14, between 2 and 20 mSv in 8 and between 20 and 30 mSv in 2, whilst 33 did not know their dose readings. The use of basic radiation protection tools as well as the knowledge and measurement of radiation exposure among interventional cardiologists working in Africa is low. The unavailability of some of the protective tools and a knowledge gap in terms of radiation protection and monitoring of self-exposure were some of the reasons for suboptimal self-protection against ionising radiation among our respondents. We suggest that initiatives be taken by all stakeholders to train this group of medical professionals in basic radiation protection to avoid unnecessary exposure to themselves, co-workers and patients.

Multicentre prospective observational study protocol for radiation exposure from gastrointestinal fluoroscopic procedures (REX-GI study)

IntroductionRecently, the use of various endoscopic procedures under X-ray fluoroscopic guidance, such as endoscopic retrograde cholangiopancreatography (ERCP), interventional endoscopic ultrasonography (EUS), enteral endoscopy and stenting, has been rapidly increasing because...

SCATTER RADIATION IN THE FLUOROSCOPY-GUIDED INTERVENTIONAL ROOM.

Radiation scattered throughout the room during fluoroscopy-guided interventional (FGI) procedures was quantified at different locations using nanoDot optically stimulated luminescence dosemeters. All the tube angulation imaging shows that the radiation spectrum resembled a single peak distribution. The left anterior oblique 90° shows the highest single peak distribution (28.65mSv/h). The single peak distribution for standard anteroposterior, left anterior oblique 45° and right anterior oblique 45° imaging was 13.32, 22.99 and 17.40mSv/h, respectively. All tube angulation shows that the position of the interventional radiologist experienced a higher radiation level compared to other staffs. The doses of radiation varied widely around the perimeter of the patient's table and changed in accordance to imaging angles during procedures. Knowledge pertaining to radiation exposure levels is integral in order to avoid adverse risks, particularly among staff.

Does a fluoro-assisted direct anterior approach for total hip arthroplasty pose an excessive risk of radiation exposure to the surgeon?

Introduction: Intraoperative fluoroscopy can be easily used because patients are placed in the supine position during total hip arthroplasty via direct anterior approach (DAA-THA) to reduce complications. However, the cumulative level of radiation exposure by intraoperative fluoroscopy increases as the annual number of cases increases, increasing the risk of influencing the health of both the patients and medical workers. The objective of the study was to compare the radiation exposure time of DAA-THA with osteosynthesis and to determine if the level of radiation exposure exceeded safety limits. Material and methods: DAA-THA was performed in 313 patients between January 2016 and July 2018 and 60 patients with proximal femoral fracture were treated with osteosynthesis. The intraoperative fluoroscopy time was retrospectively surveyed and compared between these two groups. A total of eight surgeons operated DAA-THA employing the same procedure using a traction table. A total of nine surgeons operated osteosynthesis and fluoroscopy was appropriately used during reduction and implant insertion. Results: The mean operative time of DAA-THA was 103.3 min and that of osteosynthesis was 83.3 min, showing a significant difference (p < 0.05). The mean intraoperative fluoroscopy time was 0.83 min (SD ± 0.68) in DAA-THA and 8.91 min (SD ± 8.34) in osteosynthesis showing a significant difference (p < 0.05). Conclusions: The intraoperative exposure level was significantly lower and the fluoroscopy time was significantly shorter in DAA-THA than in osteosynthesis for proximal femoral fracture. It was clarified that the annual cumulative radiation exposure level in DAA-THA does not exceed the tissue dose limit.

Benefits of Low-Dose CT Scan of Head for Patients With Intracranial Hemorrhage.

Objectives:For patients with intracranial hemorrhage (ICH), routine follow-up computed tomography (CT) scans are typically required to monitor the progression of intracranial pathology. Remarkable levels of radiation exposure are accumulated during repeated CT scan. However, the effects and associated risks have still remained elusive. This study presented an effective approach to quantify organ-specific radiation dose of repeated CT scans of head for patients with ICH. We also indicated whether a low-dose CT scan may reduce radiation exposure and keep the image quality highly acceptable for diagnosis.Methods:Herein, 72 patients with a history of ICH were recruited. The patients were divided into 4 groups and underwent CT scan of head with different tube current–time products (250, 200, 150, and 100 mAs). Two experienced radiologists visually rated scores of quality of images according to objective image noise, sharpness, diagnostic acceptability, and artifacts due to physiological noise on the same workstation. Organ-/tissue-specific radiation doses were analyzed using Radimetrics.Results:In conventional CT scan group, signal to noise ratio (SNR) and contrast to noise ratio (CNR) of ICH images were significantly higher than those in normal brain structures. Reducing the tube current–time product may decrease the image quality. However, the predilection sites for ICH could be clearly identified. The SNR and CNR in the predilection sites for ICH were notably higher than other areas. The brain, eye lenses, and salivary glands received the highest radiation dose. Reducing tube current–time product from 250 to 100 mA can significantly reduce the radiation dose.Discussion:We demonstrated that low-dose CT scan of head can still provide reasonable images for diagnosing ICH. The radiation dose can be reduced to ∼45% of the conventional CT scan group.

Augmented Reality Surgical Navigation in Spine Surgery to Minimize Staff Radiation Exposure.

Prospective observational study. To assess staff and patient radiation exposure during augmented reality surgical navigation in spine surgery. Surgical navigation in combination with intraoperative three-dimensional imaging has been shown to significantly increase the clinical accuracy of pedicle screw placement. Although this technique may increase the total radiation exposure compared with fluoroscopy, the occupational exposure can be minimized, as navigation is radiation free and staff can be positioned behind protective shielding during three-dimensional imaging. The patient radiation exposure during treatment and verification of pedicle screw positions can also be reduced. Twenty patients undergoing spine surgery with pedicle screw placement were included in the study. The staff radiation exposure was measured using real-time active personnel dosimeters and was further compared with measurements using a reference dosimeter attached to the C-arm (i.e., a worst-case staff exposure situation). The patient radiation exposures were recorded, and effective doses (ED) were determined. The average staff exposure per procedure was 0.21 ± 0.06 μSv. The average staff-to-reference dose ratio per procedure was 0.05% and decreased to less than 0.01% after a few procedures had been performed. The average patient ED was 15.8 ± 1.8 mSv which mainly correlated with the number of vertebrae treated and the number of cone-beam computed tomography acquisitions performed. A low-dose protocol used for the final 10 procedures yielded a 32% ED reduction per spinal level treated. This study demonstrated significantly lower occupational doses compared with values reported in the literature. Real-time active personnel dosimeters contributed to a fast optimization and adoption of protective measures throughout the study. Even though our data include both cone-beam computed tomography for navigation planning and intraoperative screw placement verification, we find low patient radiation exposure levels compared with published data. 3.

Don't be Caught Half-dressed When Working with Radiation.

A typical 2-piece personal protective equipment apron covers only half the body. However, with radiation exposure there is evidence of the following: (1) Left-sided head exposure estimates equal to 100,000 chest X-rays over a 20-year career, (2) direct linear relationship between stroke and concentration of dose, (3) increases in ischemic heart disease and myocardial infarction, (4) accelerated aging processes, and (5) increased double-stranded DNA breaks in circulating lymphocytes when lower legs are exposed. Every exposure to ionizing radiation involves a health risk that accumulates. Interventionalists are treating more patients, more complex patients, using new complicated devices. Juxtaposed with the global obesity epidemic, the result is an unprecedented level of radiation exposure for those who use radiation in their daily work. By implementing a simple system of shields, we can dramatically reduce our radiation dose. This would give us a better chance to live a longer, healthier life, and pass quality DNA to our children. This narrative review examines the efficacy of protective barriers to reduce medical occupational radiation exposure and risk.

Cumulative solar ultraviolet radiation exposure and basal cell carcinoma of the skin in a nationwide US cohort using satellite and ground-based measures

BackgroundBasal cell carcinoma of the skin (BCC) is the most common cancer in populations of European ancestry. Although consistently linked with basal cell carcinoma of the skin in case-control studies, few prospective cohort studies have evaluated the shape of the exposure-response of basal cell carcinoma associated with cumulative radiant solar ultraviolet exposure (UVR).MethodsWe followed 63,912 white cancer-free US radiologic technologists from entry (1983–1998) to exit (2003–2005) with known ultraviolet irradiance at up to 5 residential locations. Using generalized-additive and relative risk models we analyzed the exposure-response of basal cell carcinomas associated with ambient cumulative ultraviolet radiant exposure using ground-based National Solar Radiation database Average Daily Total Global data and satellite-based National Aeronautics and Space Administration Total Ozone Mapping Spectrometer data.ResultsThere were 2151 technologists with an incident primary basal cell carcinoma. Risk of basal cell carcinoma rose with increasing cumulative ultraviolet radiation exposure using both measures, such that 1 MJ cm− 2 increased basal cell carcinoma risk by 8.48 (95% CI 5.22, 11.09, p < 0.001) and by 10.15 (95% CI 6.67, 13.10, p < 0.001) per 10,000 persons per year using the Average Daily Total Global and Total Ozone Mapping Spectrometer ultraviolet data, respectively; relative risk was likewise elevated. There was some evidence of upward curvature in the cumulative ultraviolet exposure response using both exposure measures with a greater increase in risk of basal cell carcinoma at higher levels of ultraviolet radiation exposure, but less evidence for curvature in relative risk. There are indications of substantial variation of relative risk with time after exposure and age at exposure, so that risk is highest for the period 10–14 years after ultraviolet radiation exposure and for those exposed under the age of 25.ConclusionsWe observed increases in risk of basal cell carcinoma and a similar exposure-response for ground-based and satellite ultraviolet radiation measures. Our observations suggest that interventions should concentrate on persons with higher levels of ultraviolet radiation exposure.

Challenges in Clinical Management of Radiation-Induced Illnesses During Exploration Spaceflight.

INTRODUCTION: Analysis of historical solar particle events (SPEs) provides context for some understanding of acute radiation exposure risk to astronauts who will travel outside of low-Earth orbit. Predicted levels of radiation exposures to exploration crewmembers could produce some health impacts, including nausea, emesis, and fatigue, though more severe clinical manifestations are unlikely. Using current models of anticipated physiological sequelae, we evaluated the clinical challenges of managing radiation-related clinical concerns during exploration spaceflight.METHODS: A literature review was conducted to identify terrestrial management standards for radiation-induced illnesses, focusing on prodromal symptom treatment. Terrestrial management was compared to current spaceflight medical capabilities to identify gaps and highlight challenges involved in expanding capabilities for future exploration spaceflight.RESULTS: Current spaceflight medical resources, such as those found on the International Space Station, may be sufficient to manage some aspects of radiation-induced illness, although effective treatment of all potential manifestations would require substantial expansion of capabilities. Terrestrial adjunctive therapies or more experimental treatments are unavailable in current spaceflight medical capabilities but may have a role in future management of acute radiation exposure.DISCUSSION: Expanded medical capabilities for managing radiation-induced illnesses could be included onboard future exploration vehicles. However, this would require substantial research, time, and funding to reach flight readiness, and vehicle limitations may restrict such capabilities for exploration missions. The benefits of including expanded capabilities should be weighed against the likelihood of significant radiation exposure and extensive mission design constraints.Blue RS, Chancellor JC, Suresh R, Carnell LS, Reyes DP, Nowadly CD, Antonsen EL. Challenges in clinical management of radiation-induced illnesses during exploration spaceflight. Aerosp Med Hum Perform. 2019; 90(11):966-977.

Measurement and mapping of the electromagnetic radiation in the urban environment

ABSTRACTPeople are increasingly exposed to electromagnetic radiation with the rapid development of technologies such as broadcasting and mobile communication system. There is a concern that long-term exposure at low levels may be associated with various non-specific physical symptoms and ecological effects on animals and plants. It is extremely important to measure and analyze the electromagnetic radiation levels in order to protect people from the possible effects of electromagnetic radiation. A large-scale assessment of the effects of electromagnetic radiation on health or on ecology requires the ambient electromagnetic radiation levels over areas too vast to cover with conventional measurement methods. In this article, detailed information about the measurement tools and measurement method are given. The electromagnetic radiation exposure levels were measured on the main streets in the dense urban areas of Beijing, the capital of China. We apply ordinary kriging as an interpolation technique to assess the electromagnetic radiation exposure in large outdoor areas based on car-mounted measurements along the surrounding roads. The electromagnetic radiation exposure levels for larger areas can be investigated visually on the electromagnetic pollution map, which can assist decision makers by identifying the hotspots.

2924 Risk of Malignancy Due to Radiation Exposure in Patients With IBD

INTRODUCTION: Diagnostic imaging is routinely used in the management of IBD and in most cases, comes at the cost of repeated radiation exposure to the patient. We aim to show correlation between increased rates of cancer in patients with IBD and increased levels of radiation exposure. It is our purpose to demonstrate that efforts should be made to assessment and monitor total radiation exposure in patients with IBD. METHODS: We used a case-control design to compare patients with cancer diagnosis cases vs No cancer diagnosis controls. Cases were a composite of 74-cancer diagnosis. Cases were obtained from Cerner Healthfacts database, including 67 hospitals, using ICD9/10 codes for cancer after radiation exposure due to CT scans identified by CPT codes (74175, 74174, 74150, 74176, 74160, 74178, 74177, and 74170) in IBD patients, while controls were randomly selected from the remaining IBD patients with CT scans. Using sociodemographic and other medical diagnoses within the database, we screened candidate variables for a multivariable regression analysis for being a case and included all variables in the regression with P &lt; 0.10 on univariate analysis. RESULTS: Between 01/01/2010 and 12/31/2016, we identified 132 patients with cancer out of 2,768 IBD patients who had radiation exposure (4.8%). Table 1 shows indication for the cancer. Combined with 2,636 controls, our study population had an average age of 48.0 (IQR: 34-62), 86.3% were white, and 59.3% were female. The two variables with P &lt; 0.10 on univariable comparisons were included in the final model. After adjusting for confounders, older patients, and those on higher radiation doses had increased odds for developing cancer (Table 2). Steroid use and Immunomodulatory therapy, while significant on univariable analysis, were no longer significant risk factors after adjusting for confounders. CONCLUSION: Diagnostic imaging is a vital tool used to determine disease severity, extent, and response to treatment in IBD. As the disease tends to relapse and remit, repeat diagnostic imaging is a continuous part of disease management resulting in cumulative exposure to ionizing radiation over the lifetime of a patient. Patients with IBD have an increased risk of developing colorectal and small intestinal cancers than the general population irrespective of their exposure to radiation. Our data shows that additionally, the increased burden of radiation exposure increases the rates of cancer in these patients.

Long-term experience and analysis of data on diagnostic reference levels: the good, the bad, and the ugly.

To analyze 11-year data of France for temporal trends in dose indices and dose optimization and draw lessons for those who are willing to work on creation and update of diagnostic reference levels (DRLs). The data from about 3000 radiology departments leading to about 750,000 imaging exams between 2004 and 2015 was analyzed, and patterns of reductions in dose for those below and above the DRLs were estimated and correlated with technology change. Dose optimization achieved was important and significant in departments which were above or just below the DRL (p = .006) but not in those which were around half of the DRL values. The decrease in 75th percentile value of Kerma air product (KAP) for chest radiography by 27.4% between 2004 and 2015 was observed with the number of flat panel detectors increase from 6 to 43%. A good correlation between the detector type distribution and the level of patient radiation exposure is observed. Otherwise, setting DRLs for standard-sized patient excludes patients lower and higher weighted than "standard." The concept of DRL may become obsolete unless lessons drawn from the experience of users are taken into account. While establishing DRLs should be part of the regulations, setting up and updating values should be governed by bodies whose decision-making cycle is short, at the most 1year. A local rather than national approach, taking into account body habitus and image quality, needs to be organized. • The technology changes faster than regulations. Requirement of DRL establishment should be part of the regulations; however, setting and updating values should be the role of professional societies. • The concept of DRL, highlighting the 75th percentile values and dedicated to standard-sized adult, misses optimization opportunities in the majority of patients who are below the 75th percentile value and outside the range of standard-sized adult. • The ugly aspects of the DRL concept include its non-applicability to individuals, no customization to clinical indications, and lack of consideration of image quality.

Genetic, epigenetic and microbiome characterisation of an earthworm species (Octolasion lacteum) along a radiation exposure gradient at Chernobyl

The effects of exposure to different levels of ionising radiation were assessed on the genetic, epigenetic and microbiome characteristics of the “hologenome” of earthworms collected at sites within the Chernobyl exclusion zone (CEZ). The earthworms Aporrectodea caliginosa (Savigny, 1826) and Octolasion lacteum (Örley, 1881) were the two species that were most frequently found at visited sites, however, only O. lacteum was present at sufficient number across different exposure levels to enable comparative hologenome analysis. The identification of morphotype O. lacteum as a probable single clade was established using a combination of mitochondrial (cytochrome oxidase I) and nuclear genome (Amplified Fragment Length Polymorphism (AFLP) using MspI loci). No clear site associated differences in population genetic structure was found between populations using the AFLP marker loci. Further, no relationship between ionising radiation exposure levels and the percentage of methylated loci or pattern of distribution of DNA methylation marks was found. Microbiome structure was clearly site dependent, with gut microbiome community structure and diversity being systematically associated with calculated site-specific earthworm dose rates. There was, however, also co-correlation between earthworm dose rates and other soil properties, notably soil pH; a property known to affect soil bacterial community structure. Such co-correlation means that it is not possible to attribute microbiome changes unequivocally to radionuclide exposure. A better understanding of the relationship between radionuclide exposure soil properties and their interactions on bacterial microbiome community response is, therefore, needed to establish whether these the observed microbiome changes are attributed directly to radiation exposure, other soil properties or to an interaction between multiple variables at sites within the CEZ.