Quantifying decreased radiation exposure from modern CT scan surveillance programs of germ cell tumors.

2016 ◽  
Vol 34 (2_suppl) ◽  
pp. 478-478
Author(s):  
Stephanie Anne Holler Howard ◽  
Michael Rosenthal ◽  
Lei Qin ◽  
Brandon David Bernard ◽  
Clair Beard ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Radiation Exposure ◽  
Transport Model ◽  
Biological Effects ◽  
Absolute Risk ◽  
Clinical Stage ◽  
Germ Cell Tumors ◽  
Ct Scans ◽  
Rank Test ◽  
The Impact

478 Background: Active surveillance (AS) is increasingly used to manage clinical stage I testicular cancer (CS1TC,) but has the risk of radiation exposure from CT scans. Modern CT scanners with iterative reconstruction techniques (IRT) produce equivalent image quality with less radiation dose compared with traditional filtered back projection (FBP). Data examining timing of CS1TC relapses on AS have suggested it is safe to decrease CT scanning of abdomen and pelvis from the NCCN 2009 guideline of approximately 16 scans over 5 years to 7 scans. We examine the impact of the CT upgrade and decreased scans on radiation dose and associated risks. Methods: This IRB-approved study enrolled 24 CS1TC patients who had CT scans on the same Toshiba Aquilion 64 CT before and after IRT software installation. Dose-length product and CT dose index volume were recorded. A medical physicist calculated effective doses. Radiation doses were compared using the Wilcoxon signed rank test. Median effective dose per scan was multiplied by scan number based on 16 and 7 scan 5 year AS protocols to calculate an estimated cumulative dose (ECD). Lifetime attributable risk (LAR) of dying of a radiation-associated solid tumor was estimated for a single exposure at age 35 using the excess absolute risk transport model from the Biological Effects of Ionizing Radiation VII analysis of long-term atomic bomb survivors. Results: Median pre and post upgrade doses were 12.5 mSv and 7.7 mSv respectively (p < 0.0001). A linear regression model with a constrained zero intercept fit to the data found that IRT dose was best estimated as 61% of FBP dose (95% CI 0.56 – 0.66). Table 1 lists ECD and LAR data for both AS regimens pre and post upgrade. Conclusions: IRT, as part of an integrated approach to optimize patient outcome, should reduce CT-related risks by about 39%. This reduction, combined with the scan reduction of newer AS regimens, further significantly lowers the already small potential mortality of imaging associated cancers. [Table: see text]

IMPACT OF THE TABLE HEIGHT AND THE OPERATOR’S HEIGHT ON THE LEVEL OF RADIATION DELIVERED TO INTERVENTIONAL CARDIOLOGISTS

2019 ◽  
Vol 187 (1) ◽  
pp. 21-27 ◽  
Author(s):  
Laurent Faroux ◽  
Thierry Blanpain ◽  
Anthony Fernandez ◽  
Pierre Nazeyrollas ◽  
Sophie Tassan-Mangina ◽  
...  
Keyword(s):  
Multivariate Analysis ◽  
Radiation Dose ◽  
Radiation Exposure ◽  
Primary Endpoint ◽  
Health Professionals ◽  
Maximum Distance ◽  
X Ray ◽  
Coronary Interventions ◽  
Coronary Procedures ◽  
The Impact

ABSTRACT Interventional cardiologists count among the health professionals that are most exposed to ionising radiation. To minimise exposure, it is recommended that the patient be placed at the maximum distance possible from the X-ray source, but this recommendation has not been clinically validated. We aimed to investigate the impact of the average table height on the level of radiation delivered to cardiologists performing coronary interventions. The population for analysis included all invasive coronary procedures performed in our centre from March to June 2017. The primary endpoint was operator radiation exposure, as assessed using personal electronic dosimeters located on the operator’s left arm. In total, 225 invasive coronary procedures were analysed. When the average table height was 1126 mm or more, the operators received a radiation dose that was, on average, 53% lower than when the table was lower than 1126 mm. This reduction remained significant by multivariate analysis adjusted for the operator.

Effect of number of computed tomography (CT) scans during follow-up (FUP) of patients with clinical stage I (CSI) seminoma: A trial-level meta-analysis.

2018 ◽  
Vol 36 (6_suppl) ◽  
pp. 564-564
Author(s):  
Patrizia Giannatempo ◽  
Daniele Raggi ◽  
Elena Tagliabue ◽  
Mario Catanzaro ◽  
Davide Biasoni ◽  
...  
Keyword(s):  
High Risk ◽  
Meta Analysis ◽  
Statistical Significance ◽  
Clinical Stage ◽  
Continuous Variable ◽  
Ct Scans ◽  
Occurrence Rate ◽  
Prognostic Effect ◽  
Level Data ◽  
The Impact

564 Background: Despite the overall high cure-rate for patients (pts) with CSI seminoma (sem) regardless of the intervention used, huge discrepancy exists in the number of CT scans that are proposed to pts during FUP period, mainly during active surveillance (AS). The impact of such discrepancy in diagnosing pts with a high-risk relapse was assessed in published literature with a meta-analysis (MA). Methods: We searched for arms of studies of AS or active treatment (AT, adjuvant chemotherapy and radiotherapy) in pts with CSI sem. Meta-analytic techniques were used to pool and compare study level data of AS and AT groups and to study the impact of the number of CT scans (as a continuous variable) during FUP upon the % of pts with CSIII or with IGCCCG intermediate (int) prognosis sem at relapse. Results: 22 studies were analyzed (33 arms, n = 11025 pts). 39.6% had a high-risk sem, 38.8% (n = 4274) underwent AS vs 61.2% (n = 6751) AT. The number of CT scans ≤2y ranged 4-8, and 0-7 for AS and AT groups. Overall, 922 pts experienced a relapse (651 in AS and 271 in AT arms), 73.9% <2y and 22.3% at 2-5y FUP. Statistical modeling showed that the estimated rates of CSIII relapse (6% in AS, 32% in AT group, p = 0.0068) and int prognosis relapse (2% in AS, 11% in AT group, p = 0.0051), were divergent for the two groups. A higher number of CT scans in the first 2 years of FUP tended to reduce the occurrence rate of both endpoints, but failed to reach statistical significance in AS (p = 0.334 for CSIII, unidentifiable for int prognosis relapse), as well as in AT (p = 0.438, p = 0.103). The number of CT scans in 3-5y FUP had an even weaker prognostic effect. Similar trends were observed in AS cohort after adjusting for the CSI risk group. Conclusions: In this trial-level MA we did not find a statistically-significant association between the number of CT scans performed during FUP of CSI sem pts and the diagnosis of high-risk relapses. Huge discrepancy in the total number of CT scans was generally found between arms. In contrast, as expected, the pattern of relapse of CSI sem was different according to the treatment group. Based on these results, there is room for consistently reducing the number of CT scans during FUP of CSI sem pts undergoing AS.

scholarly journals Radiation Dose Reduction during Radial Cardiac Catheterization: Evaluation of a Dedicated Radial Angiography Absorption Shielding Drape

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Andrew Ertel ◽  
Jeffrey Nadelson ◽  
Adhir R. Shroff ◽  
Ranya Sweis ◽  
Dean Ferrera ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Radiation Exposure ◽  
Cardiac Catheterization ◽  
Patient Comfort ◽  
Bleeding Complications ◽  
Catheterization Laboratory ◽  
Cardiac Catheterization Laboratory ◽  
Radiation Scatter ◽  
The Right ◽  
The Impact

Objectives. Radiation scatter protection shield drapes have been designed with the goal of decreasing radiation dose to the operators during transfemoral catheterization. We sought to investigate the impact on operator radiation exposure of various shielding drapes specifically designed for the radial approach. Background. Radial access for cardiac catheterization has increased due to improved patient comfort and decreased bleeding complications. There are concerns for increased radiation exposure to patients and operators. Methods. Radiation doses to a simulated operator were measured with a RadCal Dosimeter in the cardiac catheterization laboratory. The mock patient was a 97.5 kg fission product phantom. Three lead-free drape designs were studied. The drapes were placed just proximal to the right wrist and extended medially to phantom’s trunk. Simulated diagnostic coronary angiography included 6 minutes of fluoroscopy time and 32 seconds of cineangiography time at 4 standard angulated views (8 s each), both 15 frames/s. ANOVA with Bonferroni correction was used for statistical analysis. Results. All drape designs led to substantial reductions in operator radiation exposure compared to control (P<0.0001). The greatest decrease in radiation exposure (72%) was with the L-shaped design. Conclusions. Dedicated radial shielding drapes decrease radiation exposure to the operator by up to 72% during simulated cardiac catheterization.

scholarly journals Radiation exposure in interventional cardiology: relationship between patient radiation dose, demographic characteristics and procedural factors

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
C McCaughey ◽  
R Kumar ◽  
J Kumar ◽  
S Matiullah
Keyword(s):  
Regression Analysis ◽  
Radiation Dose ◽  
Radiation Exposure ◽  
Interventional Cardiology ◽  
Coronary Intervention ◽  
Multivariate Regression Analysis ◽  
Operator Technique ◽  
Femoral Access ◽  
Radial Access ◽  
The Impact

Abstract Introduction There has been a significant increase in Interventional Cardiology (IC) procedures over last few decades across the globe. The introduction of newer techniques and procedure types in IC has contributed to an overall increase in radiation exposure to both operators and patients alike. Unlike diagnostic imaging, IC procedures are heterogeneous and vary in their complexity based on a myriad of factors, such as patient disease characteristics, anatomy, nature of lesions and operator technique. Purpose The aim of the study is to evaluate the demographic and procedural characteristics associated with increased radiation dose. Limited studies exist on the impact of demographic and procedural characteristics on cumulative radiation dose. Methods Single-centre retrospective observational study of elective Percutaneous Coronary Intervention (PCI) patients from October 2018 to December 2018 in a 24/7 Irish pPCI centre. Patient level data including weight, height, demographic and procedural characteristics were collected for 65 consecutive elective PCI cases. Radiation exposure metrics, including Kerma Area Product (Pka), Reference Air Kerma (Ka,r) and Fluoroscopy Time (FT), were also collected. A Mann-Whitney U Test was used to assess for differences in radiation exposure between groups and a multivariate regression analysis was performed in order to identify those variables which contributed to radiation exposure. Results Median total radiation exposure for our cohort was (Q1–3) -Pka 109 (61–154) Gy·cm2, Ka,r 1746 (1,082–2,530)mGy and FT 16 (10–25)mins. Males (n=48) had a significantly higher radiation exposure Pka 126 (84–171) vs 56 (27–114)Gy·cm2 p=0.001; Ka,r 2094 (1256–2936) mGy p=0.006) than females. Those who underwent femoral access had significantly lower radiation exposure (Pka 50 (38–77) vs 114 (63–158) Gy·cm2 p=0.019; Ka,r (897 (725–1094) vs 2020 (1092–2618) mGy; p=0.018) when compared to radial access. Increasing body mass index (BMI) (p=0.03), multi vessel PCI (p=0.001) and the use of a “sheathless” technique (p=0.029) were associated with increasing radiation exposure (r2=0.630 Pka; Ka,r r2=0.611). Stent characteristics and all other clinical risk factors (HTN, smoking, DM, renal impairment, previous PCI) had no significant impact on radiation exposure. Conclusion Radiation exposure during IC in our cohort was within the range of most European Diagnostic Reference Levels (DRL's). Increased BMI and male gender were associated with increased radiation exposure. Procedural characteristics such as radial access, multi vessel PCI and the use of sheathless technique were independently associated with increasing radiation exposure. We recommend dose documentation of all procedures for these patients to avoid radiation hazards; with periodic assessment of statistical dose recording and planned follow up. Regression analysis Funding Acknowledgement Type of funding source: None

DEVELOPMENT OF A SPECIALISED TAPE MEASURE TO ESTIMATE THE SIZE-SPECIFIC DOSE ESTIMATE

2020 ◽  
Vol 191 (3) ◽  
pp. 369-375
Author(s):  
Tomokazu Shohji ◽  
Kazuki Kuriyama ◽  
Nobutaka Yanano ◽  
Yo Katoh
Keyword(s):  
Computed Tomography ◽  
Radiation Dose ◽  
Radiation Exposure ◽  
Ct Images ◽  
Ct Scans ◽  
Dose Estimate ◽  
Ct Examination ◽  
Tape Measure ◽  
Wide Range ◽  
Standard Deviations

Abstract The risk in computed tomography (CT) examinations is radiation exposure. We aimed to develop a specialised tape measure for determining the size-specific dose estimate (SSDE) for patients undergoing CT scans. The scanning parameters used were those of the abdominal protocol in our institute. With this method, the SSDE220 and standard deviations obtained from CT images for the liver, pelvic and lung areas, corresponded closely to the SSDEtape and standard deviations obtained using the tape measure. We thus devised a new idea that allows the estimation of the SSDE220 using a specialised tape measure before the CT examination, allowing for an informed explanation of the radiation dose to the patient. Although the tape measure developed in this study is specific to one particular CT instrument, the method could be adapted to a wide range of radiography applications.

scholarly journals Four-Year Cumulative Radiation Exposure in Patients Undergoing Computed Tomography Angiography for Suspected Pulmonary Embolism

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Edwin A. Takahashi ◽  
Hyo-Chun Yoon
Keyword(s):  
Pulmonary Embolism ◽  
Radiation Dose ◽  
Radiation Exposure ◽  
Ct Scans ◽  
Suspected Pulmonary Embolism ◽  
Effective Radiation Dose ◽  
Medical Radiation ◽  
Medical Radiation Exposure ◽  
Effective Radiation ◽  
Acute Pe

Purpose.The objective of this study was to determine the estimated effective radiation dose of pulmonary CT angiography (CTA) for suspected pulmonary embolism (PE) contributing to total medical radiation exposure over a 4-year period.Materials and Methods.This investigation retrospectively reviewed 300 patients who presented to the emergency department and received a pulmonary CTA scan for suspected PE. We evaluated these patients' electronic medical record to determine their estimated radiation exposure to CT scans during the following four years. Using DLP toEconversion coefficients, we calculated the cumulative effective radiation dose each subject received.Results.A total of 900 CT scans were reviewed in this study. Pulmonary CTA delivered an average effective radiation dose of 10.7 ± 2.5 mSv and accounted for approximately 65% of subjects' 4-year cumulative medical radiation dose. Only 6.3% of subjects had a positive acute PE according to their radiology report.Conclusion.Pulmonary CTA accounted for the majority of subjects’ medically related effective radiation dose over a 4-year period. With only a minority of subjects having positive findings for acute PE, increased efforts should be made to clinically assess pretest probability before the consideration of imaging.

Effect of Thermal Insulation on Image Quality and Radiation Dose in Polytrauma Computed Tomography

2020 ◽  
Vol 71 (2) ◽  
pp. 238-243
Author(s):  
Paweł Podsiadło ◽  
Robert Chrzan ◽  
Grzegorz Liszka ◽  
Tomasz Sanak ◽  
Sylweriusz Kosiński ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Image Quality ◽  
Radiation Dose ◽  
Thermal Insulation ◽  
Noise Intensity ◽  
Independent Risk Factor ◽  
Ct Scans ◽  
Self Heating ◽  
The Impact ◽  
Image Homogeneity

Purpose: Unintentional drop in body temperature in trauma victims is an independent risk factor for mortality. We aimed to assess the impact of thermal insulation on image quality and radiation dose in polytrauma computed tomography (CT). Methods: Thirteen different insulating covers were used to wrap CT phantoms. Images were assessed subjectively at a radiological workstation and analyzed digitally with dedicated software evaluating the noise intensity, spatial resolution, and image homogeneity. The radiation dose was measured using a dosimeter. Results: Most materials did not cause significant artifacts apart from 2 heating pads. Although the radiation dose was increased by the majority of insulating covers (up to 64.66%), certain covers decreased the absorbed radiation (up to −7.35%). Conclusions: The majority of insulating systems do not cause artifacts in CT scans. When using covers with self-heating warmers, removing the heating pad is suggested due to the risk of considerable artifacts appearing. Certain insulating covers may increase or decrease the radiation dose.

scholarly journals CT of the medial clavicular epiphysis for forensic age estimation: hands up?

2021 ◽  
Author(s):  
Magdalini Tozakidou ◽  
Rieke L. Meister ◽  
Lennart Well ◽  
Kay U. Petersen ◽  
Sebastian Schindera ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Effective Dose ◽  
Age Estimation ◽  
Image Noise ◽  
Ct Scans ◽  
Forensic Age Estimation ◽  
Quantitative Image ◽  
The Impact ◽  
Medial Clavicular Epiphysis ◽  
Scan Length

Abstract Purpose The aim of this study was to assess the impact of arm position in computed tomography (CT) of the clavicle performed for forensic age estimation on clavicular position, image noise, and radiation dose. Methods and materials Forty-seven CT scans of the medial clavicular epiphysis performed for forensic age estimation were conducted with either hands and arms held upwards (CTHU, 28 persons) or positioned at the body (CTHD, 19 persons). Presets were identical for both positions (70 mAs/140 kVp; Brilliance iCT, Philips). Each CT scan was reconstructed with an iterative algorithm (i-Dose 4) and evaluated at the middle of the sternoclavicular joint. Clavicular angle was measured on a.p. topograms in relation to a horizontal line. Quantitative image noise was measured in air at the level of medial clavicular epiphysis. Effective dose and scan length were recorded. Results Hands-up position compared with hands-down position resulted in a lower lateral body diameter (CTHU 41.1 ± 3.6 cm vs. CTHD 44.6 ± 3.1 cm; P = 0.03), a reduced quantitative image noise (CTHU: 39.5 ± 9.2; CTHD: 46.2 ± 8.3; P = 0.02), and lower CTDIvol (5.1 ± 1.4 mGy vs. 6.7 ± 1.8 mGy; P = 0.001). Scan length was longer in patients examined with hands up (HU: 8.5 ± 3.4 cm; HD: 6.2 ± 2.1 cm; P = 0.006). Mean effective dose for CTHU was 0.79 ± 0.32 mSv compared with 0.95 ± 0.38 mSv in CTHD (P = 0.12). Clavicular angle was 17° ± 6° in patients with hands down and 32° ± 7° in patients with hands up (P < 0.001). Conclusion By elevated arm positioning, the image quality of clavicular CT scans can be improved while maintaining radiation dose compared with hands down. Clavicular position differs according to the hand position. Thus, positioning patients with elevated hands is advisable for forensic clavicular CT examinations, but multiplanar CT reconstructions should be adjusted to clavicular position and scan length should be reduced to a minimum.

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