Introduction
Diagnostic Reference Levels (DRL) of procedures involving ionizing radiation are important tools to optimizing radiation doses delivered to patients and in identifying cases where the ...levels of doses are unusually high. This is particularly important for paediatric patients undergoing computed tomography (CT) examinations as these examinations are associated with relatively high‐dose.
Methods
Paediatric CT studies, performed at our institution from January 2010 to March 2014, have been retrospectively analysed to determine the 75th and 95th percentiles of both the volume computed tomography dose index (CTDIvol) and dose‐length product (DLP) for the most commonly performed studies to:
establish local diagnostic reference levels for paediatric computed tomography examinations performed at our institution,
benchmark our DRL with national and international published paediatric values, and
determine the compliance of CT radiographer with established protocols.
Results
The derived local 75th percentile DRL have been found to be acceptable when compared with those published by the Australian National Radiation Dose Register and two national children's hospitals, and at the international level with the National Reference Doses for the UK. The 95th percentiles of CTDIvol for the various CT examinations have been found to be acceptable values for the CT scanner Dose‐Check Notification. Benchmarking CT radiographers shows that they follow the set protocols for the various examinations without significant variations in the machine setting factors.
Conclusion
The derivation of DRL has given us the tool to evaluate and improve the performance of our CT service by improved compliance and a reduction in radiation dose to our paediatric patients. We have also been able to benchmark our performance with similar national and international institutions.
•Evaluating and updating Austrian NDRLs for computed tomography.•Findings of this study are lower than the Austrian NDRLs and correspond well to German and Swiss NDRLs.•Urolithiasis CT scans in ...Austria are more frequently conducted without low-dose protocols.•3rd quartile DLP depends on gender, the use of iterative reconstruction and year of manufacture of the CT-scanners.
To define National Diagnostic Reference Levels (NDRLs) for computed tomography (CT) for Austria on adult patients.
In the course of a nationwide survey on common CT-examinations between June 2018 and November 2018, datasets were requested from all Austrian hospitals and radiology centers with CT-scanners. All facilities were asked to report a minimum sample of 10 representative dose length product (DLP) values per examination type and CT-scanner, including information about scan sequences, iterative reconstruction (IR) algorithms and, if available, patient data. Examination types included into the survey were the most common CT-indications for the anatomic regions head, facial bones, thorax, abdomen and pelvis. 3rd quartiles of CT-scanner median DLPs were calculated and compared to Austrian and international NDRLs.
For 76 % of all operating CT-scanners, DLP data was submitted varying from 13 to 172 scanners per examination type. Mean year of manufacture of the CT-scanners was 2011, ranging from 2003 to 2018. In 66 % of the examinations, IR was used. 3rd quartile is on average 21 % lower for scanners using IR algorithms as opposed to scanners or protocols not using IR. In the case of gender differences, the DLP for females is on average 17 % lower than for males.
The new recommendations for CT NDRLs for Austria based on a nationwide survey are on average 13 % lower than the current Austrian NDRLs and correspond well to recent German and Swiss NDRLs. 3rd quartiles for DLP are dependent on gender, the use of IR and year of manufacture of the CT-scanners.
Abstract
Purpose
Recent developments in medical technology have broadened the spectrum of X-ray procedures and changed exposure practice in X-ray facilities. For this reason, diagnostic reference ...levels (DRLs) for diagnostic and interventional X-ray procedures were updated in 2016 and 2018, respectively. It is the aim of this paper to present the procedure for the update of the DRLs and to give advice on their practical application.
Materials and Methods
For the determination of DRLs, data from different independent sources that collect dose-relevant data from different facilities in Germany were considered. Seven different weight intervals were specified for classifying pediatric X-ray procedures. For each X-ray procedure considered, the 25th, 50th, and 75th percentile of the respective national distribution of the dose-relevant parameters were determined. Additionally, effective doses that correspond to the DRLs were estimated.
Results
In procedures with already existing DRLs before 2016, the values were lowered by circa 20 % on average. Numerous DRLs were established for the first time (9 for interventional procedures, 10 for CT examinations).
Conclusion
For dose optimizations even below the new national DRLs, the BfS recommends establishing local reference levels, using dose management software (particularly in CT and interventional radiology), adapting dose-relevant parameters of X-ray protocols to the individual patient size, and establishing internal radiation protection teams responsible for optimizing X-ray procedures in clinical practice. When applying good medical practice and using modern equipment, the median dose values of the nationwide dose distributions can not only be easily achieved but can even be undercut.
Key Points:
German diagnostic reference levels (DRLs) für diagnostic and interventional X-ray procedures were updated in 2016 and 2018, respectively.
For X-ray procedures for which DRLs existed already before the update, the updated DLRs were lowered by circa 20 %, on average.
For CT and interventional radiology, new DRLs were established.
X-ray procedures have to be optimized even below the DRLs.
Citation Format
Schegerer A, Loose R, Heuser LJ et al. Diagnostic Reference Levels for Diagnostic and Interventional X-Ray Procedures in Germany: Update and Handling. Fortschr Röntgenstr 2019; 191: 739 – 751
Zusammenfassung
Ziel
Die Entwicklungen der Medizintechnik in den letzten Jahren haben das Spektrum medizinischer Röntgenanwendungen erweitert und die Untersuchungspraxis in Röntgeneinrichtungen verändert. Infolgedessen wurden 2016 und 2018 die diagnostischen Referenzwerte (DRW) für diagnostische bzw. interventionelle Röntgenanwendungen aktualisiert. Ziel dieser Arbeit ist es, das Prozedere der Aktualisierung und die aktualisierten DRW vorzustellen sowie Hinweise zu ihrer praktischen Anwendung zu geben.
Material und Methoden
Für die Aktualisierung der DRW wurden verschiedene, voneinander unabhängige Datenquellen berücksichtigt, die Dosis-relevante Untersuchungsparameter von verschiedenen Einrichtungen aus dem gesamten Bundesgebiet registrieren. Röntgenanwendungen an Kindern wurden in 7 verschiedene Gewichtsklassen eingeteilt. Für jede erfasste Röntgenanwendung wurde die 25., 50. und 75. Perzentile der entsprechenden nationalen Verteilung der Dosis-relevanten Untersuchungsparameter bestimmt. Für die aktualisierten und neu festgelegten DRW wurden die zugehörigen effektiven Dosiswerte abgeschätzt.
Ergebnisse
Die DRW für Röntgenanwendungen, die schon vor 2016 existierten, konnten im Mittel um circa 20 % gesenkt werden. Für zahlreiche Röntgenanwendungen wurden neue DRW festgelegt (für die interventionelle Radiologie 9, für die Computertomografie 10).
Schlussfolgerungen
Um Röntgenanwendungen auch unterhalb der neuen nationalen DRW zu optimieren, empfiehlt das BfS, lokale Referenzwerte festzulegen und anzuwenden, Dosismanagementsoftware (v. a. für den Bereich der CT und interventionellen Radiologie) einzusetzen, Dosis-relevante Protokollparameter der Röntgenuntersuchung bzw. des interventionell-radiologischen Eingriffs systematisch an die Patientenstatur anzupassen und einrichtungsinterne Strahlenschutzteams zu etablieren. Bei guter Praxis und Einsatz moderner Geräte-Technologien können die durch die 50. Perzentile der nationalen Verteilungen vorgegebenen Expositionsniveaus erreicht und sogar unterschritten werden.
Kernaussagen:
Die diagnostischen Referenzwerte (DRW) für diagnostische und interventionelle Röntgenanwendungen wurden 2016 bzw. 2018 aktualisiert.
DRW für Röntgenanwendungen, für die schon vor 2016 DRW existierten, wurden im Mittel um circa 20 % gesenkt.
Für die CT und interventionelle Radiologie wurden neue DRW festgelegt.
Röntgenanwendungen sind auch unterhalb der DRW zu optimieren.
Zitierweise
Schegerer A, Loose R, Heuser LJ et al. Diagnostic Reference Levels for Diagnostic and Interventional X-Ray Procedures in Germany: Update and Handling. Fortschr Röntgenstr 2019; 191: 739 – 751
Diagnostic and therapeutic interventional cardiology procedures are essential tools for evaluating congenital pathologies in paediatric patients. However, these procedures may expose patients to high ...levels of ionizing radiation. In this paper, we present the results of the radiation doses received by patients undergoing interventional cardiac procedures at a paediatric hospital in Brazil, aiming to establish local Diagnostic Reference Levels (DRL). The data were collected over a period of three years (2019–2022), and 148 procedures were analyzed, comprising 53% male (78) and 47% female (70) patients. These procedures included both diagnostic (59%) and therapeutic (41%) cardiac catheterization interventions. The average patient weight was 21.4 ± 1.7 kg (2.0–112.0 kg), with an average age of 5.3 ± 0.4 years (0.0–17.1 years). Comprehensive data for each procedure were extracted from Radiation Dose Structure Reports generated by the equipment. The results showed significant differences between diagnostic and therapeutic procedures, and the DRL values were estimated considering the age and weight of the patients. The DRL values correspond to the 3rd quartile of the dose distribution for each group. The following local DRL values were estimated, considering the patient's ages. For diagnostic procedures, the PKA defined according to the age groups <1, 1–5, 5–10, 10–15, and >15 years were respectively: 1.4, 2.8, 3.1, 4.3 and 12.0 Gy cm2. For therapeutic procedures, the DRL values for patients with the same ages were: 2.0, 3.7, 5.4, 7.4, and 30.9 Gy cm2. For the total procedures, the PKA values were 1.7, 3.2, 4.9, 6.6, and 24.5 Gy cm2, respectively. The suggested local DRL values for weight groups (<5, 5–15, 15–30, 30–50, and 50–80 kg) for PKA in diagnostic procedures were: 1.3, 2.2, 3.2, 4.1, and 7.9 Gy cm2, respectively. For therapeutic procedures, the PKA values were 1.1, 2.7, 5.4, 5.5, and 30.9 Gy cm2, respectively. For the total procedures, the PKA values were 1.25, 2.5, 4.6, 4.2, and 18.3 Gy cm2, respectively. For establishing PKA DRL, patient weight was found to be preferable over age, whereas for Ka,r, both approaches yielded nearly identical results.
•Local DRL values are proposed for standard age and weight ranges for cardiac interventional procedures.•PKA and Ka,r values are determined according to the age and weight of patients.•The correlation between patient weight and age are determined.•To determine the PKA DRL, patient weight is preferable.•Statistically significant differences between diagnostic and therapeutic procedures are detected.
A comprehensive search was performed to examine the literature on diagnostic reference levels (DRL) for computed tomography (CT) and radiography examinations that are performed routinely in Jordan. ...EBSCO, Scopus, and Web of Science were used for the search. The acronym "DRL" and the additional phrase "dose reference levels" were used to search for articles in literature. Seven papers that reported DRL values for radiography and CT scans in Jordan were identified. One study reported DRLs for conventional radiography, two studies reported CT DRLs in pediatrics, and the remaining four studies provided DRL values for adult CT scans. The most popular techniques for determining the DRLs were the entrance surface dose, volume CT dose index (CTDIvol), and dose-length product (DLP) values. Variations in Jordanian DRL values were noted across both modalities. Lower radiation doses and less variation in DRL values may be achieved by educating and training radiographers to better understand dose reduction strategies. To limit dose variance and enable dosage comparison, CT DRLs must be standardized in accordance with the guidelines of the International Commission on Radiological Protection (ICRP).
•Greek DRLs were revised for 7 adult CT exams and established for 5 additional ones.•Revised DRLs exhibited lower reduction compared to other national studies.•Incorporation of advanced technologies ...showcased potential for further optimisation.•The study underscores the importance of ongoing optimisation efforts.
The escalating use of Computed Tomography (CT) imaging necessitates establishment and periodic revision of Diagnostic Reference Levels (DRLs) to ensure patient protection optimization. This paper presents the outcomes of a national survey conducted from 2019 to 2022, focusing on revising DRLs for adult CT examinations. Dosimetric data from 127 scanners in 120 medical facilities, representing 25% of the country's CT scanners, were collected, emphasizing geographic distribution and technology representation. Τhe parameters used for DRLs were the CTDIvol and the DLP of a typical acquisition of the region of interest (scan DLP). In addition to the 7 CT examination for which the DRL values were revised, establishment of DRLs for neck, cervical spine, pelvic bones-hips, coronary artery calcium (Ca) score and cardiac computed tomography angiography (CCTA) examinations was performed.
Revised DRLs exhibited a 15 % average decrease in CTDIvol and a 7 % average decrease in scan DLP from the initial DRLs. This reduction of dosimetric values is relatively low compared to other national studies. The findings revealed wide variations in dosimetric values and scan lengths among scanners, emphasizing the need for standardization and optimization. Incorporation of advanced technologies like Iterative Reconstruction (IR) showcased potential for further dose reduction, yet challenges in uniform implementation persist. The study underscores the importance of ongoing optimisation efforts, particularly in the context of increased CT utilization and evolving technology. The revised DRLs have been officially adopted in Greece, emphasizing the commitment to safe and effective CT practices.
Objectives
The diagnostic reference level (DRL) is a useful tool for the optimisation of medical exposures. Thus, a Working Party coordinated by the Italian National Institute of Health and the ...National Workers Compensation Authority has been formed to provide Italian DRLs, for both diagnostic and interventional procedures, to be used as appropriate for the implementation of the 2013/59 European Directive into the national regulation.
Materials and methods
The multidisciplinary Working Party was formed by professionals involved in diagnostic and interventional radiology medical exposures and started from a critical revision of both the literature and the results of previous Italian surveys. The procedures were divided into five sections for adult (projection radiography, mammography, diagnostic fluoroscopy, CT and interventional radiology) and two sections for paediatric patients (projection radiography and CT). The provided DRL values have been identified for “normal” adult patients and for age-classes of paediatric patients.
Results
Some of the DRL values provided by the Working Party are reported in this study as an example, divided by adult/paediatric patients, radiological technique and examination: specifically, DRLs for new radiological practices and new dose quantities as DRLs metric were introduced. The median value (rather than the mean) for each procedure, derived from a sample of patients, has to be compared with the corresponding DRL value, and dosimetric data related to a minimum number of patients should be collected for each examination.
Conclusions
The approach to the definition and use of DRLs through guidelines of national Authorities in collaboration with scientific Associations should simplify the periodical updating and could be useful for keeping the optimisation of medical exposures faithful to the development of radiological practice.
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