Little guidance exists on how to stratify radiation dose according to diagnostic task. Changing dose for different cancer types is currently not informed by the American College of Radiology Dose ...Index Registry dose survey.
A total of 9602 patient examinations were pulled from 2 National Cancer Institute designated cancer centers. Computed tomography dose (CTDIvol) was extracted, and patient water equivalent diameter was calculated. N-way analysis of variance was used to compare the dose levels between 2 protocols used at site 1, and three protocols used at site 2.
Sites 1 and 2 both independently stratified their doses according to cancer indications in similar ways. For example, both sites used lower doses (P < 0.001) for follow-up of testicular cancer, leukemia, and lymphoma. Median dose at median patient size from lowest to highest dose level for site 1 were 17.9 (17.7-18.0) mGy (mean 95% confidence interval) and 26.8 (26.2-27.4) mGy. For site 2, they were 12.1 (10.6-13.7) mGy, 25.5 (25.2-25.7) mGy, and 34.2 (33.8-34.5) mGy. Both sites had higher doses (P < 0.001) between their routine and high-image-quality protocols, with an increase of 48% between these doses for site 1 and 25% for site 2. High-image-quality protocols were largely applied for detection of low-contrast liver lesions or subtle pelvic pathology.
We demonstrated that 2 cancer centers independently choose to stratify their cancer doses in similar ways. Sites 1 and 2 dose data were higher than the American College of Radiology Dose Index Registry dose survey data. We thus propose including a cancer-specific subset for the dose registry.
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.
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.
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.
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.
DRLs 2020 has been revised, and Ka,r and PKA for each procedure have been set for IVR along with the reference fluoroscopic dose rate. The total dose of IVR includes fluoroscopic and digital ...acquisition (DA) doses, but in actual clinical practice, the ratio varies greatly depending on the procedure (diagnosis/treatment purpose and procedure content), and there are not many detailed data on the ratio. Therefore, we evaluated previous efforts that optimized radiation protection through examining dose for each procedure and the ratio of fluoroscopic and DA doses to total dose, and reviewing protocols. Since the ratio of fluoroscopy and DA dose differs depending on the procedure, it was suggested that the radiation dose exposed to patients can be optimized by sharing the dose information with physicians and constructing a protocol while considering the image quality for each procedure.
The study aims at measuring the entrance surface dose (ESD) of the thyroid gland of infant patients undergoing anterior-posterior (AP) chest x-ray in Usmanu Danfodiyo University Teaching Hospital ...Sokoto (UDUTHS). The study further determines the effective dose to the thyroid on infant patients undergoing AP chest x-ray. Also, compare the entrance surface dose of infant patients obtained from the study with other similar studies and diagnostic reference levels (DRLs) recommended by the International Commission on Radiological Protection ICRP. This is a prospective cross-sectional study and the primary source of data was obtained. Pediatric patients used for the study who are referred to the radiology department for an anteroposterior chest x-ray, UDUTH, Sokoto state, Nigeria. A non-probability sampling technique was adopted for the patient who came in for a chest x-ray (AP) and as recommended by ICRP that a minimum of 10 patients should be used to determine the ESD for each projection, therefore 15 patients were adopted for this study. The result of the ESD obtained for the thyroid on infant patients undergoing chest x-ray (AP) was averaged and the mean of the ESD was 1.38 mGy. This result was compared to similar studies done within the country and outside the country and with the European Commission on radiological protection as seen in Table 6 and Figure 3. The ESD obtained in this study is much higher than those obtained in similar studies as well as the recommended Diagnostic Reference Levels (DRLs). The method adopted in the study was recommended by the international commission on radiological protection, as a result of this, comparisons were reliably made with the reference values and similar studies. The result has shown that entrance surface doses and radiation doses to the thyroid exceed the permissible value in Usmanu Danfodiyo University Teaching Hospital (UDUTH) Sokoto.
Interventional procedures are accompanied with high levels of patient exposure and even with the possibility of radiation skin damage. That’s why any actions leading to reduction of patients’ ...exposure levels are of utmost importance. Implementation of diagnostic reference levels is considered to be one of the most successful actions to reduce patient exposure levels. However the basic concept of diagnostic reference levels cannot be used for interventional radiology due to fact that procedures are not standardized. The article studies the main difficulties in applying the standard concept of diagnostic reference levels for interventional radiology procedures and proposes a new concept, taking into account the specifics of these procedures; the domestic and international documents are analyzed. The list of interventional procedures for diagnostic reference levels establishment is suggested based on the statistical data on performed procedures in the Russian Federation. The results of this study were used for the new Russian guidelines “Optimization of radiation protection of patients undergoing medical radiation diagnostic examinations through the use of diagnostic reference levels”.
Diagnostic reference levels (DRLs) are established for standard-sized patients; however, patient dose in CT depends on patient size. The purpose of this study was to introduce a method for setting ...size-dependent local diagnostic reference levels (LDRLs) and to evaluate these LDRLs in comparison with size-independent LDRLs and with respect to image quality.
One hundred eighty-four aortic CT angiography (CTA) examinations performed on either a second-generation or third-generation dual-source CT scanner were included; we refer to the second-generation dual-source CT scanner as "CT1" and the third-generation dual-source CT scanner as "CT2." The volume CT dose index (CTDI
) and patient diameter (i.e., the water-equivalent diameter) were retrieved by dose-monitoring software. Size-dependent DRLs based on a linear regression of the CTDI
versus patient size were set by scanner type. Size-independent DRLs were set by the 5th and 95th percentiles of the CTDI
values. Objective image quality was assessed using the signal-to-noise ratio (SNR), and subjective image quality was assessed using a 4-point Likert scale.
The CTDI
depended on patient size and scanner type (R
= 0.72 and 0.78, respectively; slope = 0.05 and 0.02 mGy/mm; p < 0.001). Of the outliers identified by size-independent DRLs, 30% (CT1) and 67% (CT2) were adequately dosed when considering patient size. Alternatively, 30% (CT1) and 70% (CT2) of the outliers found with size-dependent DRLs were not identified using size-independent DRLs. A negative correlation was found between SNR and CTDI
(R
= 0.36 for CT1 and 0.45 for CT2). However, all outliers had a subjective image quality score of sufficient or better.
We introduce a method for setting size-dependent LDRLs in CTA. Size-dependent LDRLs are relevant for assessing the appropriateness of the radiation dose for an individual patient on a specific CT scanner.
To reduce the risks involved with ionising radiation exposure, typical values (TVs) and diagnostic reference levels (DRLs) have been established to help keep radiation doses ‘as low as reasonably ...practicable. TVs/DRLs provide standardised radiation dose metrics that can be used for comparative purposes. However, for paediatrics, such values should consider the size of the child instead of their age. This study aimed to establish and compare paediatric TVs for chest, abdomen and pelvis radiography.
Study methods followed processes for establishing paediatric DRLs as outlined by the Health Information and Quality Authority (HIQA). Kerma-area product (KAP) values, excluding rejected images, were retrospectively acquired from the study institution's Picture Archiving and Communications System (PACS). Paediatric patients were categorised into the following weight-based groupings (5 to <15 kg, 15 to <30 kg, 30 to <50 kg, 50 to 80 kg) and stratified based on the examination that was performed (chest, abdomen, and pelvis), and where it was performed (the different X-ray rooms). Anonymised data were inputted into Microsoft Excel for analysis. Median and 3rd quartile KAP values were reported together with graphical illustrations.
Data from 407 X-ray examinations were analysed. For the previously identified weight categories (5 to <15 kg, 15 to <30 kg, 30 to <50 kg, 50 to 80 kg), TVs for the chest were 0.10, 0.19, 0.37 and 0.53 dGy.cm2, respectively. For the abdomen 0.39, 1.04, 3.51 and 4.05 dGy.cm2 and for the pelvis 0.43, 0.87, 3.50 and 7.58 dGy.cm2. Between X-ray rooms TVs varied against the institutional TVs by -60 to 119 % (chest), -50 to 103 % (abdomen) and -14 and 24 %% (pelvis).
TVs in this study follow established trends with patient weight and examination type and are comparable with published literature. Variations do exist between individual examination rooms and reasons are multifactorial. Given that age and size do not perfectly correlate further work should be undertaken around weight-based TVs/DRLs in the paediatric setting.
Pour réduire les risques liés à l'exposition aux rayonnements ionisants, des valeurs typiques (VT) et des niveaux de référence diagnostiques (NRD) ont été établis pour aider à maintenir les doses « au niveau le plus bas raisonnablement possible ».
Les VT/NRD fournissent des doses de rayonnement standardisées qui peuvent être utilisées à des fins de comparaison. Toutefois, en pédiatrie, ces mesures devraient tenir compte de la taille de l'enfant plutôt que de son âge. Cette étude visait à établir et à comparer les VT pédiatriques pour la radiographie du thorax, de l'abdomen et du bassin.
Les méthodes de l'étude ont suivi les processus d'établissement des NRD pédiatriques décrits par la Health Information and Quality Authority (HIQA). Les valeurs du produit Kerma-Area (KAP), à l'exclusion des images rejetées, ont été obtenues rétrospectivement à partir du système d'archivage et de communication d'images (PACS) de l'institution étudiée. Les patients pédiatriques ont été classés dans les catégories d'âge suivantes (1 mois à <4 ans,; 4 à <10 ans, 10 à <14 ans, 14 à 16 ans) et stratifiés en fonction de l'examen effectué (thorax, abdomen et bassin) et de l'endroit où il a été effectué (les différentes salles de radiologie). Les données anonymisées ont été saisies dans Microsoft Excel pour l'analyse. Les valeurs médianes et du 3e quartile de KAP ont été rapportées avec des diagrammes à barres.
Les données de 407 examens radiologiques ont été analysées.
Pour les catégories d'âge précédemment identifiées (1 mois à <4 ans, 4 à <10 ans, 10 à <14 ans, 14 à 16 ans), les valeurs VT pour le thorax étaient de 0,10, 0,19, 0,37 et 0,53 dGy.cm2. Pour l'abdomen, elles étaient respectivement de 0,39, 1,04, 3,51 et 4,05 dGy.cm2 et pour le bassin de 0,43, 0,87, 3,50 et 7,58 dGy.cm2. Entre les salles de radiologie, les VT varient par rapport à la VT institutionnelle de -60 à 119% (thorax), -50 à 103% (abdomen) et -14 à 24% (bassin).
Les VT de cette étude suivent les tendances établies en fonction de l'âge du patient et du type d'examen et sont comparables à la littérature publiée. Il existe des variations entre les différentes salles d'examen et les raisons sont multifactorielles. Étant donné que l'âge et la taille ne sont pas parfaitement corrélés, il conviendrait de poursuivre les travaux sur les VT/NRD basés sur le poids.
•Study covering 95 % of the performed EP procedures in Bulgaria was performed.•EP procedures were divided in 2 groups-catheter ablations and diagnostic EP studies.•Detailed complexity classification ...is proposed for ablations (simple or complex)
The implementation of diagnostic reference levels (DRLs) is an essential tool for optimisation of the routine practice, better management of patient exposure while maintaining sufficient image quality. National DRLs for electrophysiology (EP) procedures are not available in our country.
The main purpose of the study was to propose, for first time in Bulgaria, national DRLs (NDRLs) for EP studies and ablation procedures of two different levels of complexity. The proposed DRLs can be later used to establish NDRLs by the national authority with regulatory functions related to medical exposure.
A retrospective study was done with the three highest volume Bulgarian EP centers, where over 95% of all cardiac ablations were performed. Data were extracted from the electronic registry for invasive electrophysiology BG-EPHY. Independently of the proposed NDRLs, we also compared the air kerma-area product (KAP) between the participating centers for procedures of the same level of complexity.
The proposed NDRL in terms of KAP were: 5.2 Gy.cm2 for diagnostic EP studies, 25.5 Gy.cm2 for simple ablations, and 52.1 Gy.cm2 for complex ablations. There was a significant variation in KAP for procedures with the same degree of complexity within each center.
This study is the first to propose NDLRs for EP studies and ablation procedures of two levels of complexity in Bulgaria. The results identified EP procedures requiring further optimization of patient protection and provided a basis for future comparisons and standardization with further investigations on the topic. The proposed NDRLs are recommended to be used for better management of radiation exposure during EP procedures of different levels of complexity.
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