A comparison of mean glandular dose diagnostic reference levels within the all-digital Irish National Breast Screening Programme and the Irish Symptomatic Breast Services

A Survey of Mean Glandular Doses and Suggestions on National Diagnostic Reference Levels for Digital Mammography in China

ABSTRACT

The primary purpose of this study was to report the mean glandular doses and to determine the national diagnostic reference levels for digital mammography based on data between 2016 and 2018 in China. The data from 19,076 mammograms (4,769 examinations) by random sampling from 118 digital mammography systems were compiled. Exposure factors included age, compressed breast thickness, kVp, mAs, target/filter combination, entrance surface air kerma, and mean glandular doses, which were retrospectively surveyed and recorded from the monitor. The national diagnostic reference levels (75th percentiles) in mean glandular dose were calculated across median value obtained for all included data and stratified to specific compressed breast thickness ranges. The patients' ages ranged from 22 to 88 y, with a median age of 45. The applied voltage and output medians were 28 kVp and 75.1 mAs for all exposure, respectively. The median CBTs were 45 mm and 48 mm for craniocaudal views and mediolateral oblique views, and the corresponding median mean glandular doses were 1.32 mGy and 1.40 mGy, respectively. The national diagnostic reference level at compressed breast thickness of 40-50 mm was 1.67 mGy for CC views and 1.71 mGy for MLO views. The median mean glandular doses varied significantly and increased with compressed breast thickness, demonstrating the necessity of establishing DRL according to breast thickness and optimizing the clinic's digital mammography practice in China.

Glandular doses and diagnostic reference levels (DRLs) for Saudi breast cancer screening programme (2012-2021)

The aim of this study was to report the diagnostic reference levels (DRLs) corresponding to different compressed breast thickness (CBT) ranges. To achieve this, mammographic examinations with 187,788 exposures were analysed. The mean average glandular (AGD) dose was calculated per view, examination, and center. Moreover, the DRL values corresponding to different CBT ranges were reported. The result of the mean AGD per view was found to be 1.36 mGy for craniocaudal (CC) and 1.54 mGy for Mediolateral oblique (MLO), while the mean AGD per examination for all women was 1.45 mGy. The DRL values corresponding to CBTs between 20 to 79 mm ranges were below 2 mGy. These results were from a population of mean age = 49 ± 8 years and mean CBT = 58 ± 8 mm, and was imaged with mean exposures of 29 ± 1 kVp and 74 ± 31 mAs, and a mean compression force of 135±37 N. In conclusion, good mammography practice has been shown, as DRL values are within the limits suggested by the international organizations.

Establishing national diagnostic reference levels in radiography, mammography, and dual-energy x-ray absorptiometry services in Ireland and comparing these with European diagnostic reference levels

OBJECTIVES

The aim of this work was to establish national diagnostic reference levels (DRLs) in Ireland and compare these to existing European DRLs where available. This work surveyed all radiological facilities providing radiography, mammography, and dual-energy x-ray absorptiometry (DXA) services in Ireland.

METHODS

A list of common procedures and clinical tasks was established. A national database of service providers was used to identify the appropriate medical radiological facilities providing these services. These facilities were issued with an online survey. National DRLs were set as the 75th percentile of the distribution of median values obtained. A national median dose was also established. The broad categorisation of equipment type was also considered. Where differences between DRLs established using different detector types were deemed statistically significant, equipment-specific national DRLs were established.

RESULTS

National DRLs were established for 12 adult radiography projections. Equipment-specific (computed radiography and digital radiography) adult DRLs were established for four radiography projections. Paediatric DRLs were established for 11 radiography projections, including two based on clinical indications, for a range of paediatric weight categories. National DRLs were established for unilateral two-view mammography and breast tomosynthesis as well as for four DXA clinical indications and projections. All but one Irish DRL figure was found to be below or equal to European data.

CONCLUSIONS

This work provided a unique opportunity to establish national DRLs based on census data for a range of procedures and clinical tasks across radiography, mammography and DXA and compare these with European levels.

CLINICAL RELEVANCE STATEMENT

This work established national diagnostic reference levels (DRLs) based on census data for a range of procedures and clinical tasks across radiography, mammography and dual-energy x-ray absorptiometry. The establishment of national DRLs is an essential component in the optimisation of patient radiation dose.

KEY POINTS

• Diagnostic reference levels are easily measured quantities intended for use as an aid to optimise patient dose and to identify when levels of patient dose are unusually high. • Data from all medical radiological facilities in Ireland was obtained to establish national diagnostic reference level (DRL) values and national median dose values in radiography, x-ray breast imaging and dual-energy x-ray absorptiometry (DXA) scanning and these were compared to existing European DRLs where available. • National DRL values were established for the first time in breast tomosynthesis, DXA scanning, and paediatric radiography.

Establishment of regional diagnostic reference levels for digital mammography in Western Province of Sri Lanka

The radiation dose to the breasts should be kept to a minimum as breast tissues are highly sensitive to radiation. In mammography, the mean glandular dose (MGD) is used to specify the patient dose. In this study, data on the MGD during diagnostic mammographic examinations was collected using the database from six digital mammography facilities available in the Western Province in Sri Lanka. Examinations involving breast pathology, breast implants, or compressed breast thicknesses (CBT) outside the range of 20-110 mm were excluded in this study. The mean MGD per breast was 3.50 mGy, with a mean CBT of 57 mm. The mean MGD per facility varies from 1.58 to 2.27 mGy, with overall 75th and 95th percentiles of 2.15 and 2.82 mGy, respectively. The 75th and 95th percentile MGD per image, for the average CBT of 57 ± 12 mm, were 2.00 and 2.65 mGy respectively. The 75th percentile value of the MGD is suggested for the Western Province and it depends on the specific CBT.

Mammography Diagnostic Reference Levels (DRLs) in Ghana

INTRODUCTION

Diagnostic Reference Levels (DRLs) are essential for optimisation in mammography. A local DRL for screen-film mammography has been established in Ghana but none exists for the digital mammography systems. Furthermore, technological advancement is phasing out the use of screen-film mammography and replacing it with digital mammography systems. This study aims to establish the local DRLs used in digital mammography across three institutions in Ghana to guide mammography practice.

METHODS

Average glandular dose (AGD), compressed breast thickness (CBT), age of patients, entrance surface exposure (ESE), kVp, and mAs were retrospectively extracted from three digital mammography systems. The 75th and 95th percentile values were obtained for the AGD of each mammography projection and at CBT of 60 ± 5 mm. The correlation between the AGD and CBT, kVp, mAs, and ESE were investigated.

RESULTS

The 75th percentile for the AGD at CBT of 60 ± 5 mm for Centres 1, 2, 3, and all centres were 2.3, 1.8, 2.1, and 2.0 mGy respectively. The DRLs obtained were comparably higher than international studies except those of the United Kingdom. The AGD showed a strong positive correlation with the CBT, kVp, mAs, and ESE. There was variability in the AGD applied across the three centres for the craniocaudal (CC) and mediolateral oblique (MLO) projections. The mean AGD, mAs, and ESE for all the three centres and per centre recorded were higher than previous studies, but the mean kVp and CBT were lower than previous studies.

CONCLUSION

The higher DRLs estimated in this preliminary study indicates that there is a need for dose optimisation in digital mammography practice in Ghana to improve radiation protection.

IMPLICATIONS FOR PRACTICE

The findings will guide the process of optimisation and limit the variations in the radiation dose during mammography practice.

AVERAGE GLANDULAR DOSES AND NATIONAL DIAGNOSTIC REFERENCE LEVELS IN MAMMOGRAPHY EXAMINATIONS IN TURKEY

In order to establish national diagnostic reference levels for mammography examinations, entrance skin air kerma, entrance skin dose and average glandular doses (AGDs) were calculated for a total of 25 624 cranio-caudal (CC) and mediolateral oblique (MLO) projections of 6309 patients for 40-49 and 50-64 age groups. The average entrance skin air kerma and entrance skin dose values for both age groups were found to be higher in MLO projections compared with CC projections. The minimum and maximum values of AGDs were determined as 0.4 and 7.9 mGy for both projections. The maximum numbers of AGDs for CC and MLO projections were calculated in the range of 1.1-1.5 and 1.6-2.0 mGy, respectively. The third quartile values of AGDs were calculated for each compressed breast thickness between 20 and 99 mm. The first national diagnostic reference levels of the country were established for each 10-mm compressed breast thickness in mammography examinations.

INSTITUTIONAL BREAST DOSES IN DIGITAL MAMMOGRAPHY

The objective of this study was to survey breast dose in screening mammography, establish institutional doses and compare them with the corresponding dose values. Three hundred women between the ages of 40 and 80 years old participated in the study. All mammographic examinations were performed with a digital mammography system. The women characteristics (age, weight, height, BMI), technical and exposure parameters (anode/filter material, projection, compressed breast thickness (CBT), compression force, tube voltage, tube load), the entrance surface dose (ESD) and the average glandular dose (AGD) were recorded. The mean, median, 75th and 95th percentiles of the AGD and ESD distributions were estimated for all examinations, for right and left breast, as well as for CBT within 55-65 mm, for Cranio-Caudal (CC) and Medio-Lateral Oblique (MLO) projections. A statistical analysis was also performed, to investigate the impact of the recorded parameters on the ESD and AGD. The mean/median values of the ESD and AGD for all examinations, for CC and MLO projections were 4.60/4.29 and 5.42/5.25 mGy and 1.18/1.13 and 1.32/1.30 mGy, respectively. The mean/median values of the ESD and AGD for CC and MLO projections at CBT range 55-65 mm were 5.29/5.08 and 5.56/5.42 mGy and 1.30/1.24 and 1.36/1.32 mGy, respectively. The 75th percentile for CC and MLO projections were estimated 5.79 and 6.17 mGy, as well as 1.41 and 1.48 mGy in terms of ESD and AGD values, respectively. The 95th percentile of the ESD and AGD for CC and MLO projections were also 7.40 and 7.53 mGy and 1.76 and 1.78 mGy, respectively. The tube voltage, tube load, age and CBT had a significant influence on the dose values. The estimated values were found to be comparable, or in most cases lower, than the corresponding 75th and 95th percentile values from previous studies.

EXPOSURE PARAMETERS OF MAMMOGRAMS WITH AND WITHOUT MASS LESIONS FROM A SOUTH AFRICAN BREAST CARE CENTRE

In South African breast care centres, full-field digital mammography units provide breast imaging services to symptomatic and asymptomatic women simultaneously. This study evaluated the technical exposure parameters of 800 mammograms of which 100 mammograms had obvious mass lesions in the fibroglandular tissue. The average breast compression force of mammograms with mass lesions in the fibroglandular tissue was 18.4% less than the average breast compression force of mammograms without mass lesions. The average mean glandular dose (MGD), tube potential (kVp) and compressed breast thickness (CBT) values were 2.14 mGy, 30.5 kVp and 63.9 mm, respectively, for mammograms with mass lesions, and 1.45 mGy, 29.6 kVp and 56.9 mm, respectively, for mammograms without mass lesions. Overall, the average MGD and mean CBT of mammograms with mass lesion were significantly higher compared to those without mass lesions (p < 0.05), although there was no significant difference in their tube potentials (p > 0.05).

European radiographers' challenges from mammography education and clinical practice - an integrative review

Objectives

This study aims to identify European radiographers’ challenges in clinical performance in mammography and the main areas of mammography that require more and better training.

Methods

An extensive search was performed to identify relevant studies focused on clinical practice, education and training in mammography published between January 2010 and December 2015 in the English language. The data were analysed by using deductive thematic analysis.

Results

A total of 27 full text articles were read, evaluating their quality. Sixteen articles out of 27 were finally selected for this integrative review. The main challenges of radiographers’ mammography education/training can be divided into three groups: training needs, challenges related to radiographers, and challenges related to the organization of education. The most common challenges of clinical performance in mammography among European radiographers involved technical performance, the quality of practices, and patient-centeredness.

Conclusions

The introduction of harmonized mammography guidelines across Europe may serve as an evidence-based tool to be implemented in practice and education. However, the variability in human and material resources as well as the different cultural contexts should be considered during this process.

Teaching Points

• Radiographers’ awareness of their professional identity and enhancing multiprofessional cooperation in mammography.

• Radiographers’ responsibilities regarding image quality (IQ) and optimal breast imaging performance.

• Patient-centred mammography services focusing on the psychosocial needs of the patient.

• Challenges: positioning, QC-testing, IQ-assessment, optimization of breast compression, communication, teamwork, and patient-centred care.

• Introduction of evidence-based guidelines in Europe to harmonize mammography practice and education.

Diagnostic reference levels in digital mammography: a systematic review

This study aims to review the literature on existing diagnostic reference levels (DRLs) in digital mammography and methodologies for establishing them. To this end, a systematic search through Medline, Cinahl, Web of Science, Scopus and Google scholar was conducted using search terms extracted from three terms: DRLs, digital mammography and breast screen. The search resulted in 1539 articles of which 22 were included after a screening process. Relevant data from the included studies were summarised and analysed. Differences were found in the methods utilised to establish DRLs including test subjects types, protocols followed, conversion factors employed, breast compressed thicknesses and percentile values adopted. These differences complicate comparison of DRLs among countries; hence, an internationally accepted protocol would be valuable so that international comparisons can be made.