Performance of artificial intelligence in 7533 consecutive prevalent screening mammograms from the BreastScreen Australia program.

OBJECTIVES: To assess the performance of an artificial intelligence (AI) algorithm in the Australian mammography screening program which routinely uses two independent readers with arbitration of discordant results. METHODS: A total of 7533 prevalent round mammograms from 2017 were available for analysis. The AI program classified mammograms into deciles on the basis of breast cancer (BC) risk. BC diagnoses, including invasive BC (IBC) and ductal carcinoma in situ (DCIS), included those from the prevalent round, interval cancers, and cancers identified in the subsequent screening round two years later. Performance was assessed by sensitivity, specificity, positive and negative predictive values, and the proportion of women recalled by the radiologists and identified as higher risk by AI. RESULTS: Radiologists identified 54 women with IBC and 13 with DCIS with a recall rate of 9.7%. In contrast, 51 of 54 of the IBCs and 12/13 cases of DCIS were within the higher AI score group (score 10), a recall equivalent of 10.6% (a difference of 0.9% (CI -0.03 to 1.89%, p = 0.06). When IBCs were identified in the 2017 round, interval cancers classified as false negatives or with minimal signs in 2017, and cancers from the 2019 round were combined, the radiologists identified 54/67 and 59/67 were in the highest risk AI category (sensitivity 80.6% and 88.06 % respectively, a difference that was not different statistically). CONCLUSIONS: As the performance of AI was comparable to that of expert radiologists, future AI roles in screening could include replacing one reader and supporting arbitration, reducing workload and false positive results. CLINICAL RELEVANCE STATEMENT: AI analysis of consecutive prevalent screening mammograms from the Australian BreastScreen program demonstrated the algorithm's ability to match the cancer detection of experienced radiologists, additionally identifying five interval cancers (false negatives), and the majority of the false positive recalls. KEY POINTS: • The AI program was almost as sensitive as the radiologists in terms of identifying prevalent lesions (51/54 for invasive breast cancer, 63/67 when including ductal carcinoma in situ). • If selected interval cancers and cancers identified in the subsequent screening round were included, the AI program identified more cancers than the radiologists (59/67 compared with 54/67, sensitivity 88.06 % and 80.6% respectively p = 0.24). • The high negative predictive value of a score of 1-9 would indicate a role for AI as a triage tool to reduce the recall rate (specifically false positives).

A brief intervention for improving alcohol literacy and reducing harmful alcohol use by women attending a breast screening service: a randomised controlled trial.

OBJECTIVES: To assess the effectiveness of a brief alcohol intervention for improving awareness of alcohol as a breast cancer risk factor, improving alcohol literacy, and reducing alcohol consumption by women attending routine breast screening. DESIGN: Single-site, double-blinded randomised controlled trial. SETTING: Maroondah BreastScreen (Eastern Health, Melbourne), part of the national breast cancer screening program. PARTICIPANTS: Women aged 40 years or more, with or without a history of breast cancer and reporting any alcohol consumption, who attended the clinic for routine mammography during 5 February - 27 August 2021. INTERVENTION: Active arm: animation including brief alcohol intervention (four minutes) and lifestyle health promotion (three minutes). CONTROL ARM: lifestyle health promotion only. MAJOR OUTCOME MEASURE: Change in proportion of women who identified alcohol use as a clear risk factor for breast cancer (scaled response measure). RESULTS: The mean age of the 557 participants was 60.3 years (standard deviation, 7.7 years; range, 40-87 years); 455 had recently consumed alcohol (82%). The proportions of participants aware that alcohol use increased the risk of breast cancer were larger at four weeks than at baseline for both the active intervention (65% v 20%; odds ratio [OR], 41; 95% confidence interval [CI], 18-97) and control arms of the study (38% v 20%; OR, 4.9; 95% CI, 2.8-8.8), but the change over time was greater for the active intervention arm (arm × time: P < 0.001). Alcohol literacy also increased to a greater extent in the active than the control arm, but alcohol consumption did not significantly change in either arm. CONCLUSION: A tailored brief alcohol intervention for women attending breast screening was effective for improving awareness of the increased breast cancer risk associated with alcohol use and alcohol literacy more broadly. Such interventions are particularly important given the rising prevalence of risky drinking among middle-aged and older women and evidence that even very light alcohol consumption increases breast cancer risk. REGISTRATION: ClinicalTrials.gov, NCT04715516 (prospective; 20 January 2021).

Comparison of propagation-based CT using synchrotron radiation and conventional cone-beam CT for breast imaging.

OBJECTIVES: To evaluate and compare the image quality of propagation-based phase-contrast computed tomography (PB-CT) using synchrotron radiation and conventional cone-beam breast computed tomography (CBBCT) based on various radiological image quality criteria. METHODS: Eight excised breast tissue samples of various sizes and containing different lesion types were scanned using PB-CT at a synchrotron facility and using CBBCT at a university-affiliated breast imaging centre. PB-CT scans were performed at two different mean glandular dose (MGD) levels: standard (5.8 mGy) and low (1.5 mGy), for comparison with CBBCT scans at the standard MGD (5.8 mGy). Image quality assessment was carried out using six quality criteria and six independent medical imaging experts in a reading room with mammography workstations. The interobserver agreement between readers was evaluated using intraclass correlation coefficient (ICC), and image quality was compared between the two breast imaging modalities using the area under the visual grading characteristic curve (AUCVGC). RESULTS: Interobserver agreement between the readers showed moderate reliability for five image criteria (ICC: ranging from 0.488 to 0.633) and low reliability for one criterion (image noise) (ICC 0.307). For five image quality criteria (overall quality, perceptible contrast, lesion sharpness, normal tissue interfaces, and calcification visibility), both standard-dose PB-CT images (AUCVGC 0.958 to 1, p ≤ .05) and low dose PB-CT images (AUCVGC 0.785 to 0.834, p ≤ .05) were of significantly higher image quality than standard-dose CBBCT images. CONCLUSIONS: Synchrotron-based PB-CT can achieve a significantly higher radiological image quality at a substantially lower radiation dose compared with conventional CBBCT. KEY POINTS: • PB-CT using synchrotron radiation results in higher image quality than conventional CBBCT for breast imaging. • PB-CT using synchrotron radiation requires a lower radiation dose than conventional CBBCT for breast imaging. • PB-CT can help clinicians diagnose patients with breast cancer.

Pilot trial of digital breast tomosynthesis (3D mammography) for population-based screening in BreastScreen Victoria.

OBJECTIVES: To estimate detection measures for tomosynthesis and standard mammography; to assess the feasibility of using tomosynthesis in population-based screening for breast cancer. DESIGN, SETTING: Prospective pilot trial comparing tomosynthesis (with synthesised 2D images) and standard mammography screening of women attending Maroondah BreastScreen, a BreastScreen Victoria service in the eastern suburbs of Melbourne. PARTICIPANTS: Women at least 40 years of age who presented for routine breast screening between 18 August 2017 and 8 November 2018. MAIN OUTCOME MEASURES: Cancer detection rate (CDR); proportion of screens that led to recall for further assessment. RESULTS: 5018 tomosynthesis and 5166 standard mammography screens were undertaken in 10 146 women; 508 women (5.0% of screens) opted not to undergo tomosynthesis screening. With tomosynthesis, 49 cancers (40 invasive, 9 in situ) were detected (CDR, 9.8 [95% CI, 7.2-13] per 1000 screens); with standard mammography, 34 cancers (30 invasive, 4 in situ) were detected (CDR, 6.6 [95% CI, 4.6-9.2] per 1000 screens). The estimated difference in CDR was 3.2 more detections (95% CI, -0.32 to 6.8) per 1000 screens with tomosynthesis; the difference was greater for repeat screens and for women aged 60 years or more. The recall rate was greater for tomosynthesis (4.2%; 95% CI, 3.6-4.8%) than standard mammography (3.0%; 95% CI, 2.6-3.5%; estimated difference, 1.2%; 95% CI, 0.46-1.9%). The median screen reading time for tomosynthesis was 67 seconds (interquartile range [IQR] 46-105 seconds); for standard mammography, 16 seconds (IQR, 10-29 seconds). CONCLUSIONS: Breast cancer detection, recall for assessment, and screen reading time were each higher for tomosynthesis than for standard mammography. Our preliminary findings could form the basis of a large scale comparative evaluation of tomosynthesis and standard mammography for breast screening in Australia. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry, ACTRN12617000947303.

Advantages of breast cancer visualization and characterization using synchrotron radiation phase-contrast tomography.

The aim of this study was to highlight the advantages that propagation-based phase-contrast computed tomography (PB-CT) with synchrotron radiation can provide in breast cancer diagnostics. For the first time, a fresh and intact mastectomy sample from a 60 year old patient was scanned on the IMBL beamline at the Australian Synchrotron in PB-CT mode and reconstructed. The clinical picture was described and characterized by an experienced breast radiologist, who underlined the advantages of providing diagnosis on a PB-CT volume rather than conventional two-dimensional modalities. Subsequently, the image quality was assessed by 11 breast radiologists and medical imaging experts using a radiological scoring system. The results indicate that, with the radiation dose delivered to the sample being equal, the accuracy of a diagnosis made on PB-CT images is significantly higher than one using conventional techniques.

X-Ray Phase-Contrast Technology in Breast Imaging: Principles, Options, and Clinical Application.

OBJECTIVE: The purpose of this article is to review different x-ray phase-contrast breast imaging techniques and their potential application in clinical settings. CONCLUSION: Phase-contrast imaging depicts not only the absorption contrast but also the refraction contrast of the transmitted x-ray beam. Early data suggest that this new modality may overcome some of the diagnostic limitations associated with current clinically available mammography systems and that it has potential for improving breast cancer detection.

A feasibility study of X-ray phase-contrast mammographic tomography at the Imaging and Medical beamline of the Australian Synchrotron.

Results are presented of a recent experiment at the Imaging and Medical beamline of the Australian Synchrotron intended to contribute to the implementation of low-dose high-sensitivity three-dimensional mammographic phase-contrast imaging, initially at synchrotrons and subsequently in hospitals and medical imaging clinics. The effect of such imaging parameters as X-ray energy, source size, detector resolution, sample-to-detector distance, scanning and data processing strategies in the case of propagation-based phase-contrast computed tomography (CT) have been tested, quantified, evaluated and optimized using a plastic phantom simulating relevant breast-tissue characteristics. Analysis of the data collected using a Hamamatsu CMOS Flat Panel Sensor, with a pixel size of 100 µm, revealed the presence of propagation-based phase contrast and demonstrated significant improvement of the quality of phase-contrast CT imaging compared with conventional (absorption-based) CT, at medically acceptable radiation doses.

Effectiveness of hybrid digital breast tomosynthesis/digital mammography compared to digital mammography in women presenting for routine screening at Maroondah BreastScreen: Study protocol for a co-designed, non-randomised prospective trial.

BACKGROUND: Digital breast tomosynthesis (DBT) for breast cancer screening has been shown in international trials to increase cancer detection compared with mammography; however, results have varied across screening settings, and currently there is limited and conflicting evidence on interval cancer rates (a surrogate for screening effectiveness). Australian pilot data also indicated substantially longer screen-reading time for DBT posing a barrier for adoption. There is a critical need for evidence on DBT to inform its role in Australia, including evaluation of potentially more feasible models of implementation, and quantification of screening outcomes by breast density which has global relevance. METHODS: This study is a prospective trial embedded in population-based Australian screening services (Maroondah BreastScreen, Eastern Health, Victoria) comparing hybrid screening comprising DBT (mediolateral oblique view) and digital mammography (cranio-caudal view) with standard mammography screening in a concurrent group attending another screening site. All eligible women aged ≥40 years attending the Maroondah service for routine screening will be enrolled (unless they do not provide verbal consent and opt-out of hybrid screening; are unable to provide consent; or where a 'pushback' image on hybrid DBT cannot be obtained). Each arm will enrol 20,000 women. The primary outcomes are cancer detection rate (per 1000 screens) and recall rate (percentage). Secondary outcomes include 'opt-out' rate; cohort characteristics; cancer characteristics; assessment outcomes; screen-reading time; and interval cancer rate at 24-month follow-up. Automated volumetric breast density will be measured to allow stratification of outcomes by mammographic density. Stratification by age and screening round will also be undertaken. An interim analysis will be undertaken after the first 5000 screens in the intervention group. DISCUSSION: This is the first Australian prospective trial comparing hybrid DBT/mammography with standard mammography screening that is powered to show differences in cancer detection. Findings will inform future implementation of DBT in screening programs world-wide and provide evidence on whether DBT should be adopted in the broader BreastScreen program in Australia or in subgroups of screening participants. TRIAL REGISTRATION: The trial is registered with the Australian New Zealand Clinical Trials Registry (ANZCTR, ACTRN12623001144606, https://www.anzctr.org.au/). Registration will be updated to reflect trial progress and protocol amendments.

Assessment of screen-recalled abnormalities for digital breast tomosynthesis versus digital mammography screening in the BreastScreen Maroondah trial.

INTRODUCTION: Australia's first population-based pilot trial comparing digital breast tomosynthesis (DBT) and digital mammography (DM) screening reported detection measures in 2019. This study describes the trial's secondary outcomes pertaining to the assessment process in women screened with DBT or DM, including the type of recalled abnormalities and the procedures performed. METHODS: Women with suspected abnormalities at screening were recalled for further investigation. Outcome measures were number of lesions assessed, types of imaging findings recalled to assessment, and data on testing and assessment outcomes; these were reported using descriptive analyses of lesion-specific data. RESULTS: A total of 274 lesions and 203 lesions were reported in the DBT-screened and DM-screened groups, respectively. There were a higher proportion of lesions depicted as calcifications (32.4% vs 21.3%), and a lower proportion of lesions depicted as asymmetrical densities (3.2% vs 15.7%) for DBT recalls than DM recalls. A lower proportion of DBT-recalled lesions was assessed with additional mammography than DM-recalled lesions (49.3% vs 93.1%). Higher proportions of DBT-recalled lesions than DM-recalled lesions were investigated with clinical breast examination (50.4% vs 39.9%), core needle biopsy (45.6% vs 28.6%) and open biopsy (4.0% vs 1.0%). Similar proportions of DBT- and DM-recalled lesions were assessed using ultrasound (76.3% vs 71.4%). CONCLUSION: Assessment of screen-recalled lesions showed that, compared with DM, DBT found more benign and more malignant lesions, and generally required more procedures except for less additional mammography workup. These findings show that a transition to DBT screening changes the assessment workload.

The financial implications of investigating false-positive and true-positive mammograms in a national breast cancer screening program.

Objectives To determine the total annual screening and further-investigation costs of investigating false-positive and true-positive mammograms in the Australian population breast-screening program. Methods This economic analysis used aggregate-level retrospective cohort data of women screened at a breast-screening clinic. Counts and frequencies of each diagnostic workup-sequence recorded were scaled up to national figures and costed by estimating per-patient costs of procedures using screening clinic cost data. Main outcomes and measures estimated were percentage share of total annual screening and further-investigation costs for the Australian population breast-screening program of investigating false-positive and true-positive mammograms. Secondary outcomes determined were average costs of investigating each false-positive and true-positive mammogram. Sensitivity analyses involved recalculating results excluding subgroups of patients below and above the screening age range of 50-74 years. Results Of 8235 patients, the median age was 60.35 years with interquartile range of 54.17-67.17 years. A total of 15.4% (ranging from 13.4 to 15.4% under different scenarios) of total annual screening and further-investigation costs were from investigating false-positive mammograms. This exceeded the share of costs from investigating true-positives (13%). Conclusions We have developed a transparent and non-onerous approach for estimating the costs of false-positive and true-positive mammograms associated with the national breast-screening program. While determining an optimal balance between false-positives and true-positive rates must rely primarily on health outcomes, costs are an important consideration. We recommend that future research adopts and refines similar approaches to facilitate better monitoring of these costs, benchmark against estimates from other screening programs, and support optimal policy development.

Two-year follow-up of participants in the BreastScreen Victoria pilot trial of tomosynthesis versus mammography: breast density-stratified screening outcomes.

OBJECTIVE: This follow-up study of BreastScreen Victoria's pilot trial of digital breast tomosynthesis aimed to report interval cancer rates, screening sensitivity, and density-stratified outcomes for tomosynthesis vs mammography screening. METHODS: Prospective pilot trial [ACTRN-12617000947303] in Maroondah BreastScreen recruited females ≥ 40 years presenting for screening (August 2017-November 2018) to DBT; concurrent screening participants who received mammography formed a comparison group. Follow-up of 24 months from screen date was used to ascertain interval cancers; automated breast density was measured. RESULTS: There were 48 screen-detected and 9 interval cancers amongst 4908 tomosynthesis screens, and 34 screen-detected and 16 interval cancers amongst 5153 mammography screens. Interval cancer rate was 1.8/1000 (95%CI 0.8-3.5) for tomosynthesis vs 3.1/1000 (95%CI 1.8-5.0) for mammography (p = 0.20). Sensitivity of tomosynthesis (86.0%; 95% CI 74.2-93.7) was significantly higher than mammography (68.0%; 95% CI 53.3-80.5), p = 0.03. Cancer detection rate (CDR) of 9.8/1000 (95%CI 7.2-12.9) for tomosynthesis was higher than that of 6.6/1000 (95%CI 4.6-9.2) for mammography (p = 0.08); density-stratified analyses showed CDR was significantly higher for tomosynthesis than mammography (10.6/1000 vs 3.5/1000, p = 0.03) in high-density screens. Recall rate for tomosynthesis was significantly higher than for mammography (4.2% vs 3.0%, p < 0.001), and this increase in recall for tomosynthesis was evident only in high-density screens (5.6% vs 2.9%, p < 0.001). CONCLUSION: Although interval cancer rates did not significantly differ between screened groups, sensitivity was significantly higher for tomosynthesis than mammography screening. ADVANCES IN KNOWLEDGE: In a program-embedded pilot trial, both increased cancer detection and recall rates from tomosynthesis were predominantly observed in high-density screens.

Risky alcohol consumption among women in Australia attending breast screening services: an exploratory cross-sectional study.

BACKGROUND AND AIMS: Alcohol is a major modifiable risk factor for female breast cancer, with breast cancer risk now associated with substantially lower consumption levels than those previously deemed safe. This study sought to measure risky drinking among women attending breast screening services in Australia according to new national alcohol guidelines and to compare daily, weekly and recent (past 12 months) consumption to Australian gender and age population norms. DESIGN, SETTING AND PARTICIPANTS: This study was a retrospective analysis of cross-sectional data from the Lifepool Project (collected October 2011-January 2016) in Victoria, Australia, comprising a convenience sample of women attending breast screening services aged 40+ years. MEASUREMENTS: Typical and heavy alcohol consumption patterns over the previous 12 months (frequency, quantity), socio-demographic (e.g. age, education) and health-related (e.g. menopause status, breast cancer history) characteristics. Primary outcomes were the proportion of women drinking at a level exceeding new guidelines for weekly and daily alcohol consumption. FINDINGS: Of 49 240 women, mean age was 59.94 years (standard deviation = 7.14, range = 40-94 years). Most women had consumed alcohol during the past 12 months [41 628, 85.48%, 95% confidence interval (CI) = 85.16, 85.79]. One in five women (8464, 18.34%, 95% CI = 17.99, 18.69) were drinking at a level exceeding new national guidelines for weekly consumption (i.e. greater than 10 standard drinks per week), and one in six (7446, 15.60%, 95% CI = 15.28, 15.93) were exceeding new guidelines for consumption on a single day (i.e. greater than four standard drinks on any 1 day, more than once per month). The proportion of women in this sample drinking daily (4.21-11.19%), weekly (34.73-50.71%) and in the past 12 months (74.96-90.81%) was significantly greater among nearly all age groups (by decade), compared with Australian gender and age norms [drinking daily (3.4-9.1%), weekly (27.1-37.6%) and in the past 12 months (64.4-81.9%)]. CONCLUSIONS: There appears to be a high prevalence of risky alcohol consumption among a large convenience sample of breast screening service clients in Australia using new national alcohol guidelines introduced in December 2020.

Propagation-based phase-contrast imaging of the breast: image quality and the effect of X-ray energy and radiation dose.

OBJECTIVES: Propagation-based phase-contrast computed tomography (PB-CT) is a new imaging technique that exploits refractive and absorption properties of X-rays to enhance soft tissue contrast and improve image quality. This study compares image quality of PB-CT and absorption-based CT (AB-CT) for breast imaging while exploring X-ray energy and radiation dose. METHODS: Thirty-nine mastectomy samples were scanned at energy levels of 28-34keV using a flat panel detector at radiation dose levels of 4mGy and 2mGy. Image quality was assessed using signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), spatial resolution (res) and visibility (vis). Statistical analysis was performed to compare PB-CT images against their corresponding AB-CT images scanned at 32keV and 4mGy. RESULTS: The PB-CT images at 4mGy, across nearly all energy levels, demonstrated superior image quality than AB-CT images at the same dose. At some energy levels, the 2mGy PB-CT images also showed better image quality in terms of CNR/Res and vis compared to the 4mGy AB-CT images. At both investigated doses, SNR and SNR/res were found to have a statistically significant difference across all energy levels. The difference in vis was statistically significant at some energy levels. CONCLUSION: This study demonstrates superior image quality of PB-CT over AB-CT, with X-ray energy playing a crucial role in determining image quality parameters. ADVANCES IN KNOWLEDGE: Our findings reveal that standard dose PB-CT outperforms standard dose AB-CT across all image quality metrics. Additionally, we demonstrate that low dose PB-CT can produce superior images compared to standard dose AB-CT in terms of CNR/Res and vis.

A Brief Intervention for Improving Alcohol Literacy and Addressing Harmful Alcohol Use Among Women Attending an Australian Breast Screening Service (Health4her): Protocol for a Hybrid Effectiveness-Implementation Trial.

BACKGROUND: Alcohol consumption is a major modifiable risk factor for female breast cancer, even in small amounts. However, awareness of this risk remains low. National breast screening programs are uniquely positioned to provide timely and targeted health information and behavior change strategies to improve alcohol literacy and reduce consumption. A breast screening service is a novel health care setting for brief alcohol intervention, with the potential for extensive reach. OBJECTIVE: This study aimed to conduct a formative evaluation with breast screening service consumers to understand the need for, and acceptability of, brief alcohol intervention in the breast screening setting and collaboratively design a brief alcohol intervention (Health4Her); to test the effectiveness of Health4Her in improving knowledge of alcohol as a breast cancer risk factor (primary outcome), improving alcohol literacy, and reducing consumption among women attending a breast screening service; and to examine the implementation strategy through process evaluation. METHODS: This was a hybrid type II effectiveness-implementation trial comprising a randomized controlled trial (RCT) alongside a mixed methods program evaluation guided by applicable elements of the Reach, Effectiveness, Adoption, Implementation, and Maintenance framework and Consolidated Framework for Implementation Research. Formative evaluation comprised a retrospective analysis of alcohol consumption data (n=49,240), a web-based survey (n=391), and focus groups and interviews (n=31) with breast screening service consumers. Women attending routine mammography, drinking at any level, were recruited to the single-site, double-blind RCT (n=558), and completed a baseline assessment before randomization (1:1) to receive Health4Her (alcohol brief intervention + lifestyle information) or control (lifestyle information) via animation on an iPad. Follow-up assessments were performed 4 and 12 weeks after randomization. The process evaluation included evaluation of trial administrative data, participant quantitative (n=497) and qualitative feedback (n=30), and site staff qualitative feedback (n=11). RESULTS: This research was funded in March and May 2019. Data collection for the formative evaluation and trial recruitment occurred between January and April 2020 and February and August 2021, respectively, with finalization of follow-up data collection in December 2021. Quantitative process evaluation data were collected during trial implementation, and collection of participant and staff feedback was finalized in December 2021. Results of the retrospective analysis of alcohol consumption data from breast screening service consumers is anticipated to be published in March 2023 and the results of the RCT to be published in March 2023. CONCLUSIONS: This study is anticipated to generate new substantial knowledge on the alcohol consumption and literacy needs of women attending breast screening and the extent to which these can be addressed using a novel, tailored brief alcohol intervention. The study design permits the evaluation of the effectiveness and implementation of Health4Her to predict and facilitate uptake in breast screening services. TRIAL REGISTRATION: ClinicalTrials.gov NCT04715516; https://clinicaltrials.gov/ct2/show/NCT04715516. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR1-10.2196/44867.

Indeterminate (B3) Breast Lesions and the Ongoing Role of Diagnostic Open Biopsy.

INTRODUCTION: Due to their uncertain malignant potential, indeterminate breast lesions on core needle biopsy (CNB) require diagnostic open biopsy (DOB). This study evaluated DOB results given largely benign pathology. Lesions included are atypical papilloma, atypical ductal hyperplasia (ADH), atypical lobular hyperplasia (ALH), and radial scar/complex sclerosing lesions (RS/CSL). Methodology. A retrospective audit from 2010 to 2017 analysed patients with a screen-detected suspicious lesion and indeterminate (B3) CNB diagnosis. Primary outcome was the malignancy upgrade rate, with secondary evaluation of patient factors predictive of malignancy including age, symptoms, mammogram characteristics, lesion size, biopsy method, and past and family history. RESULTS: 152 patients (median age 57 years) were included, with atypical papillomas being the largest subgroup (44.7%). On DOB histology, 99.34% were benign, resulting in a 0.66% malignancy upgrade rate. Patient characteristic analysis identified 86.84% of B3 lesions were in patients greater than 50 years old. 90.13% were asymptomatic, whilst 98.68% and 72.37% had a negative past and family history. Majority 46.71% of lesions had the mammogram characteristic of being a mass. However, with 57.89% of the lesion imaging size less than 4 mm, a corresponding 60.5% of core needle biopsies were performed stereotactically. The small malignant subgroup limited predictive factor evaluation. CONCLUSION: Albeit a low 0.66% malignancy upgrade rate in B3 lesions, no statistically significant patient predictive factors were identified. Until predictive factors and further assessment of vacuum-assisted excision (VAE) techniques evolve, DOB remains the standard of care.

Effect of x-ray energy on the radiological image quality in propagation-based phase-contrast computed tomography of the breast.

Purpose: Breast cancer is the most common cancer in women in developing and developed countries and is responsible for 15% of women's cancer deaths worldwide. Conventional absorption-based breast imaging techniques lack sufficient contrast for comprehensive diagnosis. Propagation-based phase-contrast computed tomography (PB-CT) is a developing technique that exploits a more contrast-sensitive property of x-rays: x-ray refraction. X-ray absorption, refraction, and contrast-to-noise in the corresponding images depend on the x-ray energy used, for the same/fixed radiation dose. The aim of this paper is to explore the relationship between x-ray energy and radiological image quality in PB-CT imaging. Approach: Thirty-nine mastectomy samples were scanned at the imaging and medical beamline at the Australian Synchrotron. Samples were scanned at various x-ray energies of 26, 28, 30, 32, 34, and 60 keV using a Hamamatsu Flat Panel detector at the same object-to-detector distance of 6 m and mean glandular dose of 4 mGy. A total of 132 image sets were produced for analysis. Seven observers rated PB-CT images against absorption-based CT (AB-CT) images of the same samples on a five-point scale. A visual grading characteristics (VGC) study was used to determine the difference in image quality. Results: PB-CT images produced at 28, 30, 32, and 34 keV x-ray energies demonstrated statistically significant higher image quality than reference AB-CT images. The optimum x-ray energy, 30 keV, displayed the largest area under the curve ( AUC VGC ) of 0.754 ( p = 0.009 ). This was followed by 32 keV ( AUC VGC = 0.731 , p ≤ 0.001 ), 34 keV ( AUC VGC = 0.723 , p ≤ 0.001 ), and 28 keV ( AUC VGC = 0.654 , p = 0.015 ). Conclusions: An optimum energy range (around 30 keV) in the PB-CT technique allows for higher image quality at a dose comparable to conventional mammographic techniques. This results in improved radiological image quality compared with conventional techniques, which may ultimately lead to higher diagnostic efficacy and a reduction in breast cancer mortalities.

Propagation-Based Phase-Contrast CT of the Breast Demonstrates Higher Quality Than Conventional Absorption-Based CT Even at Lower Radiation Dose.

RATIONALE AND OBJECTIVES: Propagation-based phase-contrast CT (PB-CT) is an advanced X-ray imaging technology that exploits both refraction and absorption of the transmitted X-ray beam. This study was aimed at optimizing the experimental conditions of PB-CT for breast cancer imaging and examined its performance relative to conventional absorption-based CT (AB-CT) in terms of image quality and radiation dose. MATERIALS AND METHODS: Surgically excised breast mastectomy specimens (n = 12) were scanned using both PB-CT and AB-CT techniques under varying imaging conditions. To evaluate the radiological image quality, visual grading characteristics (VGC) analysis was used in which 11 breast specialist radiologists compared the overall image quality of PB-CT images with respect to the corresponding AB-CT images. The area under the VGC curve was calculated to measure the differences between PB-CT and AB-CT images. RESULTS: The highest radiological quality was obtained for PB-CT images using a 32 keV energy X-ray beam and by applying the Homogeneous Transport of Intensity Equation phase retrieval with the value of its parameter γ set to one-half of the theoretically optimal value for the given materials. Using these optimized conditions, the image quality of PB-CT images obtained at 4 mGy and 2 mGy mean glandular dose was significantly higher than AB-CT images at 4 mGy (AUCVGC = 0.901, p = 0.001 and AUCVGC = 0.819, p = 0.011, respectively). CONCLUSION: PB-CT achieves a higher radiological image quality compared to AB-CT even at a considerably lower mean glandular dose. Successful translation of the PB-CT technique for breast cancer imaging can potentially result in improved breast cancer diagnosis.

Toward Improving Breast Cancer Imaging: Radiological Assessment of Propagation-Based Phase-Contrast CT Technology.

RATIONALE AND OBJECTIVES: This study employs clinical/radiological evaluation in establishing the optimum imaging conditions for breast cancer imaging using the X-ray propagation-based phase-contrast tomography. MATERIALS AND METHODS: Two series of experiments were conducted and in total 161 synchrotron-based computed tomography (CT) reconstructions of one breast mastectomy specimen were produced at different imaging conditions. Imaging factors include sample-to-detector distance, X-ray energy, CT reconstruction method, phase retrieval algorithm applied to the CT projection images and maximum intensity projection. Observers including breast radiologists and medical imaging experts compared the quality of the reconstructed images with reference images approximating the conventional (absorption) CT. Various radiological image quality attributes in a visual grading analysis design were used for the radiological assessments. RESULTS: The results show that the application of the longest achievable sample-to-detector distance (9.31 m), the lowest employed X-ray energy (32 keV), the full phase retrieval, and the maximum intensity projection can significantly improve the radiological quality of the image. Several combinations of imaging variables resulted in images with very high-quality scores. CONCLUSION: The results of the present study will support future experimental and clinical attempts to further optimize this innovative approach to breast cancer imaging.