Deep Learning for Breast Cancer Risk Prediction: Application to a Large Representative UK Screening Cohort.

Purpose To develop an artificial intelligence (AI) deep learning tool capable of predicting future breast cancer risk from a current negative screening mammographic examination and to evaluate the model on data from the UK National Health Service Breast Screening Program. Materials and Methods The OPTIMAM Mammography Imaging Database contains screening data, including mammograms and information on interval cancers, for more than 300 000 female patients who attended screening at three different sites in the United Kingdom from 2012 onward. Cancer-free screening examinations from women aged 50-70 years were performed and classified as risk-positive or risk-negative based on the occurrence of cancer within 3 years of the original examination. Examinations with confirmed cancer and images containing implants were excluded. From the resulting 5264 risk-positive and 191 488 risk-negative examinations, training (n = 89 285), validation (n = 2106), and test (n = 39 351) datasets were produced for model development and evaluation. The AI model was trained to predict future cancer occurrence based on screening mammograms and patient age. Performance was evaluated on the test dataset using the area under the receiver operating characteristic curve (AUC) and compared across subpopulations to assess potential biases. Interpretability of the model was explored, including with saliency maps. Results On the hold-out test set, the AI model achieved an overall AUC of 0.70 (95% CI: 0.69, 0.72). There was no evidence of a difference in performance across the three sites, between patient ethnicities, or across age groups. Visualization of saliency maps and sample images provided insights into the mammographic features associated with AI-predicted cancer risk. Conclusion The developed AI tool showed good performance on a multisite, United Kingdom-specific dataset. Keywords: Deep Learning, Artificial Intelligence, Breast Cancer, Screening, Risk Prediction Supplemental material is available for this article. ©RSNA, 2024.

A modern way to teach and practice manual therapy.

BACKGROUND: Musculoskeletal conditions are the leading contributor to global disability and health burden. Manual therapy (MT) interventions are commonly recommended in clinical guidelines and used in the management of musculoskeletal conditions. Traditional systems of manual therapy (TMT), including physiotherapy, osteopathy, chiropractic, and soft tissue therapy have been built on principles such as clinician-centred assessment, patho-anatomical reasoning, and technique specificity. These historical principles are not supported by current evidence. However, data from clinical trials support the clinical and cost effectiveness of manual therapy as an intervention for musculoskeletal conditions, when used as part of a package of care. PURPOSE: The purpose of this paper is to propose a modern evidence-guided framework for the teaching and practice of MT which avoids reference to and reliance on the outdated principles of TMT. This framework is based on three fundamental humanistic dimensions common in all aspects of healthcare: safety, comfort, and efficiency. These practical elements are contextualised by positive communication, a collaborative context, and person-centred care. The framework facilitates best-practice, reasoning, and communication and is exemplified here with two case studies. METHODS: A literature review stimulated by a new method of teaching manual therapy, reflecting contemporary evidence, being trialled at a United Kingdom education institute. A group of experienced, internationally-based academics, clinicians, and researchers from across the spectrum of manual therapy was convened. Perspectives were elicited through reviews of contemporary literature and discussions in an iterative process. Public presentations were made to multidisciplinary groups and feedback was incorporated. Consensus was achieved through repeated discussion of relevant elements. CONCLUSIONS: Manual therapy interventions should include both passive and active, person-empowering interventions such as exercise, education, and lifestyle adaptations. These should be delivered in a contextualised healing environment with a well-developed person-practitioner therapeutic alliance. Teaching manual therapy should follow this model.

A qualitative analysis of free-text patient satisfaction responses in Care Response, a database of patient-reported outcome and experience measures.

BACKGROUND: Databases have become important tools in improving health care. Care Response is a database containing information on tens of thousands of chiropractic patients internationally. It has been collecting patient-reported outcomes and patient satisfaction information for more than 10 years. The purpose of this study was to contribute to the understanding of patient perceptions and priorities for chiropractic care by analysing free text entered into the patient reported experience measure (PREM) questionnaires within the Care Response system. METHODS: There were two questions of interest on the PREM for this study. One requested information about "good points" patients perceived about patients' care experience, and the other requested information on "improvements" that could make the experience better. We conducted a word frequency analysis using a word counting macro in Microsoft Word, then used those results as a starting point for a qualitative analysis. Data were collected on 30 May 2022. RESULTS: The people who participated in the Care Response system often reported positive experiences with their chiropractors, including that they had reduced pain, improved function, and felt validated in their clinical condition. In addition, they appreciated having diagnostic and treatment procedures explained to them. They valued friendly, professional, and on-time service. The negative experiences were the opposite: being rushed through treatment, that the treatment was not worth the cost, or that they weren't treated professionally, empathetically, or with respect for them as individuals. The most important themes that emerged under "good points" were satisfaction (with care), value (as a person), safety, comfort, and professionalism. Their opposites, dissatisfaction, lack of value, lack of safety, lack of comfort, and lack of professionalism emerged as the most important themes under "improvements". We report some nuances of patient experience that have not previously been explored in the literature. CONCLUSIONS: Respondents seemed to value effective care provided in a safe, professional, friendly, and aesthetically pleasing environment. Chiropractors should note these priorities and engage with patients according to them. Education institutions should consider how good practice in these areas might be incorporated into curricula.

Virtual temporal bone simulators and their use in surgical training: a narrative review.

OBJECTIVE: Temporal bone dissection is a difficult skill to acquire, and the challenge has recently been further compounded by a reduction in conventional surgical training opportunities during the coronavirus disease 2019 pandemic. Consequently, there has been renewed interest in ear simulation as an adjunct to surgical training for trainees. We review the state-of-the-art virtual temporal bone simulators for surgical training. MATERIALS AND METHODS: A narrative review of the current literature was performed following a Medline search using a pre-determined search strategy. RESULTS AND ANALYSIS: Sixty-one studies were included. There are five validated temporal bone simulators: Voxel-Man, CardinalSim, Ohio State University Simulator, Melbourne University's Virtual Reality Surgical Simulation and Visible Ear Simulator. The merits of each have been reviewed, alongside their role in surgical training. CONCLUSION: Temporal bone simulators have been demonstrated to be useful adjuncts to conventional surgical training methods and are likely to play an increasing role in the future.

Chiropractic Day 2023: A Report and Qualitative Analysis of How Thought Leaders Celebrate the Present and Envision the Future of Chiropractic.

Objective: This study aimed to (1) collect and analyze statements about how to celebrate chiropractic in the present and roles that chiropractors may fulfill in the future, (2) identify if there was congruence among the themes between present and future statements, and (3) offer a model about the chiropractic profession that captures its complex relationships that encompass its interactions within microsystem, mesosystem, exosystem, and macrosystem levels. Methods: For this qualitative analysis, we used pattern and grounded theory approaches. A purposive sample of thought leaders in the chiropractic profession were invited to answer the following 2 open-ended questions: (1) envision the chiropractor of the future, and (2) recommendations on how to celebrate chiropractic. Information was collected during April 2023 using Survey Monkey. The information was entered into a spreadsheet and analyzed for topic clusters, which resulted in matching concepts with social-ecological themes. The themes between the responses to the 2 questions were analyzed for congruence. We used the Standards for Reporting Qualitative Research to report our findings. Results: Of the 54 experts invited, 32 (59%) participated. Authors represented 7 countries and have a median of 32 years of chiropractic experience, with a range of 5 to 51 years. Nineteen major topics in the future statements and 23 major topics in statements about celebrating chiropractic were combined in a model. The topics were presented using the 4 levels of the social-ecological framework. Individual (microsystem): chiropractors are competent, well-educated experts in spine and musculoskeletal care who apply evidence-based practices, which is a combination of the best available evidence, clinical expertise, and patient values. Interpersonal relationships (mesosystem): chiropractors serve the best interests of their patients, provide person-centered care, embrace diversity, equity, and inclusion, consider specific health needs and the health of the whole person. Community (exosystem): chiropractors provide care within integrated health care environments and in private practices, serve the best interests of the public through participation in their communities, participate through multidisciplinary collaboration with and within the health care system, and work together as a profession with a strong professional identity. Societal (macrosystem): chiropractors contribute to the greater good of society and participate on a global level in policy, leadership, and research. There was concordance between both the future envisioning statements and the present celebration recommendations, which suggest logical validity based on the congruence of these concepts. Conclusion: A sample of independent views, including the perceptions from a broad range of chiropractic thought leaders from various backgrounds, philosophies, diversity characteristics, and world regions, were assembled to create a comprehensive model of the chiropractic profession. The resulting model shows an array of intrinsic values and provides the roles that chiropractors may provide to serve patients and the public. This study offers insights into the roles that future chiropractors may fulfill and how these are congruent with present-day values. These core concepts and this novel model may have utility during dialogs about identity, applications regarding chiropractic in policy, practice, education, and research, and building positive relationships and collaborations.

A descriptive analysis of the contents of Care Response, an international data set of patient-reported outcomes for chiropractic patients.

BACKGROUND: Databases have become an important tool in understanding trends and correlations in health care by collecting demographic and clinical information. Analysis of data collected from large cohorts of patients can have the potential to generate insights into factors identifying treatments and the characteristics of subgroups of patients who respond to certain types of care. The Care Response (CR) database was designed to capture patient-reported outcome measures (PROMs) for chiropractic patients internationally. Although several papers have been published analysing some of the data, its contents have not yet been comprehensively documented. The primary aim of this study was to describe the information in the CR database. The secondary aim was to determine whether there was suitable information available to better understand subgroups of chiropractic patients and responsiveness to care. This would be achieved by enabling correlations among patient demographics, diagnoses, and therapeutic interventions with machine learning approaches. METHODS: Data in all available fields were requested with no date restriction. Data were collected on 12 April 2022. The output was manually scanned for scope and completeness. Tables were created with categories of information. Descriptive statistics were applied. RESULTS: The CR database collects information from patients at the first clinical visit, 14, 30, and 90 days subsequently. There were 32,468 patient responses; 3210 patients completed all fields through the 90 day follow up period. 45% of respondents were male; 54% were female; the average age was 49. There was little demographic information, and no information on diagnoses or therapeutic interventions. We received StartBack, numerical pain scale, patient global impression of change, and Bournemouth questionnaire data, but no other PROMs. CONCLUSIONS: The CR database is a large set of PROMs for chiropractic patients internationally. We found it unsuitable for machine learning analysis for our purposes; its utility is limited by a lack of demographic information, diagnoses, and therapeutic interventions. However, it can offer information about chiropractic care in general and patient satisfaction. It could form the basis for a useful clinical tool in the future, if reformed to be more accessible to researchers and expanded with more information collected.

Lessons learned from independent external validation of an AI tool to detect breast cancer using a representative UK data set.

OBJECTIVE: To pilot a process for the independent external validation of an artificial intelligence (AI) tool to detect breast cancer using data from the NHS breast screening programme (NHSBSP). METHODS: A representative data set of mammography images from 26,000 women attending 2 NHS screening centres, and an enriched data set of 2054 positive cases were used from the OPTIMAM image database. The use case of the AI tool was the replacement of the first or second human reader. The performance of the AI tool was compared to that of human readers in the NHSBSP. RESULTS: Recommendations for future external validations of AI tools to detect breast cancer are provided. The tool recalled different breast cancers to the human readers. This study showed the importance of testing AI tools on all types of cases (including non-standard) and the clarity of any warning messages. The acceptable difference in sensitivity and specificity between the AI tool and human readers should be determined. Any information vital for the clinical application should be a required output for the AI tool. It is recommended that the interaction of radiologists with the AI tool, and the effect of the AI tool on arbitration be investigated prior to clinical use. CONCLUSION: This pilot demonstrated several lessons for future independent external validation of AI tools for breast cancer detection. ADVANCES IN KNOWLEDGE: Knowledge has been gained towards best practice procedures for performing independent external validations of AI tools for the detection of breast cancer using data from the NHS Breast Screening Programme.

Surgical description and outcome of ultrasound-guided minimally invasive parathyroidectomy in 50 dogs with primary hyperparathyroidism.

OBJECTIVE: To describe the surgical technique and clinical outcome of minimally invasive parathyroidectomy for primary hyperparathyroidism (PHPT) in the dog. ANIMALS: Fifty client-owned dogs with PHPT that underwent minimally invasive parathyroidectomy. STUDY DESIGN: Retrospective cohort study. METHODS: An ultrasound-guided mini lateral approach was made via a plane established between the sternocephalicus muscle and sternohyoideus muscles to expose the thyroid gland and enlarged parathyroid gland. Abnormal parathyroid glands were removed en bloc via partial thyroidectomy. The technique for bilateral disease was similar, the skin incision was made on midline and moved laterally to develop the above-mentioned plane of dissection. Age, sex, breed, bodyweight, ultrasound findings, histopathological diagnosis, surgical time, preoperative clinical signs, and clinical outcome were extracted from the records for descriptive statistics. RESULTS: A total of 62 glands were surgically removed, including 17 hyperplastic glands (17/62, 27.4%), 34 adenomas (34/62, 54.8%), and two carcinomas (2/62, 3.2%). Hypercalcemia resolved shortly after surgery in 44 dogs (44/45, 97.8%). One dog had recurrent hypercalcemia (1/45, 2.2%), one dog had persistent hypercalcemia (1/45, 2.2%), two dogs had permanent hypocalcemia requiring life-long calcitriol supplementation (2/45, 4.4%), and one dog died from clinical hypocalcemia (1/45, 2.2%). CONCLUSION: Minimally invasive parathyroidectomy was associated with a low morbidity and led to favorable outcomes in 44/45 dogs in this series. CLINICAL SIGNIFICANCE: The results of this study supports the use of minimally invasive parathyroidectomy to treat PHPT in dogs.

Development of an algorithm to convert mammographic images to appear as if acquired with different technique factors.

Purpose: We set out a fully developed algorithm for adapting mammography images to appear as if acquired using different technique factors by changing the signal and noise within the images. The algorithm accounts for difference between the absorption by the object being imaged and the imaging system. Approach: Images were acquired using a Hologic Selenia Dimensions x-ray unit for the validation, of three thicknesses of polymethyl methacrylate (PMMA) blocks with or without different thicknesses of PMMA contrast objects acquired for a range of technique factors. One set of images was then adapted to appear the same as a target image acquired with a higher or lower tube voltage and/or a different anode/filter combination. The average linearized pixel value, normalized noise power spectra (NNPS), and standard deviation of the flat field images and the contrast-to-noise ratio (CNR) of the contrast object images were calculated for the simulated and target images. A simulation study tested the algorithm on images created using a voxel breast phantom at different technique factors and the images compared using local signal level, variance, and power spectra. Results: The average pixel value, NNPS, and standard deviation for the simulated and target images were found to be within 9%. The CNRs of the simulated and target images were found to be within 5% of each other. The differences between the target and simulated images of the voxel phantom were similar to those of the natural variability. Conclusions: We demonstrated that images can be successfully adapted to appear as if acquired using different technique factors. Using this conversion algorithm, it may be possible to examine the effect of tube voltage and anode/filter combination on cancer detection using clinical images.

Balloon catheter as an extraction device for caudal vena cava adrenal tumor thrombectomy in a dog: A case report.

OBJECTIVE: To report the use of a balloon catheter as an extraction device for a posthepatic caval thrombus in a dog with a right adrenal tumor. ANIMALS: Twelve-year-old male neutered Chihuahua mix dog. STUDY DESIGN: Case report METHODS: The dog presented for the evaluation of a hepatic mass. Computed tomography of thorax and abdomen was performed, and a right lateral liver lobe mass and a right adrenal mass were noted. The adrenal mass had a caval thrombus extending almost to the level of the right atrium. Traditional methods of tumor thrombectomy were unsuccessful. Extraction of the thrombus was facilitated by passing a balloon catheter through the caudal vena cavotomy until it was cranial to the thrombus, inflating the balloon and slowly withdrawing the catheter. RESULTS: A malignant pheochromocytoma was diagnosed on histology. The dog had a subjectively assessed good quality of life until it was euthanized 118 days postoperatively for acute dyspnea. CONCLUSION: Balloon catheter-assisted thrombectomy was successful in removing an extensive caval thrombus that was otherwise difficult to extract via conventional methods. This technique can be considered in cases with extensive tumor thrombus either as a method of choice or when other methods of thrombus extraction have failed.

Radiation doses in the United Kingdom breast screening programmes 2016-2019.

OBJECTIVES: To record the radiation doses involved in UK breast screening and to identify any changes since previous publications related to technical factors and the population screened. METHODS: Mammographic exposure factors for 68,998 women imaged using 411 X-ray sets spread across the UK were compiled. Local output and half value layer measurements for each X-ray set were used to estimate mean glandular dose (MGD) using the standard UK method. RESULTS: Mean MGDs in digital mammography have increased by 11% since 2010-12 for both medio-lateral oblique (MLO) and cranio-caudal (CC) views. The mean compressed breast thickness (CBT) has increased (4.8% CC, 5.2% MLO) over the same period. The mean MLO CBT value of 62.4 ± 0.1 mm is outside the 50 to 60 mm range used for diagnostic reference levels. The increase in MGD is consistent with the CBT changes. The mean MGD in the 50 to 60 mm CBT range is 1.44 ± 0.03 mGy for MLO views. CBT varies with age and peaks at 51. CONCLUSIONS: Mean CBT has increased with time, and this has increased mean MGDs for digital mammography. CBT also varies with age. ADVANCES IN KNOWLEDGE: Updated average MGDs in the UK are provided. There is evidence that breast size is increasing in the UK and that mean CBT is affected by age-related changes in the breast.

Post-survey Likert constructions: an adaptive method for generalizing perceptions of environmental variability.

Environmental perceptions are inherently based on an individual's existing knowledge, experiences, and future expectations. Methods for measuring environmental perception, therefore, must capture a range of experiences while also being flexible enough to integrate these experiences into a coherent unit for analysis. Many research topics require cross-cultural comparisons in order to corroborate findings; however, assessments of environmental perception are often place- and context-specific. We propose here post-survey Likert constructions (PSLCs), using semi-structured interviews to construct a five-point scale system from multiple household responses after the completion of interviews. This method is able to capture the natural variability in the population using the respondents' own language and characterizations of phenomena. We applied this method to measure the perceived environmental variability of residents living in a dynamic flooding landscape in the Okavango Delta, Botswana. The PSLC method captures the differences in environmental perception in a location with different settlement and cultural histories, multiple language groups, and different environmental conditions. The method easily transfers to other environments and populations, allowing for potential cross-cultural comparisons of perceived environmental variability. This publication responds to calls for increased transparency in reporting the development, execution, advantages, and disadvantages of methods related to environmental change.

Classical Hodgkin's lymphoma masquerading as Riedel's thyroiditis.

We present the case of a 38-year-old woman with a progressively tender swelling of the thyroid gland, who was treated as Riedel's thyroiditis based on two fine needle aspirations and a core biopsy. She was later found, on partial thyroidectomy, to have nodular sclerosis classical Hodgkin's lymphoma.

Virtual clinical trial to compare cancer detection using combinations of 2D mammography, digital breast tomosynthesis and synthetic 2D imaging.

OBJECTIVES: This study was designed to compare the detection of subtle lesions (calcification clusters or masses) when using the combination of digital breast tomosynthesis (DBT) and synthetic mammography (SM) with digital mammography (DM) alone or combined with DBT. METHODS: A set of 166 cases without cancer was acquired on a DBT mammography system. Realistic subtle calcification clusters and masses in the DM images and DBT planes were digitally inserted into 104 of the acquired cases. Three study arms were created: DM alone, DM with DBT and SM with DBT. Five mammographic readers located the centre of any lesion within the images that should be recalled for further investigation and graded their suspiciousness. A JAFROC figure of merit (FoM) and lesion detection fraction (LDF) were calculated for each study arm. The visibility of the lesions in the DBT images was compared with SM and DM images. RESULTS: For calcification clusters, there were no significant differences (p > 0.075) in FoM or LDF. For masses, the FoM and LDF were significantly improved in the arms using DBT compared to DM alone (p < 0.001). On average, both calcification clusters and masses were more visible on DBT than on DM and SM images. CONCLUSIONS: This study demonstrated that masses were detected better with DBT than with DM alone and there was no significant difference (p = 0.075) in LDF between DM&DBT and SM&DBT for calcifications clusters. Our results support previous studies that it may be acceptable to not acquire digital mammography alongside tomosynthesis for subtle calcification clusters and ill-defined masses. KEY POINTS: • The detection of masses was significantly better using DBT than with digital mammography alone. • The detection of calcification clusters was not significantly different between digital mammography and synthetic 2D images combined with tomosynthesis. • Our results support previous studies that it may be acceptable to not acquire digital mammography alongside tomosynthesis for subtle calcification clusters and ill-defined masses for the imaging technology used.

Ecological and human dimensions of avocado expansion in México: Towards supply-chain sustainability.

Avocados have become a global commodity, and environmental and socioeconomic impacts in the regions where avocados are grown have increased in tandem with production. In this article, we synthesize the current state of knowledge about the impacts of avocado production in Michoacán, México, the global center of avocado production. Environmental impacts on biodiversity, soil, and hydrological systems stem from deforestation and forest fragmentation that result from avocado expansion. The avocado industry has brought some economic benefits, namely increased employment and reductions in poverty and out-migration, but inequity in the region limits the positive socioeconomic impacts. We draw comparisons to other commodity studies and propose that lessons learned from such research could be utilized to make the avocado supply chain more sustainable. Ultimately, steps could be taken at all levels of the commodity chain to improve sustainability, including improved farming practices, policies protecting smallholders and local capital, and increased consumer awareness.

Sphenoid sinusitis: a rare cause of ischaemic stroke.

We present the case of a 61-year-old woman who presented to the accident and emergency department with an ischaemic stroke, on a background of receiving intravenous and oral antibiotics to treat chronic left sphenoid sinusitis. Initially presenting with right-sided weakness and aphasia, a diagnosis of acute ischaemic stroke was made. Antibiotics had been commenced 1 month prior to the ischaemic stroke. Imaging at that time showed changes in keeping with chronic sphenoid sinusitis along with a small dehiscence in the lateral wall of the left sphenoid sinus and thrombosis of the left superior ophthalmic vein. During that admission blood cultures grew Streptococcus constellatus, a member of the Streptococcus milleri group. We discuss the unusual aetiology of this stroke, the emerging evidence associating chronic rhinosinusitis with stroke and the complex multidisciplinary approach required for management in this case.

Effect of glandularity on the detection of simulated cancers in planar, tomosynthesis, and synthetic 2D imaging of the breast using a hybrid virtual clinical trial.

PURPOSE: The purpose of this study was to measure the threshold diameter of calcifications and masses for 2D imaging, digital breast tomosynthesis (DBT), and synthetic 2D images, for a range of breast glandularities. This study shows the limits of detection for each of the technologies and the strengths and weaknesses of each in terms of visualizing the radiological features of small cancers. METHODS: Mathematical voxel breast phantoms with glandularities by volume of 9%, 18%, and 30% with a thickness of 53 mm were created. Simulated ill-defined masses and calcification clusters with a range of diameters were inserted into some of these breast models. The imaging characteristics of a Siemens Inspiration X-ray system were measured for a 29 kV, tungsten/rhodium anode/filter combination. Ray tracing through the breast models was undertaken to create simulated 2D and DBT projection images. These were then modified to adjust the image sharpness, and to add scatter and noise. The mean glandular doses for the images were 1.43, 1.47, and 1.47 mGy for 2D and 1.92, 1.97, and 1.98 mGy for DBT for the three glandularities. The resultant images were processed to create 2D, DBT planes and synthetic 2D images. Patches of the images with or without a simulated lesion were extracted, and used in a four-alternative forced choice study to measure the threshold diameters for each imaging mode, lesion type, and glandularity. The study was undertaken by six physicists. RESULTS: The threshold diameters of the lesions were 6.2, 4.9, and 6.7 mm (masses) and 225, 370, and 399 µm, (calcifications) for 2D, DBT, and synthetic 2D, respectively, for a breast glandularity of 18%. The threshold diameter of ill-defined masses is significantly smaller for DBT than for both 2D (p≤0.006) and synthetic 2D (p≤0.012) for all glandularities. Glandularity has a significant effect on the threshold diameter of masses, even for DBT where there is reduced background structure in the images. The calcification threshold diameters for 2D images were significantly smaller than for DBT and synthetic 2D for all glandularities. There were few significant differences for the threshold diameter of calcifications between glandularities, indicating that the background structure has little effect on the detection of calcifications. We measured larger but nonsignificant differences in the threshold diameters for synthetic 2D imaging than for 2D imaging for masses in the 9% (p = 0.059) and 18% (p = 0.19) glandularities. The threshold diameters for synthetic 2D imaging were larger than for 2D imaging for calcifications (p < 0.001) for all glandularities. CONCLUSIONS: We have shown that glandularity has only a small effect on the detection of calcifications, but the threshold diameter of masses was significantly larger for higher glandularity for all of the modalities tested. We measured nonsignificantly larger threshold diameters for synthetic 2D imaging than for 2D imaging for masses at the 9% (p = 0.059) and 18% (p = 0.19) glandularities and significantly larger diameters for calcifications (p < 0.001) for all glandularities. The lesions simulated were very subtle and further work is required to examine the clinical effect of not seeing the smallest calcifications in clusters.

Quantitative breast density analysis to predict interval and node-positive cancers in pursuit of improved screening protocols: a case-control study.

BACKGROUND: This study investigates whether quantitative breast density (BD) serves as an imaging biomarker for more intensive breast cancer screening by predicting interval, and node-positive cancers. METHODS: This case-control study of 1204 women aged 47-73 includes 599 cancer cases (302 screen-detected, 297 interval; 239 node-positive, 360 node-negative) and 605 controls. Automated BD software calculated fibroglandular volume (FGV), volumetric breast density (VBD) and density grade (DG). A radiologist assessed BD using a visual analogue scale (VAS) from 0 to 100. Logistic regression and area under the receiver operating characteristic curves (AUC) determined whether BD could predict mode of detection (screen-detected or interval); node-negative cancers; node-positive cancers, and all cancers vs. controls. RESULTS: FGV, VBD, VAS, and DG all discriminated interval cancers (all p < 0.01) from controls. Only FGV-quartile discriminated screen-detected cancers (p < 0.01). Based on AUC, FGV discriminated all cancer types better than VBD or VAS. FGV showed a significantly greater discrimination of interval cancers, AUC = 0.65, than of screen-detected cancers, AUC = 0.61 (p < 0.01) as did VBD (0.63 and 0.53, respectively, p < 0.001). CONCLUSION: FGV, VBD, VAS and DG discriminate interval cancers from controls, reflecting some masking risk. Only FGV discriminates screen-detected cancers perhaps adding a unique component of breast cancer risk.