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Artificial intelligence (AI) algorithms are used in an increasing range of aspects of our lives. In particular, medical applications of AI are being developed and deployed, including many in image analysis. Deep learning methods, which have recently proved successful in image classification, rely on large volumes of clinical data generated by healthcare institutions. Such data is collected from their served populations. In this opinion article, using digital mammographic screening as an example, we briefly consider the background to AI development and some issues around its deployment. We highlight the importance of high quality clinical data as fundamental to these technologies, and question how the ownership of resultant tools should be defined. Though many of the ethical issues concerning the development and use of medical AI technologies continue to be discussed, the value of the data on which they rely remains a subject that is seldom considered. This potentially controversial issue can and should be addressed in a way which is beneficial to all parties, particularly the population in general and the patients we serve.

BackgroundNeoadjuvant chemotherapy (NACT) is used to downstage breast cancer prior to surgery. Image monitoring is essential to guide treatment and to assess in vivo chemosensitivity. Breast MRI is considered the gold-standard imaging technique; however, it is contraindicated or poorly tolerated in some patients and may be hard to access. Evidence suggests contrast enhanced spectral mammography (CESM) may approach the accuracy of MRI. This novel pilot study investigates whether the addition of digital breast tomosynthesis (DBT) to CESM increases the accuracy of response prediction.ResultsSixteen cancers in fourteen patients were imaged with CESM+DBT and MRI following completion of NACT. Ten cancers demonstrated pathological complete response (pCR) defined as absence of residual invasive disease. Greatest accuracy for predicting pCR was with CESM contrast-enhancement only (accuracy 81.3%, sensitivity 100%, specificity 57.1%), followed by MRI (accuracy 62.5%, sensitivity 44.4%, specificity 85.7%). Concordance with invasive tumour size was greater for CESM than MRI, concordance-coefficients 0.70 vs 0.66 respectively. MRI demonstrated greatest concordance with whole tumour size followed by CESM contrast-enhancement plus microcalcification, concordance-coefficients 0.86 vs 0.69. The addition of DBT did not improve accuracy for prediction of pCR or residual disease size. Whereas CESM+DBT tended to underestimate size of residual disease, MRI tended to overestimate but no significant differences were seen (p>0.05).ConclusionsCESM contrast-enhancement plus microcalcification is similar to MRI for predicting residual disease post-NACT. Size of enhancement alone demonstrates best concordance with invasive disease. Inclusion of residual microcalcification improves concordance with DCIS. The addition of DBT to CESM does not improve accuracy.HighlightsNo benefit of adding DBT to CESM for NACT response predictionCESM appears similar to MRI for predicting response to NACTCESM has greatest accuracy for residual invasive tumour size.CESM+calcification has greater accuracy for predicting residual in situ disease.

Background: As a breast cancer screening test, FAST MRI has the potential to combine the sensitivity of dynamic contrast enhanced breast MRI (DCE-MRI) with costs nearer to those of mammography. In the UK the NHS Breast Screening Programme (NHSBSP) screens women aged 50-70 with a mammogram every 3 years and has a workforce of radiologists, breast clinicians and advanced practitioner radiographers who interpret over 2 million screening mammograms annually. For FAST MRI to be used as a UK population screening tool it will need to be interpreted by the existing multi-professional workforce of mammogram readers. Our research team developed a single study day of standardised training in FAST MRI interpretation. In our single centre pilot study, a group of readers with no previous experience of DCE-MRI interpretation achieved an accuracy just 5% less than expert DCE-MRI readers (Br J Radiol 2019:92 DOI:10.1259/bjr.20190663). Our current study aimed to validate the feasibility of training the NHSBSP workforce in FAST MRI interpretation. We developed display software (MedXViewer) containing ground truth information for each FAST MRI case to train and assess mammogram readers, who represented multiple NHSBSP sites in the South West Region of England. Methods: The study was funded by the National Institute for Health Research (Research for Patient Benefit funding stream; ISRCTN 16624917). A per breast analysis of the frequency of results against the true outcome was obtained overall and for each reader. Differences in accuracy, sensitivity and specificity across reader groups (group 1 = mammogram readers experienced in DCE-MRI interpretation; group 2 = mammogram readers with no previous experience in DCE-MRI interpretation) were analysed using a multilevel generalised mixed model to account for multiple readers per case. Results: 37 NHSBSP mammogram readers at 6 NHSBSP sites attended the training day and completed interpretation of the summative assessment dataset (17 in group 1 and 20 in group 2). All 37 readers completed the reading task of 125 cases (250 breasts), for a total of 9250 reads. Median interpretation time was 99.08 seconds (interquartile range 66.83-150.54). The table below shows per breast analysis comparing the readers’ classification with the true outcome (cancer or normal): The concordance with the ground truth (accuracy) of 83% achieved by Group 2 (4129/5000 (95% CI 82-84%)) was significantly lower than that achieved by Group 1 (3814/4250 (90%; 89-91%); p Conclusions: This study validates the feasibility of training the workforce of mammogram readers to interpret FAST MRI with only one day of standardised training. Improvement in performance with experience by the group 2 readers indicates a learning curve and suggests the performance gap between the two groups might be narrowed by further training for group 2. TotalGroup 1Group 2MeasureConcordance (Accuracy)7943/9250 (86%)3814/4250 (90%)4129/5000 (83%)True positive rate (Sensitivity)1806/2109 (86%)858/969 (89%)948/1140 (83%)True negative rate (Specificity)6137/7141 (86%)2956/3281 (90%)3181/3860 (82%)False positive rate1004/7141 (14%)325/3281 (10%)679/3860 (18%)False negative rate303/2109 (14%)111/969 (11%)192/1140 (17%) Citation Format: Lyn IL Jones, Rebecca Geach, Sam A Harding, Andrea Marshall, Sadie McKeown-Keegan, Sian Taylor-Phillips, Premkumar Elangovan, Mark Halling-Brown, Sarah Vinnicombe, Elizabeth O'Flynn, Hesam Ghiasvand, Claire T Hulme, Janet A Dunn. Training multi-professional mammogram readers to interpret abbreviated breast MRI (FAST MRI): A UK multi-centre study [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS3-31.

Background: Abbreviated breast MRI (abMRI) is being introduced in breast screening trials and clinical practice, particularly for women with dense breasts. Upscaling abMRI provision requires the workforce of mammogram-readers to learn to effectively interpret abMRI. The purpose of this study was to examine the diagnostic accuracy of mammogram-readers to interpret abMRI after a single day of standardised small-group training and to compare diagnostic performance of mammogram-readers experienced in full-protocol breast MRI (fpMRI) interpretation (Group 1) with that of those without fpMRI interpretation experience (Group 2).Methods: Mammogram-readers were recruited from six NHS Breast Screening Programme sites. Small-group hands-on workstation training was provided, with subsequent prospective, independent, blinded interpretation of an enriched dataset with known outcome. A simplified form of abMRI (first-post-contrast-subtracted-images (FAST MRI), displayed as maximum-intensity-projection (MIP) and subtracted slice-stack), was used. Per-breast and per-lesion diagnostic accuracy analysis was undertaken, with comparison across groups, and double-reading simulation of a consecutive screening subset.Results: 37 readers (Group 1: 17, Group 2: 20) completed the reading task of 125 scans (250 breasts) (total = 9250 reads). Overall sensitivity was 86% (95% Confidence Interval (CI) 84-87%; 1776/2072) and specificity, 86% (95%CI 85-86%; 6140/7178). Group 1 showed significantly higher sensitivity (843/952; 89%; 95%CI 86-91%) and higher specificity (2957/3298; 90%; 95%CI 89-91%) than Group 2 (sensitivity = 83%; 95%CI 81-85% (933/1120) pConclusions: Single day abMRI interpretation-training for mammogram-readers achieved an overall diagnostic performance within benchmarks published for fpMRI but was insufficient for diagnostic accuracy of mammogram-readers new to breast MRI to match that of experienced fpMRI readers. Novice MRI reader performance improved during the reading task, suggesting additional training could further narrow this performance gap.

Objectives To investigate the relationship between periprostatic adipose tissue (PPAT) adipokine expression and prostate cancer (PCa) aggressiveness using both pathological features of radical prostatectomy (RP) and multiparametric magnetic resonance imaging ( MRI) variables. Patients and methods Sixty-nine men were recruited to assess immunohistochemical expression of tumour necrosis factor (TNF)α and vascular endothelial growth factor (VEGF) of periprostatic fat of RP specimens. Per cent immunopositivity was quantified on scanned slides using the Aperio Positive Pixel Count algorithm for PPAT TNFα, VEGF and androgen receptors. Periprostatic fat volume (PFV) was segmented on contiguous T1 -weighted axial MRI slices from the level of the prostate base to apex. PFV was normalized to prostate volume (PV) to account for variations in PV (normalized PFV = PFV/PV). MRI quantitative values (Kep , Ktrans and apparent diffusion coefficient) were measured from the PCa primary lesion using Olea Sphere software. Patients were stratified into three groups according to RP Gleason score (GS): ≤6, 7(3 + 4) and ≥7(4 + 3). Results The mean rank of VEGF and TNFα was significantly different between the groups [H(2) = 11.038, P = 0.004] and [H(2) = 13.086, P = 0.001], respectively. Patients with stage pT3 had higher TNFα (18.2 ± 8.95) positivity than patients with stage pT2 (13.27 ± 10.66; t [67] = -2.03, P = 0.047). TNFα expression significantly correlated with Ktrans (ρ = 0.327, P = 0.023). TNFα (P = 0.043), and VEGF (P = 0.02) correlated with high grade PCa (GS ≥ 7) in RP specimens and also correlated significantly with upgrading of GS from biopsy to RP histology. Conclusions The expression levels of TNFα and VEGF on immunostaining significantly correlated with aggressivity of PCa. As biomarkers, these indicate the risk of having high grade PCa in men undergoing RP.

Prediction of pathological complete response (pCR) of primary breast cancer to neoadjuvant chemotherapy (NACT) may influence planned surgical approaches in the breast and axilla. The aim of this project is to assess the value of interim shear wave elastography (SWE), ultrasound (US) and magnetic resonance imaging (MRI) after 3 cycles in predicting pCR. 64 patients receiving NACT had baseline and interim US, SWE and MRI examinations. The mean lesion stiffness at SWE, US and MRI diameter was measured at both time points. We compared four parameters with pCR status: a) Interim mean stiffness ≤ or 50 kPa; b) Percentage stiffness reduction; c) Percentage US diameter reduction and d) Interim MRI response using RECIST criteria. The Chi square test was used to assess significance. Interim stiffness of ≤ or 50 kPa gave the best prediction of pCR with pCR seen in 10 of 14 (71 %) cancers with an interim stiffness of ≤ 50 kPa, compared to 7 of 50 (14 %) of cancers with an interim stiffness of 50 kPa, (p 0.0001) (sensitivity 59 %, specificity 91 %, PPV 71 %, NPV 86 % and diagnostic accuracy 83 %). Percentage reduction in stiffness was the next best parameter (sensitivity 59 %, specificity 85 %, p 0.0004) followed by reduction in MRI diameter of 30 % (sensitivity 50 % and specificity 79 %, p = 0.03) and % reduction in US diameter (sensitivity 47 %, specificity 81 %, p = 0.03). Similar results were obtained from ROC analysis. SWE stiffness of breast cancers after 3 cycles of NACT and changes in stiffness from baseline are strongly associated with pCR after 6 cycles. Die Prädiktion der pathologischen Komplettremission (pCR) bei primärem Mammakarzinom nach neoadjuvanter Chemotherapie (NACT) kann die geplante chirurgische Herangehensweise in Brust und Axilla beeinflussen. Ziel dieser Arbeit ist die Beurteilung des Wertes von Interim Shearwave-Elastografie (SWE), Ultraschall (US) und Magnetresonanztomografie (MRI) nach 3 Zyklen für die Vorhersage einer pCR. Bei 64 Patienten mit NACT wurden Anfangs- und Interim-Untersuchungen mittels US, SWE und MRT durchgeführt. Die mittlere Steifigkeit der Läsion mittels SWE-, US- und MRT-Durchmesser wurde zu beiden Zeitpunkten bestimmt. Wir verglichen vier Parameter mit dem pCR-Status: a) Interim mittlere Steifigkeit ≤ oder 50 kPa, b) prozentuale Reduktion der Steifigkeit, c) prozentuale Reduktion des US-Durchmessers und d) Interim MRT-Antwort mittels RECIST-Kriterien. Der Chi-Square-Test wurde zur Beurteilung der Signifikanz angewandt. Die Interim-Steifigkeit von ≤ oder 50 kPa führte zur besten Prädiktion einer pCR, mit einer pCR bei 10 von 14 (71 %) Karzinomen mit einer Interim-Steifigkeit von ≤ 50 kPa im Vergleich zu 7 von 50 (14 %) Karzinomen mit einer Interim-Steifigkeit von 50 kPa. (p 0,0001) (Sensitivität 59 %, Spezifität 91 %, positiver Vorhersagewert 71 %, negativer Vorhersagewert 86 % und diagnostische Treffsicherheit 83 %). Die prozentuale Reduktion der Steifigkeit war der zweitbeste Parameter (Sensitivität 59 %, Spezifität 85 %, p 0,0004) gefolgt der Reduktion des MRI-Durchmessers um 30 % (Sensitivität 50 % und Spezifität 79 %, p = 0,03) und einer prozentualen Reduktion des US-Durchmessers (Sensitivität 47 %, Spezifität 81 %, p = 0,03). Ähnliche Ergebnisse wurden mittels ROC-Analyse erzielt. Die SWE-Steifigkeit von Mammakarzinomen nach 3 NACT-Zyklen und die Veränderungen der Steifigkeit im Bezug zum Anfangswert sind eng mit einer pCR nach 6 Zyklen assoziiert.

Introduction Women with mammographically dense breasts have an increased risk of breast cancer. Dense breasts can limit detection of small breast lesions due to overlapping fibroglandular tissue. BRAID is a randomised, multi-centre UK study assessing the impact of supplementary imaging, including abbreviated breast MRI (ABB-MRI), in detection of breast cancer in women aged 50-70 years with dense breasts. ABB-MRI is a shorter protocol breast MRI, allowing much faster acquisition times. The aim of this study is to review the feasibility of introducing ABB-MRI into the NHS setting as a part of a research trial. Protocol ABB-MRI is performed on a 1.5 tesla MRI scanner. Sequences obtained include a 2 mm axial T2 weighted sequence, a dual echo (Dixon water/fat separation) 3D DCE acquisition consisting of one pre- and two post-contrast images with generation of post-contrast subtracted images and post-processed MIP images. Scheduling ABB-MRIs are performed on a dedicated breast MRI list. Participants arrive 30 minutes prior to appointment time with pre-filled safety questionnaire. ABB-MRIs are scheduled for a 20-minute appointment slot, allowing 10 women to be scanned in a 3-hour session. Specific roles are allocated to staff members. Improving Efficiency of ABB-MRI in the UK Challenges encountered are similar to those encountered with FDP: IV cannulation, BMI and claustrophobia. Dedicated MR sessions with standard contrast doses and prefilled safety questionnaires help improve efficiency of sessions and allow examination times under 15 minutes.

Objective: Full-field digital mammography (FFDM) has limited sensitivity for cancer in younger women with denser breasts. Digital breast tomosynthesis (DBT) can reduce the risk of cancer being obscured by overlying tissue. The primary study aim was to compare the sensitivity of FFDM, DBT and FFDM-plus-DBT in women under 60 years old with clinical suspicion of breast cancer. Methods: This multicentre study recruited 446 patients from UK breast clinics. Participants underwent both standard FFDM and DBT. A blinded retrospective multireader study involving 12 readers and 300 mammograms (152 malignant and 148 benign cases) was conducted. Results: Sensitivity for cancer was 86.6% with FFDM [95% CI (85.2–88.0%)], 89.1% with DBT [95% CI (88.2–90%)], and 91.7% with FFDM+DBT [95% CI (90.7–92.6%)]. In the densest breasts, the maximum sensitivity increment with FFDM +DBT over FFDM alone was 10.3%, varying by density measurement method. Overall specificity was 81.4% with FFDM [95% CI (80.5–82.3%)], 84.6% with DBT [95% CI (83.9–85.3%)], and 79.6% with FFDM +DBT [95% CI (79.0–80.2%)]. No differences were detected in accuracy of tumour measurement in unifocal cases. Conclusions: Where available, DBT merits first-line use in the under 60 age group in symptomatic breast clinics, particularly in women known to have very dense breasts. Advances in knowledge: This study is one of very few to address the accuracy of DBT in symptomatic rather than screening patients. It quantifies the diagnostic gains of DBT in direct comparison with standard digital mammography, supporting informed decisions on appropriate use of DBT in this population.

In the UK, women between 50-70 years are invited for 3-yearly mammography screening irrespective of their likelihood of developing breast cancer. The only risk adaption is for women with >30% lifetime risk who are offered annual magnetic resonance imaging (MRI) and mammography, and annual mammography for some moderate-risk women. Using questionnaires, breast density, and polygenic risk scores, it is possible to stratify the population into the lowest 20% risk, who will develop

Background In patients who have had axillary nodal metastasis diagnosed prior to neoadjuvant chemotherapy for breast cancer, there is little consensus on how to manage the axilla subsequently. The aim of this study was to explore whether a combination of breast magnetic resonance imaging (MRI) assessed response and primary tumour pathology factors could identify a subset of patients that might be spared axillary node clearance. Methods A retrospective data analysis was performed of patients with core biopsy-proven axillary nodal metastasis prior to commencement of neoadjuvant chemotherapy (NAC) who had subsequent axillary node clearance (ANC) at definitive breast surgery. Breast tumour and axillary response at MRI before, during and on completion of NAC, core biopsy tumour grade, tumour type and immunophenotype were correlated with pathological response in the breast and the number of metastatic nodes in the ANC specimens. Results Of 87 consecutive patients with MRI at baseline, interim and after neoadjuvant chemotherapy who underwent ANC at time of breast surgery, 33 (38%) had no residual macrometastatic axillary disease, 28 (32%) had 1–2 metastatic nodes and 26 (30%) had more than 2 metastatic nodes. Factors that predicted axillary nodal complete response were MRI complete response in the breast (p p = 0.02) and non-lobular tumour type (p = 0.015). Conclusion MRI assessment of breast tumour response to NAC and core biopsy factors are predictive of response in axillary nodes, and can be used to guide decision making regarding appropriate axillary surgery.

INTRODUCTION: With the increased use of neoadjuvant therapy for breast cancer, there is a need for pre-operative prediction of prognosis. We aimed to assess the prognostic value of tumour stiffness measured by ultrasound shear wave elastography (SWE). METHODS: A consecutive cohort of patients with invasive breast cancer underwent breast ultrasound (US) including SWE. The following were recorded prospectively: US diameter, stiffness at SWE, presentation source, core biopsy grade, oestrogen receptor (ER) status and pre-operative nodal status. Breast cancer-specific survival (BCSS) was analysed with regard to US size and stiffness, tumour grade on core biopsy, ER status, presentation mode and pre-operative nodal status. Analysis used Cox proportional hazards regression. RESULTS: Of the 520 patients, 42 breast cancer and 53 non-breast cancer deaths were recorded at mean follow-up of 5.4 years. Hazard ratios (HR) for tertiles of stiffness were 1, 4.8 and 8.1 (P = 0.0001). HR for 2 groups based on US size < or ≥ 20 mm were 1 and 5.1 (P < 0.0001). HR for each unit increase in tumour grade on core biopsy was 3.9 (P < 0.0001). The HR for ER positivity compared to ER negativity was 0.21 (P < 0.001). BCSS was also associated with presentation mode and pre-operative nodal status. In a multivariable model, stiffness, US size and ER status were independently associated with BCSS. CONCLUSION: Multiple pre-operative factors including stromal stiffness at SWE have independent prognostic significance. A larger dataset with longer follow-up could be used in the future to construct a pre-operative prognostic model to guide treatment decisions.

Objectives To investigate whether interim changes in hetereogeneity (measured using entropy features) on MRI were associated with pathological residual cancer burden (RCB) at final surgery in patients receiving neoadjuvant chemotherapy (NAC) for primary breast cancer. Methods This was a retrospective study of 88 consenting women (age: 30–79 years). Scanning was performed on a 3.0 T MRI scanner prior to NAC (baseline) and after 2–3 cycles of treatment (interim). Entropy was derived from the grey-level co-occurrence matrix, on slice-matched baseline/interim T2-weighted images. Response, assessed using RCB score on surgically resected specimens, was compared statistically with entropy/heterogeneity changes and ROC analysis performed. Association of pCR within each tumour immunophenotype was evaluated. Results Mean entropy percent differences between examinations, by response category, were: pCR: 32.8%, RCB-I: 10.5%, RCB-II: 9.7% and RCB-III: 3.0%. Association of ultimate pCR with coarse entropy changes between baseline/interim MRI across all lesions yielded 85.2% accuracy (area under ROC curve: 0.845). Excellent sensitivity/specificity was obtained for pCR prediction within each immunophenotype: ER+: 100%/100%; HER2+: 83.3%/95.7%, TNBC: 87.5%/80.0%. Conclusions Lesion T2 heterogeneity changes are associated with response to NAC using RCB scores, particularly for pCR, and can be useful across all immunophenotypes with good diagnostic accuracy. Key Points • Texture analysis provides a means of measuring lesion heterogeneity on MRI images. • Heterogeneity changes between baseline/interim MRI can be linked with ultimate pathological response. • Heterogeneity changes give good diagnostic accuracy of pCR response across all immunophenotypes. • Percentage reduction in heterogeneity is associated with pCR with good accuracy and NPV.

The main harm of overdiagnosis is overtreatment. However a form of overdiagnosis also occurs when foci of cancer are found by imaging in addition to the symptomatic lesion when this leads to additional treatment which does not benefit the patient. Even if overtreatment is avoided, knowledge of the diagnosis can still cause psychological harm. Overdiagnosis is an inevitable effect of mammographic screening as the benefit comes from diagnosing breast cancer prior to clinical detectability. Estimates of the rate of overdiagnosis at screening are around 10%. DCIS represents 20% of cancers detected by screening and is the main focus in the overdiagnosis debate. Detection and treatment of low grade DCIS and invasive tubular cancer would appear to represent overdiagnosis in most cases. Supplementary screening with tomosynthesis or US are both likely to increase overdiagnosis as both modalities detect predominantly low grade invasive cancers. MRI causes overdiagnosis because it is so sensitive that it detects real tumour foci which after radiotherapy and systemic therapy do not, in many cases go on and cause local recurrence if the women had had no MRI and undergone breast conservation and adjuvant therapy with these small foci left in situ.

Background Increasing numbers of breast cancer patients receive neoadjuvant chemotherapy (NACT). We seek to investigate whether baseline mammographic and ultrasound features are associated with complete pathological response (pCR) after NACT. Methods A database of NACT patients was reviewed. Baseline imaging parameters assessed were ultrasound: posterior effect; echo pattern; margin and lesion diameter; mammography: spiculation and microcalcification. Core biopsy grade and immunophenotype were documented. Data were analysed for the whole study group and by immunophenotype. Results Of the 222 cancers, 83 (37%) were triple negative (TN), 61 (27%) ER positive/HER-2 negative and 78 (35%) HER-2 positive. A pCR occurred in 46 of 222 cancers (21%). For the whole group, response was associated with high core biopsy grade (grade 3 vs. grade 1 or 2) (26% vs. 9%, p = 0.0044), absence of posterior shadowing on ultrasound (26% vs. 10%, p p p p Conclusion A pCR is less likely when there is mammographic spiculation. Small ultrasound size is associated with pCR in HER-2 positive tumours. These findings may be helpful when discussing NACT and surgical options with patients. Trial registration UK Clinical Trials Gateway: registration number 16712.

To define the shear wave elastography (SWE) characteristics of breast cancer histological types by size in a large cohort.Consecutive patients with US visible masses underwent SWE. All those with confirmed invasive breast cancer were included in the study. Histologic type was ascertained from core biopsy and surgical resection specimens. For each type, mean and median values for Emean and Emax were ascertained. Commoner tumour types were further analysed by invasive size. The significance of differences was established using the Chi-square test.1137 tumours constituted the study group. The proportion of tumours with Emean below 50 kPa was higher in tubular cancers (23%) compared to ductal carcinomas of no specific type (DNST) (6%) (p0.001). Emax below 80 kPa was seen in 34% of tubular cancers compared to 16% of DNST (p0.002). Emean and Emax for lobular, mucinous, papillary and metaplastic cancers were not different from those of DNST. There were no significant differences in Emean or Emax between tumour types once broken down according to invasive size.Most breast cancer histological types have similar SWE characteristics. The exception is tubular cancer which has significantly lower stiffness than other histologic types, accounted for largely by their small size.

Rationale and Objectives To investigate if anisotropy at two-dimensional shear wave elastography (SWE) suggests malignancy and whether it correlates with prognostic and predictive factors in breast cancer. Materials and Methods Study group A of 244 solid breast lesions was imaged with SWE between April 2013 and May 2014. Each lesion was imaged in radial and in antiradial planes, and the maximum elasticity, mean elasticity, and standard deviation were recorded and correlated with benign/malignant status, and if malignant, correlated with conventional predictive and prognostic factors. The results were compared to a study group B of 968 solid breast lesions, which were imaged in sagittal and in axial planes between 2010 and 2013. Results Neither benign nor malignant lesion anisotropy is plane dependent. However, malignant lesions are more anisotropic than benign lesions ( P ≤ 0.001). Anisotropy correlates with increasing elasticity parameters, breast imaging-reporting and data system categories, core biopsy result, and tumor grade. Large cancers are significantly more anisotropic than small cancers ( P ≤ 0.001). The optimal anisotropy cutoff threshold for benign/malignant differentiation of 150 kPa 2 achieves the best sensitivity (74%) with a reasonable specificity (63%). Conclusions Anisotropy may be useful during benign/malignant differentiation of solid breast masses using SWE. Anisotropy also correlates with some prognostic factors in breast cancer.

Objective: A computational model has been created to estimate the abdominal thickness of a patient following an X-ray examination; its intended application is assisting with patient dose audit of paediatric X-ray examinations. This work evaluates the accuracy of the computational model in a clinical setting for adult patients undergoing anteroposterior (AP) abdomen X-ray examinations. Methods: The model estimates patient thickness using the radiographic image, the exposure factors with which the image was acquired, a priori knowledge of the characteristics of the X-ray unit and detector and the results of extensive Monte Carlo simulation of patient examinations. For 20 patients undergoing AP abdominal X-ray examinations, the model was used to estimate the patient thickness; these estimates were compared against a direct measurement made at the time of the examination. Results: Estimates of patient thickness made using the model were on average within ±5.8% of the measured thickness. Conclusion: The model can be used to accurately estimate the thickness of a patient undergoing an AP abdominal X-ray examination where the patient’s size falls within the range of the size of patients used to create the computational model. Advances in knowledge: This work demonstrates that it is possible to accurately estimate the AP abdominal thickness of an adult patient using the digital X-ray image and a computational model.

The purpose is to develop and validate an automated method for detecting image unsharpness caused by patient motion blur in digital mammograms. The goal is that such a tool would facilitate immediate re-taking of blurred images, which has the potential to reduce the number of recalled examinations, and to ensure that sharp, high-quality mammograms are presented for reading. To meet this goal, an automated method was developed based on interpretation of the normalized image Wiener Spectrum. A preliminary algorithm was developed using 25 cases acquired using a single vendor system, read by two expert readers identifying the presence of blur, location, and severity. A predictive blur severity score was established using multivariate modeling, which had an adjusted coefficient of determination, R2 =0.63±0.02, for linear regression against the average reader-scored blur severity. A heatmap of the relative blur magnitude showed good correspondence with reader sketches of blur location, with a Spearman rank correlation of 0.70 between the algorithmestimated area fraction with blur and the maximum of the blur area fraction categories of the two readers. Given these promising results, the algorithm-estimated blur severity score and heatmap are proposed to be used to aid observer interpretation. The use of this automated blur analysis approach, ideally with feedback during an exam, could lead to a reduction in repeat appointments for technical reasons, saving time, cost, potential anxiety, and improving image quality for accurate diagnosis.

Background Fully automated assessment of mammographic density (MD), a biomarker of breast cancer risk, is being increasingly performed in screening settings. However, data on body mass index (BMI), a confounder of the MD–risk association, are not routinely collected at screening. We investigated whether the amount of fat in the breast, as captured by the amount of mammographic non-dense tissue seen on the mammographic image, can be used as a proxy for BMI when data on the latter are unavailable. Methods Data from a UK case control study (numbers of cases/controls: 414/685) and a Norwegian cohort study (numbers of cases/non-cases: 657/61059), both with volumetric MD measurements (dense volume (DV), non-dense volume (NDV) and percent density (%MD)) from screening-age women, were analysed. BMI (self-reported) and NDV were taken as measures of adiposity. Correlations between BMI and NDV, %MD and DV were examined after log-transformation and adjustment for age, menopausal status and parity. Logistic regression models were fitted to the UK study, and Cox regression models to the Norwegian study, to assess associations between MD and breast cancer risk, expressed as odds/hazard ratios per adjusted standard deviation (OPERA). Adjustments were first made for standard risk factors except BMI (minimally adjusted models) and then also for BMI or NDV. OPERA pooled relative risks (RRs) were estimated by fixed-effect models, and between-study heterogeneity was assessed by the I 2 statistics. Results BMI was positively correlated with NDV (adjusted r = 0.74 in the UK study and r = 0.72 in the Norwegian study) and with DV (r = 0.33 and r = 0.25, respectively). Both %MD and DV were positively associated with breast cancer risk in minimally adjusted models (pooled OPERA RR (95% confidence interval): 1.34 (1.25, 1.43) and 1.46 (1.36, 1.56), respectively; I 2 = 0%, P >0.48 for both). Further adjustment for BMI or NDV strengthened the %MD–risk association (1.51 (1.41, 1.61); I 2 = 0%, P = 0.33 and 1.51 (1.41, 1.61); I 2 = 0%, P = 0.32, respectively). Adjusting for BMI or NDV marginally affected the magnitude of the DV–risk association (1.44 (1.34, 1.54); I 2 = 0%, P = 0.87 and 1.49 (1.40, 1.60); I 2 = 0%, P = 0.36, respectively). Conclusions When volumetric MD–breast cancer risk associations are investigated, NDV can be used as a measure of adiposity when BMI data are unavailable.

OBJECTIVE: Does method of tumour volume measurement on MRI influence prediction of treatment outcome in patients with primary breast cancer undergoing neoadjuvant chemotherapy (NAC)?. METHOD: The study comprised of 136 women with biopsy-proven breast cancer scheduled for MRI monitoring during NAC treatment. Dynamic contrast-enhanced images were acquired at baseline (pre-NAC) and interim (post three NAC cycles) time points. Functional tumour volumes (FTVs), automatically derived using vendor software and enhancing tumour volumes (ETVs), user-derived using a semi-automated thresholding technique, were calculated at each time point and percentage changes calculated. Response, assessed using residual cancer burden (RCB) score on surgically resected specimens, was compared statistically with volumetric changes and receiver operating characteristic analysis performed. RESULTS: Mean volumetric differences for each RCB response category were (FTV/ETV): pathological complete response (pCR) 95.5/96.8%, RCB-I 69.8/66.7%, RCB-II 64.0/65.5%, RCB-III 25.4/24.0%. Differences were significant between pCR and RCB-II/RCB-III categories (p

Pleomorphic invasive lobular carcinoma (pILC) is a distinct morphological variant of ILC with a poorer prognosis than classical ILC (cILC). The aim of this study was to ascertain whether the conventional imaging appearances of the two entities differ. A single-center retrospective review of conventional imaging was undertaken in 150 consecutive patients with histopathologically confirmed ILC (38 pILC; 112 cILC) between April 2010 and July 2015. Mammographic and sonographic findings were evaluated using the BI-RADS lexicon by a radiologist blinded to pathology, and the findings in the two groups were compared. The degree of discrepancy between imaging and pathological sizing in the two groups was evaluated. Lesions were mammographically occult in 11% of pILC and 14% of cILC (p = 0.56). On mammography, skin or trabecular thickening and microcalcification were commoner in pILC than cILC (13% vs. 1%, p

ObjectivesTo assess the feasibility of delivering and evaluating a weight management (WM) programme for overweight patients with a family history (FH) of breast cancer (BC) or colorectal cancer (CRC).Study designA two-arm (intervention vs usual care) randomised controlled trial.SettingNational Health Service (NHS) Tayside and NHS Grampian.ParticipantsPeople with a FH of BC or CRC aged≥18 years and body mass index of ≥25 kg/m2referred to NHS genetic services.InterventionParticipants were randomised to a control (lifestyle booklet) or 12-week intervention arm where they were given one face-to-face counselling session, four telephone consultations and web-based support. A goal of 5% reduction in body weight was set, and a personalised diet and physical activity (PA) programme was provided. Behavioural change techniques (motivational interviewing, action and coping plans and implementation intentions) were used.Primary outcomeFeasibility measures: recruitment, programme implementation, fidelity measures, achieved measurements and retention, participant satisfaction assessed by questionnaire and qualitative interviews.Secondary outcomesMeasured changes in weight and PA and reported diet and psychosocial measures between baseline and 12-week follow-up.ResultsOf 480 patients approached, 196 (41%) expressed interest in the study, and of those, 78 (40%) patients were randomised. Implementation of the programme was challenging within the time allotted and fidelity to the intervention modest (62%). Qualitative findings indicated the programme was well received. Questionnaires and anthropometric data were completed by >98%. Accelerometer data were attained by 84% and 54% at baseline and follow-up, respectively. Retention at 12 weeks was 76%. Overall, 36% of the intervention group (vs 0% in control) achieved 5% weight loss. Favourable increases in PA and reduction in dietary fat were also reported.ConclusionsA lifestyle programme for people with a family history of cancer is feasible to conduct and acceptable to participants, and indicative results suggest favourable outcomes.Trial registration numberISRCTN13123470; Pre-results.

This chapter looks at photon scattering applications in medicine. In the energy range of interest there are two types of scattering events, incoherent (Compton) and coherent (Rayleigh) scattering, and this chapter looks at how these events can be usefully used in the diagnosis and treatment of disease. In the first part we present an overview of Compton cameras for gamma imaging in the context of proton beam therapy, where they can be used for proton range verification. Proton beam therapy is currently in need of range verification for quality assurance and to improve treatment efficacy and safety. We will first briefly introduce potential methods for in vivo proton range verification, of which prompt gamma imaging is a promising example. We describe the process of gamma emission during proton irradiation, as well as the challenges of its detection and interpretation. The use of Compton camera for prompt gamma imaging has advantages over other gamma detectors since it does not require mechanical collimators and has a typical field of view of 180°. The Compton camera’s principle of operation and design criteria for prompt gamma imaging are described, as well as image reconstruction techniques such as back-projection and stochastic origin ensemble.

Purpose Apparent Diffusion Coefficient (ADC) measurements are increasingly used for assessing breast cancer response to neoadjuvant chemotherapy although little data exists on ADC measurement reproducibility. The purpose of this work was to investigate and characterise the magnitude of errors in ADC measures that may be encountered in such follow-up studies- namely scanner stability, scan–scan reproducibility, inter- and intra- observer measures and the most reproducible measurement of ADC. Methods Institutional Review Board approval was obtained for the prospective study of healthy volunteers and written consent acquired for the retrospective study of patient images. All scanning was performed on a 3.0-T MRI scanner. Scanner stability was assessed using an ice-water phantom weekly for 12 weeks. Inter-scan repeatability was assessed across two scans of 10 healthy volunteers (26–61 years; mean: 44.7 years). Inter- and intra-reader analysis repeatability was measured in 52 carcinomas from clinical patients (29–70 years; mean: 50.0 years) by measuring the whole tumor ADC value on a single slice with maximum tumor diameter (ADCS) and the ADC value of a small region of interest (ROI) on the same slice (ADCmin). Repeatability was assessed using intraclass correlation coefficients (ICC) and coefficients of repeatability (CoR). Results Scanner stability contributed 6% error to phantom ADC measurements (0.071 × 10−3 mm2/s; mean ADC = 1.089 × 10−3 mm2/s). The measured scan-scan CoR in the volunteers was 0.122 × 10−3 mm2/s, contributing an error of 8% to the mean measured values (ADCscan1 = 1.529 × 10−3 mm2/s; ADCscan2 = 1.507 × 10−3 mm2/s). Technical and clinical observers demonstrated excellent intra-observer repeatability (ICC > 0.9). Clinical observer CoR values were marginally better than technical observer measures (ADCS = 0.035 × 10−3 mm2/s vs. 0.097 × 10−3 mm2/s; ADCmin = 0.09 × 10−3 mm2/s vs. 0.114 × 10−3 mm2/s). Inter-reader ICC values were good 0.864 (ADCS) and fair 0.677 (ADCmin). Corresponding CoR values were 0.202 × 10−3 mm2/s and 0.264 × 10−3 mm2/s, respectively. Conclusions Both scanner stability and scan–scan variation have minimal influence on breast ADC measurements, contributing less than 10% error of average measured ADC values. Measurement of ADC values from a small ROI contributes a greater variability in measurements compared with measurement of ADC across the whole visible tumor on one slice. The greatest source of error in follow-up studies is likely to be associated with measures made by multiple observers, and this should be considered where multiple measures are required to assess response to treatment.

The term "breast density" or mammographic density (MD) denotes those components of breast parenchyma visualised at mammography that are denser than adipose tissue. MD is composed of a mixture of epithelial and stromal components, notably collagen, in variable proportions. MD is most commonly assessed in clinical practice with the time-honoured method of visual estimation of area-based percent density (PMD) on a mammogram, with categorisation into quartiles. The computerised semi-automated thresholding method, Cumulus, also yielding area-based percent density, is widely used for research purposes; however, the advent of fully automated volumetric methods developed as a consequence of the widespread use of digital mammography (DM) and yielding both absolute and percent dense volumes, has resulted in an explosion of interest in MD recently. Broadly, the importance of MD is twofold: firstly, the presence of marked MD significantly reduces mammographic sensitivity for breast cancer, even with state-of-the-art DM. Recognition of this led to the formation of a powerful lobby group ('Are You Dense') in the US, as a consequence of which 32 states have legislated for mandatory disclosure of MD to women undergoing mammography. Secondly, it is now widely accepted that MD is in itself a risk factor for breast cancer, with a four-to sixfold increased relative risk in women with PMD in the highest quintile compared to those with PMD in the lowest quintile. Consequently, major research efforts are underway to assess whether use of MD could provide a major step forward towards risk-adapted, personalised breast cancer prevention, imaging, and treatment.

Periprostatic and pelvic fat have been shown to influence prostate cancer behaviour through the secretion of chemokines and growth factors, acting in a paracrine mode. We have measured periprostatic fat volume (PFV) with normalisation to prostate gland volume on pelvic magnetic resonance imaging (MRI) and have correlated this with grade (Gleason score; GS) and pathological staging (pT) of prostate cancer (PCa) following radical prostatectomy (RP). PFV was determined using a segmentation technique on contiguous T1-weighted axial MRI slices from the level of the prostate base to the apex. The abdominal fat area (AFA) and subcutaneous fat thickness (SFT) were measured using T1-weighted axial slices at the level of the umbilicus and the upper border of the symphysis pubis, respectively. PFV was normalised to prostate volume (PV) to account for variations in PV (NPFV = PFV/PV). Patients were stratified into three risk groups according to post-operative GS: ≤6, 7(3 + 4), and ≥7(4 + 3). NPFV was significantly different between the groups (p = 0.001) and positively correlated with post-operative GS (ρ = 0.294, p n = 26) compared to those who continued to be low grade (1.99 ± 0.82; n = 17); however, this did not reach statistical significance (p = 0.11).

Background Mammographic density (MD) is one of the strongest breast cancer risk factors. Its age-related characteristics have been studied in women in western countries, but whether these associations apply to women worldwide is not known. Methods and findings We examined cross-sectional differences in MD by age and menopausal status in over 11,000 breast-cancer-free women aged 35–85 years, from 40 ethnicity- and location-specific population groups across 22 countries in the International Consortium on Mammographic Density (ICMD). MD was read centrally using a quantitative method (Cumulus) and its square-root metrics were analysed using meta-analysis of group-level estimates and linear regression models of pooled data, adjusted for body mass index, reproductive factors, mammogram view, image type, and reader. In all, 4,534 women were premenopausal, and 6,481 postmenopausal, at the time of mammography. A large age-adjusted difference in percent MD (PD) between post- and premenopausal women was apparent (–0.46 cm [95% CI: −0.53, −0.39]) and appeared greater in women with lower breast cancer risk profiles; variation across population groups due to heterogeneity (I2) was 16.5%. Among premenopausal women, the √PD difference per 10-year increase in age was −0.24 cm (95% CI: −0.34, −0.14; I2 = 30%), reflecting a compositional change (lower dense area and higher non-dense area, with no difference in breast area). In postmenopausal women, the corresponding difference in √PD (−0.38 cm [95% CI: −0.44, −0.33]; I2 = 30%) was additionally driven by increasing breast area. The study is limited by different mammography systems and its cross-sectional rather than longitudinal nature. Conclusions Declines in MD with increasing age are present premenopausally, continue postmenopausally, and are most pronounced over the menopausal transition. These effects were highly consistent across diverse groups of women worldwide, suggesting that they result from an intrinsic biological, likely hormonal, mechanism common to women. If cumulative breast density is a key determinant of breast cancer risk, younger ages may be the more critical periods for lifestyle modifications aimed at breast density and breast cancer risk reduction., Valerie McCormack and colleagues reveal reduced breast density with increased age in women from different ethnic groups; however increased breast density in young women is a cancer risk., Author summary Why was this study done? Breast density, a measure of the amount of dense to fatty tissue in the breast, is a strong marker of breast cancer risk. Breast density determinants have been studied in high-income countries, but not in women worldwide. What did the researchers do and find? We studied how breast density differed by age and menopausal status in diverse groups of women from 22 countries worldwide. For over 11,000 women, mammograms were read centrally and risk factor data harmonised. We found that, regardless of the country and ethnic group of women, breast density was much lower in postmenopausal than in premenopausal women of the same age. Additionally, as a relative proportion of breast area, breast density was lower in older women both among premenopausal and postmenopausal women. Among premenopausal women, breast density changed with age without an increase in breast area, but among postmenopausal women, the latter also increased. What do these findings mean? That this change in breast density with age is seen internationally suggests that the change is due to a universal biological mechanism inherent to all women. If cumulative breast density is a key determinant of breast cancer risk, younger ages may be the more critical periods for lifestyle modifications aimed at breast density and breast cancer risk reduction.

Background Bleomycin is an integral part of combination chemotherapy in germ cell tumours. Pulmonary toxicity often necessitates drug cessation and death occurs in 1%–2% of patients. A continuous infusion of bleomycin might reduce lung toxicity when compared with the conventional weekly boluses given as part of standard BEP chemotherapy. Patients and methods A phase 3 trial was conducted based on 212 men with IGCCCG good prognosis metastatic germ cell tumours with 1 : 1 randomization. They were stratified for age, smoking history and renal function. Patients received either conventional BEP with weekly bleomycin (30 000 units/week i.v. bolus) or as a 90 000 unit infusion on day 1 over 72 h. The primary endpoint was CT assessed lung toxicity, secondary endpoints included progression-free survival (PFS), changes in lung function testing and quality of life. Repeated measures mixed effects model was used to analyse the data. Results CT assessed lung toxicity for the infusional and conventional arm patients were respectively 80% versus 62% at the end of treatment and 54% versus 51% at 1-year post-treatment. There was no significant difference between the two arms for CT assessed lung toxicity (estimated regression coefficient=1.4, 95% CI: −0.36, 3.16). Older patients had higher toxicity (coefficient = 4.81, 95% CI: 3.04, 6.58). Lung toxicity increased after 1 cycle and peaked at end of treatment (P ≤ 0.002) and then declined. Lung function testing did not predict for subsequent lung damage. The median follow-up was 2.5 years. Two-year PFS rate (infusional: 93%, conventional: 94%; hazard ratio=0.91, 95% CI: 0.33, 2.52) was similar. Cough (P = 0.002) but not shortness of breath (P ≥ 0.09) was associated with bleomycin toxicity. Conclusions Infusional bleomycin has no advantage over standard administration. It supports abandoning routine pulmonary function testing, instead the presence of cough should be sought and the early use of CT scanning of the chest to evaluate potential lung toxicity is preferred.

Breast cancer is the commonest cancer in women in the UK, accounting for 30% of all new cancers in women, with an estimated 49,500 new cases in 20101. With the widespread negative publicity around over-diagnosis and over-treatment of low risk breast cancers, interest in the application of non-invasive treatments such as magnetic resonance imaging (MRI) guided high intensity focused ultrasound (HIFU) has increased. Development has begun of novel US transducers and platforms specifically designed for use with breast lesions, so as to improve the range of breast lesions that can be safely treated. However, before such transducers can be evaluated in patients in clinical trials, there is a need to establish their efficacy. A particular issue is the accuracy of temperature monitoring of FUS with MRI in the breast, since the presence of large amounts of surrounding fat can hinder temperature measurement. An appropriate anatomical model that imposes similar physical constraints to the breast and that responds to...

It is proposed that integrating ultrasound transducer arrays at the tip of tools such as biopsy needles could enable valuable, real-time image feedback during interventional procedures. High-resolution ultrasound imaging has the potential to aid navigation of interventional tools, and to assist diagnosis or treatment via in-vivo tissue characterisation in the breast, amongst many other applications. In order to produce miniature transducer arrays incorporated within biopsy needle-sized packages (2–5 mm diameter), the challenges in micromachining and handling transducer materials at this scale must be overcome. This paper presents fabrication processes used in the micromachining of a 16 element 15 MHz PIN-PMN-PT piezocrystal-polymer composite array and its integration into an 11 G breast biopsy needle. Particular emphasis is given to the manufacturing of the 1–3 dice-and-fill piezocrystal composite, and establishing electrical interconnects. Characterisation measurements have demonstrated operation of each of the 16 elements within the needle case.

Aim To assess how accurately the sentinel lymph node (SLN) can be identified percutaneously, using gamma probe and ultrasound technology. Materials and methods Women with breast cancer, scheduled for wide local excision or mastectomy with SLN biopsy (SLNB), were included. Peri-areolar intradermal injection of technetium-99 nanocolloid was performed on the morning of surgery and 1–2 ml of blue dye was injected in the peri-areolar region once the patient was anaesthetized. Prior to surgery, a gamma probe was used over the skin to identify any hot spot that could represent a SLN. Ultrasound, guided by the hot spot, was then used to visualize potential SLNs and guide the insertion of a localizing wire. The accuracy in localizing the SLN by preoperative gamma-probe guided ultrasonography was assessed by comparison to SLNB. Results A SLN was correctly identified and marked using gamma-probe guided ultrasonography in 44 of 59 cases (75%; 95% CI: 63–86%). Conclusion This study supports the case for investigating percutaneous gamma probe and ultrasound guided interventions in the axilla in women with breast cancer, as a potential alternative to surgical SLNB.

Shear wave elastography (SWE) is a promising adjunct to greyscale ultrasound in differentiating benign from malignant breast masses. The purpose of this study was to characterise breast cancers which are not stiff on quantitative SWE, to elucidate potential sources of error in clinical application of SWE to evaluation of breast masses. Three hundred and two consecutive patients examined by SWE who underwent immediate surgery for breast cancer were included. Characteristics of 280 lesions with suspicious SWE values (mean stiffness >50 kPa) were compared with 22 lesions with benign SWE values (50 kPa. • ‘Soft’ invasive cancers are frequently small (≤10 mm), low grade and screen-detected. • Pure DCIS masses are more often soft than invasive cancers (>40 %). • Large symptomatic masses are better evaluated with SWE than small clinically occult lesions. • When assessing small lesions, ‘softness’ should not raise the threshold for biopsy.

Shear wave elastography (SWE) shows promise as an adjunct to greyscale ultrasound examination in assessing breast masses. In breast cancer, higher lesion stiffness on SWE has been shown to be associated with features of poor prognosis. The purpose of this study was to assess whether lesion stiffness at SWE is an independent predictor of lymph node involvement. Patients with invasive breast cancer treated by primary surgery, who had undergone SWE examination were eligible. Data were retrospectively analysed from 396 consecutive patients. The mean stiffness values were obtained using the Aixplorer® ultrasound machine from SuperSonic Imagine Ltd. Measurements were taken from a region of interest positioned over the stiffest part of the abnormality. The average of the mean stiffness value obtained from each of two orthogonal image planes was used for analysis. Associations between lymph node involvement and mean lesion stiffness, invasive cancer size, histologic grade, tumour type, ER expression, HER-2 status and vascular invasion were assessed using univariate and multivariate logistic regression. At univariate analysis, invasive size, histologic grade, HER-2 status, vascular invasion, tumour type and mean stiffness were significantly associated with nodal involvement. Nodal involvement rates ranged from 7 % for tumours with mean stiffness 150 kPa. At multivariate analysis, invasive size, tumour type, vascular invasion, and mean stiffness maintained independent significance. Mean stiffness at SWE is an independent predictor of lymph node metastasis and thus can confer prognostic information additional to that provided by conventional preoperative tumour assessment and staging.

Jennifer Ferguson2, Guy Stevens1, Robert Hills2, Kate Gower Thomas1 1Breast Test Wales, Cardiff, UK; 2Cardiff University School of Medicine, Cardiff, UK Correspondence: Jennifer Ferguson Introduction To determine the rate and classification of interval breast cancer (IC) in the two years preceeding and following the introduction of digital mammography in 2011 in a national screening programme. Methods Two 2-year bands were used to ensure completed data for pre and post digital groups. Retrospective analysis of a prospectively collected database of IC was undertaken, identifying women who had undergone screening in the two years prior to and after the introduction of digital screening mammography (1.1.10 until 31.12.11 and 1.1.12 until 31.12.13). Chi squared analysis was used to compare the rate between the two groups and the rate of false negative (FN) and minimal signs (MS) categories considered together. Results Of 87,868 screened before digital between 1.1.10 and 31.12.11, 103 developed IC (0.12%) and of 100,672 screened with digital between 1.1.12 and 31.12.13, 145 developed IC (0.14%) (p = 0.12). Those women with FN and MS interval cancer numbered 17 (16.5%) predigital and 41 (28.3%) with digital; (p = 0.04). The number of true IC was similar in the pre (49.5%) and post (46.9%) groups. Conclusion The rate if IC is similar to the NHSBSP standard (1.2 per 1000 women screened). Despite earlier groups indicating that digital technology will lessen the number of IC, especially those ‘missed’ (FN and MS groups) which are often asymmetric densities and poorly defined masses, this has not been found in our study. The reasons for this will be discussed and examples will be shown.

Background Full-field digital mammography, which is gradually being introduced in most clinical and screening settings, produces two types of images: raw and processed. However, the extent to which mammographic density measurements, and their ability to predict breast cancer risk, vary according to type of image is not fully known. Methods We compared the performance of the semi-automated Cumulus method on digital raw, “analogue-like” raw and processed images, and the performance of a recently developed method - Laboratory for Breast Radiodensity Assessment (LIBRA) - on digital raw and processed images, in a case-control study (414 patients (cases) and 684 controls) by evaluating the extent to which their measurements were associated with breast cancer risk factors, and by comparing their ability to predict breast cancer risk. Results Valid Cumulus and LIBRA measurements were obtained from all available images, but the resulting distributions differed according to the method and type of image used. Both Cumulus and LIBRA percent density were inversely associated with age, body mass index (BMI), parity and postmenopausal status, regardless of type of image used. Cumulus percent density was strongly associated with breast cancer risk, but with the magnitude of the association slightly stronger for processed (risk increase per one SD increase in percent density (95 % CI): 1.55 (1.29, 1.85)) and “analogue-like” raw (1.52 (1.28, 1.80)) than for raw (1.35 (1.14, 1.60)) images. LIBRA percent density produced weaker associations with risk, albeit stronger for processed (1.32 (1.08, 1.61)) than raw images (1.17 (0.99, 1.37)). The percent density values yielded by the various density assessment/type of image combinations had similar ability to discriminate between patients and controls (area under the receiving operating curve values for percent density, age, BMI, parity and menopausal status combined ranged from 0.61 and 0.64). Conclusions The findings showed that Cumulus can be used to measure density on all types of digital images. They also indicate that LIBRA may provide a valid fully automated alternative to the more labour-intensive Cumulus. However, the same digital image type and assessment method should be used when examining mammographic density across populations, or longitudinal changes in density within a single population. Electronic supplementary material The online version of this article (doi:10.1186/s13058-016-0756-7) contains supplementary material, which is available to authorized users.