Timely follow-up of positive cancer screening results: A systematic review and recommendations from the PROSPR Consortium.

Timely follow-up for positive cancer screening results remains suboptimal, and the evidence base to inform decisions on optimizing the timeliness of diagnostic testing is unclear. This systematic review evaluated published studies regarding time to follow-up after a positive screening for breast, cervical, colorectal, and lung cancers. The quality of available evidence was very low or low across cancers, with potential attenuated or reversed associations from confounding by indication in most studies. Overall, evidence suggested that the risk for poorer cancer outcomes rises with longer wait times that vary within and across cancer types, which supports performing diagnostic testing as soon as feasible after the positive result, but evidence for specific time targets is limited. Within these limitations, we provide our opinion on cancer-specific recommendations for times to follow-up and how existing guidelines relate to the current evidence. Thresholds set should consider patient worry, potential for loss to follow-up with prolonged wait times, and available resources. Research is needed to better guide the timeliness of diagnostic follow-up, including considerations for patient preferences and existing barriers, while addressing methodological weaknesses. Research is also needed to identify effective interventions for reducing wait times for diagnostic testing, particularly in underserved or low-resource settings. CA Cancer J Clin 2018;68:199-216. © 2018 American Cancer Society.

Abbreviated Breast MRI for Supplemental Screening in Patients With Dense Breasts: Comparison of Baseline Versus Subsequent-Round Examinations.

Background: Abbreviated breast MRI (AB-MR) achieves a higher cancer detection rate (CDR) versus digital breast tomosynthesis when applied for baseline (i.e. first-round) supplemental screening in individuals with dense breasts. Limited literature has evaluated subsequent (i.e., sequential) AB-MR screening rounds. Objectives: This study aimed to compare outcomes between baseline and subsequent rounds of screening AB-MR in individuals with dense breasts at otherwise average risk of breast cancer. Methods: This retrospective study included patients with dense breasts and at otherwise average breast-cancer risk who underwent AB-MR for supplemental screening between December 20, 2016 and May 10, 2023. Clinical interpretations and results of recommended biopsies for AB-MR examinations were extracted from the EMR. Baseline and subsequent-round AB-MR examinations were compared. Results: The final sample included 2585 AB-MR examinations (2007 baseline, 578 subsequent-round) performed for supplemental screening in 2007 women (mean age, 57.1 years) with dense breasts. Among baseline examinations, 1658 (82.6%) were assessed as BI-RADS category 1 or 2, 171 (8.5%) as category 3, and 178 (8.9%) as category 4 or 5. Among subsequent-round examinations, 533 (92.2%) were assessed as BI-RADS category 1 or 2, 20 (3.5%) as category 3, and 25 (4.3%) as category 4 or 5 (p<.001). Abnormal interpretation rate (AIR) was 17.4% (349/2007) among baseline examinations, versus 7.8% (45/578) among subsequent-round examinations (p<.001). Among baseline examinations, PPV2 was 21.3% (38/178), PPV3 was 26.6% (38/143), and CDR was 18.9 per 1000 (38/2007). Among subsequent-round examinations PPV2 was 28.0% (7/25) (p=.45), PPV3 was 29.2% (7/24) (p=.81), and CDR was 12.1 per 1000 (7/578) (p=.37). All 45 cancers diagnosed by baseline or subsequent-round AB-MR were stage 0 or 1. Seven cancers diagnosed by subsequent-round AB-MR had a mean interval since prior AB-MR of 872 days, size of 0.3-1.2 cm, and node-negative status at surgical axillary evaluation. Conclusion: Subsequent rounds of AB-MR screening in individuals with dense breasts had lower AIR compared to baseline examinations while maintaining high CDR. All cancers detected by subsequent-round examinations were early-stage node-negative cancers. Clinical Impact: The findings support sequential AB-MR for supplemental screening in individuals with dense breasts. Further investigations are warranted to optimize the screening interval.

Quality Improvement Report: Design and Implementation of a Radiology E-Consult Service.

Electronic consultations (e-consults) mediated through an electronic health record system or web-based platform allow synchronous or asynchronous physician-to-physician communication. E-consults have been explored in various clinical specialties, but relatively few instances in the literature describe e-consults to connect health care providers directly with radiologists.The authors outline how a radiology department can implement an e-consult service and review the development of such a service in a large academic health system. They describe the logistics, workflow, turnaround time expectations, stakeholder management, and pilot implementation and highlight challenges and lessons learned.

Integrating 1H MRS and deuterium labeled glucose for mapping the dynamics of neural metabolism in humans.

In the technique presented here, dubbed 'qMRS', we quantify the change in 1H MRS signal following administration of 2H-labeled glucose. As in recent human DMRS studies, we administer [6,6'-2H2]-glucose orally to healthy subjects. Since 2H is not detectable by 1H MRS, the transfer of the 2H label from glucose to a downstream metabolite leads to a reduction in the corresponding 1H MRS resonance of the metabolite, even if the total concentration of both isoforms remains constant. Moreover, introduction of the deuterium label alters the splitting pattern of the proton resonances, making indirect detection of the deuterated forms- as well as the direct detection of the decrease in unlabeled form- possible even without a 2H coil. Because qMRS requires only standard 1H MRS acquisition methods, it can be performed using commonly implemented single voxel spectroscopy (SVS) and chemical shift imaging (CSI) sequences. In this work, we implement qMRS in semi-LASER based CSI, generating dynamic maps arising from the fitted spectra, and demonstrating the feasibility of using qMRS and qCSI to monitor dynamic metabolism in the human brain using a 7T scanner with no auxiliary hardware.

First-generation clinical dual-source photon-counting CT: ultra-low-dose quantitative spectral imaging.

OBJECTIVE: Evaluation of image characteristics at ultra-low radiation dose levels of a first-generation dual-source photon-counting computed tomography (PCCT) compared to a dual-source dual-energy CT (DECT) scanner. METHODS: A multi-energy CT phantom was imaged with and without an extension ring on both scanners over a range of radiation dose levels (CTDIvol 0.4-15.0 mGy). Scans were performed in different modes of acquisition for PCCT with 120 kVp and DECT with 70/Sn150 kVp and 100/Sn150 kVp. Various tissue inserts were used to characterize the precision and repeatability of Hounsfield units (HUs) on virtual mono-energetic images between 40 and 190 keV. Image noise was additionally investigated at an ultra-low radiation dose to illustrate PCCT's ability to remove electronic background noise. RESULTS: Our results demonstrate the high precision of HU measurements for a wide range of inserts and radiation exposure levels with PCCT. We report high performance for both scanners across a wide range of radiation exposure levels, with PCCT outperforming at low exposures compared to DECT. PCCT scans at the lowest radiation exposures illustrate significant reduction in electronic background noise, with a mean percent reduction of 74% (p value ~ 10-8) compared to DECT 70/Sn150 kVp and 60% (p value ~ 10-6) compared to DECT 100/Sn150 kVp. CONCLUSIONS: This paper reports the first experiences with a clinical dual-source PCCT. PCCT provides reliable HUs without disruption from electronic background noise for a wide range of dose values. Diagnostic benefits are not only for quantification at an ultra-low dose but also for imaging of obese patients. KEY POINTS: PCCT scanners provide precise and reliable Hounsfield units at ultra-low dose levels. The influence of electronic background noise can be removed at ultra-low-dose acquisitions with PCCT. Both spectral platforms have high performance along a wide range of radiation exposure levels, with PCCT outperforming at low radiation exposures.

Special Report of the RSNA COVID-19 Task Force: Crisis Leadership of Major Health System Radiology Departments during COVID-19.

Severe acute respiratory syndrome coronavirus 2 has spread across the world since December 2019, infecting 100 million and killing millions. The impact on health care institutions during the coronavirus disease 2019 pandemic has been considerable, with exhaustion of institutional and personal protective equipment resources during local outbreaks and crushing financial consequences for many institutions. Establishing adaptive principles of leadership is necessary during crises, fostering quick decision-making and workflow modifications, while a rapid review of data must determine necessary course corrections. This report describes concepts of crisis leadership teams that can help maximize their effectiveness during the current and future pandemics.

Mean Apparent Diffusion Coefficient Is a Sufficient Conventional Diffusion-weighted MRI Metric to Improve Breast MRI Diagnostic Performance: Results from the ECOG-ACRIN Cancer Research Group A6702 Diffusion Imaging Trial.

Background The Eastern Cooperative Oncology Group and American College of Radiology Imaging Network Cancer Research Group A6702 multicenter trial helped confirm the potential of diffusion-weighted MRI for improving differential diagnosis of suspicious breast abnormalities and reducing unnecessary biopsies. A prespecified secondary objective was to explore the relative value of different approaches for quantitative assessment of lesions at diffusion-weighted MRI. Purpose To determine whether alternate calculations of apparent diffusion coefficient (ADC) can help further improve diagnostic performance versus mean ADC values alone for analysis of suspicious breast lesions at MRI. Materials and Methods This prospective trial (ClinicalTrials.gov identifier: NCT02022579) enrolled consecutive women (from March 2014 to April 2015) with a Breast Imaging Reporting and Data System category of 3, 4, or 5 at breast MRI. All study participants underwent standardized diffusion-weighted MRI (b = 0, 100, 600, and 800 sec/mm2). Centralized ADC measures were performed, including manually drawn whole-lesion and hotspot regions of interest, histogram metrics, normalized ADC, and variable b-value combinations. Diagnostic performance was estimated by using the area under the receiver operating characteristic curve (AUC). Reduction in biopsy rate (maintaining 100% sensitivity) was estimated according to thresholds for each ADC metric. Results Among 107 enrolled women, 81 lesions with outcomes (28 malignant and 53 benign) in 67 women (median age, 49 years; interquartile range, 41-60 years) were analyzed. Among ADC metrics tested, none improved diagnostic performance versus standard mean ADC (AUC, 0.59-0.79 vs AUC, 0.75; P = .02-.84), and maximum ADC had worse performance (AUC, 0.52; P < .001). The 25th-percentile ADC metric provided the best performance (AUC, 0.79; 95% CI: 0.70, 0.88), and a threshold using median ADC provided the greatest reduction in biopsy rate of 23.9% (95% CI: 14.8, 32.9; 16 of 67 BI-RADS category 4 and 5 lesions). Nonzero minimum b value (100, 600, and 800 sec/mm2) did not improve the AUC (0.74; P = .28), and several combinations of two b values (0 and 600, 100 and 600, 0 and 800, and 100 and 800 sec/mm2; AUC, 0.73-0.76) provided results similar to those seen with calculations of four b values (AUC, 0.75; P = .17-.87). Conclusion Mean apparent diffusion coefficient calculated with a two-b-value acquisition is a simple and sufficient diffusion-weighted MRI metric to augment diagnostic performance of breast MRI compared with more complex approaches to apparent diffusion coefficient measurement. © RSNA, 2020 Online supplemental material is available for this article.

What happened to the US cancer cooperative groups? A status update ten years after the Institute of Medicine report.

The US cancer cooperative groups (cooperative groups) were founded in the 1950s to establish a standing infrastructure to conduct multi-institutional cancer clinical trials. Initially funded almost entirely by the US National Cancer Institute (NCI), over the years, the research conducted by the Cooperative Groups has evolved to meet the demands of cancer clinical research, with a scope now encompassing trials to advance cancer treatment, cancer control, biomarker development and validation, and health services research, with a corresponding broadening of their funding sources. The cooperative groups are also a critical mechanism for educating the next generation of cancer clinical trialists from many different disciplines. This review outlines the overall mission, structure, and funding of the cooperative groups, beginning in 1955 when they were first established by the NCI, and describes the considerable progress against cancer achieved over the past decade.

Five Consecutive Years of Screening with Digital Breast Tomosynthesis: Outcomes by Screening Year and Round.

Background Limited data exist beyond prevalence rounds of digital breast tomosynthesis (DBT) screening. Purpose To compare DBT outcomes over multiple years and rounds to outcomes of digital mammography (DM) screening. Materials and Methods Retrospective analysis included 1 year of DM and 5 years of DBT screening (September 2011 to September 2016); 67 350 examinations were performed in 29 310 women. Recall rate (RR) percentage, cancer detection rate (CDR) per 1000 women screened, false-negative rate per 1000 women screened, positive predictive value of recall (PPV1) percentage, positive predictive value of biopsies performed percentage, sensitivity, and specificity were calculated. Cancers diagnosed within 1 year of screening were captured by means of linkage to state cancer registry, and biologic characteristics were grouped by prognostic factors. Performance trends across DBT rounds were compared with those from DM rounds by using logistic regression to account for examinations in the same woman. Analyses were adjusted for age, race, breast density, baseline examination, and reader. Results There were 56 839 DBT and 10 511 DM examinations. The mean patient age (± standard deviation) was 56 years ±11 for the entire cohort, 55 years ±11 for the DBT group, and 57 years ±11 for the DM group. RRs were significantly lower for the DBT group (8.0%, 4522 of 56 839; 95% confidence interval [CI]: 7.7, 8.2) than for the DM group (10.4%, 1094 of 10 511; 95% CI: 9.8, 11.0) (P < .001). CDRs were higher with DBT (6.0 per 1000 women screened; 95% CI: 5.4, 6.7 per 1000 women screened; 340 of 56 839) than with DM (5.1 per 1000 women screened; 95% CI: 3.9, 6.6 per 1000 women screened; 54 of 10 511) (P = .25), but this difference was not statistically significant. Both RR and CDR remained improved compared with DM for 5 years of DBT at the population level. False-negative rates were slightly lower for DBT (0.6 per 1000 women screened; 95% CI: 0.4, 0.8 per 1000 women screened; 33 of 56 839) than DM (0.9 per 1000 women screened; 0.4, 1.6 per 1000 women screened; nine of 10 511) overall (P = .30), but the difference was not statistically significant. In adjusted analyses, RR, biopsy recommendation rates, and PPV1 were improved for DBT versus DM (P ≤ .001). Compared with DM, a higher proportion of DBT-detected cancers were invasive (70% [238 of 340] vs 68.5% [37 of 54]) and had poor prognoses characteristics (32.6% [76 of 233] vs 25.0% [nine of 36]). Conclusion Favorable outcomes with digital breast tomosynthesis screening were sustained over multiple years and rounds. Digital breast tomosynthesis screening was associated with detection of a higher proportion of poor-prognosis cancers than was digital mammography. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Moy and Heller in this issue.

Comparison of Abbreviated Breast MRI vs Digital Breast Tomosynthesis for Breast Cancer Detection Among Women With Dense Breasts Undergoing Screening.

Importance: Improved screening methods for women with dense breasts are needed because of their increased risk of breast cancer and of failed early diagnosis by screening mammography. Objective: To compare the screening performance of abbreviated breast magnetic resonance imaging (MRI) and digital breast tomosynthesis (DBT) in women with dense breasts. Design, Setting, and Participants: Cross-sectional study with longitudinal follow-up at 48 academic, community hospital, and private practice sites in the United States and Germany, conducted between December 2016 and November 2017 among average-risk women aged 40 to 75 years with heterogeneously dense or extremely dense breasts undergoing routine screening. Follow-up ascertainment of cancer diagnoses was complete through September 12, 2019. Exposures: All women underwent screening by both DBT and abbreviated breast MRI, performed in randomized order and read independently to avoid interpretation bias. Main Outcomes and Measures: The primary end point was the invasive cancer detection rate. Secondary outcomes included sensitivity, specificity, additional imaging recommendation rate, and positive predictive value (PPV) of biopsy, using invasive cancer and ductal carcinoma in situ (DCIS) to define a positive reference standard. All outcomes are reported at the participant level. Pathology of core or surgical biopsy was the reference standard for cancer detection rate and PPV; interval cancers reported until the next annual screen were included in the reference standard for sensitivity and specificity. Results: Among 1516 enrolled women, 1444 (median age, 54 [range, 40-75] years) completed both examinations and were included in the analysis. The reference standard was positive for invasive cancer with or without DCIS in 17 women and for DCIS alone in another 6. No interval cancers were observed during follow-up. Abbreviated breast MRI detected all 17 women with invasive cancer and 5 of 6 women with DCIS. Digital breast tomosynthesis detected 7 of 17 women with invasive cancer and 2 of 6 women with DCIS. The invasive cancer detection rate was 11.8 (95% CI, 7.4-18.8) per 1000 women for abbreviated breast MRI vs 4.8 (95% CI, 2.4-10.0) per 1000 women for DBT, a difference of 7 (95% CI, 2.2-11.6) per 1000 women (exact McNemar P = .002). For detection of invasive cancer and DCIS, sensitivity was 95.7% (95% CI, 79.0%-99.2%) with abbreviated breast MRI vs 39.1% (95% CI, 22.2%-59.2%) with DBT (P = .001) and specificity was 86.7% (95% CI, 84.8%-88.4%) vs 97.4% (95% CI, 96.5%-98.1%), respectively (P < .001). The additional imaging recommendation rate was 7.5% (95% CI, 6.2%-9.0%) with abbreviated breast MRI vs 10.1% (95% CI, 8.7%-11.8%) with DBT (P = .02) and the PPV was 19.6% (95% CI, 13.2%-28.2%) vs 31.0% (95% CI, 17.0%-49.7%), respectively (P = .15). Conclusions and Relevance: Among women with dense breasts undergoing screening, abbreviated breast MRI, compared with DBT, was associated with a significantly higher rate of invasive breast cancer detection. Further research is needed to better understand the relationship between screening methods and clinical outcome. Trial Registration: ClinicalTrials.gov Identifier: NCT02933489.

Characterizing and eliminating errors in enhancement and subtraction artifacts in dynamic contrast-enhanced breast MRI: Chemical shift artifact of the third kind.

PURPOSE: To characterize errors in enhancement in breast dynamic contrast-enhanced (DCE) MRI studies as a function of echo time and determine the source of dark band artifacts in clinical subtraction images. METHODS: Computer simulations, oil and water substitute (methylene chloride), as well as an American College of Radiology quality control phantom were tested. Routine clinical DCE breast MRI study was bracketed with (accelerated) in-phase DCE acquisitions in five patients. RESULTS: Simulation results demonstrated up to -160% suppression of the expected enhancement caused by differential enhancement of fat and water. Two-dimensional gradient-recalled echo and fat-suppressed 3D GRE phantom imaging confirmed the simulation results and showed that fat suppression does not eliminate the artifact. In vivo in-phase DCE images showed increased enhancement consistent with predictions and also confirmed increased spatial blurring on in-phase 3D gradient-recalled echo images. Combined multi-dimensional partial Fourier and parallel imaging provided a time-equivalent in-phase DCE MRI acquisition. CONCLUSION: Errors in expected enhancement occur in DCE breast MRI subtraction images because of differential enhancement of fat and water and incomplete fat signal suppression. These errors can lead to artificial suppression of enhancement as well as dark band artifacts on subtraction images. These artifacts can be eliminated with a time-equivalent in-phase fat-suppressed 3D gradient-recalled echo sequence. Understanding chemical shift artifact of the third kind, a unique artifact of artificial enhancement suppression in the presence of intravoxel fat and water signal, will aid DCE breast MRI image interpretation. In-phase acquisitions (combined with simultaneous minimum echo time or opposed-phase echoes) may facilitate qualitative, quantitative and longitudinal analysis of contrast enhancement. Magn Reson Med 79:2277-2289, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

MRI, Clinical Examination, and Mammography for Preoperative Assessment of Residual Disease and Pathologic Complete Response After Neoadjuvant Chemotherapy for Breast Cancer: ACRIN 6657 Trial.

OBJECTIVE: The objective of our study was to determine the accuracy of preoperative measurements for detecting pathologic complete response (CR) and assessing residual disease after neoadjuvant chemotherapy (NACT) in patients with locally advanced breast cancer. SUBJECTS AND METHODS: The American College of Radiology Imaging Network 6657 Trial prospectively enrolled women with ≥ 3 cm invasive breast cancer receiving NACT. Preoperative measurements of residual disease included longest diameter by mammography, MRI, and clinical examination and functional volume on MRI. The accuracy of preoperative measurements for detecting pathologic CR and the association with final pathology size were assessed for all lesions, separately for single masses and nonmass enhancements (NMEs), multiple masses, and lesions without ductal carcinoma in situ (DCIS). RESULTS: In the 138 women with all four preoperative measures, longest diameter by MRI showed the highest accuracy for detecting pathologic CR for all lesions and NME (AUC = 0.76 and 0.84, respectively). There was little difference across preoperative measurements in the accuracy of detecting pathologic CR for single masses (AUC = 0.69-0.72). Longest diameter by MRI and longest diameter by clinical examination showed moderate ability for detecting pathologic CR for multiple masses (AUC = 0.78 and 0.74), and longest diameter by MRI and longest diameter by mammography showed moderate ability for detecting pathologic CR for tumors without DCIS (AUC = 0.74 and 0.71). In subjects with residual disease, longest diameter by MRI exhibited the strongest association with pathology size for all lesions and single masses (r = 0.33 and 0.47). Associations between preoperative measures and pathology results were not significantly influenced by tumor subtype or mammographic density. CONCLUSION: Our results indicate that measurement of longest diameter by MRI is more accurate than by mammography and clinical examination for preoperative assessment of tumor residua after NACT and may improve surgical planning.

No impact of breast magnetic resonance imaging on 15-year outcomes in patients with ductal carcinoma in situ or early-stage invasive breast cancer managed with breast conservation therapy.

BACKGROUND: For women undergoing breast conservation therapy (BCT), the added value of breast magnetic resonance imaging (MRI) at the time of initial diagnosis remains controversial. The current study was performed to determine long-term outcomes after BCT for women with and without pretreatment breast MRI. METHODS: Between 1992 and 2001, a total of 755 women with ductal carcinoma in situ or early-stage invasive breast cancer underwent breast-conserving surgery (with axillary lymph node staging for invasive carcinoma) followed by definitive breast radiotherapy. Evaluation at the time of the initial diagnosis included conventional mammography in all subjects and breast MRI in 215 women (28%). Clinical, pathologic, and treatment characteristics were comparable for patients with and without breast MRI. Outcomes were determined using the Kaplan-Meier method and compared using the log-rank method. RESULTS: At a median follow-up of 13.8 years, there were 49 local failures (15 women with and 34 women without breast MRI, respectively). The 15-year local failure rates were 8% for women with and 8% for women without MRI (P = .59). There also were no differences noted between women with and without breast MRI with regard to 15-year rates of overall survival (77% vs 71%; P = .24), freedom from distant metastases (86% vs 90%; P = .08), and contralateral breast cancer (10% vs 8%; P = .10). Multivariate analysis demonstrated no significant impact of breast MRI on local failure (P = .96). CONCLUSIONS: Breast MRI during the initial evaluation for BCT appears to have no significant impact on 15-year rates for local control, overall survival, freedom from distant metastases, or contralateral breast cancer. The routine use of pretreatment breast MRI is not indicated for patients undergoing BCT. Cancer 2017;123:1324-1332. © 2016 American Cancer Society.

Mammographic breast density decreases after bariatric surgery.

PURPOSE: Breast density (BD), an important risk factor for breast cancer, can change over time in some women, but the underlying mechanism is unclear. Very little is known about the impact of surgical weight loss on BD. Our hypothesis is that weight loss after bariatric surgery is associated with a significant and favorable change in mammographic BD. METHODS: We identified 1097 women 40 years of age or older who underwent gastric bypass or sleeve gastrectomy at our institution from 2010 to 2014. Women who did not have either pre- and post-bariatric surgery mammograms performed at our institution were excluded; 110 had both mammograms and comprised the cohort. Breast density was determined both qualitatively, using reported BI-RADS density, and quantitatively, using the Laboratory for Individualized Breast Radiodensity Assessment. RESULTS: Qualitative BI-RADS density, quantitative breast area, and percent BD significantly decreased in post-bariatric surgery mammograms (p = 0.009, <0.001, and <0.001, respectively). CONCLUSIONS: Our retrospective study demonstrated that surgical weight loss was associated with a significant decrease in breast density. Additional studies are warranted to validate our findings and elucidate the molecular mechanisms underlying breast density change after weight loss surgery.

BI-RADS Category 3 Comparison: Probably Benign Category after Recall from Screening before and after Implementation of Digital Breast Tomosynthesis.

Purpose To evaluate Breast Imaging Reporting and Data System (BI-RADS) category 3 assessment at diagnostic examination after recall from screening in a large urban population after implementation of digital breast tomosynthesis (DBT) by focusing both on overall use and use stratified by recalled finding type and outcome at 2 years. Materials and Methods This was an intuitional review board-approved and HIPAA-compliant retrospective review of 10 728 digital mammography (DM) examinations from September 1, 2010, to August 30, 2011, and 15 571 screening DBT examinations from October 1, 2011, to February 28, 2013. The recall populations for DM and DBT were 1112 of 10 728 (10.4% of women screened) and 1366 of 15 571 (8.8% of women screened), respectively. Recall examinations were classified according to finding type: calcifications, asymmetry or focal asymmetry, mass, and architectural distortion. Differences between groups were compared by using the χ2 test. Results Although there was no significant change in the utilization rate of BI-RADS category 3 in those patients screened with DM compared with DBT (168 of 10 728, 1.6% for DM vs 206 of 15 571, 1.3% for DBT; P = .102), there was a mean overall reduction of 2.4 women per 1000 (95% confidence interval [CI]: -0.5, 5.4) recommended for short-term follow-up. Lesion types given a BI-RADS category 3 assessment after diagnostic work-up did not change. The distribution of recalled finding types significantly changed with DBT, with increased recall examinations for architectural distortion and mass (P < .001) and decreased recall examinations for asymmetries (P ≤ .001). There was no change in recall examinations for calcifications (P = .977). Conclusion Screening with DBT did not significantly change the utilization rate of BI-RADS category 3 classification; however, the overall number of patients recommended for short-interval follow-up decreased by a mean of 2.4 women per 1000 (95% CI: -0.5, 5.4). © RSNA, 2017 Online supplemental material is available for this article.

Non-caloric sweetener provides magnetic resonance imaging contrast for cancer detection.

BACKGROUND: Image contrast enhanced by exogenous contrast agents plays a crucial role in the early detection, characterization, and determination of the precise location of cancers. Here, we investigate the feasibility of using a non-nutritive sweetener, sucralose (commercial name, Splenda), as magnetic resonance imaging (MRI) contrast agent for cancer studies. METHODS: High-resolution nuclear-magnetic-resonance spectroscopy and MR studies on sucralose solution phantom were performed to detect the chemical exchange saturation transfer (CEST) property of sucralose hydroxyl protons with bulk water (sucCEST). For the animal experiments, female Fisher rats (F344/NCR) were used to generate 9L-gliosarcoma model. MRI with CEST experiments were performed on anesthetized rats at 9.4 T MR scanner. Following the baseline CEST scans, sucralose solution was intravenously administered in control and tumor bearing rats. CEST acquisitions were continued during and following the administration of sucralose. Following the sucCEST, Gadolinium-diethylenetriamine pentaacetic acid was injected to perform Gd-enhanced imaging for visualizing the tumor. RESULTS: The sucCEST contrast in vitro was found to correlate positively with the sucralose concentration and negatively with the pH, indicating the potential of this technique in cancer imaging. In a control animal, the CEST contrast from the brain was found to be unaffected following the administration of sucralose, demonstrating its blood-brain barrier impermeability. In a 9L glioma model, enhanced localized sucCEST contrast in the tumor region was detected while the unaffected brain region showed unaltered CEST effect implying the specificity of sucralose toward the tumorous tissue. The CEST asymmetry plots acquired from the tumor region before and after the sucralose infusion showed elevation of asymmetry at 1 ppm, pointing towards the role of sucralose in increased contrast. CONCLUSIONS: We show the feasibility of using sucralose and sucCEST in study of preclinical models of cancer. This study paves the way for the potential development of sucralose and other sucrose derivatives as contrast agents for clinical MRI applications.

MR spectroscopy of breast cancer for assessing early treatment response: Results from the ACRIN 6657 MRS trial.

PURPOSE: To estimate the accuracy of predicting response to neoadjuvant chemotherapy (NACT) in patients with locally advanced breast cancer using MR spectroscopy (MRS) measurements made very early in treatment. MATERIALS AND METHODS: This prospective Health Insurance Portability and Accountability Act (HIPAA)-compliant protocol was approved by the American College of Radiology and local-site institutional review boards. One hundred nineteen women with invasive breast cancer of ≥3 cm undergoing NACT were enrolled between September 2007 and April 2010. MRS measurements of the concentration of choline-containing compounds ([tCho]) were performed before the first chemotherapy regimen (time point 1, TP1) and 20-96 h after the first cycle of treatment (TP2). The change in [tCho] was assessed for its ability to predict pathologic complete response (pCR) and radiologic response using the area under the receiver operating characteristic curve (AUC) and logistic regression models. RESULTS: Of the 119 subjects enrolled, only 29 cases (24%) with eight pCRs provided usable data for the primary analysis. Technical challenges in acquiring quantitative MRS data in a multi-site trial setting limited the capture of usable data. In this limited data set, the decrease in tCho from TP1 to TP2 had poor ability to predict either pCR (AUC = 0.53, 95% confidence interval [CI]: 0.27-0.79) or radiologic response (AUC = 0.51, 95% CI: 0.27-0.75). CONCLUSION: The technical difficulty of acquiring quantitative MRS data in a multi-site clinical trial setting led to a low yield of analyzable data, which was insufficient to accurately measure the ability of early MRS measurements to predict response to NACT. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:290-302.

Variation in Mammographic Breast Density Assessments Among Radiologists in Clinical Practice: A Multicenter Observational Study.

Background: About half of the United States has legislation requiring radiology facilities to disclose mammographic breast density information to women, often with language recommending discussion of supplemental screening options for women with dense breasts. Objective: To examine variation in breast density assessment across radiologists in clinical practice. Design: Cross-sectional and longitudinal analyses of prospectively collected observational data. Setting: 30 radiology facilities within the 3 breast cancer screening research centers of the Population-based Research Optimizing Screening through Personalized Regimens (PROSPR) consortium. Participants: Radiologists who interpreted at least 500 screening mammograms during 2011 to 2013 (n = 83). Data on 216 783 screening mammograms from 145 123 women aged 40 to 89 years were included. Measurements: Mammographic breast density, as clinically recorded using the 4 Breast Imaging Reporting and Data System categories (heterogeneously dense and extremely dense categories were considered "dense" for analyses), and patient age, race, and body mass index (BMI). Results: Overall, 36.9% of mammograms were rated as showing dense breasts. Across radiologists, this percentage ranged from 6.3% to 84.5% (median, 38.7% [interquartile range, 28.9% to 50.9%]), with multivariable adjustment for patient characteristics having little effect (interquartile range, 29.9% to 50.8%). Examination of patient subgroups revealed that variation in density assessment across radiologists was pervasive in all but the most extreme patient age and BMI combinations. Among women with consecutive mammograms interpreted by different radiologists, 17.2% (5909 of 34 271) had discordant assessments of dense versus nondense status. Limitation: Quantitative measures of mammographic breast density were not available for comparison. Conclusion: There is wide variation in density assessment across radiologists that should be carefully considered by providers and policymakers when considering supplemental screening strategies. The likelihood of a woman being told she has dense breasts varies substantially according to which radiologist interprets her mammogram. Primary Funding Source: National Institutes of Health.

Expanding the Scope of an Automated Radiology Recommendation-Tracking Engine: Initial Experiences and Lessons Learned.

An automated radiology recommendation-tracking engine for incidental focal masses in the liver, pancreas, kidneys, and adrenal glands was launched within our institution in July 2013. For 2 years, the majority of CT, MR, and US examination reports generated within our health system were mined by the engine. However, the need to expand the system beyond the initial four organs was soon identified. In July 2015, the second phase of the system was implemented and expanded to include additional anatomic structures in the abdomen and pelvis, as well as to provide non-radiology and non-imaging options for follow-up. The most frequent organs with incidental findings, outside of the original four, included the ovaries and the endometrium, which also correlated to the most frequently ordered imaging follow-up study of pelvic ultrasound and non-imaging follow-up study of endometrial biopsies, respectively. The second phase expansion has demonstrated new venues for augmenting and improving radiologist roles in optimal communication and management of incidental findings.

Using lessons from breast, cervical, and colorectal cancer screening to inform the development of lung cancer screening programs.

Multiple advisory groups now recommend that high-risk smokers be screened for lung cancer by low-dose computed tomography. Given that the development of lung cancer screening programs will face many of the same issues that have challenged other cancer screening programs, the National Cancer Institute-funded Population-based Research Optimizing Screening through Personalized Regimens (PROSPR) consortium was used to identify lessons learned from the implementation of breast, cervical, and colorectal cancer screening that should inform the introduction of lung cancer screening. These lessons include the importance of developing systems for identifying and recruiting eligible individuals in primary care, ensuring that screening centers are qualified and performance is monitored, creating clear communication standards for reporting screening results to referring physicians and patients, ensuring follow-up is available for individuals with abnormal test results, avoiding overscreening, remembering primary prevention, and leveraging advances in cancer genetics and immunology. Overall, this experience emphasizes that effective cancer screening is a multistep activity that requires robust strategies to initiate, report, follow up, and track each step as well as a dynamic and ongoing oversight process to revise current screening practices as new evidence regarding screening is created, new screening technologies are developed, new biological markers are identified, and new approaches to health care delivery are disseminated. Cancer 2016;122:1338-1342. © 2016 American Cancer Society.