Comparison of screening CEDM and MRI for women at increased risk for breast cancer: A pilot study.

OBJECTIVES: Contrast enhanced digital mammography (CEDM) is a new breast imaging technology increasingly used in the diagnostic setting but its utility in the pure screening setting has not been reported. The goal of this pilot study is to prospectively compare screening CEDM to breast MRI in women with an increased risk for breast cancer. METHODS: In this IRB-approved HIPAA-compliant study, 318 women at increased breast cancer risk were consented (December 2012-May 2015) to undergo CEDM in addition to their scheduled MRI. CEDM was performed within 30days of screening MRI. CEDM was interpreted blinded to MRI. The reference standard was defined as a combination of pathology and 2-year imaging follow-up. RESULTS: Data from 307/318 patients were evaluable. Three cancers (two invasive cancers, one ductal carcinoma in situ) were detected at first round screening: MRI detected all three and CEDM detected the two invasive cancers. None of the three cancers was seen on the low energy mammograms which are comparable to conventional mammography. At 2year imaging follow up, there were 5 additional screen detected cancers and no palpable cancers. The positive predictive value 3 (PPV3) for CEDM was 15% (2/13, 95% CI: 2-45%) and 14% for MRI (3/21, 95% CI: 3-36%). The specificity of CEDM and MRI were 94.7% and 94.1% respectively. CONCLUSIONS: Both CEDM and MRI detected additional cancers not seen on conventional mammography, primarily invasive cancers. Our pilot data suggest that CEDM could be valuable as a supplemental imaging exam for women at increased risk for breast cancer who do not meet the criteria for MRI or for whom access to MRI is limited. Validation in larger multi institutional trials is warranted.

MRI appearance of invasive subcentimetre breast carcinoma: benign characteristics are common.

OBJECTIVE: This study was undertaken to examine the characteristics of cancers detected at the earliest possible point on MRI and to determine their significance. METHODS: This institutional review board-approved Health Insurance Portability and Accountability Act-compliant retrospective study evaluated invasive breast cancers ≤1 cm histologically. MRI was performed within 6 months before diagnosis. Between 1 January 2005 and 31 December 2015, 163 cancers in 161 patients were evaluated. Breast Imaging-Reporting and Data System lesion characteristics were assessed by two radiologists independently. In cases of disagreement, arbitration by a third reader was performed. RESULTS: Cancers ≤1 cm became more obviously malignant as they enlarged with regard to shape (p = 0.021), margin (p = 0.0006), internal enhancement (p = 0.0158) and kinetics (p = 0.0001). Cancers ≤5 mm had benign characteristics of circumscribed margins in 71% (71/100), round/oval shape in 67% (67/100) and persistent enhancement in 41% (41/100). High T2 signal was found in 17% (28/62), distributed equally among different sizes (p = 0.3920). In ≤5-mm cancers (59%, 12/29), a comparison study to show interval growth was more often needed to determine the need for biopsy. When interval growth determined biopsy, this was evident within 24 months and cancers remained node negative despite this delay. CONCLUSION: Benign characteristics are present in most invasive cancers ≤5 mm. Small cancers on MRI may need to demonstrate growth to determine need for biopsy. Advances in knowledge: MR lesion characteristics may not be helpful in determining whether small lesions on MR are benign or malignant. However, as 97% of cancers in our study showed interval change when a prior MR for comparison was available, new lesions or increasing size should lead to consideration of biopsy.

Breast Cancers Detected at Screening MR Imaging and Mammography in Patients at High Risk: Method of Detection Reflects Tumor Histopathologic Results.

Purpose To compare the clinical, imaging, and histopathologic features of breast cancers detected at screening magnetic resonance (MR) imaging, screening mammography, and those detected between screening examinations (interval cancers) in women at high risk. Materials and Methods This retrospective institutional review board-approved, HIPAA-compliant review of 7519 women at high risk for breast cancer who underwent screening with MR imaging and mammography between January 2005 and December 2010 was performed to determine the number of screening-detected and interval cancers diagnosed. The need for informed consent was waived. Medical records were reviewed for age, risk factors (family or personal history of breast cancer, BRCA mutation status, history of high-risk lesion or mantle radiation), tumor histopathologic results, and time between diagnosis of interval cancer and most recent screening examination. The χ(2) test and logistic regression methods were used to compare the features of screening MR imaging, screening mammography, and interval cancers. The Wilcoxon signed-rank test was used to calculate P values. Results A total of 18 064 screening MR imaging examinations and 26 866 screening mammographic examinations were performed. Two hundred twenty-two cancers were diagnosed in 219 women, 167 (75%) at MR imaging, 43 (19%) at mammography, and 12 (5%) interval cancers. Median age at diagnosis was 52 years. No risk factors were associated with screening MR imaging, screening mammography, or interval cancer (P > .06). Cancers found at screening MR imaging were more likely to be invasive cancer (118 of 167 [71%]; P < .0001). Of the 43 cancers found at screening mammography, 38 (88%) manifested as calcifications and 28 (65%) were ductal carcinoma in situ. Interval cancers were associated with nodal involvement (P = .005) and the triple-negative subtype (P = .03). Conclusion In women at high risk for breast cancer who underwent screening with mammography and MR imaging, invasive cancers were more likely to be detected at MR imaging, whereas most cancers detected at screening mammography were ductal carcinoma in situ. Interval cancers were found infrequently and were more likely to be node positive and of the triple-negative subtype. (©) RSNA, 2016.

Detection of Internal Mammary Adenopathy in Patients With Breast Cancer by PET/CT and MRI.

OBJECTIVE: The purpose of this study was to assess the prevalence of internal mammary node (IMN) adenopathy in patients with breast cancer and compare breast MRI and PET/CT for detection of IMN adenopathy. MATERIALS AND METHODS: This retrospective study included 90 women who underwent MRI and PET/CT before neoadjuvant chemotherapy for clinical stage IIA through IIIA disease. MRI and PET/CT examinations were read independently by two readers trained in breast imaging and nuclear medicine. All patients underwent follow-up MRI at the end of chemotherapy, and 10 with hypermetabolic IMNs underwent follow-up PET/CT. Histology was not obtained. Women were considered to have IMN adenopathy when nodes seen on MRI or having standardized uptake value (SUV) greater than mediastinal blood pool decreased in either size or SUV (or both) after treatment. Features including lymphovascular invasion, tumor quadrant(s), and axillary adenopathy were compared between presence and absence of IMN adenopathy using Fisher's exact test. Prevalence was determined on the basis of the percentage of patients with IMN adenopathy by either modality. The McNemar test compared the prevalence of IMN adenopathy on MRI to its prevalence on PET/CT. RESULTS: Prevalence of IMN adenopathy was 16% (14/90) by MRI and 14% (13/90) by PET/CT (p = 0.317). After chemotherapy, IMN adenopathy resolved in 12 of 14 patients (86%). In two patients with poor responses in primary tumors, IMN adenopathy persisted, and both patients developed metastatic disease within 6 months. At 3 years, survival was significantly worse in patients with IMN adenopathy than in those without (85.7% vs 53.3%, respectively; p = 0.009). CONCLUSION: In women with advanced breast cancer receiving neoadjuvant chemo-therapy, prevalence of IMN adenopathy was 16%, equally detected by breast MRI and PET/CT. Identification of IMN adenopathy may affect treatment and provides prognostic information.

Incidence of Internal Mammary Lymph Nodes with Silicone Breast Implants at MR Imaging after Oncoplastic Surgery.

PURPOSE: To assess the incidence of benign and malignant internal mammary lymph nodes (IMLNs) at magnetic resonance (MR) imaging among women with a history of treated breast cancer and silicone implant reconstruction. MATERIALS AND METHODS: The institutional review board approved this HIPAA-compliant retrospective study and waived informed consent. Women were identified who (a) had breast cancer, (b) underwent silicone implant oncoplastic surgery, and (c) underwent postoperative implant-protocol MR imaging with or without positron emission tomography (PET)/computed tomography (CT) between 2000 and 2013. The largest IMLNs were measured. A benign IMLN was pathologically proven or defined as showing 1 year of imaging stability and/or no clinical evidence of disease. Malignant IMLNs were pathologically proven. Incidence of IMLN and positive predictive value (PPV) were calculated on a per-patient level by using proportions and exact 95% confidence intervals (CIs). The Wilcoxon rank sum test was used to assess the difference in axis size. RESULTS: In total, 923 women with breast cancer and silicone implants were included (median age, 46 years; range, 22-89 years). The median time between reconstructive surgery and first MR imaging examination was 49 months (range, 5-513 months). Of the 923 women, 347 (37.6%) had IMLNs at MR imaging. Median short- and long-axis measurements were 0.40 cm (range, 0.20-1.70 cm) and 0.70 cm (range, 0.30-1.90 cm), respectively. Two hundred seven of 923 patients (22.4%) had adequate follow-up; only one of the 207 IMLNs was malignant, with a PPV of 0.005 (95% CI: 0.000, 0.027). Fifty-eight of 923 patients (6.3%) had undergone PET/CT; of these, 39 (67.2%) had IMLN at MR imaging. Twelve of the 58 patients (20.7%) with adequate follow-up had fluorine 18 fluorodeoxyglucose-avid IMLN, with a median standardized uptake value of 2.30 (range, 1.20-6.10). Only one of the 12 of the fluorodeoxyglucose-avid IMLNs was malignant, with a PPV of 0.083 (95% CI: 0.002, 0.385). CONCLUSION: IMLNs identified at implant-protocol breast MR imaging after oncoplastic surgery for breast cancer are overwhelmingly more likely to be benign than malignant. Imaging follow-up instead of immediate metastatic work-up may be warranted.

Breast carcinoma in augmented breasts: MRI findings.

OBJECTIVE: The objective of our study was to characterize the MRI features of breast carcinomas detected in augmented breasts. MATERIALS AND METHODS: A review of the MRI database identified 54 patients with biopsy-proven breast carcinoma in augmented breasts. The images were reviewed for the type and location of the implant and for the characteristics of the carcinoma. The cases included 46 (85%) invasive cancers (invasive ductal carcinoma, n = 35; invasive lobular carcinoma, n = 7; and mixed features, n = 4) and eight (15%) ductal carcinomas in situ. RESULTS: The median age of the patients at diagnosis was 49 years (range, 28-72 years). Thirty-eight of the 54 cancers (70%) were palpable. The mean tumor size was 2.8 cm (range, 0.6-9.6 cm). Of the 54 cancers, 34 (63%) presented as masses and 20 (37%) as nonmass enhancement on MRI. There was no detectable difference between implant position and lesion morphology (p = 0.55) or tumor size (p = 1.00). Twenty of 54 (37%) carcinomas abutted the implant, 13 (24%) abutted the pectoralis major muscle, and two (4%) invaded the pectoralis major muscle. Of the tumors abutting the implant, 18 of 20 (90%) spread along the implant capsule for more than 0.5 cm. This pattern of tumor spread was more common in breasts with retroglandular implants (9/16, 56%) than in those with retropectoral implants (9/38, 24%) (p = 0.03). MRI detected the index carcinoma in 16 of 54 (30%) cases, showed a greater extent of disease than was visible on mammography or ultrasound in 21 of 52 (40%) cases, and detected an unsuspected contralateral carcinoma in three of 54 (6%) cases. CONCLUSION: In augmented breasts, breast cancer often contacts either the implant or the pectoralis major muscle. Tumor spread along the implant contour is more often seen with retroglandular implants than with retropectoral implants. MRI should be considered to assess disease extent in women with augmented breasts before surgery.

Low energy mammogram obtained in contrast-enhanced digital mammography (CEDM) is comparable to routine full-field digital mammography (FFDM).

PURPOSE: Contrast enhanced digital mammography (CEDM) uses low energy and high energy exposures to produce a subtracted contrast image. It is currently performed with a standard full-field digital mammogram (FFDM). The purpose is to determine if the low energy image performed after intravenous iodine injection can replace the standard FFDM. METHODS: And Materials: In an IRB approved HIPAA compatible study, low-energy CEDM images of 170 breasts in 88 women (ages 26-75; mean 50.3) undergoing evaluation for elevated risk or newly diagnosed breast cancer were compared to standard digital mammograms performed within 6 months. Technical parameters including posterior nipple line (PNL) distance, compression thickness, and compression force on the MLO projection were compared. Mammographic findings were compared qualitatively and quantitatively. Mixed linear regression using generalized estimating equation (GEE) method was performed. Intraclass correlation coefficients (ICC) with 95% confidence interval (95%CI) were estimated to assess agreement. RESULTS: No statistical difference was found in the technical parameters compression thickness, PNL distance, compression force (p-values: 0.767, 0.947, 0.089). No difference was found in the measured size of mammographic findings (p-values 0.982-0.988). Grouped calcifications had a mean size/extent of 2.1cm (SD 0.6) in the low-energy contrast images, and a mean size/extent of 2.2 cm (SD 0.6) in the standard digital mammogram images. Masses had a mean size of 1.8 cm (SD 0.2) in both groups. Calcifications were equally visible on both CEDM and FFDM. CONCLUSION: Low energy CEDM images are equivalent to standard FFDM despite the presence of intravenous iodinated contrast. Low energy CEDM images may be used for interpretation in place of the FFDM, thereby reducing patient dose.

Preoperative breast MRI for early-stage breast cancer: effect on surgical and long-term outcomes.

OBJECTIVE: The purpose of this study was to evaluate the effect of the use of preoperative breast MRI on surgical and long-term outcomes among women with early-stage breast cancer undergoing breast conservation therapy. MATERIALS AND METHODS: A retrospective review yielded the cases of 174 women with stage 0, I, or II breast cancer who underwent preoperative MRI between 2000 and 2004. A control group of 174 patients who did not undergo preoperative MRI before breast conservation therapy was matched by age, histopathologic finding, stage, and surgeon. Features compared included breast density, presence of mammographically occult disease, margin status, lymph node involvement, lymphovascular invasion, extensive intraductal component, hormone receptor status, and use of adjuvant therapy. Outcomes, including rates of reexcision, ipsilateral recurrence, and disease-free survival, were compared by Kaplan-Meier methods and the log-rank test. RESULTS: Patients referred for preoperative breast MRI were more likely to have extremely dense breasts (28% vs 6%, p < 0.0001) and mammographically occult cancer (24% vs 9%, p = 0.0003). The two groups had identical rates of final negative margins, lymph node involvement, lymphovascular invasion, extensive intraductal component status, positive hormone receptor results, and systemic adjuvant therapy. Fewer patients in the preoperative MRI group needed reexcision (29% vs 45%, p = 0.02). The median follow-up period after treatment was 8 years. There was no significant difference in locoregional recurrence (p = 0.33) or disease-free survival (p = 0.73) rates between the two groups. CONCLUSION: Reexcision rates among patients with early breast cancer undergoing conservation therapy were lower among women who underwent preoperative breast MRI. There was no statistically significant effect of the use of preoperative MRI on rates of locoregional recurrence or disease-free survival.

MR imaging features of triple-negative breast cancers.

Triple-negative (TN) breast cancers, which are associated with a more aggressive clinical course and poorer prognosis, often present with benign imaging features on mammography and ultrasound. The purpose of this study was to compare the magnetic resonance imaging features of TN breast cancers with estrogen (ER) and progesterone (PR) positive, human epidermal growth factor receptor (HER2) negative cancers. Retrospective review identified 140 patients with TN breast cancer who underwent a preoperative breast MRI between 2003 and 2008. Comparison was made to 181 patients with ER+/PR+/HER2- cancer. Breast MRIs were independently reviewed by two radiologists blinded to the pathology. Discrepancies were resolved by a third radiologist. TN cancers presented with a larger tumor size (p = 0.002), higher histologic grade (<0.001), and were more likely to be unifocal (p = 0.018) compared with ER+/PR+/HER2- tumors. MRI features associated with TN tumors included mass enhancement (p = 0.026), areas of intratumoral high T2 signal intensity (p < 0.001), lobulated shape (p < 0.001), rim enhancement (p < 0.001), and smooth margins (p = 0.005). Among the TN tumors with marked necrosis, 26% showed a large central acellular zone of necrosis.

Breast magnetic resonance imaging for screening high-risk women.

Mammography is the only imaging modality that has been validated by multiple randomized clinical trials and meta-analyses to reduce mortality from breast cancer. Although it is demonstrated to be effective in reducing mortality from breast cancer, mammography has its limitations, especially in young high-risk women with dense breasts. Other imaging modalities have been pursued as an adjunct screening modality in this population. Of these, the most widely accepted is contrast-enhanced breast magnetic resonance (MR) imaging. This article reviews current recommendations and limitations of using MR imaging of the breast to screen asymptomatic women at high risk for breast cancer.

Bilateral contrast-enhanced dual-energy digital mammography: feasibility and comparison with conventional digital mammography and MR imaging in women with known breast carcinoma.

PURPOSE: To determine feasibility of performing bilateral dual-energy (DE) contrast agent-enhanced (CE) digital mammography and to evaluate its performance compared with conventional digital mammography and breast magnetic resonance (MR) imaging in women with known breast cancer. MATERIALS AND METHODS: This study was approved by the institutional review board and was HIPAA compliant. Written informed consent was obtained. Patient accrual began in March 2010 and ended in August 2011. Mean patient age was 49.6 years (range, 25-74 years). Feasibility was evaluated in 10 women with newly diagnosed breast cancer who were injected with 1.5 mL per kilogram of body weight of iohexol and imaged between 2.5 and 10 minutes after injection. Once feasibility was confirmed, 52 women with newly diagnosed cancer who had undergone breast MR imaging gave consent to undergo DE CE digital mammography. Positive findings were confirmed with pathologic findings. RESULTS: Feasibility was confirmed with no adverse events. Visualization of tumor enhancement was independent of timing after contrast agent injection for up to 10 minutes. MR imaging and DE CE digital mammography both depicted 50 (96%) of 52 index tumors; conventional mammography depicted 42 (81%). Lesions depicted by using DE CE digital mammography ranged from 4 to 67 mm in size (median, 17 mm). DE CE digital mammography depicted 14 (56%) of 25 additional ipsilateral cancers compared with 22 (88%) of 25 for MR imaging. There were two false-positive findings with DE CE digital mammography and 13 false-positive findings with MR imaging. There was one contralateral cancer, which was not evident with either modality. CONCLUSION: Bilateral DE CE digital mammography was feasible and easily accomplished. It was used to detect known primary tumors at a rate comparable to that of MR imaging and higher than that of conventional digital mammography. DE CE digital mammography had a lower sensitivity for detecting additional ipsilateral cancers than did MR imaging, but the specificity was higher. © RSNA, 2012.

Advances in oncologic imaging: update on 5 common cancers.

Imaging has become a pivotal component throughout a patient's encounter with cancer, from initial disease detection and characterization through treatment response assessment and posttreatment follow-up. Recent progress in imaging technology has presented new opportunities for improving clinical care. This article provides updates on the latest approaches to imaging of 5 common cancers: breast, lung, prostate, and colorectal cancers, and lymphoma.

Papilloma diagnosed at MRI-guided vacuum-assisted breast biopsy: is surgical excision still warranted?

OBJECTIVE: The objective of our study was to determine the frequency of cancer at surgery in breast lesions yielding papilloma at MRI-guided 9-gauge vacuum-assisted biopsy (VAB) and to determine whether any features are associated with cancer upgrade. MATERIALS AND METHODS: For this study, 1487 MRI-guided vacuum-assisted biopsies performed from January 2004 to March 2011 were reviewed. Lesions yielding papilloma were identified and classified as papilloma with or without atypia. Surgical findings were reviewed to determine the cancer rate. Statistical analysis was performed and 95% CIs were calculated. RESULTS: Papilloma was identified in 75 of the 1487 MRI-guided vacuum-assisted biopsies (5%). These 75 papillomas occurred in 73 women with a median age of 49 years (age range, 27-70 years). Of the 75 papillomas, 25 (33%) had atypia and 50 (67%) did not on core needle biopsy. Subsequent surgery of 67 of the 75 papillomas (89%) yielded ductal carcinoma in situ (DCIS) in four (6%; 95% CI, 2-15%). Surgery yielded DCIS in two of 23 papillomas with atypia (9%; 95% CI, 1-28%) at MRI-guided VAB and in two of 44 papillomas without atypia (5%; 95% CI, 0.4-16%) at MRI-guided VAB; these cancer rates did not differ significantly (p=0.6). Postmenopausal status (p=0.04) and histologic size of less than 0.2 cm (p=0.04) had a significant association with the cancer upgrade rate. CONCLUSION: Papilloma with or without atypia was found in 5% of patients who underwent MRI-guided VAB during the study period. Surgery revealed cancer in 6%. DCIS was found at surgery in 9% of lesions yielding papilloma with atypia versus 5% of lesions yielding papilloma without atypia. For lesions yielding papilloma with or without atypia at MRI-guided VAB, surgical excision is warranted.

Patient follow-up after concordant histologically benign imaging-guided biopsy of MRI-detected lesions.

OBJECTIVE: The purpose of this study was to review the reported experience and suggest follow-up after biopsy for MRI-detected lesions. CONCLUSION: Imaging-guided biopsy, using MRI or sonographic guidance, of MRI-detected lesions may result in false-negative results that are not appreciated at the time of the biopsy. A 6-month follow-up MRI is suggested as the most appropriate interval to identify lesions that were missed at biopsy without clinically significant delay in diagnosis of those lesions that are malignant.