Degree Of Background Parenchymal Enhancement Research Articles

The value of DCE- MRI of the breast as a diagnostic tool in assessing amorphous calcifications in screening mammography.

To evaluate the diagnostic performance of dynamic contrast-enhanced magnetic resonance imaging in differentiating benign and malignant amorphous calcifications. This study included 193 female patients with 197 suspicious amorphous calcifications detected on screening mammography. The patients' demographics, clinical follow-up, imaging, and pathology outcomes were reviewed, and sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of DCE-MRI were calculated. Of 197 lesions (193 patients) included in the study, 50 (25.4%) were histologically proved to be malignant. DCE-MRI based on breast imaging report and diagnosis system (BI-RADS) had a sensitivity of 94.4%, specificity of 85.7%, PPV of 69.1%, and NPV of 97.7% for the detection of malignant amorphous calcifications. Notably, diagnosis solely based on the presence or absence of DCE-MRI enhancement showed the same sensitivity but significantly decreased specificity (44.8%, p < 0.001) and PPV (44.8%, p < 0.001). In patients with a minimal or mild degree of background parenchymal enhancement (BPE), the sensitivity, specificity, PPV, and NPV increased to 100%, 90.6%, 78.6%, and 100%, respectively. However, in patients with a moderate degree of BPE, MRI resulted in three false negatives of ductal carcinoma in situ (DCIS). Overall, the addition of DCE-MRI detected all invasive lesions and could decrease unnecessary biopsy by 65.5%. DCE-MRI based on BI-RADS has the potential to improve the diagnosis of suspicious amorphous calcifications and avoid unnecessary biopsy, especially for those with low-degree BPE.

Efficacy of MRI-Directed Breast Ultrasound and Lesion Characteristics Affecting Visualization on Breast Ultrasound

ObjectiveTo assess the efficacy of magnetic resonance imaging (MRI)-directed ultrasound (US) in further characterizing lesions detected on MRI and to evaluate the correlation between lesion characteristics and their visibility on US. MethodsA retrospective review was performed of the records of patients with breast abnormalities detected on MRI between May 2018 and December 2020. All patients who were given a Breast Imaging-Reported and Data System Assessment Category 4 or 5 on breast MRI and sent to breast US for assessment of the MRI abnormality were included. Patients lost to follow-up or those who did not get their subsequent ultrasound at our institution were excluded. The following factors were recorded for all lesions described on the MRI reports: breast density, degree of background parenchymal enhancement, type of MRI finding (mass, areas of non-mass enhancement [NME], enhancing focus), largest dimension, T2 signal intensity, kinetics, shape, margins, enhancement pattern, and presence of ipsilateral breast malignancy. For the subset of the lesions that were identified on MRI-directed US, we recorded the following sonographic features: largest dimension, shape, and margin. The chi-square or Fisher exact tests of association were used to compare categorical characteristics. ResultsTwo hundred and thirty-three MRI-detected breast lesions were included in the study, which consisted of 171 masses, 7 enhancing foci, and 55 NME lesions. Of all lesions, 52% (89/171) of masses, 29% (16/55) of areas of NME, and 29% (2/7) of foci were seen on US. Moreover, 43 per 63 (68%) of malignant, 18 per 47 (38%) of high-risk and 46 per 123 (37%) of benign lesions were seen on MRI-directed US. Of the invasive malignant lesions, 77% (36/47) had a sonographic correlate. For masses, the average size on MRI was 1.1 cm, and MRI size had a statistically significant association with US visibility (P value 0.01). Similarly, spiculated margins on MRI for masses had a significant association with US visibility (P value 0.0006). Linear, segmental, and regional distributions of areas of NME were associated with decreased likelihood of sonographic visibility (P = 0.049). ConclusionMRI-directed US is a useful tool in the management of MRI-detected breast lesions. Our study indicates that masses, particularly those with spiculated margins on MRI, should be sent to US for further assessment. Additionally, masses are more likely to be seen under US as their size increases. MRI-directed US is less likely to visualize areas of NME and enhancing foci, which may be managed with MRI follow-up or MRI-guided biopsy depending on their level of suspicion.

Outcome of Screening MRI in Premenopausal Women as a Function of the Week of the Menstrual Cycle.

OBJECTIVE. The objective of our study was to determine whether there are differences in outcome of screening MRI examinations in premenopausal women as a function of the week of the menstrual cycle in which the study was performed. MATERIALS AND METHODS. The reports of consecutive screening MRI examinations performed from January 1, 2011, through December 31, 2012, of premenopausal women were reviewed. Only cases for which the 1st day of the last menstrual cycle was documented were included. Associations between the week of the menstrual cycle, degree of background parenchymal enhancement (BPE), final BI-RADS assessment, positive predictive values (PPVs), cancer detection rate (CDR), sensitivity, and specificity were noted. RESULTS. A total of 1536 MRI examinations of 1239 women were performed. Distribution of MRI examinations by menstrual cycle week was as follows: 21.8% (n = 335) in week 1, 35.4% (n = 544) in week 2, 23.4% (n = 360) in week 3, and 19.3% (n = 297) in week 4. In the overall comparison, there was no significant difference in BPE, BI-RADS assessment, PPV1, PPV2, PPV3, CDR, sensitivity, or specificity by the week of the menstrual cycle. When outcomes for cases with MRI performed in week 2 were compared with those of cases with MRI performed in weeks 1, 3, and 4 combined, there was no significant difference in the same outcome measures. CONCLUSION. There was no evidence of a difference in outcomes of screening MRI examinations as a function of the week of menstrual cycle in which the study is performed. The results of our study do not support the need for screening MRI to be performed in week 2 of the menstrual cycle.

Abstract PD9-07: The rate of parenchymal enhancement during DCE-MRI reflects response to neoadjuvant therapy

Abstract Background: Dynamic contrast-enhanced MRI (DCE-MRI) plays a crucial role in breast cancer detection and monitoring of therapeutic response by assessing the tumor vascular network. The MRI contrast agent enhances not only tumor tissue, but also normal breast tissue, a phenomena known as background parenchymal enhancement (BPE). The degree of BPE can be variable between different individuals, is influenced by the hormonal milieu, and displays variable anatomical and kinetic patterns. Changes in BPE intensity over the course of neoadjuvant therapy (NAT) have been found to correlate with response to therapy in both the ipsilateral and contralateral breast. The present study assesses changes in the rate of BPE over the course of NAT to predict eventual response to NAT. Importantly, this study was conducted in collaboration with community-care centers (i.e., not research-oriented medical centers). Methods: Women with locally advanced breast cancer (N = 19) were imaged four times during the course of NAT: 1) prior to the start of NAT, 2) after 1 cycle of NAT, 3) after 2-4 cycles of NAT, and 4) 1 cycle after MRI #3. Imaging data was acquired on 3T Siemens Skyra scanners equipped with a 8- or 16-channel breast coils. Gadolinium-based contrast agent (0.1 mmol/kg of Multihance or 10 mL of Gadovist) was administered intravenously at 2 mL/sec after the acquisition of baseline scans. DCE-MRI data was collected in 10 sagittal slices with a temporal resolution of 7.27 sec for a total acquisition time of eight minutes. The tumor was semi-automatically segmented using a manually drawn region of interest (ROI) followed by fuzzy c-means clustering of a post-contrast high-resolution anatomical scan. Fibroglandular parenchyma was segmented from adipose tissue using fuzzy c-means clustering and further segmented into three concentric rings at prescribed radial distances from the tumor boundary. Enhancement time courses were temporally smoothed using a moving average filter of width 5 and normalized to baseline intensity to yield relative enhancement time courses. The enhancement slope, defined as the slope of the curve at half maximal intensity, was calculated from the kinetic uptake curve for the tumor, adipose, and concentric rings of fibroglandular tissue surrounding the tumor. Results: Prior to commencing NAT, women with faster tumoral enhancement had faster fibroglandular enhancement (r = 0.62, p &amp;lt; 0.05). There was no correlation between tumor and adipose enhancement rate or fibroglandular and adipose enhancement rate. Among concentric rings of fibroglandular tissue, the tissue most distal to the tumor enhanced faster than tissue more proximal to the tumor (p &amp;lt; 0.05). Over the course of NAT, the rate of fibroglandular enhancement tended to slow (p &amp;lt; 0.01). Women who ultimately achieved pathological complete response (pCR; n = 6) displayed a faster rate of fibroglandular enhancement at the 4th MRI than women with residual tumor at the time of resection (n = 13). This correlation was preserved (p &amp;lt; 0.01) in a subset of patients who received AC◊T therapy, the most common treatment arm in this study (n = 4 pCR, n = 8 non-pCR). Furthermore, this relationship persisted when the fibroglandular enhancement rate was normalized by the tumoral enhancement rate in both the full patient cohort and in the 12 patients who received AC◊T (p &amp;lt; 0.05, both cohorts). Conclusions: These results demonstrate that the rate of fibroglandular tissue enhancement in patients receiving NAT for breast cancer reflects response to therapy. The increased rate of fibroglandular enhancement in women achieving pCR may reflect treatment-mediated vascular remodeling in healthy breast tissue. Incorporating quantitative characterization of parenchymal enhancement kinetics into treatment response models warrants further investigation. Citation Format: John Virostko, Erin M Higgins, Chengyue Wu, Anna G Sorace, Debra Patt, Boone Goodgame, Thomas E Yankeelov. The rate of parenchymal enhancement during DCE-MRI reflects response to neoadjuvant therapy [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr PD9-07.

Abstract PD9-05: Lack of background parenchymal enhancement suppression in breast MRI during neoadjuvant chemotherapy may be associated with inferior treatment response in hormone receptor positive breast cancer

Abstract Purpose In breast MRI, contrast enhancement of normal fibroglandular tissue is referred to as background parenchymal enhancement (BPE). Hormonal status significantly affects the degree of BPE, potentially due to the association with mammary vascularity and activity1-5. Studies have shown that BPE may be associated with breast cancer survival6, treatment response to neoadjuvant chemotherapy (NAC)7,8 and future breast cancer risk9. In most patients undergoing NAC, BPE is suppressed by the nonspecific anti-proliferative effects of chemotherapy on normal breast and/or ovary5,10. However, some patients exhibit equivalent or even stronger BPE post-NAC compared to pre-NAC. We hypothesized that non-suppressed BPE in post-NAC MRI may be associated with inferior treatment response. This study aimed to investigate the association between BPE suppression and treatment response as defined by pathologic complete response (pCR). Methods This study included patients with stage II/III breast cancer enrolled in the I-SPY 2 TRIAL being treated with standard NAC with or without investigational agents. The whole cohort was split into two subgroups based on hormone receptor status (HR+, n= 536; HR-, n=452). Patients underwent dynamic contrast enhanced MRIs at four time points during NAC: baseline (T0), after 3 weeks of the first regimen (T1), inter-regimen (T2), and pre-surgery (T3). Using in-house software, the contralateral breast parenchyma was automatically segmented for the entire breast volume. Quantitative BPE (qBPE) was calculated as the mean early (~150s post-contrast injection) percent enhancement of the central 50% of the axial slices. A breast radiologist reviewed all exams and excluded those where automated segmentation failed to accurately define tissue. For T1, T2 and T3, BPE was categorized based on the change from T0 as suppressed (qBPE &amp;lt; qBPE[T0]) or non-suppressed (qBPE ≥ qBPE[T0]). Chi-squared test was used to examine the association between BPE suppression and pCR, with p&amp;lt;0.05 considered statistically significant. Results HR+ cohort: pCR rates were lower for patients with non-suppressed BPE than those with suppressed BPE at every visit (T1-T3) (Table 1). The difference was statistically significant at T2 (p=0.04) and T3 (p=0.01). Table 1: HR+ cohortpCR rate (%)No. of pCR patientsNo. of non-pCR patientsTotal number of patientsP valueOverall22.8122414536BPE at T1suppressed23.6822663480.45non-suppressed20.532124156BPE at T2suppressed25.7972803770.04*non-suppressed16.01789106BPE at T3suppressed25.7982833810.01*non-suppressed12.5128496 HR- cohort: pCR rates were slightly lower for the non-suppressed BPE group, but no statistically significant association was found (Table 2). Table 2: HR- cohortpCR rate (%)No. of pCR patientsNo. of non-pCR patientsTotal number of patientsP valueOverall44.7202250452BPE at T1suppressed46.81411603010.66non-suppressed44.45265117BPE at T2suppressed48.81441512950.79non-suppressed47.3434891BPE at T3suppressed49.31461502960.94non-suppressed48.9434588 Conclusion In HR+ breast cancer, lack of BPE suppression may indicate inferior treatment response. The contrasting results in HR+ and HR- cohorts are noteworthy in terms of the possible relationship between suppression of normal mammary and ovarian activity and treatment response in HR+ cancer. Reference Radiographics 2014; 34: 234-47. Radiology 1997; 203: 137-44. Radiology 1997; 203: 145-9. Breast J 2005; 11: 236-41. AJR Am J Roentgenol 2015; 204: 669-73. Eur Radiol 2018; 28: 4705-16. Eur Radiol 2016; 26: 1590-6. Transl Oncol 2015; 8: 204-9. J Clin Oncol 2019; : JCO1800378. Radiology 2015; 277: 687-96. Citation Format: Natsuko Onishi, Wen Li, David C. Newitt, Roy Harnish, Jessica Gibbs, Ella F. Jones, Alex Nguyen, Lisa Wilmes, Bonnie N. Joe, Michael J. Campbell, Amrita Basu, Laura J. van’t Veer, Angela DiMichele, Douglas Yee, Donald A. Berry, Kathy S. Albain, Judy C. Boughey, A. Jo Chien, Amy S. Clark, Kirsten K. Edmiston, Anthony D. Elias, Erin D. Ellis, David M. Euhus, Heather S. Han, Claudine Isaacs, Qamar J. Khan, Julie E. Lang, Janice Lu, Jane L. Meisel, Zaha Mitri, Rita Nanda, Donald W. Northfelt, Tara Sanft, Erica Stringer-Reasor, Rebecca K. Viscusi, Anne M. Wallace, Rachel Yung, Michelle E. Melisko, Jane Perlmutter, Hope S. Rugo, Richard Schwab, W. Fraser Symmans, Smita M. Asare, Julie E. Yau, Christina Yau, Laura J. Esserman, Nola M. Hylton. Lack of background parenchymal enhancement suppression in breast MRI during neoadjuvant chemotherapy may be associated with inferior treatment response in hormone receptor positive breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr PD9-05.

The relationship of breast density in mammography and magnetic resonance imaging in women with triple negative breast cancer

PurposeTo evaluate the relationship between mammographic density, background parenchymal enhancement and fibroglandular tissue on MRI in women with triple negative breast cancer (TNBC) compared to women with non-triple negative breast cancer (non-TNBC). MethodsThe institutional Breast Cancer Database was queried to identify the clinicopathologic and imaging characteristics among women who underwent mammography and breast MRI between 2010-2018. Statistical analyses included Pearson’s Chi Square, Wilcoxon Rank-Sum and logistic regression. ResultsOf 2995 women, 225 (7.5 %) had TNBC with a median age of 60 years (23–96) and median follow-up of 5.69 years. Compared to women with non-TNBC, TNBC was associated with African-American race 36/225 (16 %), BRCA1,2 positivity 34/225 (15.1 %), previous history of breast cancer 35/225 (15.6 %), presenting on breast exam 126/225 (56 %) or MRI 13/225 (5.8 %), palpability 133/225 (59.1 %), more invasive ductal carcinoma (IDC) 208/225 (92.4 %), higher stage (stage III) 37/225 (16.5 %), higher grade (grade 3) 186/225 (82.7 %) (all p < 0.001), lower mammographic breast density (MBD) 18/225 (8 %) (p = 0.04), lower fibroglandular tissue (FGT) 17/225 (7.6 %) (p = 0.01), and lower background parenchymal enhancement (BPE) 89/225 (39.8 %) (p = 0.02). Nine of 225 (4 %) women with TNBC experienced recurrence with no significant association with MBD, FGT, or BPE. There was no significant difference in median age of our TNBC and non-TNBC cohorts. ConclusionsThe higher proportion of women with lower MBD, FGT and BPE in women with TNBC suggests that MBD, amount of FGT and degree of BPE may be associated with breast cancer risk in women with TNBC.

Preoperative Magnetic Resonance Imaging Features Associated with Positive Resection Margins in Patients with Invasive Lobular Carcinoma.

ObjectiveTo investigate preoperative magnetic resonance imaging (MRI) findings associated with resection margin status in patients with invasive lobular carcinoma (ILC) who underwent breast-conserving surgery.Materials and MethodsOne hundred and one patients with ILC who underwent preoperative MRI were included. MRI (tumor size, multifocality, type of enhancing lesion, distribution of non-mass enhancement [NME], and degree of background parenchymal enhancement) and clinicopathological features (age, pathologic tumor size, presence of ductal carcinoma in situ [DCIS] or lobular carcinoma in situ, presence of lymph node metastases, and estrogen receptor/progesterone receptor/human epidermal growth factor receptor type 2 status) were analyzed. A positive resection margin was defined as the presence of invasive cancer or DCIS at the inked surface. Logistic regression analysis was performed to determine pre- and postoperative variables associated with positive resection margins.ResultsAmong the 101 patients, 21 (20.8%) showed positive resection margins. In the univariable analysis, NME, multifocality, axillary lymph node metastasis, and pathologic tumor size were associated with positive resection margins. With respect to preoperative MRI findings, multifocality (odds ratio [OR] = 3.977, p = 0.009) and NME (OR = 2.741, p = 0.063) were associated with positive resection margins in the multivariable analysis, although NME showed borderline significance.ConclusionIn patients with ILC, multifocality and the presence of NME on preoperative breast MRI were associated with positive resection margins.

Comparison of Contrast-Enhanced Mammography With Conventional Digital Mammography in Breast Cancer Screening: A Pilot Study

PurposeTo perform a pilot evaluation of contrast-enhanced mammography (CEM) for screening to determine whether it can improve accuracy and reader confidence in diagnosis. Methods and MaterialsThis institutional review board–approved reader study was comprised of 64 de-identified CEM cases acquired from December 1, 2014, to June 7, 2016, including 48 negative, 5 biopsy-proven benign, and 11 biopsy-proven malignancies. Negative cases were followed for at least 2 years without evidence of cancer. Ten breast imagers of varying experience first rated the low-energy (LE) mammogram and then the CEM examination using BI-RADS categories and a 5-point Likert scale for confidence in diagnosis. ResultsThere were 635 out a total possible 640 complete reader interpretations included in this analysis. The remaining five incomplete interpretations were excluded. Median sensitivity and specificity improved with the addition of CEM (sensitivity: 0.86 [95% confidence interval {CI}: 0.74-0.95] versus 1 [95% CI: 0.83-1.00], specificity: 0.85 [95% CI: 0.64-0.94] versus 0.88 [95% CI: 0.80-0.92]). Individual receiver operating characteristic curves showed significant improvement with CEM (mean area under the curve increase = 0.056 [95% CI: 0.015-0.097], P = .002). The addition of CEM significantly improved average confidence in 5 of 10 readers when compared with LE (P < .0001) and improved pooled confidence across all tissue density categories, except the almost entirely fatty category. There was a trend toward improved confidence with increasing tissue density with CEM. Degree of background parenchymal enhancement did not affect readers’ level of improvement in confidence when interpreting CEM. SummaryCEM improved reader performance and confidence compared with viewing only LE, suggesting a role for CEM in breast cancer screening for which larger trials are warranted.

Preliminary analysis: Background parenchymal 18F-FDG uptake in breast cancer patients appears to correlate with background parenchymal enhancement and to vary by distance from the index cancer

PurposeTo investigate how breast parenchymal uptake (BPU) of 18F-FDG on positron emission tomography/ magnetic resonance imaging (PET/MRI) in patients with breast cancer is related to background parenchymal enhancement (BPE), amount of fibroglandular tissue (FGT), and age, as well as whether BPU varies as a function of distance from the primary breast cancer. Materials and MethodsIn this institutional review board (IRB)-approved retrospective study, 40 patients (all female, ages 32–80 years, mean 52 years) gave informed consent prior to undergoing contrast enhanced breast PET/MRI from 3/2015 to 2/2018. Of the 40 patients, 6 were excluded for multicentric or bilateral cancers, 1 for current lactation and 6 because the raw data from their scans were corrupted. The remaining 27 patients (all female, ages 33 to 80 years, mean age 53 years) comprised the study population. Prone PET and contrast-enhanced MR data were acquired simultaneously on a 3-T integrated PET/ MR system. BPU was measured as SUVmax of a 1.5 cm3 volume of interest 1) in the same quadrant of the ipsilateral breast, 5 mm from the index lesion; 2) in the opposite quadrant of the ipsilateral breast; and 3) in contralateral breast, quadrant matched to the opposite quadrant of the ipsilateral breast. The maximum standardized uptake value (SUVmax) of the index cancer was measured using a VOI that included the entire volume of the index lesion. Bleed from the primary tumor was corrected for (PET edge, MIM). FGT and BPE was assessed by 2 readers on a 4-point scale in accordance with BI-RADS lexicon. The Wilcoxon signed rank test and the Spearman rank correlation test were performed. ResultsBPU was significantly greater in the same quadrant as the breast cancer as compared with the opposite quadrant of the same breast (p < 0.001 for both readers) and was significantly greater in the opposite quadrant of the same breast compared to the matched quadrant of the contralateral breast (p = 0.002 for reader 1 and <0.001 for reader 2). While the FGT SUVmax in the same quadrant as the cancer correlated significantly with SUVmax of the index lesion, the FGT SUVmax in the opposite quadrant of the same breast and in the matched quadrant of the contralateral breast did not. The FGT SUVmax in the contralateral breast positively correlated with the degree of BPE and negatively correlated with age, but did not show a significant correlation with the amount of FGT for either reader. ConclusionThere appears to be an inverse correlation between metabolic activity of normal breast parenchyma and distance from the index cancer. BPU significantly correlates with BPE.

Evaluation of association between degree of background parenchymal enhancement on MRI and breast cancer subtype

PurposeEvaluate possible association between BPE and breast cancer tumor type/prognostic markers. MethodsIRB approved retrospective study from 1/2010–1/2014 identified 328 patients who had breast MRI and available clinical/pathology data. BPE was categorized according to BI-RADS. The association between BPE and breast cancer molecular subtype/prognostic factors was evaluated. ResultsNo significant association was present between high BPE and the following: HER2+ tumors, basal tumors, tumors with axillary nodal disease, high nuclear grade tumors, high Ki-67 index tumors or larger tumors. ConclusionPatients with high BPE may be at increased risk for breast cancer but not necessarily for those cancer subtypes with a poor prognosis.

Is Background Parenchymal Enhancement on Magnetic Resonance Imaging Helpful in Risk Assessment of Breast Cancer?

Objectives: Background parenchymal enhancement (BPE) on contrast-enhanced magnetic resonance imaging (CE-MRI) corresponds to hormonally active breast fibroglandular tissue. Several studi.es have reported increased odds of breast cancer in patients with marked BPE. The purpose of the present study was to evaluate BPE in contralateral breast of biopsy proven breast cancer patients and comparison of the results with control group. Methods: In a case-control study, CE-MRI of the contralateral breasts of 40 biopsy-proven breast cancer patients and 40 patients with biopsy- proven benign breast lesions, were retrospectively reviewed by an experienced radiologist and degree of BPE, and pattern of enhancement were determined, finally, BPE was compared between case and control groups using chi square test. Pearson correlation test was used to determine association between FGT amount and BPE. P value < 0.05 was considered significant. Results: In the case group, 4, 17, 14, and 5 patients had minimal, mild, moderate, and marked BPE, respectively. In the control group, 12, 24, .and 4 participants had minimal, mild, and moderate BPE, respectively. BPE was significantly higher in the case group in comparison with the control group (P value < 0.05). Patients with invasive carcinoma had significantly higher BPE in comparison with the patients with carcinoma in situ. (P value < 0.05) There was a moderate correlation (r = 0.4, P value < 0.05) between FGT amount and degree of BPE. In the case group, 3, 26, and 11 patients had mass-non mass, mass, and non mass pattern of enhancement, respectively. In the control group, 25, antl15 participants had mass, and non mass pattern of enhancement, respectively. Pattern of enhancement was not significantly different between the two groups. Conclusions: Our study revealed that patients with the diagnosis of breast cancer have greater BPE in comparison with control group. The results may be indicative for higher probability of developing breast cancer in patients with higher BPE. Therefore, CE-MRI could be a useful tool for breast cancer risk assessment.

Repeated surgeries in invasive lobular breast cancer with preoperative MRI: Role of additional carcinoma in situ and background parenchymal enhancement

ObjectivesAnalysing the influence of additional carcinoma in situ (CIS) and background parenchymal enhancement (BPE) in preoperative MRI on repeated surgeries in patients with invasive lobular carcinoma (ILC) of the breast. MethodsRetrospective analysis of 106 patients (mean age 58.6±9.9years) with 108 ILC. Preoperative tumour size as assessed by MRI, mammography and sonography was recorded and compared to histopathology. In contrast-enhanced MRI, the degree of BPE was categorised by two readers. The influence of additionally detected CIS and BPE on the rate of repeated surgeries was analysed. ResultsAdditional CIS was present in 45.4% of the cases (49/108). The degree of BPE was minimal or mild in 80% of the cases and moderate or marked in 20% of the cases. In 17 cases (15.7%) at least one repeated surgery was performed. In n=15 of these cases, repeated surgery was performed after BCT (n=9 re-excisions, n=6 conversions to mastectomy), in n=2 cases after initial mastectomy. The initial surgical procedure (p=0.008) and additional CIS (p=0.046) significantly influenced the rate of repeated surgeries, while tumour size, patient age and BPE did not (p=ns). ConclusionsAdditional CIS was associated with a higher rate of repeated surgeries, whereas BPE had no influence.

Effect of background parenchymal enhancement on breast cancer detection with magnetic resonance imaging.

To investigate whether background parenchymal enhancement (BPE) may influence the sensitivity of dynamic contrast-enhanced magnetic resonance (DCE-MR) imaging in breast cancer detection. A total of 180 consecutive women with 194 breast cancers underwent MR imaging examination. Women were assigned to two different groups depending on the degree of BPE. Group 1 consisted of women with minimal or mild BPE and group 2 of women with moderate or marked BPE. The distributions of histotypes of tumors within the two groups were compared using the χ(2) test. Difference in sensitivities of DCE-MR imaging for tumor detection between the two groups was searched for using the Student t-test. No differences in terms of distributions of histotypes of tumors between the two groups of women were found (P=0.5). The 11% difference in sensitivity of DCE-MR imaging for tumor detection between group 1 (91/92; 99%; 95% CI: 94-100%) and group 2 (90/102; 88%; 95% CI: 80-94%) was statistically significant (P=0.0058). The sensitivity of DCE-MR imaging is significantly lower in women with moderate and marked BPE as compared with women with minimal and mild BPE regardless of cancer histotype. BPE could represent a limitation for breast MR imaging interpretation and should be indicated in MR imaging reports.

Fibroglandular tissue and quantitative background parenchymal enhancement on magnetic resonance breast images are inversely correlated with menopause in Thai women

Background: There are limited data regarding background parenchymal enhancement (BPE) in breast magnetic resonance imaging (MRI) for Asian women. Objectives: To determine relationships between the amount of fibroglandular tissue (FGT) and BPE in breast MRI. Methods: A retrospective review identified 95 MRI examinations of women with normal breasts between March 2012 to July 2014 for inclusion in this study. BPE and MRI-FGT were assessed on precontrast T1-weighted fatsuppressed images by consensus and described according to the American College of Radiology Breast Imaging Reporting and Data System. We analyzed BPE, including early and peak enhancement (Eearly, Epeak), and the signal enhancement ratio (SER). Spearman rank correlations between MRI-FGT and BPE and menopausal status were compared using Mann–Whitney U tests. Results: Fourteen premenopausal and 81 postmenopausal women had scattered and heterogeneous FGT (74%) and minimal to mild BPE (84%). There was a significant correlation between age and amount of MRI-FGT (r = –2.63; P = 0.01), but not BPE or enhancement kinetics. There was no significant correlation between FGT, BPE, and enhancement kinetics. There was a significant inverse relationship between menopause and the amount of FGT, BPE, and Epeak (P pre and postmenopausal Eearly and SER (P > 0.05). Conclusions: There is no significant correlation between the amount of FGT and BPE in either premenopausal or postmenopausal women. The amount of FGT, degree of BPE, and Epeak were higher in premenopausal women. Keywords: Background parenchymal enhancement (BPE), breast MRI correlation, fibroglandular tissue (FGT), menstruation, Thai women

Prediction of background parenchymal enhancement on breast MRI using mammography, ultrasonography, and diffusion-weighted imaging.

This retrospective study assessed the effects of menopausal status and menstrual cycle on background parenchymal enhancement (BPE) of breast magnetic resonance imaging (MRI), and investigated whether the degree of BPE can be predicted by findings of mammography, ultrasonography (US), and diffusion-weighted MR imaging (DWI). There were 160 study patients (80 premenopausal, 80 postmenopausal). Degree of BPE was classified into minimal, mild, moderate, or marked. Mammographic density was classified into fatty, scattered, heterogeneously dense, and extremely dense. BP echotexture on US and BP intensity on DWI were visually classified as homogeneous or heterogeneous. Apparent diffusion coefficient (ADC) values of normal breast tissue were measured. Associations of the degree of BPE with menopausal status, menstrual cycle, or imaging features were evaluated by univariate and multivariate analyses. No significant correlation was found between mammographic density and BPE (p=0.085), whereas menopausal status (p=0.000), BP echotexture (p=0.000), and BP intensity on DWI (p= 0.000), and ADC values (p=0.000) showed significant correlations with BPE. Multivariate analysis showed that postmenopausal status was an independent predictor of minimal BPE (p=0.002, OR=3.743). In premenopausal women, there was no significant correlation between menstrual cycle and BPE, whereas BP echotexture was an independent predictor of whether BPE was less than mild or greater than moderate (p=0.001, OR=26.575). BPE on breast MRI is associated with menopausal status and the findings of US and DWI. Because premenopausal women with heterogeneous BP echotexture may be predicted to show moderate or marked BPE, scheduling of breast MRI should preferentially be adjusted to the menstrual cycle.

Comprehensive breast MRI: an update

With increasing use of clinical breast MRI and a plethora of novel techniques and sequences for lesion characterisation, a standardised approach to lesion description and reporting is increasingly important. This facilitates meaningful research and audit, particularly in the context of multicentre studies. To this end the American College of Radiology has recently published the 5th edition of the BI-RADS lexicon, with revision of the MRI section including addition of new descriptors, modification of others and deletion of some that were rarely helpful in practice, such as ‘stippled’ enhancement [1]. Categories for fibroglandular volume are now a to d, in line with the descriptors for mammography, thus avoiding confusion with assessment category. The degree of background parenchymal enhancement is now purely descriptive, from none/minimal to marked. A new descriptor is clustered rim enhancement (usually indicating DCIS). Non mass-like enhancement becomes non mass enhancement, whereas ‘ductal’ enhancement becomes linear. Overall the effect is of simplification and consistency with the mammography and ultrasound lexicons. The lexicon highlights the importance of a structured report, including the indication, scan technique, salient findings and critically, an overall assessment with a clear recommendation for further management. This approach has been validated in a number of studies correlating the assessment category with histopathological findings and/or long-term follow-up [2,3]. Use of a standardised lexicon, modified in the light of available evidence, has obviated some of the interpretative challenges of breast MRI. Use of supplemental diffusion weighted imaging may also be helpful [4]. Nonetheless, technical and clinical challenges remain. Artefacts are problematic, especially at 3T [5], and medical physics support is essential for good quality diagnostic scans, especially at higher field strength. Most importantly, it should be remembered that to date, despite the recognised superiority of breast MRI over any other modality for breast cancer detection and local staging, there is no hard evidence for improved patient outcomes. Two randomised controlled trials and seven comparative cohort studies have not shown any benefit for preoperative MRI in terms of re-excision rates; rather, there is a trend to higher mastectomy rates [6]. No convincing beneficial effects have been demonstrated in terms of in-breast tumour recurrence rates, disease-free survival or overall survival. Regarding assessment of response to neoadjuvant chemotherapy, MRI correlates better than mammography or ultrasound with final pathology, but false positive and negative studies are frequent, with underestimation of the amount of residual disease in up to 30% and overestimation in around 20% of cases [7,8]. Though evidence is accruing that MRI may be helpful in early response assessment, this is by no means standardised and is heavily dependent on many factors, not least tumour immunophenotype. Finally, though screening breast MRI for women at high risk has approximately double the sensitivity of mammography with encouraging stage shift and high rates of node negativity, there is as yet no evidence of a reduction in breast cancer mortality [9,10]. This workshop will provide an update on the BI-RADS lexicon and indications for breast MRI, with expert tuition in hands-on analysis of case studies.

Background parenchymal enhancement in breast MRIs of breast cancer patients: Impact on tumor size estimation

ObjectiveTo evaluate whether the degree of background parenchymal enhancement affects the accuracy of tumor size estimation based on breast MRI. MethodsThree hundred and twenty-two patients who had known breast cancer and underwent breast MRIs were recruited in our study. The total number of breast cancer cases was 339. All images were assessed retrospectively for the level of background parenchymal enhancement based on the BI-RADS criteria. Maximal lesion diameters were measured on the MRIs, and tumor types (mass vs. non-mass) were assessed. Tumor size differences between the MRI-based estimates and estimates based on pathological examinations were analyzed. The relationship between accuracy and tumor types and clinicopathologic features were also evaluated. ResultsThe cases included minimal (47.5%), mild (28.9%), moderate (12.4%) and marked background parenchymal enhancement (11.2%).The tumors of patients with minimal or mild background parenchymal enhancement were more accurately estimated than those of patients with moderate or marked enhancement (72.1% vs. 56.8%; p=0.003). The tumors of women with mass type lesions were significantly more accurately estimated than those of the women with non-mass type lesions (81.6% vs. 28.6%; p<0.001). The tumor of women negative for HER2 was more accurately estimated than those of women positive for HER2 (72.2% vs. 51.6%; p=0.047). ConclusionModerate and marked background parenchymal enhancement is related to the inaccurate estimation of tumor size based on MRI. Non-mass type breast cancer and HER2-positive breast cancer are other factors that may cause inaccurate assessment of tumor size.

P2-08-01: Impact of Aromatase Inhibitors on Background Parenchymal Enhancement and Amount of Fibroglandular Tissue on Breast MRI.

Abstract Background: On breast MRI, background parenchymal enhancement (BPE) and volume of fibroglandular tissue (FGT) have been shown to reflect a patient's hormonal status. Tamoxifen has been shown to reduce mammographic breast density and may serve as an early predictor of response in the prevention setting (Cuzick, JNCI 2011). We have shown that adjuvant tamoxifen can reduce BPE in the unaffected breast in women with breast cancer. We hypothesize that aromatase inhibitor (AI) induced endocrine changes in breast tissue should also be evident and therefore we performed a study to evaluate whether adjuvant AI therapy influences BPE or amount of FGT in the contralateral breast. Methods: An electronic medical record review identified 856 postmenopausal women with stage I-III breast cancer who had at least two breast MRIs and took adjuvant AI treatment. A retrospective chart review was conducted to select those patients without a history of prior tamoxifen or raloxifene treatment who had a MRI of the contralateral breast both before and during 6 to 12 months of AI treatment. After exclusion of all irradiated breasts, 168 women were eligible. MRIs were performed between August 1999 and June 2010. Two radiologists who were blind to AI treatment status, independently rated level of BPE and amount of FGT using categorical scales: BPE — Minimal, Mild, Moderate, Marked; FGT — Fatty, Scattered, Heterogeneously Dense, Dense (based on proposed BIRADS criteria for BPE and on ACR criteria for FGT). Blinded side-by-side direct comparison evaluated whether there was a category change between the two MRIs. A consensus was reached in cases of disagreement. The Wilcoxon signed-rank test was used to assess changes in rating categories for BPE and FGT between before and during AI breast MRIs. A waiver of authorization was granted by the institutional review board for this study. Results: In this study 127/168 (76%) women were treated with anastrozole, 33/168 (20%) with letrozole and 8/168 (5%) with exemestane. Based on the blinded side-by-side comparison, a category (or more) decrease in BPE occurred during treatment with AIs (p&amp;lt;0.0001). There was an overall shift from higher to lower degree of BPE in 35% (45/127) of the women taking anastrozole while a category increase occurred in only one woman (1%; p &amp;lt;0.0001). A similar result was seen in the women taking letrozole [45% (15/33) had a decrease versus 3% (1/33) an increase; p=0.0003] and exemestane [25% (2/8) had a decrease versus 12.5% (1/8) an increase; p=0.50]. For FGT a category decrease occurred in 5% (6/127) of anastrozole users while no increase occurred [0% (0/127), p=0.016]. The respective numbers for letrozole were 3% (1/33) and 0% (0/33), and nobody on exemestane had a change in FGT. Conclusions: After 6 to 12 months of treatment with adjuvant AIs, there was a statistically significant category (or more) decrease in BPE. BPE is more sensitive than FGT to changes in normal breast stroma that occur during adjuvant treatment with AIs and BPE may be a marker of anti-hormonal activity in the breasts. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-08-01.