Breast Specimen Radiography: Can It Predict Margin Status of Excised Breast Carcinoma?

RATIONALE AND OBJECTIVES: This study examined the value of intraoperative specimen radiography (SR) in determining margin status of excised breast lesions. Of interest was the concordance between the radiologic and histopathologic interpretation of margins. We investigated the influence of in situ disease and of one versus two radiologic views on this concordance. MATERIALS AND METHODS: Our study consisted of 112 women who underwent breast conservation therapy (BCT) during 2002. Margins were examined with one- or two-view SR. Margins were histologically positive if malignant cells resided < or = 1 mm from the specimen edge. The McNemar's test was used to determine concordance between SR and histopathology (HP). Because surgeons excised extra tissue in cases of positive radiologic margins, we believe that a change in margin status occurred in which true positives became false positives. Accordingly, we analyzed our data with multiple iterations in which, one by one, false positives were considered true positives. RESULTS: Concordance between SR and HP reached statistical significance after 5/17 false positives were considered true positives. Data excluding DCIS reached significance after 6 of 6 false positives were considered true positives. One- and two-view SR reached significance when 2 of 8 and 7 of 9 false positives, respectively, were considered true positives. CONCLUSION: In conclusion, our study suggests that SR can aid in margin assessment for patients undergoing BCT. We did not find that concordance between SR and HP is higher in cases of purely invasive disease. Concordance was higher in one-view SR in comparison to two-view. A larger sample size should be analyzed before recommending against using two views.     

Is Grading of Breast Fibrosis with Mammography Feasible?

PURPOSE: To establish a grading system for mammographic fibrosis and correlate it with clinical fibrosis. PATIENTS AND METHODS: Analogous to the LENT/SOMA scale a four-tiered scoring scale of breast fibrosis in mammography (G0 = absent, G1 = barely increased density, G2 = definitely increased density to G3 = very marked density) was established by two observers in a group of 16 patients. Reference mammograms were selected. Independently and blinded to clinical results, three observers scored the fibrosis in mammograms of further 31 patients examined by one radiation oncologist in a cross-sectional follow-up study. Pretreatment parenchyma density was judged according to the American College of Radiology (ACR). Interobserver correlation of mammography scoring as well as correlation of mammography and clinical findings were calculated with Cohen's weighted kappa. All patients had breast-conserving surgery and axillary resection for breast carcinoma T1-2N0-1. The breast was irradiated to a median reference dose of 55 Gy (range 50-60 Gy) with 2 Gy five times weekly or 2.5 Gy four times weekly. Two patients received chemotherapy, 14 patients tamoxifen. Median age was 55 years, median follow-up 8 years (4-15 years). RESULTS: 14 of 31 patients had clinical fibrosis, twelve G1 and two G2. In mammography, mild fibrosis (G1) was seen in 12/12/18 patients (observer 1/2/3) and moderate fibrosis (G2) in 9/10/2 patients. Interobserver correlation for observers 1 and 2 who had developed the score was fair (Cohen's weighted kappa 0.64, 95% confidence interval 0.4-0.88). However, it was weak for observer 3 (0.36 and 0.42, respectively) who relied on reference mammograms only. Independent interobserver correlation of pretreatment breast density was good for all observers (Cohen's weighted kappa 0.73-0.8). The correlation of fibrosis by mammography and palpation was weak (Cohen's weighted kappa 0.32-0.42). CONCLUSION: Grading fibrosis as depicted by mammography is possible, especially if observers prepare by jointly analyzing a training group. It may be useful to study treatment effects, e. g., of fractionation or drugs, because retrospective and repeated analysis is possible. The correlation of mammography with clinical grading should be further evaluated with more objective clinical reference tools.     

Do All Patients of Breast Carcinoma Need 3-Dimensional CT-Based Planning? A Dosimetric Study Comparing Different Breast Sizes

Evaluation of dose distribution in a single plane (i.e., 2-dimensional [2D] planning) is simple and less resource-intensive than CT-based 3-dimensional radiotherapy (3DCRT) planning or intensity modulated radiotherapy (IMRT). The aim of the study was to determine if 2D planning could be an appropriate treatment in a subgroup of breast cancer patients based on their breast size. Twenty consecutive patients who underwent breast conservation were planned for radiotherapy. The patients were grouped in 3 different categories based on their respective chest wall separation (CWS) and the thickness of breast, as “small,” “medium,” and “large.” Two more contours were taken at locations 5 cm superior and 5 cm inferior to the isocenter plane. Maximum dose recorded at specified points was compared in superior/inferior slices as compared to the central slice. The mean difference for small breast size was 1.93 (standard deviation [SD] = 1.08). For medium breas size, the mean difference was 2.98 (SD = 2.40). For the large breasts, the mean difference was 4.28 (SD = 2.69). Based on our dosimetric study, breast planning only on the single isocentric contour is an appropriate technique for patients with small breasts. However, for large- and medium-size breasts, CT-based planning and 3D planning have a definite role. These results can be especially useful for rationalizing treatment in busy oncology centers.     

Breast cancer screening: are results of French and international programmes comparable?

Full coverage of the national breast cancer screening programme was obtained in 2004. The new protocol was published in 2001. It changed the organisation implemented since 1994 for a better fit with the French decentralized health care system. Consequences on health results were analysed explaining related medical and sociological factors. The main change was the rate of positive mammograms which differed from the recall rate given in the European recommendations. With the new protocol the rate of assessments more than doubled: 6% in year 2000 and 14% in 2003. International comparisons are difficult since each country has a different organisation. Moreover the coexistence in France of organized screening and opportunistic screening causes a complex issue for evaluation of impact indicators of this population based programme.     

Ultrafast Dynamic Contrast-enhanced MRI of the Breast: How Is It Used?

Ultrafast dynamic contrast-enhanced (UF-DCE) MRI is a new approach to capture kinetic information in the very early post-contrast period with high temporal resolution while keeping reasonable spatial resolution. The detailed timing and shape of the upslope in the time–intensity curve are analyzed. New kinetic parameters obtained from UF-DCE MRI are useful in differentiating malignant from benign lesions and in evaluating prognostic markers of the breast cancers. Clinically, UF-DCE MRI contributes in identifying hypervascular lesions when the background parenchymal enhancement (BPE) is marked on conventional dynamic MRI. This review starts with the technical aspect of accelerated acquisition. Practical aspects of UF-DCE MRI include identification of target hypervascular lesions from marked BPE and diagnosis of malignant and benign lesions based on new kinetic parameters derived from UF-DCE MRI: maximum slope (MS), time to enhance (TTE), bolus arrival time (BAT), time interval between arterial and venous visualization (AVI), and empirical mathematical model (EMM). The parameters derived from UF-DCE MRI are compared in terms of their diagnostic performance and association with prognostic markers. Pitfalls of UF-DCE MRI in the clinical situation are also covered. Since UF-DCE MRI is an evolving technique, future prospects of UF-DCE MRI are discussed in detail by citing recent evidence. The topic covers prediction of treatment response, multiparametric approach using DWI-derived parameters, evaluation of tumor-related vessels, and application of artificial intelligence for UF-DCE MRI. Along with comprehensive literature review, illustrative clinical cases are used to understand the value of UF-DCE MRI.     

Dynamic 18 F-FDG PET for Assessment of Tumor Physiology in Two Breast Carcinoma Xenografts

Purpose

To compare dynamic 2-deoxy-2-[¹⁸ F]fluoro-D-glucose positron emission tomography (¹⁸ F-FDG PET) parameters in two selected human breast cancer xenografts and to evaluate associations with immunohistochemistry and histology.

Procedures

Dynamic ¹⁸ F-FDG PET of luminal-like MAS98.06 and basal-like MAS98.12 xenografts was performed, and the compartmental transfer rates (k₁,k₂,k₃), blood volume fraction (v_B) and metabolic rate of ¹⁸ F-FDG(MR_FDG) were estimated from pharmacokinetic model analysis. After sacrifice, analyses of hypoxia (pimonidazole), proliferation (Ki-67), vascularization (CD31), glucose transport receptor (GLUT1) and necrosis (HE) was performed. The level of hexokinase 2 (HK2) was estimated from Western blot analysis.

Results

The ¹⁸ F-FDG uptake curves for the two xenografts were significantly different (p < 0.05). k₁ and v_B were higher for MAS98.12 (p < 0.01), while k₃ was higher for MAS98.06 (p < 0.01). MAS98.12 had a higher fraction of stromal tissue and higher microvessel density (MVD), and it was less necrotic and hypoxic than MAS98.06. MAS98.12 had stronger positive GLUT1 staining and lower Ki-67 than MAS98.06. In both models significant correlations were found between k₁ and the GLUT1 score, between k₃ and the level of HK2, and between v_B and MVD.

Conclusions

Significant differences in dynamic ¹⁸ F-FDG parameters between the two human breast cancer xenografts were found. The differences could be explained by underlying histological and physiological characteristics.     

Comparing Breast and Abdominal Subspecialists’ Follow-Up Recommendations for Incidental Liver Lesions on Breast MRI

PurposeThe aim of this study was to compare breast imaging subspecialists’ follow-up recommendations for incidental liver lesions (ILLs) on breast MRI with abdominal subspecialty radiologists’ opinions informed by best-practice recommendations.MethodsIn this retrospective study at an academic medical center, natural language processing identified reports with ILLs among 2,181 breast MRI studies completed in 2015. Electronic health record and radiology report reviews abstracted malignancy presence or absence, prior imaging, and breast subspecialists’ recommendations regarding ILLs for random sets of 30 patients: ILLs with follow-up recommendations, ILLs without recommendations, and without ILLs. Two abdominal radiologists evaluated MRI liver findings and offered follow-up recommendations in consensus. The primary outcome was agreement between breast and abdominal subspecialists in patients with ILL follow-up recommendations compared with those without (χ² analysis). Secondary outcomes were agreement between subspecialists when ILLs were reported and referring clinicians’ adherence to follow-up recommendations.ResultsILLs were identified in 11.3% of breast MRI reports (247 of 2,181); breast subspecialists made follow-up recommendations in 12% of them (30 of 247). Abdominal subspecialists agreed with breast subspecialists when ILLs required no follow-up (29 of 30 cases) but disagreed with 28 of 30 breast subspecialists’ follow-up recommendations (agreement proportion 29 of 30 versus 2 of 30, P < .0001). Subspecialists agreed in 93% of cases (28 of 30) when breast imagers reported no ILLs. Overall, 16 of 30 breast subspecialists’ follow-up recommendations were performed; ILLs were benign in 15.ConclusionsAbdominal subspecialists disagreed frequently with breast subspecialists regarding follow-up recommendations for ILLs on breast MRI. Abdominal subspecialty consultation or embedding liver imaging decision support in breast imaging reporting workflow may reduce unnecessary imaging and improve care. Improvement opportunities may exist in other cross-subspecialty interpretation workflows.     

MRI‐Guided Ablation of Breast Cancer: Where Do We Stand Today?

The treatment of patients with localized breast cancer has changed considerably over the past few decades. The next challenge is to use image-guided minimally invasive tumor ablation techniques. The fact that MRI is the most accurate imaging modality for visualization and delineation of breast tumor margins in three dimensions and provides MRI-based temperature mapping, makes it particularly applicable for monitoring during minimally invasive ablation techniques. The overall result of the studies performed on MRI-guided minimally invasive tumor ablation studies are varying, with reported total tumor ablation rates ranging between 20% and 100%. Strict selection of patients, consensus on the treatment zone margin and optimization of MR-imaging, should make MRI-guided breast cancer tumor ablation a useful tool in clinical practice.     

Usefulness of Combined Metabolic–Volumetric Indices of 18F-FDG PET/CT for the Early Prediction of Neoadjuvant Chemotherapy Outcomes in Breast Cancer

Purpose

The purpose of this study was to investigate the usefulness of metabolic-volumetric indices of ¹⁸F- fluorodeoxy-D-glucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) for the evaluation of neoadjuvant chemotherapy outcomes in breast cancer.

Methods

Twenty-four patients with locally advanced breast cancer were enrolled in the study. They underwent baseline ¹⁸F-FDG PET/CT scan and received four or six cycles of neoadjuvant chemotherapy, interim ¹⁸F-FDG PET/CT was done after second cycle of chemotherapy. Maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of the primary lesions were calculated. Reduction rates of these parameters were obtained between baseline and interim ¹⁸F-FDG PET/CT. Chemotherapy outcomes were assessed using tumor size reduction rate and histological grading system (Miller and Payne system). Reduction rates of SUVmax, MTV, and TLG correlated with chemotherapy outcomes.

Results

MTV and TLG reduction rates showed significant correlation with tumor size reduction rate (R = 0.68, P = 0.0004; R = 0.62, P = 0.002, respectively). However, SUVmax reduction rate showed no significant correlation. MTV and TLG reduction rates were significantly higher in responders than nonresponders, as determined by Miller and Payne system (P < 0.0007, P < 0.002). However, SUVmax reduction rate showed no significant difference. On ROC analysis, the area under the MTV and TLG curves was 0.886, and that of SUVmax was 0.743. Sensitivity, specificity, positive predictive value, and negative predictive value to predict histopathologic response were the same for MTV and TLG, and the values were 100 %, 85.7 %, 83.3 %, and 100 %, respectively (at the reduction rate of 93.2 % for MTV, and 95.8 % for TLG).

Conclusion

Changes of metabolic–volumetric indices successfully reflected the neoadjuvant chemotherapy outcomes. MTV and TLG could be robust indices in discriminating pathologic responder as SUVmax, after neoadjuvant chemotherapy.     

Breast MRI: Are T2 IR sequences useful in the evaluation of breast lesions?

Aim

To evaluate the potential role of signal intensities calculated in T2 images as an adjunctive parameter in the analysis of mass-like enhancements classified as BIRADS (Breast Imaging Reporting and Data System) assessment categories 2, 3, 4 or 5 with the standard T1 criteria.

Materials and methods

After a retrospective review of 338-breast Magnetic Resonance Imaging (MRI) performed for the evaluation of a suspicious lesion we selected a group of 65 mass-like enhancements ranging from 5 to 20 mm, classified as BIRADS assessment categories 2, 3, 4 or 5, histologically proved. In all cases we calculated the ratio between the signal intensity (SI) of the nodule and the pectoralis major muscle (LMSIR, lesion to muscle signal intensity ratio) with a multiROIs (region of interest) analysis on T2 images. A ROC analysis was performed to test the ability of the two diagnostic parameters separately considered (BIRADS and LMSIR) and combined in a new mono-dimensional variable obtained by a computerized discriminant function.

Results

Histological examination assessed 34 malignant lesions (52.3%) and 31 benign lesions (47.7%). The evaluation of ROC curves gave the following results: BIRADS area under the curve (AUC) 0.913, S.E. 0.0368, LMSIR AUC 0.854, S.E. 0.0487, combined BIRADS-LMSIR AUC 0.965, S.E. 0.0191 with a definitive increase in the AUC between the overall ROC area and those of the two diagnostic modalities separately considered.

Discussion

T2-weighted SI assessment with LMSIR measurement improves the diagnostic information content of standard breast MRI and can be considered a promising potential tool in the differential diagnosis of mass-like enhancements judged as borderline lesions (BIRADS 3 and 4).