Diagnostic performance of digital breast tomosynthesis for predicting response to neoadjuvant systemic therapy in breast cancer patients: A comparison with magnetic resonance imaging, ultrasound, and full-field digital mammography.

BACKGROUND: The goals of neoadjuvant systemic therapy (NST) are to reduce tumor volume and to provide a prognostic indicator in assessing treatment response. Digital breast tomosynthesis (DBT) was developed and has increased interest in clinical settings due to its higher sensitivity for breast cancer detection compared to full-field digital mammography (FFDM). PURPOSE: To evaluate the accuracy of DBT in assessing response to NST compared to FFDM, ultrasound (US), and magnetic resonance imaging (MRI) in breast cancer patients. MATERIAL AND METHODS: In this retrospective study, 95 stages II-III breast cancer patients undergoing NST and subsequent surgeries were enrolled. After NST, the longest diameter of residual tumor measured by DBT, FFDM, US, and MRI was compared with pathology. Agreements and correlations of tumor size were assessed, and the diagnostic performance for predicting pathologic complete response (pCR) was evaluated. RESULTS: Mean residual tumor size after NST was 19.9 mm for DBT, 18.7 mm for FFDM, 16.0 mm for US, and 18.4 mm for MRI, compared with 17.9 mm on pathology. DBT and MRI correlated better with pathology than that of FFDM and US. The ICC values were 0.85, 0.87, 0.74, and 0.77, respectively. Twenty-five patients (26.3%) achieved pCR after NST. For predicting pCR, area under the receiver operating characteristic (ROC) curve for DBT, FFDM, US, and MRI were 0.79, 0.66, 0.68, and 0.77, respectively. CONCLUSION: DBT has good correlation with histopathology for measuring residual tumor size after NST. DBT was comparable to MRI in assessing tumor response after completion of NST.

Comparative analysis between synthetic mammography reconstructed from digital breast tomosynthesis and full-field digital mammography for breast cancer detection and visibility.

PURPOSE: To compare observer performance between synthetic mammography (2DSM) and full-field digital mammography (FFDM) for breast cancer detection and visibility. METHOD: A retrospective analysis was conducted on 136 histopathologically proven cases of breast cancer in patients who underwent FFDM and digital breast tomosynthesis (DBT). 2DSM images were reconstructed from DBT data, and 2DSM and FFDM images were reviewed and evaluated for mammographic features, probability of malignancy (BI-RADS classification), and lesion conspicuity. DBT images were not reviewed. Statistical differences in cancer detection rates between 2DSM and FFDM images were analyzed using the McNemar test, agreement on BI-RADS assessment between 2DSM and FFDM was assessed using Cohen's kappa test, and the Wilcoxon's signed rank test was used to compare visibility scores. RESULTS: Mean cancer detection rates with 2DSM and FFDM images were 84.6 % and 87.8 %, respectively. In subgroup analyses, differences in breast density, tumor size, and presence of calcifications were not statistically significant. Agreement between 2DSM and FFDM images for BI-RADS classification was graded as good with Cohen's k-coefficient of 0.78 ±â€¯0.05. Visibility scores in both modalities of images were similar for all lesions combined; however, 2DSM had significantly better visibility scores for calcified cancers (p < 0.01), and in dense breast tissue (p < 0.01). CONCLUSIONS: Diagnostic performances of 2DSM and FFDM images were comparable for detecting breast cancers, and it is possible that 2DSM may eliminate the need for additional FFDM during DBT-based imaging due to advances in image reconstruction methods.

Molecular imaging using PET for breast cancer.

Molecular imaging can visualize the biological processes at the molecular and cellular levels in vivo using certain tracers for specific molecular targets. Molecular imaging of breast cancer can be performed with various imaging modalities, however, positron emission tomography (PET) is a sensitive and non-invasive molecular imaging technology and this review will focus on PET molecular imaging of breast cancer, such as FDG-PET, FLT-PET, hormone receptor PET, and anti-HER2 PET.

(64)Cu-DOTA-trastuzumab PET imaging and HER2 specificity of brain metastases in HER2-positive breast cancer patients.

BACKGROUND: The purpose of this study was to determine whether brain metastases from HER2-positive breast cancer could be detected noninvasively using positron emission tomography (PET) with (64)Cu-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-trastuzumab. METHODS: PET was performed on five patients with brain metastases from HER2-positive breast cancer, at 24 or 48 h after the injection of approximately 130 MBq of the probe (64)Cu-DOTA-trastuzumab. Radioactivity in metastatic brain tumors was evaluated based on PET images in five patients. Autoradiography, immunohistochemistry (IHC), and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis were performed in one surgical case to confirm HER2 specificity of (64)Cu-DOTA-trastuzumab. RESULTS: Metastatic brain lesions could be visualized by (64)Cu-DOTA-trastuzumab PET in all of five cases, which might indicated that trastuzumab passes through the blood-brain barrier (BBB). The HER2 specificity of (64)Cu-DOTA-trastuzumab was demonstrated in one patient by autoradiography, immunohistochemistry, and LC-MS/MS. CONCLUSIONS: Cu-DOTA-trastuzumab PET could be a potential noninvasive procedure for serial identification of metastatic brain lesions in patients with HER2-positive breast cancer. TRIAL REGISTRATION: UMIN000004170.

Correlation of (18)F-BPA and (18)F-FDG uptake in head and neck cancers.

BACKGROUND AND PURPOSE: The aim of this study was to compare the accumulation of 4-borono-2-(18)F-fluoro-phenylalanine ((18)F-BPA) with that of (18)F-fluorodeoxyglucose ((18)F-FDG) in head and neck cancers, and to assess the usefulness of (18)F-FDG PET for screening candidates for boron neutron capture therapy (BNCT). MATERIAL AND METHODS: Twenty patients with pathologically proven malignant tumors of the head and neck were recruited from March 2012 to January 2014. All patients underwent both whole-body (18)F-BPA PET/CT and (18)F-FDG PET/CT within 2weeks of each other. The uptakes of (18)F-BPA and (18)F-FDG at 1h after injection were evaluated using the maximum standardized uptake value (SUVmax). RESULTS: The accumulation of (18)F-FDG was significantly correlated with that of (18)F-BPA. The SUVmax of (18)F-FDG ⩾5.0 is considered to be suggestive of high (18)F-BPA accumulation. CONCLUSIONS: (18)F-FDG PET might be an effective screening method performed prior to (18)F-BPA for selecting patients with head and neck cancer for treatment with BNCT.

MRI differentiation of cardiomyopathy showing left ventricular hypertrophy and heart failure: differentiation between cardiac amyloidosis, hypertrophic cardiomyopathy, and hypertensive heart disease.

PURPOSE: To evaluate the capability of MRI to differentiate cardiac amyloidosis (CA), end-stage hypertrophic cardiomyopathy (HCM), and hypertensive heart disease (HHD), which are important etiologies of left ventricular hypertrophy (LVH) and heart failure. MATERIALS AND METHODS: We enrolled 26 patients presenting with both LVH and heart failure: six with CA, nine with end-stage HCM, and 11 with HHD. Cardiac function, presence of pericardial or pleural effusion, and the extent and patterns of late gadolinium enhancement (LGE) were compared among the three diseases. RESULTS: Myocardial LGE was observed in all six CA patients, eight end-stage HCM patients, and six HHD patients. The number of LGE segments was significantly greater in CA than in HCM or HHD (p = 0.02 for both), and all patients with CA showed a global endocardial pattern of LGE. There were significant differences among CA, HCM, and HHD in ejection fraction and end-diastolic and end-systolic volume indices (p < 0.05 for all). Pericardial effusion was observed more frequently in CA than in HCM or HHD (p = 0.04 or 0.01, respectively). CONCLUSION: MRI is valuable for distinguishing among CA, end-stage HCM, and HHD, all of which present with LVH and heart failure.

Anemia and the risk of contrast-induced nephropathy in patients with renal insufficiency undergoing contrast-enhanced MDCT.

PURPOSE: The purpose of this study was to assess the effect of anemia on the incidence of contrast-induced nephropathy (CIN) in patients with renal impairment undergoing MDCT. MATERIALS AND METHODS: Institutional review board approval was waived for this retrospective review of 843 patients with stable renal insufficiency (eGFR between 15 and 60 mL/min) who had undergone contrast-enhanced MDCT. Baseline hematocrit and hemoglobin values were measured. Serum creatinine (SCr) was assessed at the baseline and at 48-72 h after contrast administration. RESULTS: The overall incidence of CIN in the patient population with renal insufficiency was 6.9%. CIN developed in 7.8% (54 of 695) of anemic patients, and in 2.8% (4 of 148) of non-anemic patients (P=.027). After adjustment for confounders, low hemoglobin and low hematocrit values remained independent predictors of CIN (odds ratio 4.6, 95% CI 1.0-20.5, P=.046). CONCLUSIONS: Anemia is associated with a higher incidence of CIN in patients with renal insufficiency. Anemia is a potentially modifiable risk factor for CIN, and has an unfavorable impact on prognosis in patients with renal insufficiency undergoing contrast-enhanced MDCT.

Detection of breast cancer with a computer-aided detection applied to full-field digital mammography.

A study was conducted to evaluate the sensitivity of computer-aided detection (CAD) with full-field digital mammography in detection of breast cancer, based on mammographic appearance and histopathology. Retrospectively, CAD sensitivity was assessed in total group of 152 cases for subgroups based on breast density, mammographic presentation, lesion size, and results of histopathological examination. The overall sensitivity of CAD was 91 % (139 of 152 cases). CAD detected 100 % (47/47) of cancers manifested as microcalcifications; 98 % (62/63) of those manifested as non-calcified masses; 100 % (15/15) of those manifested as mixed masses and microcalcifications; 75 % (12/16) of those manifested as architectural distortions, and 69 % (18/26) of those manifested as focal asymmetry. CAD sensitivity was 83 % (10/12) for cancers measuring 1-10 mm, 92 % (37/40) for those measuring 11-20 mm, and 92 % (92/100) for those measuring >20 mm. There was no significant difference in CAD detection efficiency between cancers in dense breasts (88 %; 69/78) and those in non-dense breasts (95 %; 70/74). CAD showed a high sensitivity of 91 % (139/152) for the mammographic appearance of cancer and 100 % sensitivity for identifying cancers manifested as microcalcifications. Sensitivity was not influenced by breast density or lesion size. CAD should be effective for helping radiologists detect breast cancer at an earlier stage.

T2-weighted cardiac magnetic resonance imaging of edema in myocardial diseases.

The purpose of this paper is to describe imaging techniques and findings of T2-weighted magnetic resonance imaging (MRI) of edema in myocardial diseases. T2-weighted cardiac MRI is acquired by combining acceleration techniques with motion and signal suppression techniques. The MRI findings should be interpreted based on coronary artery supply, intramural distribution, and comparison with delayed-enhancement MRI. In acute myocardial diseases, such as acute myocardial infarction and myocarditis, the edema is larger than myocardial scarring, whereas the edema can be smaller than the scarring in some types of nonischemic cardiomyopathy, including hypertrophic cardiomyopathy. T2-weighted MRI of edema identifies myocardial edema associated with ischemia, inflammation, vasculitis, or intervention in the myocardium and provides information complementary to delayed-enhancement MRI.

T2-weighted and delayed enhancement MRI of eosinophilic myocarditis: relationship with clinical phases and global cardiac function.

PURPOSE: To evaluate the usefulness of magnetic resonance imaging (MRI) for detection and quantification of myocardial damage related to clinical phases and cardiac function during eosinophilic myocarditis. MATERIALS AND METHODS: Four eosinophilic myocarditis patients received seven MRI studies. The left ventricular myocardium was divided into 48 layers, and we quantified the extent of abnormal intensity detected by T2-weighted or delayed enhancement MRI relative to the clinical phase and global cardiac function. RESULTS: T2-weighted imaging detected extensive myocardial hyperintensity during the acute phase of eosinophilic myocarditis. Diffuse myocardial delayed enhancement was observed in one patient during the acute phase, but not in the other. Little or no hyperintensity was detected by T2-weighted imaging or myocardial delayed enhancement during the convalescent phase. The extent of hyperenhancing myocardial layers was inversely correlated with the ejection fraction (EF) (r = -0.87). CONCLUSION: MRI can evaluate the presence and extent of myocardial damage related to the clinical phases and EF during eosinophilic myocarditis.