Temperature-dependence of beam-driven dynamics in graphene-fullerene sandwiches.

C fullerenes encapsulated between graphene sheets were investigated by aberration-corrected high-resolution transmission electron microscopy at different temperatures, namely about 93 K, 293 K and 733 K, and by molecular dynamics simulations. We studied beam-induced dynamics of the C fullerenes and the encapsulating graphene, measured the critical doses for the initial damage to the fullerenes and followed the beam-induced polymerization. We find that, while the doses for the initial damage do not strongly depend on temperature, the clusters formed by the subsequent polymerization are more tubular at lower temperatures, while sheet-like structures are generated at higher temperatures.

Magnetic resonance imaging and ultrasound for prediction of residual tumor size in early breast cancer within the ADAPT subtrials.

Background: Prediction of histological tumor size by post-neoadjuvant therapy (NAT) ultrasound and magnetic resonance imaging (MRI) was evaluated in different breast cancer subtypes.

Methods: Imaging was performed after 12-week NAT in patients enrolled into three neoadjuvant WSG ADAPT subtrials. Imaging performance was analyzed for prediction of residual tumor measuring ≤10 mm and summarized using positive (PPV) and negative (NPV) predictive values.

Early response by MR imaging and ultrasound as predictor of pathologic complete response to 12-week neoadjuvant therapy for different early breast cancer subtypes: Combined analysis from the WSG ADAPT subtrials.

We evaluated the role of early response after 3 weeks of neoadjuvant treatment (NAT) assessed by ultrasound (US), magnetic resonance imaging (MRI) and Ki-67 dynamics for prediction of pathologic complete response (pCR) in different early breast cancer subtypes. Patients with HR+/HER2+, HR-/HER2- and HR-/HER2+ tumors enrolled into three neoadjuvant WSG ADAPT subtrials underwent US, MRI and Ki-67 assessment at diagnosis and after 3 weeks of NAT. Early response was defined as complete or partial response (US, MRI) and ≥30% proliferation decrease or <500 invasive tumor cells (Ki-67).

Accuracy of multi-parametric breast MR imaging for predicting pathological complete response of operable breast cancer prior to neoadjuvant systemic therapy.

Objectives: To evaluate whether multiparametric breast-MRI, obtained before the initiation of neoadjuvant systemic therapy (NST) for operable breast cancer, predicts which cancer will achieve a pathological complete response (pCR) after the completion of NST.

Methods: This was an IRB-approved retrospective study on 31 consecutive patients (median age, 56 years) with operable invasive breast cancer (median size: 22 mm; triple-negative: 11/31 [35%], HER2-positive: 7/31 [23%], triple-positive: 13/31 [42%]) who underwent multiparametric DCE-MRI before the initiation of NST. The MRI protocol consisted of high-resolution dynamic contrast-enhanced MRI (DCE-MRI), T2-TSE, and DWI (b-values 0, 100, 800 s/mm).

Not all false positive diagnoses are equal: On the prognostic implications of false-positive diagnoses made in breast MRI versus in mammography / digital tomosynthesis screening.

Background: Breast magnetic resonance imaging (MRI) has been reported to frequently result in false-positive diagnoses, limiting its positive predictive value (PPV). However, for PPV calculation, all nonmalignant tissue changes are equally considered false-positive, although the respective prognostic importance, and thus patient management implications, of different pathologies may well differ. We investigated the pathology of false-positive diagnoses made by MRI compared with radiographic (digital mammography/tomosynthesis [DM/DBT]) screening.

Impact of Preoperative Breast MR Imaging and MR-guided Surgery on Diagnosis and Surgical Outcome of Women with Invasive Breast Cancer with and without DCIS Component.

Purpose To (a) compare the diagnostic accuracy of breast magnetic resonance (MR) imaging with that of conventional imaging (digital mammography and breast ultrasonography) in the identification of ductal carcinoma in situ (DCIS) components of biopsy-proven invasive breast cancer before surgery and (b) investigate the surgical outcome (positive margin rates and mastectomy rates) of women with breast cancer who underwent preoperative MR imaging combined with MR-guided needle biopsy and/or MR-guided lesion localization or bracketing where appropriate. Materials and Methods The authors performed a prospective two-center study of 593 consecutive patients with biopsy-proven invasive breast cancer who underwent breast MR imaging in addition to conventional imaging. MR-guided vacuum biopsy and MR-guided lesion bracketing were performed for DCIS components visible at MR imaging alone.

Supplemental Breast MR Imaging Screening of Women with Average Risk of Breast Cancer.

Purpose To investigate the utility and accuracy of breast magnetic resonance (MR) imaging as a supplemental screening tool in women at average risk for breast cancer and to investigate the types of cancer detected with MR imaging screening. Materials and Methods This prospective observational study was conducted at two academic breast centers in women aged 40-70 years without breast cancer-associated risk factors (lifetime risk <15%). Between January 2005 and December 2013, women with at least minimal residual breast tissue (American College of Radiology categories A-D) and normal conventional imaging findings (screening mammography with or without screening ultrasonography [US]) were invited to undergo supplemental MR imaging screening.

Safety and Efficacy of Magnetic Resonance-Guided Vacuum-Assisted Large-Volume Breast Biopsy (MR-Guided VALB).

Objective: Magnetic resonance (MR)-guided vacuum-biopsy is technically demanding and may fail depending on target-lesion size or breast size, and location of lesions within the breast. We developed an MR-guided vacuum-assisted biopsy protocol that collects larger amounts of tissue, aiming at an at least partial or complete ablation of the target-lesion, just as it is intended during surgical (excisional) biopsy. Rationale is to avoid biopsy failures (false-negative results due to undersampling) by collecting larger amounts of tissue.

Digital breast tomosynthesis-guided vacuum-assisted breast biopsy: initial experiences and comparison with prone stereotactic vacuum-assisted biopsy.

Purpose: To use digital breast tomosynthesis (DBT)-guided vacuum-assisted biopsy (VAB) to sample target lesions identified at full-field digital screening mammography and compare clinical performance with that of prone stereotactic (PS) VAB.

Materials And Methods: In this institutional review board-approved study, 205 patients with 216 mammographic findings suspicious for cancer were scheduled to undergo mammography-guided VAB. Written informed consent was obtained.

Assessment of BI-RADS category 4 lesions detected with screening mammography and screening US: utility of MR imaging.

Purpose: To investigate the utility of magnetic resonance (MR) imaging according to different types of Breast Imaging Reporting and Data System (BI-RADS) category 4 findings from screening mammography and/or screening ultrasonography (US).

Materials And Methods: This institutional review board-approved prospective study included 340 patients in whom 353 lesions were detected at screening mammography or US and were rated BI-RADS category 4 after appropriate conventional work-up. Written informed consent was obtained from all patients.

Abbreviated breast magnetic resonance imaging (MRI): first postcontrast subtracted images and maximum-intensity projection-a novel approach to breast cancer screening with MRI.

Purpose: We investigated whether an abbreviated protocol (AP), consisting of only one pre- and one postcontrast acquisition and their derived images (first postcontrast subtracted [FAST] and maximum-intensity projection [MIP] images), was suitable for breast magnetic resonance imaging (MRI) screening.

Methods: We conducted a prospective observational reader study in 443 women at mildly to moderately increased risk who underwent 606 screening MRIs. Eligible women had normal or benign digital mammograms and, for those with heterogeneously dense or extremely dense breasts (n = 427), normal or benign ultrasounds.

Does MRI breast "density" (degree of background enhancement) correlate with mammographic breast density?

Purpose: To investigate whether mammographic breast densities and the respective degree of MRI background enhancement would correlate. Mammographic breast density is coded to communicate how likely a cancer is obscured by parenchyma. Similarly, background enhancement in breast MRI could obscure enhancing cancer tissue.