Diagnostic performance of T2-weighted imaging and intravoxel incoherent motion diffusion-weighted MRI for predicting metastatic axillary lymph nodes in T1 and T2 stage breast cancer

Fe3O4-Cy5.5-trastuzumab magnetic nanoparticles for magnetic resonance/near-infrared imaging targeting HER2 in breast cancer

This study developed a probe Fe3O4-Cy5.5-trastuzumab with fluorescence and magnetic resonance imaging functions that can target breast cancer with high HER2 expression, aiming to provide a new theoretical method for the diagnosis of early breast cancer. Fe3O4-Cy5.5-trastuzumab nanoparticles were combined with Fe3O4for T2imaging and Cy5.5 for near-infrared imaging, and coupled with trastuzumab for HER2 targeting. We characterized the nanoparticles used transmission electron microscopy, hydration particle size, Zeta potential, UV and Fourier transform infrared spectroscopy, and examined its magnetism, fluorescence, and relaxation rate related properties. CCK-8 and blood biochemistry analysis evaluated the biosafety and stability of the nanoparticles, and validated the targeting ability of Fe3O4-Cy5.5 trastuzumab nanoparticles throughin vitroandin vivocell and animal experiments. Characterization results showed the successful synthesis of Fe3O4-Cy5.5-trastuzumab nanoparticles with a diameter of 93.72 ± 6.34 nm. The nanoparticles showed a T2relaxation rate 42.29 mM-1s-1, magnetic saturation strength of 27.58 emg g-1. Laser confocal and flow cytometry uptake assay showed that the nanoparticles could effectively target HER2 expressed by breast cancer cells. As indicated byin vitroandin vivostudies, Fe3O4-Cy5.5-trastuzumab were specifically taken up and effectively aggregated to tumour regions with prominent NIRF/MR imaging properties. CCK-8, blood biochemical analysis and histological results suggested Fe3O4-Cy5.5-trastuzumab that exhibited low toxicity to major organs and goodin vivobiocompatibility. The prepared Fe3O4-Cy5.5-trastuzumab exhibited excellent targeting, NIRF/MR imaging performance. It is expected to serve as a safe and effective diagnostic method that lays a theoretical basis for the effective diagnosis of early breast cancer. This study successfully prepared a kind of nanoparticles with near-infrared fluorescence imaging and T2imaging properties, which is expected to serve as a new theory and strategy for early detection of breast cancer.

Whole-tumor histogram models based on quantitative maps from synthetic MRI for predicting axillary lymph node status in invasive ductal breast cancer

PURPOSE

To investigate the potential of using histogram analysis of synthetic MRI (SyMRI) images before and after contrast enhancement to predict axillary lymph node (ALN) status in patients with invasive ductal carcinoma (IDC).

METHODS

From January 2022 to October 2022, a total of 212 patients with IDC underwent breast MRI examination including SyMRI. Standard T2 weight images, DCE-MRI and quantitative maps of SyMRI were obtained. 13 features of the entire tumor were extracted from these quantitative maps, standard T2 weight images and DCE-MRI. Statistical analyses, including Student's t-test, Mann-Whiney U test, logistic regression, and receiver operating characteristic (ROC) curves, were used to evaluate the data. The mean values of SyMRI quantitative parameters derived from the conventional 2D region of interest (ROI) were also evaluated.

RESULTS

The combined model based on T1-Gd quantitative map (energy, minimum, and variance) and clinical features (age and multifocality) achieved the best diagnostic performance in the prediction of ALN between N0 (with non-metastatic ALN) and N+ group (metastatic ALN ≥ 1) with the AUC of 0.879. Among individual quantitative maps and standard sequence-derived models, the synthetic T1-Gd model showed the best performance for the prediction of ALN between N0 and N+ groups (AUC = 0.823). Synthetic T2_entropy and PD-Gd_energy were useful for distinguishing N1 group (metastatic ALN ≥ 1 and ≤ 3) from the N2-3 group (metastatic ALN > 3) with an AUC of 0.722.

CONCLUSIONS

Whole-tumor histogram features derived from quantitative parameters of SyMRI can serve as a complementary noninvasive method for preoperatively predicting ALN metastases.

Beyond N Staging in Breast Cancer: Importance of MRI and Ultrasound-based Imaging

The correct N-staging in breast cancer is crucial to tailor treatment and stratify the prognosis. N-staging is based on the number and the localization of suspicious regional nodes on physical examination and/or imaging. Since clinical examination of the axillary cavity is associated with a high false negative rate, imaging modalities play a central role. In the presence of a T1 or T2 tumor and 0–2 suspicious nodes, on imaging at the axillary level I or II, a patient should undergo sentinel lymph node biopsy (SLNB), whereas in the presence of three or more suspicious nodes at the axillary level I or II confirmed by biopsy, they should undergo axillary lymph node dissection (ALND) or neoadjuvant chemotherapy according to a multidisciplinary approach, as well as in the case of internal mammary, supraclavicular, or level III axillary involved lymph nodes. In this scenario, radiological assessment of lymph nodes at the time of diagnosis must be accurate. False positives may preclude a sentinel lymph node in an otherwise eligible woman; in contrast, false negatives may lead to an unnecessary SLNB and the need for a second surgical procedure. In this review, we aim to describe the anatomy of the axilla and breast regional lymph node, and their diagnostic features to discriminate between normal and pathological nodes at Ultrasound (US) and Magnetic Resonance Imaging (MRI). Moreover, the technical aspects, the advantage and limitations of MRI versus US, and the possible future perspectives are also analyzed, through the analysis of the recent literature.