Brain metastases are a feared complication of breast cancer, occurring in 15-25% of patients and being associated with poor prognosis and reduced quality of life [1,2]. Magnetic resonance imaging (MRI) is an advanced technique that uses powerful magnetic fields and radio waves to produce detailed three-dimensional (3D) images of the brain's neuroanatomy and any potential pathology, especially in the management of brain metastases [3-5]. The review article by Mohammadi et al. provides a timely and comprehensive overview of the utility of MRI for detecting and characterizing brain metastases from breast cancer [5].

The authors performed a systematic review of 24 studies from 2000-2023 that examined MRI findings in 1580 breast cancer patients with brain metastases [5]. They found MRI to be highly useful for identifying, visualizing, and monitoring brain metastases through techniques like T1-weighted, T2-weighted, contrast-enhanced, diffusion-weighted, and perfusion imaging. Key findings were that brain metastases tended to occur in the cerebral hemispheres and have an irregular shape and variable contrast enhancement patterns. Advanced MRI methods like diffusion tensor imaging (DTI) and magnetic resonance spectroscopy (MRS) provided additional insights into the metabolism and microstructure of lesions [5-7].

This review highlights several important roles for MRI in managing brain metastases from breast cancer. First, MRI is more sensitive than CT for detecting small and morphologically complex lesions. This allows earlier diagnosis and treatment before lesions become debilitating. Second, MRI provides superior characterization of metastases versus primary brain tumors like glioblastoma. Enhancing patterns, edema, hemorrhage, and necrosis can distinguish pathologies. Third, MRI enables monitoring of treatment response through changes in size, blood flow, and metabolism. However, debate continues over which specific MRI markers are most accurate for distinguishing true progression from pseudoprogression following treatment. Some studies suggest enhancing tumor volume [8-10] is optimal, while others argue that perfusion or diffusion metrics [11-13] are more predictive. Further research is needed to clarify the strengths and limitations of particular MRI biomarkers in this context.

The authors rightly note limitations of the heterogeneity across included studies and the need to validate emerging MRI techniques in larger samples. However, the review collectively reinforces MRI as the preferred modality for imaging brain metastases from breast cancer. MRI surpasses CT in diagnostic sensitivity and specificity. Meanwhile, new methods like diffusion imaging, perfusion imaging, and MR spectroscopy open up possibilities for improving tumor characterization, treatment planning, and prognostication.

An important next step for research in this area is to correlate advanced MRI findings with tumor biology and genetics. Breast cancer subtypes defined by receptors like HER2 and genomic signatures influence metastatic behavior. MRI phenotypes may align with and provide insight into the underlying cancer biology. Studies should also examine how MRI metrics of brain metastases correlate with and potentially predict clinical outcomes like survival and neurocognitive function.

In summary, this review affirms the indispensable role of MRI in managing brain metastases from breast cancer. MRI detects lesions missed by other modalities and offers diverse techniques for visualizing tumor morphology, microenvironment, and metabolism [14-16]. Ongoing research should further optimize MRI acquisition and analysis protocols to make information actionable for prognosis and personalized therapy. MRI is positioned to have tremendous impact for a devastating complication of breast cancer.

• The most common locations for metastases were the cerebral hemispheres, frontal lobe, cerebellum, and ventricles.
• MRI findings varied based on the MRI technique, breast cancer subtype, lesion size/shape, presence of hemorrhage/necrosis, and comparison to other brain tumors.
• Quantitative MRI metrics were associated with prognosis, recurrence risk, and cognitive impairment.
• MRI allows detection, characterization, and monitoring of brain metastases through assessing size, shape, location, composition, perfusion, metabolism, and connectivity.
• Specific MRI techniques can differentiate brain metastases from primary brain tumors and ischemic lesions.
• MRI findings differ based on breast cancer subtype [HER2+ vs triple negative].
• Larger metastases tend to have more hemorrhage/necrosis than smaller ones.
• Advanced MRI techniques can predict outcomes like recurrence and treatment response.
• More research is needed to validate emerging MRI techniques and determine clinical impact of MRI findings on patient management.

SM and SG contributed to the article and approved the submitted version.

The authors declare no financial or other conflicts of interest.

No human or animal subjects were used in the research.