Although the most common site of Metastatic Breast Cancer (MBC) is bone there is currently no standardized imaging modality that offers accurate assessment of bone treatment response.

Computed Tomography (CT) is a standard method for evaluating metastatic breast cancer (MBC) but has limitations in assessing bony metastases. RECIST 1.1 criteria classify bone lesions as non-measurable unless there is measurable soft tissue involvement. CT struggles with qualitative assessment, especially for stable lesion sizes or sclerotic responses. Bone Scan (BS) using 99mTc-MDP has been the primary method for detecting bony metastases since the 1960s, offering high sensitivity but difficulties in therapy response assessment due to 'flare' reactions post-treatment. FDG-PET/CT provides functional insights by detecting metabolic changes before structural alterations, making it valuable for therapy response monitoring. However, it has limitations in visualizing metabolically silent bone metastases. Whole-body MRI (WB-MRI) is emerging as a superior tool for assessing bone marrow and monitoring therapy response in advanced breast cancer. Studies highlight WB-MRI's superior diagnostic capability compared to CT-CAP or FDG-PET/CT. For instance, WB-MRI detected progressive disease (PD) in cases missed by other modalities, demonstrating its potential to guide treatment decisions effectively. WB-MRI's advantages include excellent diagnostic performance, the absence of ionizing radiation, and no need for contrast media.

Additionally, radiology's environmental impact is increasingly recognized. Modalities like MRI, CT, BS, and PET-CT are significant contributors to greenhouse gas (GHG) emissions, with radiology accounting for approximately 1% of global healthcare-related emissions. To mitigate these effects, low-energy imaging techniques should be prioritized without compromising diagnostic accuracy. For instance, the American College of Radiology suggests ultrasound as a viable alternative to X-Ray or CT in certain cases, reducing energy use. WB-MRI presents an opportunity for sustainable and patient-friendly diagnostics, combining high efficacy with reduced environmental and biological impacts.

This study aims to quantify the energy consumption and GHG emissions associated with imaging modalities at the European Institute of Oncology in Milan, identifying the most sustainable and beneficial approach for patients with MBC. The analysis could establish a model for balancing clinical and environmental priorities in radiology departments globally.