Objective:

To evaluate the diagnostic performance of SPIO-enhanced MRI in differentiating metastatic from reactive hyperplastic lymph nodes in breast cancer patients and to explore the association between MRI signal characteristics and VEGF-C expression, which is significant for understanding lymphangiogenesis in cancer.

Key Findings:

• Reactive nodes showed a mean PSIL of 64.7% compared to 11.6% in metastatic nodes (p < 0.001).
• Patient-level ROC analysis yielded an AUC of 0.84 (95% CI: 0.73–0.95), with sensitivity of 83% and specificity of 85%.
• High VEGF-C expression was more prevalent in metastatic nodes (85.1%) compared to hyperplastic nodes (12.3%; p < 0.001).
• PSIL showed a moderate inverse correlation with VEGF-C grade (Spearman r = -0.67; p < 0.001).

Interpretation:

SPIO-enhanced MRI demonstrates strong diagnostic performance in differentiating between metastatic and reactive hyperplastic lymph nodes, with imaging characteristics correlating with histopathological findings and VEGF-C expression.

Limitations:

• Single-center study limits generalizability; findings may not apply to broader populations.
• Small sample size may affect statistical power and the robustness of conclusions.
• Further validation in larger, multicenter studies is needed to confirm these results.

Conclusion:

SPIO-enhanced MRI is a promising non-invasive method for accurately distinguishing between metastatic and reactive lymph nodes in breast cancer, warranting further investigation in diverse populations.