T2 Values of Breast Lymph Nodes At 1.5 T in Patients Pre & Post Subcutaneous Injection of Superparamagnetic Iron Oxide - Initial Results From a Sentinel Node Negative Population

Laura Johnson¹, Geoff Charles-Edwards², Jyoti Parikh³, Margaret Hall-Craggs⁴, Tobias Schaeffter⁵, Michael Douek¹

Magnetic nanoparticles administered subcutaneously can differentiate normal from abnormal lymph nodes when comparing T2 values in preclinical studies. We demonstrate the identification and characterization on MRI of the sentinel lymph node (SLN) in breast cancer following subcutaneous injection of iron-oxide nanoparticles into the affected breast. Normal (uninvolved) SLNs undergo a significant decrease in the mean T2 value post injection of Endorem. This decrease is more pronounced over time when comparing early post-injection scans (mean delay 12 minutes) with delayed scans (mean delay 119 minutes). Further work must be done to evaluate how this differs in metastatic SLNs.