Iron oxide particle-enhanced magnetic resonance imaging for detection of benign lymph nodes in the head and neck: how reliable are the results?

AIM To evaluate the accuracy of ultrasmall paramagnetic iron oxide (USPIO: Sinerem)-enhanced MRI in patients with head and neck cancer and enlarged lymph nodes compared with current staging examinations using histology as a gold standard. PATIENTS AND METHODS Seventeen patients with a histologically proven squamous cell cancer of the head and neck (SCCHN) and different N-stages underwent a non-enhanced and a USPIO-enhanced MRI examination. Signal intensity (SI) was measured in a region of interest evaluation. Pathohistological examination was used as a reference. RESULTS On a patient basis, USPIO-enhanced MRI showed a higher specificity and diagnostic accuracy (94%) compared with non-enhanced MRI (53%). One patient showed a lymph node of 6 mm in the short axial diameter which was suggested as being metastatic in Sinerem-enhanced MRI according to the enhancement pattern of Sinerem. This patient was staged as N1 with Sinerem-enhanced MRI. The histopathological examination did not confirm the Sinerem-enhanced MRI result. CONCLUSION The high values for the specifity and diagnostic accuracy of Sinerem- enhanced MRI justifies further investigations with this contrast agent. USPIO-enhanced MRI could be advantageous in avoiding surgical overtreatment.