SPIO-Enhanced Magnetic Resonance Imaging for the Detection of Metastases in Sentinel Nodes Localized by Computed Tomography Lymphography in Patients with Breast Cancer

Abstract

SPIO-enhanced MR imaging is a useful method of detecting metastases in sentinel nodes localized by CT-LG in patients with breast cancer and may avoid sentinel node biopsy when the sentinel node is diagnosed as disease-free.

A comprehensive literatures update of clinical researches of superparamagnetic resonance iron oxide nanoparticles for magnetic resonance imaging

“…A CT scan was performed after massaging the iodinated contrast agent injection site. SPIO (a 40-µL aliquot of Resovist, containing 1.115 mg iron, diluted in 20 mL normal saline, as per Motomura et al, (53) was administered locally, similar to the administration of dye and radioisotope during sentinel node detection. The injection sites of SPIO were gently massaged for 1 min.…”

“…In the series of 102 patients with breast cancer and clinically negative nodes, Motomura et al (53) reported the mean number of sentinel nodes identified by CT lymphography was 1.1 (range, 1-3). The sensitivity, specificity, and accuracy of 1.5T MRI for the diagnosis of sentinel node metastases were 84.0%, 90.9%, and 89.2%, respectively.…”

“…The sensitivity, specificity, and accuracy of 1.5T MRI for the diagnosis of sentinel node metastases were 84.0%, 90.9%, and 89.2%, respectively. In 4 of 10 patients with micro-metastases, metastases were not detected, but all 15 patients with (53) commented that further study is needed to explore the best timing and concentration of SPIO to improve the accuracy of this technique, such as fatsuppressed images, higher field magnet (as opposed to the 1.5T system used in the study of reference 53), and a special radiofrequency coil may improve accuracy.…”

What is the future of magnetic nanoparticles in the axillary management of breast cancer?

“…They have demonstrated that the sensitivity, specificity and overall accuracy of SPIO-enhanced MRI make it a useful method for detecting SLN metastases. In a study on 102 patients with breast cancer the sensitivity, specificity, and accuracy of SPIO-enhanced MRI for the detection of SLN metastases were at 84.0, 90.9, and 89.2 %, respectively [26]. In a direct comparison between conventional MRI and SPIO-enhanced MRI, it was found that SPIO-enhancement was superior in terms of sensitivity, specificity and overall accuracy [25].…”

“…The use of MNPs as MRI contrast agents provides a non-invasive method of imaging the complete lymphatic drainage basin from the tumour. This imaging subsequently allows visualization of any clinically positive lymph nodes and precise identification of their location [25,26].…”