High-resolution MR lymphography using ultrasmall superparamagnetic iron oxide (USPIO) in the evaluation of axillary lymph nodes in patients with early stage breast cancer: preliminary results

Background The purpose of this study was to examine the utility of high-resolution magnetic resonance (MR) lymphography using ultrasmall superparamagnetic iron oxide (USPIO) in the evaluation of axillary lymph nodes in patients with early stage breast cancer. Methods Ten women with breast cancer without swollen axillary lymph nodes were enrolled in this study. High-resolution MR lymphography was performed 24 h after administration of USPIO. On the MR examination, a 3-inch surface coil was placed on the sentinel lymph node (SLN) parts as defined by a radioisotope (RI) scintigraphy method, and T2*-weighted (T2*W) and T1-weighted (T1W) images were obtained. Detected nodes were differentiated as normal or diseased nodes by the enhancement patterns. The day after MR examination, SLN biopsy (SNB) was performed. The imaging results were compared to the histopathologic findings. Results On MR images, the mean number of detectable nodes was 7.9 per patient. Eight patients who histopathologically had no metastatic lymph nodes were diagnosed as nonmetastatic and two patients who had 3- and 6-mm metastatic areas in the node, respectively, were diagnosed as metastatic preoperatively. No side effects were noted. Conclusions High-resolution MR lymphography using USPIO enabled us to obtain good axillary lymph node evaluation results. These results suggest that this method of imaging may contribute to better preoperative lymph node staging.