RSNA 2006 

Abstract Archives of the RSNA, 2006


SSJ06-01

A preliminary study evaluating Lymphotropic Nanoparticle enhanced MRI (LNMRI) (Combidex) for pre-operative staging of lymph node involvement in Kidney Cancer

Scientific Papers

Presented on November 28, 2006
Presented as part of SSJ06: Molecular Imaging (Lymph Nodes)

Participants

Alexander Guimaraes MD,PhD, Presenter: Nothing to Disclose
Mansi Awasthi Saksena MD, Abstract Co-Author: Nothing to Disclose
Shahin Tabatabaei, Abstract Co-Author: Nothing to Disclose
Douglas Dahl MD, Abstract Co-Author: Nothing to Disclose
Ralph Weissleder MD, PhD, Abstract Co-Author: Stockholder, VisEn Medical, Inc Consultant, Siemens AG
Mukesh Gobind Harisinghani MD, Abstract Co-Author: Nothing to Disclose

PURPOSE

To assess LNMRI in identifying malignant nodal involvement in patients with renal neoplasms; to determine if there are contrast characteristics that distinguish malignant from benign renal tumors.

METHOD AND MATERIALS

10 patients with renal masses were imaged on a GE 1.5T system with phased array body coil. Protocols included T2 and multi-contrast T2* weighted imaging prior to and following administration of ferumoxtran-10(Combidex) for the evaluation of lymph node involvement. Surgery was performed as clinically necessary. Qualitative data analysis was performed by two blinded radiologists identifying lymph nodes on precontrast T2 and T2* weighted images. Nodes that lacked contrast uptake were deemed malignant, and those with homogeneous uptake were deemed benign. Retrospective analysis was performed on primary tumors by quantifying T2* with a mono-exponential fitting algorithm (Osirix). T2* was quantified pre, immediately post, and 24hrs following the administration of ferumoxtran-10.

RESULTS

6 of 10 patients had lymph nodes within the perinephric region that could be assessed by both MRI and histology. 5 of 6 lymph nodes demonstrated concordance (4 benign and 1 malignant). There was one false positive lymph node. Sensitivity was 100% and specificity 80%. Two primary tumors had T2* quantified (one renal cell cancer, and one oncocytoma). The renal cell cancer demonstrated a decrease in T2* of 5msec, which resolved at 24hrs. The oncocytoma demonstrated a marked decrease in T2* of 77.8 ms, which did not normalize after 24hrs.

CONCLUSION

The high sensitivity (100%) and specificity (80%) of LNMRI in distinguishing metastatic lymph nodes in patients with kidney cancer is encouraging. Dramatic differences were also observed in initial contrast uptake within primary neoplasms, which may reflect increased vascularity. More interestingly, the retention of contrast within oncocytoma (compared with clearance of contrast in renal cell cancer) suggests an inflammatory component to this poorly understood benign pathology.

CLINICAL RELEVANCE/APPLICATION

This project is a preliminary, first application of LNMRI to kidney cancer and offers potential in non-invasive classification and staging of this disease.

Cite This Abstract

Guimaraes, A, Saksena, M, Tabatabaei, S, Dahl, D, Weissleder, R, Harisinghani, M, A preliminary study evaluating Lymphotropic Nanoparticle enhanced MRI (LNMRI) (Combidex) for pre-operative staging of lymph node involvement in Kidney Cancer.  Radiological Society of North America 2006 Scientific Assembly and Annual Meeting, November 26 - December 1, 2006 ,Chicago IL. http://archive.rsna.org/2006/4429067.html