Mansi Awasthi Saksena MD, Presenter: Nothing to Disclose

Mukesh Gobind Harisinghani MD, Abstract Co-Author: Nothing to Disclose

Shahin Tabatabaei, Abstract Co-Author: Nothing to Disclose

Scott W McDougal MD, Abstract Co-Author: Nothing to Disclose

Peter Florin Hahn MD, PhD, Abstract Co-Author: Nothing to Disclose

Ralph Weissleder MD, PhD, Abstract Co-Author: Stockholder, VisEn Medical, Inc Consultant, Siemens AG

To evaluate the utility of ferumoxtran 10 induced signal intensity changes in lymph nodes for staging patients with penile cancer

4 patients, with biopsy proven penile cancer scheduled for inguinal lymphadenectomy were enrolled in the study.93 nodes were evaluated on TI-weighted spin-echo (SE), T2-weighted fast spin-echo (FSE) and T2*-weighted gradient-echo (GRE) MR imaging at l.5T, before and 24-36 hours following IV administration of USPIO (2.6 mg Fe/kg). Primary outcome parameters including sensitivity and specificity were calculated. For each lymph node quantitative signal intensity measurements were made in ROIs that were placed in the most suspicious area. The ROIs were as large as possible and included one type of tissue. Second ROI was placed in the adjacent muscle for subsequent normalization, which compensated for inhomogenous reception of the surface coil and for differences in the adjustment of the MR unit between examinations. For each lymph node a ratio of the SI of the node to that of the muscle was calculated pre and post contrast.

Of the 93 lymph nodes 87 were benign and 6 malignant on histology. The accuracy, sensitivity, specificity, positive and negative predictive value of MR-lymphography was 96.7 %, 100 %, 96.5 %, 66.6 % and 100% respectively. The mean signal intensity ratio, on T2*-weighted GRE images, for benign lymph nodes changed from 2.229 (precontrast) to 0.46 (postcontrast), signal intensity for malignant lymph nodes was relatively unchanged 2.636 (precontrast) and 1.706 (postcontrast). A t test was performed on the SI ratio values of the malignant and benign nodes on the pre and post contrast scans. The p value was not significant on the pre contrast scans (p value 0.4121) but was significant for the postcontrast scans (p value <0.0001).

Ferumoxtran-10 is a useful MR contrast agent for noninvasive characterizing lymph nodes in patients with penile cancer. Improved accuracy for lymph node characterization will help in better patient management.

Intranodal signal intensity changes on LNMRI are accurate for characterization of inguinal nodes in patients with penile cancer and LNMRI is recommended prior to inguinal lymphadenectomy.

Saksena, M, Harisinghani, M, Tabatabaei, S, McDougal, S, Hahn, P, Weissleder, R, Noninvasive Nodal Staging of Patients with Penile Cancer Using Ferumoxtran-10.  Radiological Society of North America 2006 Scientific Assembly and Annual Meeting, November 26 - December 1, 2006 ,Chicago IL. http://archive.rsna.org/2006/4437620.html