Teresa Catherine Bravo, Abstract Co-Author: Nothing to Disclose

Michael Joseph Dattoli MD, Abstract Co-Author: Nothing to Disclose

Stephen Michael Bravo MD, Presenter: Nothing to Disclose

Matthew Hayes, Abstract Co-Author: Nothing to Disclose

Alexandra Osorio MD, Abstract Co-Author: Nothing to Disclose

Patricia M. Dycus RRA, Abstract Co-Author: Nothing to Disclose

Charles Myers MD, Abstract Co-Author: Nothing to Disclose

Ferumoxytol (Feraheme) is a ferromagnetic nanoparticle with lymphotrophic biokinetics. Feraheme is delivered to lymph nodes via normal macrophages. MRI is successful in suppressing normal lymph nodes containing Feraheme. The purpose of this study is to validate this agent’s safety and determine its role as a lymph node contrast agent in the prostate cancer population.

A nonrandomized prospective evaluation of 152 prostate cancer patients. All patients received IV Feraheme. T2 MEDIC and T2* sequence imaging of the abdomen and pelvis, using Verio and Skyra 3T Siemens MR units, was performed approximately 24 hours after Feraheme infusion. Images were reviewed by 2 board certified radiologists with consensus interpretation. Lymph nodes were considered abnormal if they did not suppress after Feraheme infusion. Thirty nine patients subsequently underwent imaged guided lymph node biopsy. Radiology-pathology correlation was performed.  

Forty-nine patients demonstrated abnormal lymph nodes consistent with metastatic disease based on Feraheme imaging criteria. Thirty-nine of these patients underwent image guided lymph node biopsy, 1 underwent mediastinoscopy, and 1 underwent pelvic lymph node exoneration. A total of 84 lymph nodes were sampled. Ninety-one percent of these demonstrated metastatic prostate carcinoma, 2% demonstrated lymphoma, and 7% were normal. Forty-seven percent of all malignant lymph nodes did not fulfill traditional imaging criteria for malignancy. All of the normal lymph nodes on biopsy were either femoral or axillary lymph nodes demonstrating heterogeneous peripheral hypointense T2* signal and heterogeneous central hyperintense T2* signal.

Feraheme can be used to evaluate for the presence of lymphatic dissemination of metastatic disease in prostate cancer patients, with a lower limit of resolution of focal lymph node metastases of 3-4 mm. This improved resolution carries implications for therapeutic radiation planning in the setting of newly diagnosed or recurrent/metastatic prostate carcinoma. Feraheme may play a significant future role as a lymphatic contrast agent in the early dissemination of lymphatic metastatic disease.

3T MR after Feraheme administration has the potential to identify neoplastic nodes down to a resolution of 3-4 mm, thereby markedly improving the detection of metastatic lymph node disease.

Bravo, T, Dattoli, M, Bravo, S, Hayes, M, Osorio, A, Dycus, P, Myers, C, Efficacy of Feraheme as a Lymphatic Contrast Agent in Prostate Cancer.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14045778.html