This research study is a pilot study to evaluate a new contrast agent, ferumoxytol, for the
purpose of imaging lymph node metastases in patients with soft tissue sarcoma. This contrast
agent is an investigational drug. "Investigational" means that the drug is still being
studied and that research doctors are trying to find out more about it. It also means that
the FDA has not approved ferumoxytol for this use. This drug has been used to image adults
with other forms of cancer, however, it has only been used to image a small number of
pediatric patients. Ferumoxytol has never been used to image sarcoma.