- Results of a recent NCI trial (11-C-0098) in 15 patients revealed that using the dose of 7.5 mg/kg Fe is safe and yields homogenous and accurate signal changes in benign lymph nodes in comparison with the 4 and 6 mg/kg Fe doses. This dose was further tested in 5 patients with known or suspected nodal involvement from prostate cancer and in four of five patients positive lymph nodes had a lower signal drop than the benign nodes. The one case in which there was uptake by positive nodes may have been on a vascular basis. This pilot study stimulated interest in a larger study involving a variety of cancer types.