The goal is to develop a noninvasive MRI technique using colloidal magnetite contrast agents for sentinel lymph node (SLN) mapping and staging with application to melanoma and breast cancer patients. Peritumoral injections of these magnetite nanoparticles would limit their distribution to the lymphatic drainage basin near the primary tumor. Application of this technique would lower medical costs by assuring that SLN location and assessment would involve less doctor-patient contact and decrease patient morbidity. Our specific goals are 1) develop new magnetite nanoparticles specifically for sentinel lymph node staging or mapping. These nanoparticles will exhibit minimal retention at the site of injection and move rapidly and efficiently to the SLN. 2) Determine the effect of nanoparticle surface properties on nodal nanoparticle uptake rates. 3) Determine the effect of massage and muscular movement on efficacy of nodal loading. 4) Determine the optimum dose and imaging protocols for SLN staging. The development of this technique will enable oncologists to locate sentinel lymph nodes in cancer patients and perhaps eliminate the need for elective lymphadenectomy or sentinel lymph node dissection.
The market for a MRI contrast agent designed for sentinel lymph node detection and staging in the US alone is large with a potential of >180000 breast cancer patients and approximately 38000 melanoma patients annually. This technique may also be applicable to other solid cancers with nodal metastases. The spread of the primary tumor to the regional lymph nodes is an important prognostic indicator for long term survival of cancer patients. Unfortunately, there is no reliable non-invasive technique for assessing lymph node status in cancer patients. Our technique may eliminate the need for surgical assessment of lymph node status.
