John B. Weaver PhD, Presenter: Nothing to Disclose

Uciane K. Scarlett, Abstract Co-Author: Nothing to Disclose

Adam M. Rauwerdink, Abstract Co-Author: Nothing to Disclose

Steven N. Fiering PhD, Abstract Co-Author: Nothing to Disclose

Jose R. Conejo-Garcia MD,PHD, Abstract Co-Author: Nothing to Disclose

Magnetic detection of immunologically targeted magnetic nanoparticles can identify microscopic ovarian malignancies in mice with very high significance. The MSB signal localization must be improved to isolate the involved ovary. Support was provided by NIH CA151662.

Ovarian cancer has an extremely poor survival rate. However, the prognosis is generally very good if found early. Unfortunately, it is almost never found until it has metastasized. There is no screening mechanism capable of detecting ovarian cancer early. An effective early detection method would save many lives.

Immunologic targeting of magnetic nanoparticles to ovarian cancer was coupled with magnetic detection as a method of early ovarian cancer detection. The method was tested in a unique mouse model for ovarian cancer that provided microscopic cancers at specific times. Immunologic targeting is accomplished by injecting magnetic nanoparticles (250µgm of 100nm iron oxide) into the peritoneal cavity where they are quickly phagocytosed. Cytokine signaling draws phagocytes along with their load of endocytosed magnetic nanoparticles to the malignancy. We used magnetic spectroscopy of nanoparticle Brownian motion (MSB) to detect the nanoparticles in vivo at these fairly low concentrations. The contralateral ovary and the ovaries of genetically unchanged mice were used as controls.

The MSB signal over the cancer was 29 standard deviations larger than that over the ovaries in the normal mice (p-value 10-8). However, the spatial resolution of MSB in its current form was insufficient to completely isolate the peripheral region including the contralateral ovary and the region immediately inferior to the cancer. The signal in the lower abdomen was the same as the signal in normal mice. The cancer signal was 16 standard deviations above the peripheral region and the peripheral region was 12 standard deviations above background. Although the contralateral ovary was not an optimal control normal mice provided an adequate control. The cancer was still microscopic at the time the nanoparticle measurements were made.

Weaver, J, Scarlett, U, Rauwerdink, A, Fiering, S, Conejo-Garcia, J, Potential Ovarian Cancer Screening Method: Immunologically Targeted Nanoparticles Detected with Magnetic Spectroscopy of Nanoparticle Brownian Motion.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11034641.html