Thomas Kang Rhee MD, Presenter: Nothing to Disclose

Robert Kyu Won Ryu MD, Abstract Co-Author: Nothing to Disclose

Dingxin Wang MS, Abstract Co-Author: Nothing to Disclose

Kent Takeki Sato MD, Abstract Co-Author: Nothing to Disclose

Andrew Christian Larson PhD, Abstract Co-Author: Nothing to Disclose

Reed Ali Omary MD, Abstract Co-Author: Nothing to Disclose

Uterine artery embolization(UAE)is widely used to treat uterine fibroids, however, an animal model containing actual uterine fibroids does not exist. Development of such an animal model of uterine fibroids would allow interventional radiologists to: a)test embolic therapies; b)develop innovative imaging techniques; and, c)determine the most appropriate UAE endpoint. The rabbit VX2 cancer model has been used in the liver, lung, and kidneys. We tested the hypothesis that VX2 implantation in rabbit uterus could induce a successful fibroid model and that MRI could detect acute perfusion changes after UAE in this model.

In 6 New Zealand White rabbit uteri, VX2 cells were implanted and incubated (21-30 days). Each rabbit underwent bilateral uterine artery digital subtraction angiography once MRI(Siemens 1.5T Sonata) confirmed uterine tumor growth. Using 100-300 micron embolic particles, subsequent UAE to stasis was performed. Pre and post-UAE contrast enhanced T1-weighted MRI was performed using IV gadolinium. After UAE, rabbits were sacrificed and each uterus was harvested for pathologic analysis. Using a computer workstation, we measured signal enhancement(relative tumor signal-to-noise ratio)pre and post-UAE in 4 quadrants for each uterine tumor(n=8 separate measurements for each uterine tumor). We statistically compared mean fibroid enhancement pre and post-UAE using the student’s t-test(alpha=0.05).

In 6 rabbits, 6 discrete VX2 uterine tumors were grown, imaged, and embolized. All tumors were confirmed on pathology(2-4cm in greatest diameter). On MRI, mean tumor enhancement pre-UAE was 15.3±5.15 and post-UAE was 3.84±3.94. This difference was statistically significant (p<0.0001).

VX2 uterine implantation in rabbits successfully induces a fibroid animal model that responds to UAE. MRI can detect significant reductions in rabbit VX2 uterine tumor perfusion after UAE. Future studies assessing the use of the VX2 rabbit uterine fibroid model for chronic experiments is warranted.

Successful development of the rabbit VX2 uterine fibroid model can serve as a platform for translational research designed ultimately to improve clinical uterine fibroid therapy.

Rhee, T, Ryu, R, Wang, D, Sato, K, Larson, A, Omary, R, Rabbit VX2 Tumors as an Animal Model of Uterine Fibroids and for Uterine Artery Embolization.  Radiological Society of North America 2006 Scientific Assembly and Annual Meeting, November 26 - December 1, 2006 ,Chicago IL. http://archive.rsna.org/2006/4436322.html