Yun Jung Kim MD, Presenter: Nothing to Disclose

Kangtaek Lee, Abstract Co-Author: Nothing to Disclose

Bumsang Kim, Abstract Co-Author: Nothing to Disclose

Jin Hur MD, Abstract Co-Author: Nothing to Disclose

Byoung Wook Choi MD, Abstract Co-Author: Nothing to Disclose

To improve enhancement of tumor with a nanoparticulate contrast agent in computed tomography by pretreatment of liposome to saturate reticuloendothelial system (RES), which is expected to slow down the elimination of nanoparticulate contrast agent from the blood through RES.

We first determined the optimal time, amount, and particle size of liposome administration for saturation of RES and the optimal enhancement time point of tumor by a nanoparticulate contrast agent (pegylated gold nano particle; AuNP, 40nm). Lewis lung cancer cells (1 x 106) were inoculated to the thigh of C57BL/6 mice (n=6). Two weeks later after tumor fully had grown, the mice were divided into two groups, 1) liposome-treated group with injection of AuNP after 2 hours from liposome injection (150-400nm) to saturate RES (n=3) and 2) non-treated group with injection of AuNP only (n=3). Micro-CT scan was performed to include liver, spleen, and the tumor immediately before and 48 hours after AuNP injection. The mean increase of tumor enhancement was compared between two groups on the liver, spleen, and the tumor respectively. The immune suppression and recovery were followed by surveying gene expression of TNFα, IL-6, NOS, CD14, and histology of the liver and spleen in separate liposome-treated mice (n=3, 3 respectively).

The enhancement of tumor was greater in liposome-treated group than in non-treated group (average 164.8 vs. 48.8). That of spleen was greater in non-treated group than in treated group (average 570.0 vs. 245.1). That of liver was similar between two groups (average 506.1 in treated group vs. 530.4 in non-treated group). The enhancement of tumor in treated group increased to 288% of that in non-treated group. The enhancement of spleen in treated group decreased to 46.9% of that in non-treated group. Decreased level of gene expression of TNFα, IL-6, NOS, and CD14 and decreased number and deformed shape of macrophages by RES saturation almost recovered in 2 weeks.

RES saturation by liposome with a tolerable degree of immune suppression is feasible to improve tumor enhancement with nanoparticulate contrast agent.

It will provided the feasibility of reticuloendothelial saturation prior to administration of nanoparticulate contrast agent improving the efficacy with same amount of contrast agents or reducing the amount of administration maintaining same degree of enhancement.  

Kim, Y, Lee, K, Kim, B, Hur, J, Choi, B, Improved Tumor Enhancement with Nanoparticulate Contrast Agent in Computed Tomography by Saturation of Reticuloendothelial System.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14005916.html