Figure 3

Intraperitoneal (i.p.) administration of 1.4 MBq of ¹²⁴I-HuCC49deltaC _H 2 for microPET imaging of the LS174T xenograft mouse model. MicoPET imaging is shown at approximately 1 hour and at 24 hours after injection in coronal, sagittal, and transaxial views. At 24 hours after i.p. injection, ¹²⁴I-HuCC49deltaC_H2 was found to have specifically accumulated within the LS174T tumor implant. The area of increased activity (yellow) seen at the hind end of the mouse on the 1 hour coronal and sagittal images represents subcutaneous activity within the tail region due to previous failed tail vein injection. This subcutaneous activity within the tail region completely disappeared by the 24-hour image. Some nonspecific liver uptake is noted at 24 hours after i.p. administration of 1.4 MBq of ¹²⁴I-HuCC49deltaC_H2 secondary to use of the chelated form of the HuCC49deltaC_H2 antibody.