Radioimmunoimaging study using pretargeting system on ~(153)Sm labeled anti-C-erbB-2 monoclonal antibody in nude mice grafted with human breast carcinoma

Objective To study using pretargeting system on radioimmunoimaging of 153Sm labeled anti-C-erbB-2 monodonal antibody and normal mice IgG in nude mice with human breast carcinoma and provide the basis for clinical use .Methods Group I 3-step pretargeting injected into the tail vein with 7.4 MBg/0.1 ml labeled antibody.Group II and III injected directly into the tail vein with 7.4 MBg/0.1ml labeled antibody.SPECT were measured after 2、4、8、24 h interval of injecion.Percent injected dosage of every gram tissue(%ID/g)were measured after 4、8、24 h interval to death.Results The tumor blood ratio of groupI reached 6.53、8.11、9.25 at 2、4、8 hours respectively.Radioactivity concertratoin peaked at 8 h in tumor site.the tumor/blood ratio of groupI was higher than groupII and groupIII.(P0.05).Conclusion Pretargeting system on radioimmunoimaging improves the amounts of locatingon toumors and yields a specific enhancing effect and also improve image quality.