TABLE 1

Distribution of 1:30 ¹¹¹In-DTPA-PEG-C225

Groups	Blood	Liver	Muscle	Tumor	Tumor-to-blood	Tumor-to-muscle
1:30 ¹¹¹In-DTPA-PEG-C225	1.40 ± 0.64	25.5 ± 2.0	0.69 ± 0.22	8.68 ± 1.78	7.04 ± 1.94	13.4 ± 3.89
¹¹¹In-DTPA-C225	0.54 ± 0.24*	46.9 ± 2.5*	0.38 ± 0.08^†	11.0 ± 1.0	22.3 ± 7.2*	29.4 ± 3.3*
C225 + PEGylated C225; 30-min	4.95 ± 0.61*	16.5 ± 4.25^†	1.48 ± 0.22^†	13.85 ± 1.38^†	2.83 ± 0.49^†	9.37 ± 0.58
C225 PEGylated C225; 20-h	2.93 ± 0.60^†	10.5 ± 0.40*	0.73 ± 0.11	7.63 ± 1.96	2.59 ± 0.14^†	10.4 ± 1.19

↵*P < 0.005 compared with 1:30 ¹¹¹In-DTPA-PEG-C225 group.
↵^†P < 0.05 compared with 1:30 ¹¹¹In-DTPA-PEG-C225 group.
Nude mice with EGFR-positive human A431 tumors were injected with 1:30 ¹¹¹In-DTPA-PEG-C225 or ¹¹¹In-DTPA-C225. Additional 2 groups of mice were pretreated with native C225 30 min or 20 h before injection of 1:30 ¹¹¹In-DTPA-PEG-C225. Mice were dissected 48 h after radiotracer injection, and tissue samples were counted for radioactivity. Data are expressed as mean ± SD of 3 mice per group (%ID/g).