Comparative Evaluation of Radioiodine and Technetium-Labeled DARPin 9_29 for Radionuclide Molecular Imaging of HER2 Expression in Malignant Tumors

Table 3

Comparison of biodistribution of [¹²⁵I]I-DARPin 9_29 and [^99mTc]Tc(CO)₃-DARPin 9_29 in BALB/C nu/nu mice bearing SKOV-3 xenografts at 6 h after injection.

	Uptake (%ID/g)
	^125I-DARPin 9_29	^99mTc(CO)3-DARPin 9_29
Blood	1.2 ± 0.4	0.8 ± 0.1
Salivary glands	1.3 ± 0.3	1.7 ± 0.4
Lung	0.9 ± 0.3	1.7 ± 0.2
Liver	1.2 ± 0.2	27 ± 4
Spleen	0.9 ± 0.2	8.4 ± 3.0
Stomach	4.3 ± 3.0	1.3 ± 0.1
Kidney	3.4 ± 0.4	80 ± 11
Tumor	3.4 ± 0.7	2.9 ± 0.7
Muscle	0.3 ± 0.1	0.5 ± 0.1
Bone	0.77 ± 0.04	2.0 ± 0.8
Gastrointestinal tract^a	1.4 ± 0.3	5.3 ± 0.9

^aData for the gastrointestinal tract are presented as %ID per whole sample.  Significant difference () between uptake of [¹²⁵I]I-DARPin 9_29 and [^99mTc]Tc(CO)₃-DARPin 9_29. Data are presented as mean ± SD for four mice.