ERBB2 and neoplasm: Significantly higher tumor/blood (T/B) ratios were found for 111In-DOTA-trastuzumab Fab than 111In-DOTA-rituximab Fab for BT-20, MDA-MB-231 and MDA-MB-361 xenografts, and there was a direct association between T/B ratios and HER2 expression.