Fig. 3
89Zr-trastuzumab positron emission tomography (PET) predicts tumor response to treatment in BT-474 xenografts. Untreated (left) and treated BT-474 tumors for 7-day (middle) or 14-day (right) treatment with 75 mg/kg/body weight dasatinib were imaged with fluorodeoxyglucose (FDG)-PET (a). In the same group of mice, PET with 89Zr-trastuzumab demonstrated attenuated tracer accumulation in treated groups compared to control (b). Tumor volumes of interest (VOIs) demonstrated lower tumor uptake of 89Zr-trastuzumab in treated groups compared to control; no observed changes were detected by FDG in the control or treated groups (c). Percentage change in tumor volume during treatment correlated with 89Zr-trastuzumab uptake (d). T, tumor; L, liver; d, days; %(ID)/g, injected dose per gram of tissue