A metabolic response (based on findings from [18F]F-fluordesoxyglucose [FDG]-PET) activity after anti-HER2 treatment is included, and in an interim analysis of 40 patients presented at the San Antonio Breast Cancer Conference 2022, it was found that tracer uptake could predict metabolic response to treatment better than conventional IHC and that the tracer may be useful as an adjunct diagnostic tool. Here, ERBB2 is linked to breast cancer.