In addition, we assessed other factors that might contribute to drug accumulation and treatment efficacy, such as intra-patient variability in PK, tumor EGFR expression [10], plasma soluble EGFR (sEGFR) concentration [12], tumor perfusion on [15O]H2O PET/CT, and metabolic tumor activity on [18F]FDG PET/CT. Here, EGFR is linked to neoplasm.