EGFR and neoplasm: As the most widely used tracer in oncology, 18F-FDG has been investigated in the early prediction of outcomes after targeted treatment, including that with anti-EGFR agents such as the monoclonal antibody cetuximab.271 It was reported that an increase in peak tumor metabolism at the end of the first week of therapy implied poor PFS (P = 0.001) and OS (P < 0.001) at the end of the first week of third-line cetuximab-based therapy in metastatic colorectal cancer patients.