KIT and gastrointestinal stromal tumor: [18 F]FDG-PET could also be a surrogate marker for the efficacy of erlotinib, another EGFR-TKI, in preclinical human head and neck carcinoma models [22] and of the c-KIT inhibitor, imatinib, in models with activating c-KIT mutations in gastrointestinal stromal tumors (GISTs).