Iressa (Gefitinib) is an orally active inhibitor of epidermal growth factor receptor tyrosine kinase (EGFR-TK) involved in cell signal transduction processes critical to proliferation, apoptosis, repair, and angiogenesis of cancer cells. [11C]Iressa was first designed and synthesized as a new potential positron emission tomography (PET) cancer imaging agent for EGFR-TK in 30-40% radiochemical yield with 4.0-6.0 Ci/micromol specific activity at end of bombardment (EOB).