124I-NM404 is a new investigational agent being developed to better identify local tumors and cancerous tumors using imaging technologies such as positron emission tomography (PET) scans. An investigational drug is a drug that has not been approved by the Food and Drug Administration (FDA) and is available for research use only. 124I-NM404 is only taken up by the cancer cells, not the normal cells. Compared to traditional methods such as CT (computed tomography) or MRI (Magnetic resonance imaging), 124I-NM404 may help physicians more accurately see and evaluate cancerous tumors. This agent has been safely studied in animals and a limited number of human patients with lung cancer. This study is being done to determine the best dose to use and to fully evaluate the images that result from using this new agent.