The purpose of this study is to help develop a special PET/CT scan to help the investigator to develop a new drug and see where this drug goes in the body and how long it stays in diseased and normal tissue. The drug is called PU-AD. In this study, the investigators will give a tiny dose of PU-AD, a dose which they expect to be much too small to affect the disease. This tiny dose will be labeled with (attached to) a very small amount of radiation (called Iodine-124 or 124I) so that the investigators can follow where it goes in the body by using a PET/CT scanner. Doing this will help the investigators figure out how to best give higher doses of PU-AD to other patients in the future, and will help the investigators see if this tiny dose of PU-AD with radiation (124I-PU-AD) might be used in the future to detect disease using a PET/CT scanner.