Evaluation of the Biodistribution and Safety of 99mTC-Etarfolatide (EC20) in Normal Volunteers

Inclusion Criteria: * Subject must be 18 years of age or older. * Subject must not have any major health problems as deemed by principal investigator. * Subject must provide informed consent prior to enrollment. Exclusion Criteria: * Subject is pregnant or breast-feeding. * Subject is simultaneously participating in another investigative drug or device study. * Subject must have completed the follow-up phase of any previous study at least 30 days prior to enrollment in this study. * Subject has a known history of chronic abuse of drugs or alcohol or tests positive in pre-study urine drug abuse screen. * Subject is currently taking folic acid supplements and cannot stop taking the supplements for a period of 8 days (7 days prior to the study and one day after last imaging procedure). * Subject's physical condition unsuitable for radionuclide imaging. * Subject has been administered another radiopharmaceutical that would interfere with the assessment of the biodistribution of 99mTc-etarfolatide.