Biomarker Correlates of Hypoxia in Metastatic Melanoma

The purpose of this study is to determine if magnetic resonance imaging (MRI) or positron emission tomography (PET) imaging can be used to help doctors determine how much oxygen a tumor is getting. Hypoxyprobe will be used to determine the levels of oxygen post-surgery in the current study. If the study is successful, then imaging can be used to determine a tumor's oxygen status even in patients who are not getting surgery. Investigators want to find out how much oxygen is in the participants tumor based on how much pimo is present, and correlate this with the results of their MRI and 18F-fluoromisonidazole (FMISO) PET scan. This study is also testing the investigational radioactive substance known as FMISO. FMISO is used during PET scans to help doctors see how much oxygen a tumor is getting. Participants might be asked to participate in an optional PET scan using FMISO.