Evaluate The Utility Of 124I-cG250 for The Early Detection Of Response to Therapy In Patients With Metastatic Renal Cell Carcinoma

Pts will undergo baseline disease assessment with CT scans (chest, abd \& pelvis), 124I-cG250-PET/CT \& Tc99mMDP bone scan. W/I 7 days of their lst 124I-cG250 PET/CT, pts will start tx with sunitinib or pazopanib, dosed in successive 6-week cycles. At selected time points during the sunitinib or pazopanib cycle 1, repeat imaging with CT scan \& 124I-cG250 PET/CT will be performed. After cycle 2, pts will be followed per standard of care, i.e., pts will have a standard CT scan of the chest, abd, \& pelvis with contrast after cycles 2, 3, 4 \& 6 (or at the time of disease progression if prior to cycle 6) for determination of best response using RECIST 1.1. Each pt will have 2 124I-cG250-PET/CT scans: baseline \& week 4 (during sunitinib or pazopanib tx). All experimental imaging will take place during tx cycle 1. There will be a dosimetry sub-study for pts willing to undergo 3 additional PET/CT scans, whole body counts, \& serial blood sampling, following the lst inj of 124I-cG250.