An Investigational Scan (89Zr-DFO-GmAb PET/CT) Compared to Contrast-Enhanced CT for the Detection of Recurrent Clear Cell Renal Cell Cancer After Surgery Comparing Carbonic Anhydrase IX (CAIX) PET CT to Conventional PET CT for Post-Op Staging in Kidney Cancer

Inclusion criteria

• Histologically confirmed clear cell renal cell carcinoma (RCC) (ccRCC) (based on partial/radical nephrectomy/metastasectomy)
• For tumors with extensive sarcomatoid features, if there is evidence of areas of clear cell and high CAIX expression throughout the tumor on immunohistochemistry, they will be allowed on study
• Subjects must have undergone definitive treatment of their primary tumor (partial/radical nephrectomy) +/- resection of metastatic disease to no evidence of disease (NED) with a prior nephrectomy \< 2 years)
• Surgery must have been performed between 4-16 weeks at the time of planned imaging
• Subjects are considered to have a high risk of recurrence based on the following criteria:
• Intermediate-high risk ccRCC:
• pathologic tumor stage 2 (pT2), grade 4, or sarcomatoid, N0, M0
• pathologic tumor stage 3 (pT3), any grade, N0, M0
• High risk ccRCC:
• pathologic tumor stage 4 (pT4), any grade, N0, M0
• pT any stage, any grade, number of positive nodes (pN+), M0
• M1 now NED: pathologically-confirmed ccRCC, undergoing a resection of a solitary, isolated soft tissue metastasis within two years from initial nephrectomy
• Negative serum pregnancy tests in female patients of childbearing potential. (Women of child bearing potential \[WOCBP\] require a negative pregnancy test within 24 hours (urine) prior to receiving investigational product)
• Consent to practice double-barrier contraception until a minimum of 42 days after 89Zr-DFO-GmAb administration
• Individual must be able to remain still and lie flat for duration of the diagnostic imaging procedure (less than 1 hour)

Exclusion criteria

• Inability to provide written informed consent
• Any evidence of residual disease or known metastasis at the time of planned 89Zr-DFO-GmAb administration
• Prior post-operative imaging for confirmation of disease status
• An untreated non-renal malignancy with the following exceptions:
• Low risk prostate cancer on active surveillance (National Comprehensive Cancer Network \[NCCN\] very low/low risk)
• Non-melanoma skin cancer
• Any prior treated malignancy meeting the following characteristics:
• Treated stage I or II cancer from which the patient is currently in complete remission
• A stage III cancer from which the patient is progressing or has been disease-free for and has required active treatment (e.g. adjuvant or maintenance therapy) within the past 3 years prior to enrollment
• A hematologic malignancy from which the patient is currently in complete remission
• Contraindication to the use of iodinated contrast-enhanced CT agents, based on:
• Severe allergy (for which pre-medication cannot limit adverse reactions) or
• Estimated glomerular filtration rate (GFR) ≤ 30 ml/min/1.73m\^2
• Prior use of systemic therapy treatment for kidney cancer (PD-1, PD-L1, tyrosine kinase or TOR inhibitor) or radiotherapy within 4 weeks of enrollment
• Exposure to experimental diagnostic or therapeutic drug within 14 days from date of planned administration
• Women who are pregnant or breastfeeding
• Known hypersensitivity to girentuximab
• Known inability to remain still and lie flat imaging procedure (about 30 minutes)