CAIX PET/CT for Residual or Recurrent Post-ablative ccRCC

Inclusion Criteria: 1. Written and voluntarily given Informed Consent 2. ≥18 years of age at time of consent a. Because no dosing or adverse event data are currently available on the use of 89Zr-girentuximab in participants \<18 years of age, children are excluded from this study, but will be eligible for future pediatric trials. 3. Have the capacity to understand the study and be willing and able to comply with all protocol requirements. 4. Findings suspicious for post-ablation residual or recurrent ccRCC (subjects in cohort 1) documented at conventional imaging or biopsy, performed within 90 days prior to 89Zr-girentuximab PET scan. 5. Findings suspicious for primary ccRCC (subjects in cohort 2) documented at standard histology or conventional imaging, performed within 90 days prior to 89Zr-girentuximab PET scan. 6. Negative serum or urine pregnancy tests in female patients of childbearing potential within 72 hours prior to receiving 89Zr-girentuximab. Female patients of non-child bearing potential must provide evidence by fulfilling one of the following criteria at screening: 1. Post-menopausal defined as aged more than 50 years and amenorrheic for at least 12 months following cessation of all exogenous hormonal treatments 2. Women under 50 years old would be consider postmenopausal if they have been amenorrheic for 12 months or more following cessation of exogenous hormonal treatments and with luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels in the post-menopausal range for the institution 3. Documentation of irreversible surgical sterilization by hysterectomy, bilateral oophorectomy, or bilateral salpingectomy but not tubal ligation 7. For all participants, consent to practice double-barrier contraception until a minimum of 42 days after 89Zr-girentuximab administration. Exclusion Criteria: 1. Renal mass known to be a metastasis of another primary tumor. 2. Active non-renal malignancy requiring therapy during and up to EOT visit. 3. Planned antineoplastic therapies (for the period between IV administration of 89Zr-girentuximab and imaging). 4. Previous administration of any radionuclide within 10 of its half-lives before 89Zr-girentuximab injection day. 5. Serious non-malignant disease (e.g., psychiatric, infectious, autoimmune, or metabolic), that may interfere with the objectives of the program or with the safety or compliance of the subject, as judged by the Investigator. 6. Mental impairment that may compromise the ability to give informed consent and comply with the requirements of the program. 7. Women who are pregnant or breastfeeding. 8. Known hypersensitivity to girentuximab or DFO (desferoxamine). 9. Renal insufficiency with estimated glomerular filtration rate eGFR ≤ 40 mL/min/ 1.73 m²