Imaging tumour thrombus of clear cell renal cell carcinoma: FDG PET or PSMA PET? Direct in vivo comparison of two technologies

Clear cell renal cell carcinoma (ccRCC) is the most common subtype of renal malignancy in adults.1 The disease is usually radiologically imaged with computed tomography (CT) or magnetic resonance imaging (MRI) for diagnosis, staging, treatment planning and follow up. Recently, functional studies targeting glucose or folate metabolism with fludeoxyglucose (FDG) or prostate specific membrane antigen (PSMA) binding ligands respectively have been reported to be used to stage the disease.2 Positron emission tomography (PET) using PSMA ligand detected larger number of lesions in comparison to conventional imaging modalities such as CT in a small prospective clinical trial.3 In this project, we directly compared the findings from FDG and PSMA PET in a patient with metastatic ccRCC. We assessed ex-vivo tumour characteristics to explain these findings