Molecular Imaging of Renal Malignancy: A Review

Abstract

Renal cell carcinoma (RCC) is a common malignancy that is often detected incidentally in patients undergoing cross-sectional imaging of the abdomen for workup of pain or other symptoms. Due to overlap in imaging findings of RCC and benign tumors, biopsy may be necessary to confirm the diagnosis. Biopsies are occasionally non-diagnostic, however, and in small lesions or patients with comorbidities may not be technically feasible. Molecular imaging techniques can characterize tumors as being more likely malignant or benign and obviate the need for invasive testing, as well as providing accurate whole-body staging in patients with known RCC. PET/CT with 18F-FDG and other radionuclides can identify primary renal masses with higher malignant potential and also allows for sensitive detection of metastatic RCC. SPECT/CT imaging with 99mTc-sestamibi can provide useful information to support the diagnosis of benign oncocytic neoplasms over more aggressive RCC subtypes. Investigational molecular imaging techniques such as immunoPET and hyperpolarized 13C MRI have also shown promise in renal mass characterization. This review article aims to outline the various molecular imaging modalities available in the evaluation of primary renal tumors and in whole-body staging of metastatic RCC.