Characterizing Indeterminate Renal Masses with Molecular Imaging: the Role of ^99mTc-MIBI SPECT/CT

The majority of enhancing renal masses cannot be characterized through imaging as malignant or benign; however, such characterization could save patients from unnecessary surgery and/or biopsy and associated morbidity. Herein, we review the recent literature on the emerging use of ^99mTc-MIBI SPECT/CT in preoperative differentiation of enhancing renal masses.

Recent reports have shown that ^99mTc-MIBI SPECT/CT imaging can differentiate mitochondrial-rich, benign, or indolent renal masses from renal cell carcinoma. These studies demonstrate good correlation between a positive ^99mTc-MIBI SPECT/CT scan and a pathologically proven diagnosis of renal oncocytoma and hybrid oncocytic/chromophobe tumor. In addition, there is excellent correlation between a negative scan and a diagnosis of clear cell subtype of renal cell carcinoma. Preoperative ^99mTc-MIBI SPECT/CT offers a non-invasive method for differentiating renal lesions with low aggressiveness from other RCCs, in particular, clear cell renal cell carcinoma.