Benign and malignant kidney tumors were accurately differentiated by the addition of 99mTc-MIBI SPECT/CT to conventional MRI or CT, according to a study published in the Clinical Nuclear Medicine.1

“This noninvasive scan may prevent patients with a potentially benign kidney tumor from having to undergo a surgery,” said Mohamad E. Allaf, MD, MEA, an endowed professor of urology at the Johns Hopkins University School of Medicine in Baltimore, Maryland, in a press release.2

Conventional MRI and CT do not differentiate between benign and malignant kidney tumors. The purpose of this study was to determine if the addition of 99mTc-MIBI SPECT/CT could improve the diagnosis of these conditions.

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The study included 48 patients with stage T1 solid renal masses diagnosed by conventional CT and MRI.  Prospective evaluation of patients by 99mTc-MIBI SPECT/CT occurred within 8 weeks of the conventional imaging. Two blinded readers diagnosed the kidney mass after conventional imaging and after 99mTc-MIBI SPECT/CT. Surgical pathology was evaluated by blinded pathologists.

The differential diagnostic confidence increased in 29.2% of renal masses. The initial diagnosis by conventional MRI and CT was changed from malignant to benign in 9 cases, which were pathologically confirmed in 7 cases and chromophobe renal cell carcinoma in 2 cases. Five cases were changed from benign to malignant, which were pathologically confirmed.

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Conventional MRI and CT resulted in an area under the receiver operator curve of 0.60, which improved to 0.85 after 99mTc-MIBI SPECT/CT review (P for difference = .03).

The results of this study suggest that 99mTc-MIBI SPECT/CT use can improve the differentiation between benign and malignant kidney tumors, potentially reducing unnecessary care for some patients.


  1. Sheikhbahaei S, Jones CS, Porter KK, et al. Defining the added value of 99mTc-MIBI SPECT/CT to conventional cross-sectional imaging in the characterization of enhancing solid renal masses. Clin Nucl Med. 2017;42:e188-e193. doi: 10.1097/RLU.0000000000001534
  2. Noninvasive imaging test shown accurate in ruling out kidney cancers [news release]. Baltimore, MD: Johns Hopkins Medicine; April 19, 2017. noninvasive_imaging_test_shown_accurate_in_ruling_out_kidney_cancers. Accessed April 20, 2017.