A series of studies conducted by a team of researchers at John Hopkins Medicine reveals that an already available noninvasive imaging test increases the veracity of kidney tumor classification. According to the report, the 99mTc-sestamibi SPEC/CT to MRI or CT improves diagnostic accuracy and can spare many patients in the United States from needing to undergo unnecessary surgery.
The research team notes the sestamibi SPECT/CT test provides further diagnostic data when utilized in combination with the traditional MRI or CT and can help improve the clinicians’ ability to determine the difference in malignant and benign kidney tumors.
MEA Endowed Professor of Urology at Johns Hopkins University School of Medicine, Mohamad E. Allaf, M.D., said, “Sestamibi SPECT/CT lets radiologists and urologists ‘see’ the most common benign kidney tumor, something CT and MRI have not succeeded in doing alone.”
The test is currently being utilized at Johns Hopkins, sparing a handful of patients from unnecessary surgical removal of a tumor or total nephrectomy, surgical removal of a kidney, which would require the patient to remain on dialysis for the remainder of their life.
“This noninvasive scan may prevent patients with a potentially benign kidney tumor from having to undergo a surgery to remove the tumor or potentially entire kidney, along with its associated risks and high costs,” Dr. Allaf says.
The team of researcher tested 48 Johns Hopkins’ patients with a kidney tumor utilizing the sestamibi SPECT/CT prior to surgery. Radiologists participating in the study were prohibited from knowing the results of the surgeries or communicating with each other. They rated both the conventional images and sestamibi SPECT/CT images malignant and benign utilizing a 5-point scale, 1 equaled unquestionably benign and 5 equaled unquestionably cancerous.
In the postoperative phase, similarly “blinded” pathologists, who were unaware of the radiographic imaging results, examined the surgically removed tumors. The pathology results revealed that out of the 48 tumors, 8 turned out to be benign. The other 40 tumors were identified as malignant renal cell carcinomas and other tumor types.
The researchers discovered that adding sestamibi SPECT/CT, 7 to 9 tumors could be identified successfully. Utilizing sestamibi SPECT/CT in conjunction with an MRI or CT outperformed traditional imaging along, according to a statistical analysis, which measures tradeoffs between specificity and sensitivity. A value of 0.50 on this measure signifies that a specific diagnostic test is no better than chance. Conventional imaging alone had a value of 0.60, while the sestamibi SPECT/CT in conjunction with conventional imaging had a value of 0.85.
In the United States each year, an estimated 5,600 surgically removed tumors are classified as benign.
The researchers note that further studies are needed to substantiate the preciseness of the sestamibi SPECT/CT, which seems to be a less expensive and quicker noninvasive alternative to surgery.
The study was published in the journal Clinical Nuclear Medicine in March 2017.