SNM has issued guidelines to assist breast imaging practitioners in patient selection, performance, interpretation and reporting for breast scintigraphy with 99mTc-sestamibi breast-specific gamma imaging.
The guidelines indicate the use of breast scintigraphy in:
• Patients with recently detected breast malignancy;
• Patients at high risk for breast malignancy;
• Patients with indeterminate breast abnormalities and remaining diagnostic concerns;
• Patients with technically difficult breast imaging;
• Patients for whom breast MRI would be indicated; and
• Monitoring neoadjuvant tumor response in patients undergoing preoperative chemotherapy.
Approximately 925 MBq [25 mCi] of the radiopharmaceutical should be administered using an indwelling venous catheter or butterfly needle followed by 10 ml of saline to flush the vein, according to the guidelines.
The guidelines suggest that the sensitivity, specificity and accuracy of the test depend upon several factors, including the size of the breast neoplasm being imaged. While the sensitivity of this test for subcentimeter tumors approaches 95 percent, sensitivity decreases with lesion size.
The report to the referring physician should indicate the most likely diagnosis and should recommend appropriate follow-up as with any breast imaging study, using Breast Imaging-Reporting and Data System (BIRADS) classification.