Molecular breast imaging technique shows greater sensitivity over mammography, ultrasound and MRI for difficult to diagnose breast cancer

Dec 3 2008

Breast-Specific Gamma Imaging (BSGI) has been proven to be a highly sensitive imaging technique for the diagnosis of invasive lobular carcinoma (ILC), a difficult to diagnose breast cancer.

BSGI is a molecular breast imaging technique that can see lesions independent of tissue density and discover very early stage cancers. When compared to mammography, ultrasound and magnetic resonance imaging (MRI), BSGI has the greatest sensitivity for detecting ILC, according to findings presented today at the annual meeting of the Radiological Society of North America (RSNA).

"Our study compares the sensitivity of mammography, ultrasound, MRI and BSGI in the detection of ILC. We found BSGI to have the greatest sensitivity of all four techniques," said Dr. Rachel Brem, Director of Breast Imaging and Intervention at George Washington University Medical Center in Washington, D.C., and Vice Chair of the Department of Radiology.

This study was a retrospective multi-center study of women with biopsy-proven pure ILC. Patients had imaging performed with mammography and BSGI. Ultrasound and MRI results, if performed, and pathologic tumor size were included for analysis. The sensitivity of mammography, ultrasound, MRI and BSGI was determined for each modality and compared. Twenty-six women, ages 46 to 82 (mean age of 62.8), with 28 biopsy proven pure ILC, mean size of 22.3mm (2mm -90mm) were included.

BSGI had the greatest sensitivity for the detection of ILC with a sensitivity of 93 percent. Mammography, ultrasound and MRI demonstrated sensitivities of 79 percent, 68 percent and 83 percent, respectively.

The BSGI for the study was conducted using a Dilon 6800 Gamma Camera, a high-resolution, small field-of-view gamma camera, optimized to perform BSGI. With BSGI, the patient receives a pharmaceutical tracing agent that is absorbed by all the cells in the body. Due to their increased rate of metabolic activity, cancerous cells in the breast absorb a greater amount of the tracing agent than the normal surrounding tissue and generally appear as "hot spots" on the BSGI image.

Dr. Brem has published many articles on breast cancer-related topics in her areas of interest, which include new technologies for the early diagnosis of breast cancer and BSGI.

"BSGI is an effective adjunct imaging modality for the diagnosis of breast cancer and has a promising role in the diagnosis of ILC," said Dr. Brem.

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