Sunday, November 11, 2012

Nuclear Medicine: Low-Dose Molecular Breast Imaging Evaluated in the Detection of Breast Cancer

Breast-specific gamma imaging (BSGI), also known as molecular breast imaging (MBI), is a modality that identifies breast tumors overlooked by ultrasound and mammography, especially in women with dense breasts.
Although the radiation dose linked to this procedure is already low enough to be used in specific instances, new research is being conducted to find ways to additionally decrease the dose so that MBI may be used in yearly breast cancer screening for high-risk women with dense breast tissue.

 The MBI procedure is now available in hundreds of breast centers United States and is typically utilized as an adjunct combined with mammography and ultrasound to aid in the diagnosis of breast cancer. New research findings were presented at the Chicago International Breast Course, held in Chicago (IL, USA), October 2012, by Dr. Marcela Bohm-Velez, the lead investigator of an ongoing trial conducted by radiologists at Weinstein Imaging Associates (Pittsburgh, PA, USA).

 In the MBI procedure, the patient is imaged with a pharmaceutical tracer. Lessening the amount of tracer required for imaging reduces the radiation dose to the patient. According to the findings obtained by Dr. Bohm-Velez and her coauthors, MBI can be conducted using approximately 50% of the amount of tracer typically used, thereby exposing the patient to a much lower radiation dose. In their prospective trial, 72 patients had low-dose MBI followed by imaging at the standard dose, and their findings indicate that low-dose MBI provided the same diagnostic results as the images performed at the traditional dose.

 “The pioneering research done at the Mayo Clinic [Rochester, MN, USA] indicated low-dose is an option for the dual-head MBI system and our research indicates that it is an option for the single-head MBI systems as well. We have found that it is possible to cut the dose in half and still produce diagnostically useful images,” said Dr. Bohm-Velez. “In our previous work, we found that MBI had a higher sensitivity for breast cancer than mammography or ultrasound and this work is a natural extension. The uptake of the tracer in the breast tissue is complex and highly variable, and our goal is to help the medical community develop strategies for obtaining the best images possible. We have made several observations regarding the rate of tracer washout from the breast tissue and the impact of patient’s weight on tracer uptake. We are currently working to submit our results for peer-reviewed publication this fall.”

 Dilon Diagnostics’ (a brand of Dilon Technologies, Inc.; Newport News, VA, USA) flagship system, the Dilon 6800, is a high-resolution, small field-of-view (FOV) gamma camera, optimized to perform MBI/BSGI, and images the metabolic activity of breast lesions by uptake of the radiotracer. Many leading medical centers in the United States are now offering MBI/BSGI to their patients. The new declipseSPECT is the first intraoperative, handheld, three-dimensional (3D) image viewing and navigation system with applications in SLNB breast, I-125 seed localization, and sentinel lymph node biopsy (SLNB) of the head and neck.

Source:
medimaging.net