WE‐A‐213CD‐01: Molecular Imaging of the Breast

Abstract

Molecular imaging of the breast using either SPECT or PET based radiopharmaceuticals is a relatively new area of focus for nuclear medicine and has grown in importance over the last few years with the development of specialized small field of view gamma cameras and small PET systems designed to provide high resolution functional images of the breast. Molecular Breast Imaging (MBI) / Breast Specific Gamma imaging (BSGI): MBI and BSGI are currently performed with Tc‐99m sestamibi and have shown a high sensitivity for the detection of small breast lesions, with reported sensitivities of ∼90%. Sensitivity is lowest for tumors < 5 mm in size. This talk will review the technology behind both MBI and BSGI and the primary clinical applications. It will also review the potential use of MBI as a screening technique. Recent studies have shown that it may be considerably more sensitive than mammography in women with dense breast tissue. A significant issue with MBI / BSGI is radiation burden and this talk will review efforts to increase the sensitivity of these technologies to allow a reduction in the administered dose of radiopharmaceutical, and thereby achieve a comparable radiation burden to mammography. Positron Emission Mammography (PEM): PEM is currently performed on a dual detector system incorporating 2 scanning arrays of BGO crystals providing limited angle tomographic imaging. Studies using F‐18 FDG have shown PEM to have comparable sensitivity to MRI for the detection of breast cancer. It is a useful tool in the preoperative assessment of disease extent and in evaluating response to neoadjuvant therapy. As with single photon systems, sensitivity is lowest for tumors < 5 mm in size. Current systems employ doses of 10 mCi F‐18 FDG. Recent technical developments have seen the emergence of systems using small ring detectors or rotating planar detectors that provide full tomographic views of the breast. Clinical studies are expected to show improvements in spatial resolution and a reduction in the administered dose of F‐18 required. COI: The author and Mayo Clinic receive royalties from patents licensed to Gamma Medica Ideas, a manufacturer of MBI systems. Learning Objective:1) Understand the different technologies (PEM,MBI, BSGI) and detector configurations now available for molecular imaging of the breast. 2) Understand the potential applications for molecular imaging of the breast in both the diagnostic and screening environments. 3) Compare the strengths and weakness of molecular imaging techniques with other breast imaging modalities. 4) Appreciate the potential future applications of this technology in the understanding of breast disease. 5) Demonstrate understanding of the radiation dose implications of current radiopharmaceuticals and how the dose can be reduced with new technologies and radiopharmaceuticals.