Stephen W. Phillips MD, Presenter: Nothing to Disclose

Michael Kieran OConnor PhD, Abstract Co-Author: Nothing to Disclose

Carrie B Hruska BENG, Abstract Co-Author: Nothing to Disclose

Deborah J Rhodes MD, Abstract Co-Author: Nothing to Disclose

Dana Howard Whaley MD, Abstract Co-Author: Nothing to Disclose

Douglas Collins MD, Abstract Co-Author: Nothing to Disclose

We previously demonstrated that Molecular Breast Imaging (MBI) using a Cadmium-Zinc-Telluride (CZT) gamma camera had a sensitivity of 74% for breast lesions 10 mm in diameter. We have recently finished construction of the first dual-headed MBI unit. The purpose of this study was to determine the incremental gain in sensitivity with this dual-detector system for the detection of sub-10mm lesions.

Two opposing 20 x 20 cm CZT detectors were mounted on an upright gantry. Tc-99m sestamibi studies (20 mCi/injection) were performed in 66 patients with suspected breast lesions (BIRAD 4-5) and with an estimated diameter < 2 cm on US or mammography. All patient were scheduled for biopsy. Patients were imaged seated. Using light pain-free compression, 10-minute craniocaudal and mediolateral oblique views were obtained of each breast.

Of the 66 patients studied, 36 had confirmed breast cancer at surgery. A total of 53 lesions were identified in these 36 patients. These were primarily invasive ductal (38) or invasive lobular (10) carcinomas. There were 4 cases of ductal carcinoma in-situ and one tubular carcinoma. Forty nine tumors were identified on MBI for an overall sensitivity of 92%. 7/8 tumors 5mm in size were detected (sensitivity 88%). 20/22 tumors 6-10 mm in size were detected (sensitivity 91%). Hence sensitivity for all tumors 10 mm was 90%. For tumors > 10 mm in size, 22/23 were detected (sensitivity 96%). All 4 tumors missed by MBI were IDC. Of these one was 2 mm in size and below the resolving power of the system and a 13 mm lesion was not seen due to a positioning error.

Preliminary results with a dual-detector MBI system demonstrate very high sensitivity (90%) for the detection of small breast tumors ( 10 mm). Results are superior to those obtained with a single detector system. This technology is currently under evaluation as an adjunct to mammography for screening women at high risk of breast cancer who have mammographically dense breasts.

MBI using a specialized dual-head gamma camera demonstrates very high sensitivity for the detection of small breast tumors and is a promising new tool in breast imaging

Phillips, S, OConnor, M, Hruska, C, Rhodes, D, Whaley, D, Collins, D, Molecular Breast Imaging Using a Dual-headed CZT Gamma Camera System: Preliminary Results in Patients with Small Breast Lesions.  Radiological Society of North America 2006 Scientific Assembly and Annual Meeting, November 26 - December 1, 2006 ,Chicago IL. http://archive.rsna.org/2006/4434351.html