Source: DGNews  |  Posted 2 years ago

By Kristina Rebelo

SAN DIEGO -- April 27, 2009 -- Breast-specific gamma imaging (BSGI) plays an important role in the clinical management of patients at high risk for breast cancer, as well as in those with known disease, according to a study presented here at the American Society of Breast Surgeons (ASBS) 10th Annual Meeting.

BSGI images actual cancer activity -- as opposed to magnetic resonance imaging (MRI) and ultrasound, which image tissue structure. This retrospective study sought to determine how many additional lesions could be found using BSGI as an adjunct to mammography in patients with known breast cancer. It also sought to determine how BSGI screening might change clinical management.

"All patients [in this study] already had a [breast-cancer] diagnosis prior to BSGI scans," explained lead author Brigid K. Killelea, MD, MPH, St. Luke's-Roosevelt Hospital Center/Beth Israel Medical Center, New York, New York, presenting here on April 24.

A review was performed of some 230 patients who underwent BSGI at Beth Israel Medical Center from January 2006 to December 2007. The women were injected intravenously with 30 mCi of technetium-99 sestamibi; craniocaudal and mediolateral oblique projections were then taken.

Study images were classified as positive (focal increased radiotracer uptake) or negative (no uptake or scattered heterogeneous physiologic uptake). Patients receiving positive results underwent directed ultrasound.

BSGI results, when applicable, were compared with biopsy results.

BSGI examinations were performed on all 230 patients. Among those who underwent BSGI for a newly diagnosed cancer (n = 23), 3 were found to have additional areas of abnormality, Dr. Killelea said. Two patients (8.7%) were diagnosed with a second mammographically occult malignancy, and 1 patient opted for a prophylactic mastectomy. Among the 207 patients who underwent BSGI for other reasons, 49 (24%) required further evaluation. Eight additional cancers (3.9%) were detected overall.

Of the 8 cancers detected using BSGI, 5 were identified as invasive carcinoma with the smallest tumour being 0.4 cm. Three of the cancers were ductal carcinoma in situ. The remaining pathology results included 2 papillomas, 1 atypical ductal hyperplasia, 1 lobular carcinoma in situ, and 37 benign biopsies.

The case management was changed in 23% of patients based on BSGI findings. Additional areas of cancer were detected in 4.8% of patients.

The study concluded that BSGI plays an important role in the management of patients at high risk for breast cancer, and that larger clinical trials are needed to assess the sensitivity and specificity of BSGI.

Dr. Killelea told conference attendees that a biopsy tool is in development to be used in conjunction with BSGI, and that new gamma cameras are smaller and designed specifically for the breast.

[Presentation title: Does Breast-Specific Gamma Imaging Alter Patient Management?]