Results of a multicenter patient registry to determine the clinical impact of breast-specific gamma imaging, a molecular breast imaging technique.

OBJECTIVE: Molecular breast imaging techniques, such as breast-specific gamma imaging, are increasingly being used as adjunctive diagnostic technologies to mammography and ultrasound. This multicenter clinical patient registry was designed to quantify the impact of this modality on the management of the breast patient population in clinical practice and to identify the subgroups of patients benefiting from its use. MATERIALS AND METHODS: There were 1042 patients included in this analysis, and breast-specific gamma imaging typically was recommended when the patient had at least two of the following indications: equivocal or negative mammogram or sonogram and an unresolved clinical concern; personal history of breast cancer or current cancer diagnosis; palpable masses negative on mammographic and sonographic examination; radiodense breast tissue; or high risk for breast cancer. Pathologic analysis or follow-up imaging, if biopsy was not conducted, was used as the reference standard, and lesions were classified as positive (i.e., malignant or high risk) in 250 cases and as negative (i.e., benign) in 792 cases. RESULTS: Breast-specific gamma imaging was positive in 408 patients (227 malignant or high-risk lesions requiring additional intervention), negative in 634 patients (23 with malignant or high-risk lesions), and indeterminate in 69 patients (all benign lesions). Breast-specific gamma imaging had an overall sensitivity of 91% and specificity of 77%. CONCLUSION: Breast-specific gamma imaging significantly contributed to the detection of malignant or high-risk lesions in patients with negative or indeterminate mammographic findings, and it provided improved management when compared with ultrasound.

Detecting infiltrating lobular carcinoma using scintimammographic breast specific gamma imaging.

UNLABELLED: This study evaluated the effectiveness of scintimammography performed with gamma cameras optimized for breast imaging in the detection of infiltrating lobular carcinoma. This new procedure, Breast Specific Gamma Imaging (BSGI), was conducted on 105 patient presenting with 113 breast lesions. Studies were conducted at two medical centers using three prototype cameras [14, 16]. Biopsy and pathology reports were obtained for all cases and, of the 34 detected carcinomas, 6 were determined to be infiltrating lobular type without mixed component other than lobular carcinoma in situ. Of the 6 lesions, 4 were smaller than 1 cm, the smallest moasuring 3 mm at biopsy. BSGI detected all 6 of the lobular carcinomas and correctly identified the secondary lesion in the only multifocal case. The BSGI foci sizes matched the lesion size at biopsy to within +/-5.5 mm, with about an equal number of cases ovar and under estimated. CONCLUSION: BSGI provides an effective tool for the detection of lobular carcinoma and in the determination of lesion size and multifocality.

High-resolution scintimammography: a pilot study.

UNLABELLED: This study evaluated a novel high-resolution breast-specific gamma camera (HRBGC) for the detection of suggestive breast lesions. METHODS: Fifty patients (with 58 breast lesions) for whom a scintimammogram was clinically indicated were prospectively evaluated with a general-purpose gamma camera and a novel HRBGC prototype. The results of conventional and high-resolution nuclear studies were prospectively classified as negative (normal or benign) or positive (suggestive or malignant) by 2 radiologists who were unaware of the mammographic and histologic results. All of the included lesions were confirmed by pathology. RESULTS: There were 30 benign and 28 malignant lesions. The sensitivity for detection of breast cancer was 64.3% (18/28) with the conventional camera and 78.6% (22/28) with the HRBGC. The specificity with both systems was 93.3% (28/30). For the 18 nonpalpable lesions, sensitivity was 55.5% (10/18) and 72.2% (13/18) with the general-purpose camera and the HRBGC, respectively. For lesions < or = 1 cm, 7 of 15 were detected with the general-purpose camera and 10 of 15 with the HRBGC. Four lesions (median size, 8.5 mm) were detected only with the HRBGC and were missed by the conventional camera. CONCLUSION: Evaluation of indeterminate breast lesions with an HRBGC results in improved sensitivity for the detection of cancer, with greater improvement shown for nonpalpable and < or =1-cm lesions.