High-resolution gamma-camera for molecular breast imaging: First clinical results.

Scintimair mography is a molecular breast imaging technique using tumour-seeking radiopharmaceuticals; with standard gamma-cameras, is proved of value especially when mammography is indeterminate and in women with dense breasts; nevertheless, this technique shows a high sensitivity only for cancers >1 cm. The issue of detecting small cancers is critical for the future development and clinical usefulness of breast imaging with radiopharmaceuticals, because other modalities are increasingly employed for early identification of small abnormalities. The use of high-resolution dedicated cameras for breast imaging is the best option to improve small cancers' detection: they allow greater flexibility in patient positioning, and the availability of projections similar to those of mammography. Moreover, the detector can be placed directly against the breast, and a mild compression is possible, with the results of reducing breast thickness, increasing the target-to-background ratio and the sensitivity. Our first clinical findings using the dedicased camera Lumagem 3200S (Gamma Medica, Inc., Northridge, USA) are very satisfactory. Till now, 29 patients with BI-RADS category III and IV lesions

Intraoperative gamma imaging of axillary sentinel lymph nodes in breast cancer patients.

Sentinel lymph node (SLN) biopsy is now standard practice in the management of many breast cancer patients. Localization protocols vary in complexity and rates of success. The least complex involve only intraoperative gamma counting of radiotracer uptake or intraoperative visualization of blue-dye uptake; the most complex involve preoperative gamma imaging, intraoperative counting and intraoperative dye visualization. Intraoperative gamma imaging may improve some protocols. This study was conducted to obtain preliminary experience and information regarding intraoperative imaging. Sixteen patients were enrolled: 8 in a protocol that included intraoperative counting and dye visualization (probe/dye), 8 in a protocol that involved intraoperative imaging, counting and dye visualization (camera/probe/dye). Preoperative imaging of all 16 patients was performed using a GE 500 gamma camera with a LEAP collimator (300 cpm/muCi). The results of this imaging were not, however, given to the surgeon until the surgeon had completed the procedures required for the study. A Care Wise C-Trak probe was used for intraoperative counting. A Gamma Medica Inc. GammaCAM/OR (12.5 x 12.5 cm FOV) with a LEHR collimator (135 cpm/muCi) was used for intraoperative imaging. Times from start of surgery to external detection of a radioactive focus and to completion of excision of SLNs were recorded. Foci were detected preoperatively via imaging in 16/16 patients. Intraoperative external detection using the probe was accomplished in less than 4 min (mean = 1.5 min) in 15/16 patients, and via intraoperative imaging in 6/8 patients. The average time for completion of excision of nodes was 19 min for probe/dye and 28 min for camera/probe/dye. In one probe/dye case, review of the preoperative images prompted the surgeon to resume axillary dissection and remove one additional SLN.

Scintimammography with dedicated breast camera detects and localizes occult carcinoma.

UNLABELLED: This study assessed the utility of scintimammography using a standard gamma-camera and a dedicated breast camera as an adjuvant to mammography and clinical examination. METHODS: The study population comprised 37 patients with dense breasts and a family or personal history of breast cancer. The subjects had no suggestive clinical or mammographic findings. After intravenous administration of (99m)Tc-sestamibi, the patients were imaged using a conventional gamma-camera and a dedicated breast camera that allowed breast compression during image acquisition. Images were interpreted independently by 2 reviewers. All patients with positive scintimammography findings underwent biopsy. RESULTS: Dedicated breast camera results were positive in 13.5% (5/37) of patients. Biopsy of these 5 patients yielded 3 carcinomas: an infiltrating lobular carcinoma, a ductal carcinoma in situ, and an infiltrating tubular carcinoma. These 3 carcinomas were undetectable by clinical breast examination or mammography, even on retrospective review. Only one of these, the tubular carcinoma, was readily detectable by the standard gamma-camera. CONCLUSION: Scintimammography using a dedicated breast camera may augment mammography and clinical breast examination for the subset of women who have dense breast tissue and are at high risk of breast cancer.