B. Cavanaugh

Shear-wave Elastography Improves the Specificity of Breast US: The BE1 Multinational Study of 939 Masses

PURPOSE To determine whether adding shear-wave (SW) elastographic features could improve accuracy of ultrasonographic (US) assessment of breast masses. MATERIALS AND METHODS From September 2008 to September 2010, 958 women consented to repeat standard breast US supplemented by quantitative SW elastographic examination in this prospective multicenter institutional review board-approved, HIPAA-compliant protocol. B-mode Breast Imaging Reporting and Data System (BI-RADS) features and assessments were recorded. SW elastographic evaluation (mean, maximum, and minimum elasticity of stiffest portion of mass and surrounding tissue; lesion-to-fat elasticity ratio; ratio of SW elastographic-to-B-mode lesion diameter or area; SW elastographic lesion shape and homogeneity) was performed. Qualitative color SW elastographic stiffness was assessed independently. Nine hundred thirty-nine masses were analyzable; 102 BI-RADS category 2 masses were assumed to be benign; reference standard was available for 837 category 3 or higher lesions. Considering BI-RADS category 4a or higher as test positive for malignancy, effect of SW elastographic features on area under the receiver operating characteristic curve (AUC), sensitivity, and specificity after reclassifying category 3 and 4a masses was determined. RESULTS Median participant age was 50 years; 289 of 939 (30.8%) masses were malignant (median mass size, 12 mm). B-mode BI-RADS AUC was 0.950; eight of 303 (2.6%) BI-RADS category 3 masses, 18 of 193 (9.3%) category 4a lesions, 41 of 97 (42%) category 4b lesions, 42 of 57 (74%) category 4c lesions, and 180 of 187 (96.3%) category 5 lesions were malignant. By using visual color stiffness to selectively upgrade category 3 and lack of stiffness to downgrade category 4a masses, specificity improved from 61.1% (397 of 650) to 78.5% (510 of 650) (P<.001); AUC increased to 0.962 (P=.005). Oval shape on SW elastographic images and quantitative maximum elasticity of 80 kPa (5.2 m/sec) or less improved specificity (69.4% [451 of 650] and 77.4% [503 of 650], P<.001 for both), without significant improvement in sensitivity or AUC. CONCLUSION Adding SW elastographic features to BI-RADS feature analysis improved specificity of breast US mass assessment without loss of sensitivity.

VPAC1 Receptors for Imaging Breast Cancer: A Feasibility Study

VPAC1 encodes G-protein–coupled receptors expressed on all breast cancer (BC) cells at the onset of the disease, but not on benign lesions. Our extensive preclinical studies have shown that 64Cu-TP3805 has a high affinity for VPAC1, is stable in vivo, and has the ability to distinguish spontaneously grown malignant BC masses from benign lesions. Our long-term goal is to develop 64Cu-TP3805 as an agent to perform in vivo histology, to distinguish malignant lesions from benign masses noninvasively and thereby avoid patient morbidity and the excess economic costs of benign biopsies. Methods: 18F-FDG obtained commercially served as a control. 64Cu-TP3805 was prepared using a sterile kit containing 20 μg of TP3805. Radiochemical purity and sterility were examined. Nineteen consenting women with histologically proven BC were given 370 MBq of 18F-FDG. One hour later, 6 of these patients were imaged with PET/CT and 13 with positron emission mammography (PEM). Two to 7 d later, 6 PET/CT patients received 111 MBq (±10%) (n = 2), 127 MBq (±10%) (n = 2), or 148 MBq (±10%) (n = 2) of 64Cu-TP3805 and were imaged 2 and 4 h later. Thirteen PEM patients received 148 MBq (±10%) of 64Cu-TP3805 and were imaged 15 min, 1 h, 2 h, and 4 h later. Standardized uptake value (SUV) was calculated for PET/CT patients, and PUV/BGV (PEM uptake value/background value) was calculated for PEM patients. Tumor volume was also calculated. Results: The radiochemical purity of 64Cu-TP3805 was 97% ± 2%, and specific activity was 44.4 GBq (1.2 Ci)/μmol. In 19 patients, a total of 24 lesions were imaged (15 invasive ductal carcinoma, 1 high-grade mammary carcinoma, 3 lobular carcinoma, 1 invasive papilloma, and 4 sentinel lymph nodes). All lesions were unequivocally detected by 64Cu-TP3805 and by 18F-FDG. The average tumor volume as determined by PET/CT with 64Cu-TP3805 was 90.6% ± 16.1% of that with 18F-FDG PET/CT, and the average SUV was 92% ± 26.4% of that with 18F-FDG. For PEM, the tumor volume with 64Cu-TP3805 was 113% ± 37% of that with 18F-FDG and the PUV/BGV ratio was 97.7% ± 24.5% of that with 18F-FDG. Conclusion: 64Cu-TP3805 is worthy of further investigation in patients requiring biopsy of suggestive imaging findings, to further evaluate its ability to distinguish malignant lesions from benign masses noninvasively.

New Image Processing Technique for Evaluating Breast Microcalcifications A Comparative Study

The purpose of this study was to evaluate a new commercial image processing technique (MicroPure; Toshiba America Medical Systems, Tustin, CA) for identifying breast microcalcifications compared to gray scale ultrasound imaging (US) using mammography as the reference standard.

Ultrasound Detection of Microcalcifications in Surgical Breast Specimens

The objective was to evaluate a commercial image processing technique (MicroPure, Canon Medical Systems, Tustin, CA, USA) for detection of microcalcifications in breast surgical specimens. Twenty women scheduled for surgical excision of an area with breast calcifications were enrolled, their surgical specimens underwent grayscale ultrasound (US) and MicroPure examination using an Aplio XG scanner (Canon). Four independent and blinded readers analyzed 54 US and 54 MicroPure digital clips to determine the number of calcifications and scored image quality and artifacts on a 10-point scale. All readers saw significantly more microcalcifications with MicroPure than with US, 14.0 ± 12.0 versus 3.0 ± 3.2 (p <0.0001). Three readers preferred MicroPure image quality over that of US (p <0.009) and vice versa for one reader (p = 0.003). Three readers saw fewer Coopers ligament artifacts with MicroPure than with US (p <0.0001); one reader saw no significance difference between them (p = 0.58). In conclusion MicroPure identified more breast microcalcifications than grayscale US in ex vivo surgical breast specimens.