Comparing Quantitative Immunohistochemical Markers of Angiogenesis to Contrast-Enhanced Subharmonic Imaging.

OBJECTIVES: Different methods for obtaining tumor neovascularity parameters based on immunohistochemical markers were compared to contrast-enhanced subharmonic imaging (SHI). METHODS: Eighty-five athymic nude female rats were implanted with 5 × 10(6) breast cancer cells (MDA-MB-231) in the mammary fat pad. The contrast agent Definity (Lantheus Medical Imaging, North Billerica, MA) was injected, and SHI was performed using a modified Sonix RP scanner (Analogic Ultrasound, Richmond, British Columbia, Canada) with a L9-4 linear array (transmitting/receiving frequencies, 8/4 MHz). Afterward, specimens were stained for endothelial cells (CD31), vascular endothelial growth factor (VEGF), and cyclooxygenase 2 (COX-2). Tumor neovascularity was assessed in 4 different ways using a histomorphometry system (×100 magnification: (1) over the entire tumor; (2) in small sub-regions of interest (ROIs); (3) in the tumor periphery and centrally; and (4) in 3 regions of maximum marker expression (so-called hot spots). Results from specimens and from SHI were compared by linear regression. RESULTS: Fifty-four rats (64%) showed tumor growth, and 38 were successfully imaged. Subharmonic imaging depicted the tortuous morphologic characteristics of tumor neovessels and delineated small areas of necrosis. The immunohistochemical markers did not correlate with SHI measures over the entire tumor area or over small sub-ROIs (P > .18). However, when the specimens were subdivided into central and peripheral regions, COX-2 and VEGF correlated with SHI in the periphery (r = -0.42; P = .005; and r = -0.32; P = .049, respectively). CONCLUSIONS: When comparing quantitative contrast measures of tumor neovascularity to immunohistochemical markers of angiogenesis in xenograft models, ROIs corresponding to the biologically active region should be used to account for tumor heterogeneity.

When a Toolkit Is Not Enough: A Review on What Is Needed to Promote the Use and Uptake of Immunization-Related Resources.

INTRODUCTION: Evidence-based resources, including toolkits, guidance, and capacity-building materials, are used by routine immunization programs to achieve critical global immunization targets. These resources can help spread information, change or improve behaviors, or build capacity based on the latest evidence and experience. Yet, practitioners have indicated that implementation of these resources can be challenging, limiting their uptake and use. It is important to identify factors that support the uptake and use of immunization-related resources to improve resource implementation and, thus, adherence to evidence-based practices. METHODS: A targeted narrative review and synthesis and key informant interviews were conducted to identify practice-based learning, including the characteristics and factors that promote uptake and use of immunization-related resources in low- and middle-income countries and practical strategies to evaluate existing resources and promote resource use. RESULTS: Fifteen characteristics or factors to consider when designing, choosing, or implementing a resource were identified through the narrative review and interviews. Characteristics of the resource associated with improved uptake and use include ease of use, value-added, effectiveness, and adaptability. Factors that may support resource implementation include training, buy-in, messaging and communication, human resources, funding, infrastructure, team culture, leadership support, data systems, political commitment, and partnerships. CONCLUSION: Toolkits and guidance play an important role in supporting the goals of routine immunization programs, but the development and dissemination of a resource are not sufficient to ensure its implementation. The findings reflect early work to identify the characteristics and factors needed to promote the uptake and use of immunization-related resources and can be considered a starting point for efforts to improve resource use and design resources to support implementation.

Intraoperative Imaging with Second Window Indocyanine Green for Head and Neck Lesions and Regional Metastasis.

While optical imaging with near-infrared (NIR) fluorescent dye has been used in oncologic surgery, its use in the head and neck has not been established. We aimed to evaluate the feasibility of using NIR to visualize primary tumor and regional metastasis in head and neck malignancy. Patients undergoing resection of primary head and neck tumors were included in this pilot study. Each patient was injected with indocyanine green dye (ICG) the day prior to surgery. The VisionSense Iridium camera system was used to visualize the primary lesion, its margins, and neck dissection specimen intraoperatively. Fourteen patients were enrolled. Eighty-six percent of primary tumors showed fluorescence as compared with surrounding tissues. ICG positivity showed 100% sensitivity for pathologic nodes in 7 neck dissection specimens; however, for 3 patients, nonpathologic nodes also showed ICG positivity. NIR imaging with ICG dye can be considered for intraoperative imaging of head and neck lesions.

High and low frequency subharmonic imaging of angiogenesis in a murine breast cancer model.

This project compared quantifiable measures of tumor vascularity obtained from contrast-enhanced high frequency (HF) and low frequency (LF) subharmonic ultrasound imaging (SHI) to 3 immunohistochemical markers of angiogenesis in a murine breast cancer model (since angiogenesis is an important marker of malignancy and the target of many novel cancer treatments). Nineteen athymic, nude, female rats were implanted with 5×10(6) breast cancer cells (MDA-MB-231) in the mammary fat pad. The contrast agent Definity (Lantheus Medical Imaging, N Billerica, MA) was injected in a tail vein (dose: 180µl/kg) and LF pulse-inversion SHI was performed with a modified Sonix RP scanner (Analogic Ultrasound, Richmond, BC, Canada) using a L9-4 linear array (transmitting/receiving at 8/4MHz in SHI mode) followed by HF imaging with a Vevo 2100 scanner (Visualsonics, Toronto, ON, Canada) using a MS250 linear array transmitting and receiving at 24MHz. The radiofrequency data was filtered using a 4th order IIR Butterworth bandpass filter (11-13MHz) to isolate the subharmonic signal. After the experiments, specimens were stained for endothelial cells (CD31), vascular endothelial growth factor (VEGF) and cyclooxygenase-2 (COX-2). Fractional tumor vascularity was calculated as contrast-enhanced pixels over all tumor pixels for SHI, while the relative area stained over total tumor area was calculated from specimens. Results were compared using linear regression analysis. Out of 19 rats, 16 showed tumor growth (84%) and 11 of them were successfully imaged. HF SHI demonstrated better resolution, but weaker signals than LF SHI (0.06±0.017 vs. 0.39±0.059; p<0.001). The strongest overall correlation in this breast cancer model was between HF SHI and VEGF (r=-0.38; p=0.03). In conclusion, quantifiable measures of tumor neovascularity derived from contrast-enhanced HF SHI appear to be a better method than LF SHI for monitoring angiogenesis in a murine xenograft model of breast cancer (corresponding in particular to the expression of VEGF); albeit based on a limited sample size.