Abstract 1501: Evaluation of tumor vascularity in colorectal cancer using contrast enhanced ultrasonograpy in comparison with microvessel density

Abstract Background : The relationship between tumor vascularity and malignant potential in colorectal cancer a(CRC) is reported by many authors. Therefore, to assess the tumor vascularity before surgical treatment is thought to be one of very important factors in CRC patients. Contrast enhanced ultrasonography (CEUS) can visualize the tumor vascularity vividly. We aim to determine the reliability of CEUS for the assessment of vascularity of CRC and to analyze the relationship between tumor vascularity and clinicopathological characteristics. In addition, to find the clinical application, we assessed the efficacy of chemotherapy in unresectable advanced CRC patients by CEUS. Methods : 56 patients undergoing surgical resection of CRC were studied. An ultrasound system (GE health care, LOGIC 7) is used and visualized the colo-rectal tumor using a 4.5MHZ probe. The 2nd generated ultrasonic contrast medium (Belfulbuttan, Sonazoid) is injected intravenously. Approximately 20 s after injection, microbubbles were obtained to enhance the B-mode image. Using the tumor image showing the strongest vascularity, region of interest were determined to measure mean echo intensity in the tumor. Their images were analyzed with NIH image program (developed by the US National Institutes of health) and calculated tumor vascularity as Vascular Index (VI). The clinicopathological features are based on the TNM classification from UICC. Using surgical specimens, tumor vascularity was assessed by immunohistochemistry as microvessel density in order to do statistical analysis for the correlation between VI, clinicopathologic features and microvessel density. Results : CEUS could visualize the tumor vascularity in all patients. In advanced CRC patients, we observed that the tumor invaded into other organ, such as prostate gland, small intestine and so on. The VI correlated significantly with depth of tumor invasion, liver metastasis and microvessel density. Furthermore, in patients with abundant vascularity in tumor before treatment, chemotherapy led to the reduction of VI prior to the radiographically visible difference in tumor size. Conclusion : CEUS can evaluate the tumor vascularity non-invasively and is very useful for the evaluation of their pathological diagnosis and the efficacy of chemotherapy in CRC. Citation Format: Takaomi Okawa, Hiromi Nogami, Munenori Takaoka. Evaluation of tumor vascularity in colorectal cancer using contrast enhanced ultrasonograpy in comparison with microvessel density. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1501. doi:10.1158/1538-7445.AM2015-1501