Vascularity index as a novel parameter for the in vivo assessment of angiogenesis in patients with cervical carcinoma

BACKGROUND, The importance of angiogenesis now is well recognized. Conventi onally, tumor angiogenesis is assessed by determination of microvessel dens ity (MVD) in the surgical specimen. This study examines tumor angiogenesis using power Doppler ultrasound and a quantitative image processing system. The authors hope to develop an ill vivo and noninvasive method for quantita ting tumor angiogenesis. METHODS. Thirty-five patients with FIGO Stage IB-IIA cervical carcinoma exh ibiting visible cervical tumors by transvaginal ultrasound were included in this study. All patients underwent radical abdominal hysterectomy and pelv ic lymph node dissection. Transvaginal power Doppler ultrasound was perform ed before surgery to search for blood flow signals from the tumor. The intr atumoral vascularity index (VI) and resistance index (RI) were calculated. The VI was defined as the number of colored pixels divided by the number of total pixels in the defined tumor section. Maximal VI and minimal RI of a certain tumor were used for analysis. Clinical and pathologic data also wer e recorded. The MVD of the excised tumor was assessed immunohistochemically using a monoclonal antibody against CD34. RESULTS. Significantly higher VI values were noted in Stage II tumors compa red with Stage I tumors (19.01 +/- 10.90% vs. 9.09 +/- 6.59%; P = 0.008), t umors invading + 50% of the cervical stroma compared with tumors invading < 50% of the cervical stroma (13.20 +/- 8.20% vs. 5.72 +/- 5.00%; P = 0.003) , tumors with lymphovascular emboli compared with tumors without lymphovasc ular emboli (17.28 +/- 8.26% vs. 6.98 +/- 5.09%; P = 0.001), and tumors wit h pelvic lymph node metastases compared with tumors without pelvic lymph no de metastases (26.16 +/- 7.88% vs. 8.00 +/- 4.95%; P = 0.021). None of the variables mentioned earlier showed a significant difference in terms of the RI values. No correlation was noted between intratumoral RI and VI in resp ective tumors (P = 0.53). Analysis of VI revealed linear regression with re gard to tumor size (P < 0.001, correlation coefficient [r] = 0.586) and dep th of stromal invasion (P = 0.002, r = 0.497). In addition, the MVD exhibit ed a linear relation with VI (P = 0.006, r = 0.454), tumor size (P = 0.005, r = 0.465), and depth of stromal invasion (P = 0.009, r = 0.436) using sim ple regression analysis. No correlation could be found between MVD and RI. CONCLUSIONS. In cervical carcinoma, intratumoral VI assessment by power Dop pler ultrasound and quantitative image processing system showed better corr elation with tumor stage, tumor size, and pathologic findings including dep th of stromal invasion, lymphovascular emboli, and pelvic lymph node metast ases than intratumoral RI. The in vivo indicator of angiogenic activity (VI ) is well correlated with the conventional indicator of tumor angiogenic ac tivity (MVD). Thus, VI could be a useful parameter for the in vivo assessme nt of global tumor angiogenesis. Cancer 1999;85:651-7. (C) 1999 American Ca ncer Society.