Tumor Angiogenesis And Dynamic CT In Renal Tumor: Radiology-pathology Correlation

Objective To find a noninvasive method to evaluate tumor angiogenesis by a correlation study between dynamic CT and tumor microvessel density (MVD), expression of vascular endothelial growth factor(VEGF), and evaluatate whether the enhanced pattern would be useful in differentiating the histomorphologic types of renal tumors. Methods 〧our phases CT scans were performed for renal tumors. The scan included unenhanced and three enhanced series beginning 40, 90, and 180 sec after the start of administration. Enhanced parameters included the 40 second (E40) ,90 second (E90),180 second(E180) attenuation value of tumor after injection and the changed attenuation value C1(between the unenhanced and E40), C2 (E40 and E90), C3(E90and E180).In addition , the single-section CT dynamic scan was performed for nine renal tumors with the scan parameters (7sec time delay after injection, 3sec per rotation, 12 scan times), then blood flow(BF)graphies obtained. The injection rate of contrast material was 3 ml per sec, the contract dosage was 75ml. (2) Histologic specimens were stained with anti-VEGF antibody and anti CD34 antibody.Results (1)18 patients were involved in this study which include clear cell carcinoma(n=8), granular cell carcinoma(n=1), mixed cell carcinoma(n=2), papillary carcinoma(n=4), chromophobe carcinoma(n=l), renal pelvic transitional cell(n=l), and angiomyolipoma(n=1). (2)VEGF expression hassignificant correlation with MVD (r=0.719, p=0.001). (3) VEGF protein expression of malignant renal tumor were correlation with E40, E90, E180 (r=0. 785, p=0. 000; r=0. 699, p=0. 002; r=0. 513, p=0. 035). (4)VEGF protein expression of malignant renal tumor were also correlation with C1, C2 and C3(r=0. 769, p=0. 000; r=- 0. 764, p=0. 000; r=- 0. 493, p=0.044). (5)MVD of malignant renal tumor were correlation with E40, E90, E180(r=0. 880, p=0. 000; r=0. 855, p=0.000; r=0. 791, p=0. 000). (6)MVD of malignant renal tumor were correlation with Cl, C2 and C3 too(r=0. 836,p=0. 000; r=-0.875,p=0.000; r=-0. 433, p=0. 075). (7)The TBF has a correlation with MVD(r=0. 783, p=0. 013). (8)The enhancement pattern of clear cell carcinoma, granular cell carcinoma, mixed cell carcinoma showed rapid enhancment and washout(type A). The enhancement pattern of papillary carcinoma, chromophobe carcinoma, renal pelvic transitional cell showed slow enhancment and washout (type B) . the angiornyolipoma showed a gradual enhancement (type C).(9)The sensitivity and specificity for differentiating type A tumors from the other types were 82% and 86% when 86. 5 HU was used as the cutoff value in the E40.Conclusions (1)There is great correlation between parameters of dynamic CT and vascular genesis. It suggested that dynamic CT could be used to assess renal tumor angiogenesis.(2) Enhancement pattern and degree of enhancement , special in E40 , can serve as a supplemental roles in the diffirentiating types of renal tomor.