结直肠癌的代谢体积与微血管密度和血行转移的关系

Correlation between metabolic tumor volume （MTV） and microvessel density （MVD） and bloodborne metastasis in colorectal carcinoma

目的探讨正电子发射计算机断层扫描（PET—CT）显像的代谢体积（MTV）与结直肠癌血管生成和血行转移的关系。方法对36例经病理证实的结直肠癌患者术前行PET-CT扫描，应用PET VCRA软件以最大标准摄取值（SUVmax）的40％为阈值自动勾画感兴趣区（ROI），软件自动测量SUVmax和MTV。对组织标本应用CD34免疫组化标记血管，测量微血管密度（MVD），分析SUVmax和MTV与肿瘤分化程度、T分期、MVD和血行转移的关系。结果14例有血行转移者SUVmax、MTV和MVD分别为15．15±5．41、（22．99±18．63）cm^3和（14．17±3．63）个／视野，22例无血行转移者SUVmax、MTV和MVD分别为10．65±3．79、（16．95±11．82）cm^3和（11．27±3．69）个／视野，差异均有统计学意义（均P〈0．05）。Pearson相关分析结果显示，SUVmax与MVD无相关关系（r=0．257，P=0．130），MTV与MVD呈正相关关系（r=0．621，P〈0．001）。高MVD组和低MVD组的SUVmax差异无统计学意义（P=0．364），高MVD组的MTV高于低MVD组（P=0．001）。MTV预测结直肠癌血行转移的受试者工作特征曲线下面积为0．729；当MTV=14．975cm。时，其敏感度、特异度、阴性预测值和阳性预测值为85．7％、54．5％、72.3％和64．2％，预测血行转移效能最佳。SUVmax、MTV、MVD和血行转移与分化程度均无关（均P〉0．05）。结直肠癌患者的T分期与MTV、MVD和血行转移均有关（均P〈0．05）。结论MTV与结直肠癌肿瘤血管生成和血行转移有关，MTV≥14．975cm^3的患者血行转移的风险性较高，临床需要采取更有效的干预措施。

Objective To explore the correlation between metabolic tumour volume （MTV） and microvessel density （MVD） and blood-borne metastasis in coloreetal carcinoma. Methods Thirty-six patients with CRC conformed by pathology underwent PET-CT examination before operation. SUVmax and MTV were obtained by PET VCRA software. The blood vessels were identified with CD34 immunohistochemical staining, and the MVD was recorded. The correlation between SUVmax and MTV with histological differentiation, T stage, MVD and blood-borne metastasis was analyzed. Results The SUVmax, MTV and MVD in patients with blood-borne metastasis were 5.15±5.41, （22.99±18.63） cm^3 and 14.17± 3.63, and were 10.65±3.79, （ 16.95± 11.82） cm^3 and 11.27±3.69, respectively, in patients with non-bloodborne metastasis. The differences of SUVmax, MTV and MVD between blood-borne metastasis and nonblood-borne metastasis patients were statistically significant（ all P〉0.05）. Pearson correlation analysis found that there was no linear correlation between SUVmax and MVD, and the SUVmax was not statistically significant between high and low MVD groups （t = 0.919, P= 0.364）. But there was a linear correlation between MTV and MVD （r=0.621 ,P=0.000） ,and the MTV was statistically significant between high and low MVD groups （t = 3.567, P = 0.001 ）. The receiver-operating characteristic curves showed that MTV could be used to predict blood-borne metastasis of CRC, and the best cutoff value for MTV was 14.975 cm^3, and the sensitivity, specificity, negative predictive value and positive predictive value were 85.7%, 54.5%,72.3% and 64.2%, respectively. There were no significant relationships between SUVmax, MTV, MVD, blood-borne melastasis and histological differentiation （P〉0.05）. With the increased T stage, the MTV, MVD and the probability of blood-borne metastasis v, ere also increased （ all P〈0.05）. Conclusions There are correlations between MTV and MVI） and blood-borne metastasis in CRC. The risk of blood-borne metastasis in patients with MTV〉 14.975 cm^3 is higher, and needs to take more effective intervention.