基于18氟-脱氧葡萄糖正电子发射计算机断层成像术的最大标准化摄取值和放射线基线比值与结直肠癌术后预后的关系

Correlation of 18F-FDG PET-CT maximum standard uptake value and T/N ratio with the prognosis of postoperative colorectal cancer

目的：探讨18氟-脱氧葡萄糖正电子发射计算机断层成像术（18F-FDG PET-CT）所测得的原发灶最大标准化摄取值（SUVmax）和肿瘤与正常组织的放射线基线比值（T／N比值）与结直肠癌患者预后的关系。方法回顾性分析2009年1月至2013年12月间，于中山大学附属第一医院行手术治疗的92例结直肠癌患者的临床资料，所有患者术前均行18F-FDG PET-CT检查，分析原发灶SUVmax和T／N比值与临床病理因素间的关系，采用受试者工作特征（ROC）曲线的方法获得SUVmax、T／N比值及肿瘤最大径预测无瘤生存时间的最佳界值点及其灵敏度和特异度，并进一步分析各临床病理因素与预后的关系，采用Cox比例风险模型进行多因素预后分析。结果原发灶SUVmax与肿瘤TNM分期、肿瘤部位、肿瘤分化程度及肿瘤最大径有关，而T／N比值只与病理类型有关（均P＜0．05）。预测无瘤生存时间（DFS）最佳界值点分别为SUVmax＝12．2（灵敏度为67．6％、特异度为63．6％）；T／N比值＝6．9（灵敏度为51．4％、特异度为74．5％）；肿瘤最大径＝4．3 cm（灵敏度为56．8％、特异度为80．0％）。单因素预后分析显示，年龄、肿瘤TNM分期、肿瘤部位、肿瘤分化程度、肿瘤最大径、T／N比值及CA125水平与预后有关（P＜0．05）；多因素预后分析结果显示，肿瘤TNM分期（P＝0．000，OR值＝3．98，95％ CI：2．12～7．45）、肿瘤部位（P＝0．009，OR值＝0．43，95％ CI：0．23～0．81）、肿瘤分化程度（P＝0．001，OR 值＝7．52，95％ CI：2．12～25．90）及 T／N 比值（P＝0．008，OR 值＝2．92，95％ CI：1．33～6．41）是影响结直肠癌患者术后无瘤生存的独立预后因素，而原发灶SUVmax并不是其独立预后因素。结论在结直肠癌患者术后预后评估中，18F-FDG PET-CT所测得的T／N比值较原发灶SUVmax更具参考价值。

Objective To assess the correlation of primary colorectal cancer （CRC） lesions′maximum standardized uptake value （SUVmax） and tumor to normal tissue SUVmax ratio （T/N ratio） detected by 18F-deoxyglucose positron emission computed tomography （18F-FDG PET-CT） imaging with the postoperative prognosis. Methods Clinicopathological data of 92 CRC patients who underwent curative resection after the PET-CT examination and received 18F-FDG PET-CT examination from January 2009 to December 2013 in the First Affiliated Hospital of Sun Yat-sen University were reviewed retrospectively. The correlation of SUVmax and T/N ratio in primary lesions with clinicopathological factors was analyzed. The optimal cutoff point of disease-free survival time of SUVmax, T/N ratio and the maximum tumor diameter were investigated by using ROC curve analysis. Association of clinicopathological factors and prognosis was examined and the Cox proportional hazard regression model was used in the multivariate analysis. Results Primary SUVmax was associated with tumor TNM staging, location, differentiation degree and the maximum tumor diameter, while T/N ratio was only associated with pathological type （all P〈0.05）. The optimal cutoff point of disease-free survival time of SUVmax, T/N ratio and the maximum tumor diameter were 12.2 （sensitivity 67.6%, specificity 63.6% ）, 6.9 （sensitivity 51.4%, specificity 74.5%） and 4.3 cm （sensitivity 56.8%, specificity 80.0%） respectively. Univariate analysis showed that age, TNM staging, tumor location, differentiation degree, the maximum tumor diameter, T/N ratio and CA125 level were significant predictors of survival. Multivariate analysis demonstrated that TNM staging （P=0.000, OR=3.98, 95% CI：2.12-7.45）, tumor location （P=0.009, OR=0.43, 95% CI：0.23-0.81）, tumor differentiation degree （P=0.001, OR=7.52, 95% CI：2.12-25.9） and T/N ratio （P=0.008, OR=2.92, 95% CI：1.33-6.411） were independent predictors of survival. However, SUVmax was not independent predictor of disease-free survival. Conclusion For postoperative prognosis of colorectal cancer patients, T/N ratio is more valuable than the of primary tumor SUVmax.