基于PET不同SUV阈值计算肺癌肿瘤代谢体积的方法比较

The comparison of different computing methods of tumor size of lung carcinoma based on different SUV thresholds

目的:比较肺癌患者三种SUV阈值所得MTV,以期获得最接近肿瘤实际体积的计算阈值。方法:回顾性收集2015年1月至2017年12月期间在西安交通大学第一附属医院因肺癌行手术治疗并获得肿瘤完整体积的53例患者作为研究对象,所有患者术前1周内均行18 F-FDG PET/CT全身显像,以SUV 2.5、40%SUV max、50%SUV max作为阈值通过系统软件计算肿瘤的MTV,与术后肿瘤切除体积(tumor volume,TV)进行相关及回归分析。结果:三种阈值计算所得MTV与术后肿瘤切除体积(TV)均存在相关性及回归线性关系(P值均小于0.05),其中MTV 50%与肿瘤实际体积相关性和线性关系最好(r=0.873,R^2=0.762),MTV 40%次之(r=0.869,R 2=0.756),MTV 2.5与TV最弱(r=0.530,R^2=0.280)。进一步分析显示:腺癌、鳞癌组的MTV 50%与TV的相关性和线性关系均最好,MTV 40%次之。对于≤3 cm肿瘤,三种阈值所得MTV与TV相关性均较差;而对于>3 cm的肺癌,MTV 50%与TV尽管存在相关性,但不存在线性关系,MTV 40%与TV的线性关系也较差(R 2=0.154)。结论:与SUV 2.5、40%SUV max比较,采用50%SUV max作为阈值所得MTV与肺癌术后肿瘤切除体积最为接近,可较好预测肿瘤真实体积,但仍需要考虑肿瘤大小对结果的影响。

Objective:To compare of the MTVs of lung cancer patients calculated from three different thresholds so as to obtain the optimal parameter.Methods:From January 2015 to December 2017,53 patients with lung cancer received complete tumor resection in the First Affiliated Hospital of Xi'an Jiaotong University were recruited with a median age of 59(range 33~82)years old.They all underwent 18 F-FDG PET/CT whole-body imaging one week before operation.Based on the threshold of SUV 2.5,40%SUV max,50%SUV max,MTV was calculated through system software.Correlation and regression analysis were preformed between MTV and resected tumor volume(TV).Results:On the whole,significant correlation and linearity between TV and MTV were observed based on the three different threshold(P<0.05).There to,MTV 50%showed the most remarkable relationship followed by MTV 40%and MTV2.5 sequently.Parallel outcome was observed in adenocarcinoma and squamous cell carcinoma.For patients with tumor size larger than 3 cm,no prominent relationship was showed in terms of MTV 40%and MTV2.5.Although there was correlation between MTV 50%and TV,no linearity was exhibited between them.Conclusion:In contrast of SUV 2.5 and 40%SUV max,50%SUV max is the optimal threshold to predict the objective volume.Nevertheless,the impact of tumor size should be taken into account.