^18F-FDG PET/CT显像SUVmax、MTV和TLG判断弥漫性大B细胞淋巴瘤的预后价值

Prognostic significance of SUVmax, MTV and TLG on ^18F-FDG PET/CT imaging in patients with diffuse large B-cell lymphoma

目的 分析DLBCL治疗前^18F-FDG PET/CT显像中肿瘤SUVmax、MTV、TLG与LDH、预后的关系.方法 回顾性分析2008年至2012年治疗前行^18F-FDG PET/CT显像并经病理确诊的DLBCL患者46例（男24例,女22例,平均年龄52.3岁）,均有完整的临床随访数据（中位随访时间19个月）.以SUV 2.5为阈值,获得全身肿瘤的SUVmax、MTV和TLG.用Spearman检验分析上述三者与LDH的相关性.由ROC曲线分析得到SUVmax、MTV和TLG预测肿瘤进展或复发的界值.用Kaplan-Meier生存分析法和log-rank检验分析比较预后危险因素、国际预后指数（IPI）、SUVmax、MTV和TLG的预后价值.结果 SUVmax与LDH水平未见相关性（r=0.017,P＞0.05）.MTV、TLG与LDH水平呈正相关（rs=0.710和0.673,均P＜0.05）.SUVmax、MTV与TLG预测肿瘤进展或复发的界值分别为19、56 cm3和817 g.IPI低危（0-1分）、TLG＜817 g与DLBCL的PFS期延长有关且差异有统计学意义（χ^2=6.257和3.988,均P＜0.05）,年龄、LDH水平、Ann Arbor分期、结外受侵部位数、SUVmax和MTV的PFS期差异均无统计学意义（χ^2=0.508、0.001、2.662、0.814、2.700和3.530,均P＞0.05）.结论 DLBCL的MTV、TLG与LDH水平呈正相关.TLG比SUVmax、MTV具有更好的预后价值,有可能成为IPI的有益补充.

Objective To explore the predictive value and relationship with LDH of SUVmax,MTV and TLG calculated from ^18F-FDG PET/CT results in patients with DLBCL.Methods From 2008 to 2012,forty-six patients （24 males,22 females,average age 52.3 years） with newly diagnosed DLBCL who underwent ^18F-FDG PET/CT scan for staging before chemotherapy were retrospectively included in this study.All patients underwent standard treatment and subsequently had clinical follow-up （median follow-up time：19 months）.SUVmax,MTV and TLG of tumor tissue were calculated from PET/CT images with the SUV cut-off value of 2.5,and were evaluated for their association with LDH level and survival.The correlations between SUVmax,MTV,TLG and LDH were analyzed using Spearman rank correlation.The ROC curve was plotted to estimate the most discriminating decision threshold （cut-off point） for each parameter to maximize the sensitivity and specificity in predicting the progression or recurrence.The relationships between age,LDH level,Ann Arbor stage,extranodal involvement,international prognostic index （IPI）,SUVmax,MTV,TLG and PFS were statistically estimated by the Kaplan-Meier method and log-rank test.Results No statistically significant correlation between SUVmax and LDH level （r=0.017,P〉0.05）.There were significant positive correlations between MTV and LDH level （r =0.710,P 〈 0.05） and between TLG and LDH level （r =0.673,P〈0.05）.The optimal cut-offs of SUVmax,MTV and TLG were 19,56 cm3 and 817 g for the progression or recurrence.The low-risk IPI （0-1） was associated with reduced PFS compared with intermediatehigh IPI （2-4） and high TLG （≥817 g） was associated with reduced PFS compared with low TLG （〈817 g）（χ^2 =6.257,3.988,both P〈0.05）.Age,LDH level,Ann Arbor stage,extranodal involvement,SUVmax and MTV did not significantly affect PFS （χ^2=0.508,0.001,2.662,0.814,2.700,3.530,all P〉0.05）.Conclusions MTV and TLG correlate with level of LDH in DLBCL.TLG may be more useful than SUVmax or MTV for predicting PFS in DLBCL.