Abstract: Background　Clinical staging of small cell lung cancer （SCLC） is critical for its prognosis.18F-FDG PET/CT can show the shape，involvement range and metabolic status of the lesion.The purpose of this study is to explore the value of metabolic indicator，18F-FDG PET/CT in the diagnosis，clinical staging，efficacy evaluation and prognosis prediction of SCLC．Objective　To analyze the performance of metabolic parameters measured by 18F-FDG PET/CT imaging for predicting the prognosis of SCLC．Methods　Eighty-six cases of newly diagnosed SCLC who received 18F-FDG PET/CT imaging examination in the Third Affiliated Hospital of Qiqihar Medical University and the Fourth Affiliated Hospital of Harbin Medical University from 2007 to 2016 were enrolled，and divided into limited stage （LS） SCLC group （n=45） and extensive stage （ES） SCLC group （n=41） according to the examination results.The clinical data and metabolic parameters measured by 18F-FDG PET/CT imaging，including maximum standardized uptake value （SUVmax），mean standardized uptake value （SUVmean），peak standardized uptake value （SUVpeak），metabolic tumor volume （MTV） and total lesion glycolysis （TLG） with a fixed threshold of 40% SUVmax in LS SCLC group，and SUVmax，MTV，TLG of primary lesion，the biggest SUVmax of all lesions，the sum of metabolic volume （MTVsum） and TLG （TLGsum） in ES SCLC group were collected.Multivariate Cox proportional hazards analysis was performed to analyze the predictors of overall survival （OS） and progression free survival （PFS）．Results　Except the rate of receiving thoracic radiation therapy was higher in the LS SCLC group （P<0.05），two groups showed no significant differences in male-to-female ratio，mean age，prevalence of smoking history，mean ECOG score，prevalence of pleural effusion，TNM stage distribution，rate of receiving systemic chemotherapy，rate of receiving whole-brain radiation as a preventative therapy，prevalence of lactate dehydrogenase （LDH） ≥245 U/L，prevalence of carcinoembryonic antigen （CEA） ≥5 μg/L，prevalence of neuron-specific enolase （NSE） ≥15.2 μg/L （P>0.05）．The follow-up of 3-105 months showed that during this period，29 survived （including 24 LS SCLC patients and 5 ES SCLC patients） and 57 died （including 21 LS SCLC patients and 36 ES SCLC patients）；the mean OS and PFS were 21.3，30.6 months，respectively；the 1-，2-，3-year overall survival rates were 70.9%，51.2%，29.1%，respectively；the 1-，2-，3-year progression free survival rates were 61.6%，43.0%，32.6%，respectively.Multivariate Cox proportional hazard regression analysis showed that the ECOG score of 3 to 4 points 〔HR=3.118，95%CI（1.196，8.131）〕，TNM stage Ⅲ 〔HR=7.739，95%CI（2.017，29.691）〕，and TLG 〔HR=1.056，95%CI（1.004，1.111）〕 were independent influencing factors for OS in LS SCLC patients （P<0.05）；TLGsum 〔HR=3.898，95%CI（1.132，13.426）〕 was independent influencing factors for OS in ES SCLC patients （P<0.05）；LDH≥245 U/L 〔HR=4.957，95%CI（1.080，3.353）〕，MTV 〔HR=1.205，95%CI（1.008，1.440）〕 were independent influencing factors of PFS in LS SCLC patients （P<0.05）；ECOG score of 3-4 points〔HR=5.555，95%CI（1.697，18.183）〕，LDH≥245 U/L 〔HR=2.898，95%CI（1.326，6.335）〕，and TLGsum 〔HR=3.898，95%CI（1.355，11.211）〕 were independent influencing factors of PFS in ES SCLC patients（P<0.05）．Conclusion　The volume-based metabolic parameters measured by 18F-FDG PET/CT imaging can effectively predict the prognosis of SCLC patients.TLG and MTV are the independent factors associated with OS and PFS in LS SCLC patients，and TLGsum is an independent factor associated with OS and PFS in ES SCLC patients.But there is no significant correlation between SUVmax and prognosis.

Key words: Small cell lung carcinoma；Fluorodeoxyglucose F18；Positron-emission tomography；Tomography, X-ray computer；Prognosis

摘要： 背景　小细胞肺癌（SCLC）诊断明确后进行临床分期，对其预后十分关键。而18氟-氟代脱氧葡萄糖正电子发射断层显像/X线计算机体层成像仪（18F-FDG PET/CT）可显示病灶的形态、累及范围与代谢情况，探讨18F-FDG PET/CT代谢指标对SCLC的诊断、临床分期、疗效评价和预后预测的价值非常有必要。目的　探讨18F-FDG PET/CT代谢指标对SCLC预后的预测评估。方法　选取2007—2016年在齐齐哈尔医学院附属第三医院和哈尔滨医科大学附属第四医院行18F-FDG PET/CT检查的初诊SCLC患者86例，局限期45例、广泛期41例，记录患者的临床资料，采用18F-FDG PET/CT检测局限期SCLC患者标准摄取值最大值（SUVmax）、平均值（SUVmean）、峰值（SUVpeak）、病灶固定阈值为40%SUVmax时的肿瘤代谢体积（MTV）与糖酵解总量（TLG），以及广泛期SCLC患者原发灶的SUVmax、MTV、TLG与所有病灶的最大SUVmax、MTV之和（MTVsum）、TLG之和（TLGsum）。采用多因素Cox比例风险回归模型分析患者总生存时间（OS）与无进展生存时间（PFS）的影响因素。结果　局限期与广泛期SCLC患者性别、年龄、吸烟史、美国东部肿瘤协作组（ECOG）评分、胸腔积液发生率、TNM分期、全身化疗、预防性全脑照射治疗（PCI）、乳酸脱氢酶（LDH）≥245 U/L、癌胚抗原（CEA）≥5 μg/L、神经元特异性烯醇化酶（NSE）≥15.2 μg/L所占比例比较，差异均无统计学意义（P>0.05）；局限期SCLC患者胸部放疗（TRT）比例高于广泛期（P<0.05）。随访3~105个月，生存29例，死亡57例。中位OS、PFS分别为21.3、30.6个月，1、2、3年总生存率分别为70.9%、51.2%、29.1%，1、2、3年无进展生存率分别为61.6%、43.0%、32.6%。局限期SCLC患者生存24例，死亡21例；广泛期SCLC患者生存5例，死亡36例。多因素Cox比例风险回归分析结果表明，ECOG评分3~4分〔HR=3.118，95%CI（1.196，8.131）〕、TNM分期Ⅲ期〔HR=7.739，95%CI（2.017，29.691）〕、TLG〔HR=1.056，95%CI（1.004，1.111）〕是局限期SCLC患者OS的独立影响因素（P<0.05），TLGsum〔HR=3.898，95%CI（1.132，13.426）〕是广泛期SCLC患者OS的独立影响因素（P<0.05）。LDH≥245 U/L〔HR=4.957，95%CI（1.080，3.353）〕、MTV〔HR=1.205，95%CI（1.008，1.440）〕是局限期SCLC患者PFS的独立影响因素（P<0.05），ECOG评分3~4分〔HR=5.555，95%CI（1.697，18.183）〕、LDH≥245 U/L〔HR=2.898，95%CI（1.326，6.335）〕、TLGsum〔HR=3.898，95%CI（1.355，11.211）〕是广泛期SCLC患者PFS的独立影响因素（P<0.05）。结论　18F-FDG PET/CT体积代谢指标能有效预测SCLC患者的生存状况，其中TLG、MTV分别是局限期SCLC患者OS、PFS的独立影响因素，TLGsum是广泛期SCLC患者OS、PFS的独立影响因素，而SUVmax与预后无明显相关性。

关键词: 小细胞肺癌, 氟脱氧葡萄糖F18, 正电子发射断层显像术, 体层摄影术, X线计算机, 预后