胸腺CT密度在急性淋巴细胞白血病化疗后并发脓毒症儿童中的改变

Change in CT Density of Thymus in Children with Acute Lymphoblastic Leukemia Complicated with Post⁃Chemotherapy Sepsis

目的探讨胸腺CT密度提示儿童急性淋巴细胞白血病(ALL)化疗后并发脓毒症的临床价值。方法选取深圳市儿童医院2019年1月至2021年8月ALL患儿48例作为病例组,另选择同期经胸部CT检查排除免疫力低下及感染性疾病患儿36例为对照组,病例组根据化疗后有无并发脓毒症分为脓毒症组22例与非脓毒症组26例。回顾性分析所有研究对象胸部CT检查图像(病例组包括化疗前后CT图像)及化疗后CT复查3天内静脉血血常规和T淋巴细胞亚群结果。计量资料组间比较采用独立样本t检验及配对样本t检验,计数资料比较采用Pearsonχ^(2)检验,受试者工作特征(ROC)曲线分析胸腺平扫CT值对化疗后并发脓毒症的诊断价值。结果ALL患者化疗前胸腺CT值与对照组比较无统计学差异;化疗后脓毒症组患儿胸腺CT值[(6.30±27.80)HU]较非脓毒症组[(41.90±20.73)HU]显著减低(P<0.001)。脓毒症组患儿胸腺CT值化疗后[(6.30±27.80)HU]较化疗前[(60.62±19.78)HU]显著减低(P<0.001);化疗前后非脓毒症患者胸腺CT值无统计学差异。ROC曲线示胸腺CT值曲线下面积(AUC)为0.881,以胸腺CT值36.25 HU为截断值诊断化疗后脓毒症敏感度和特异度分别为69.2%和95.5%。结论胸腺CT值可作为儿童化疗后并发脓毒症的影像参考指标,胸腺CT值降低提示ALL患者化疗后并发脓毒症危险性增加。

Objective To investigate the clinical value of CT densityof thymus in detecting the post⁃chemotherapy sep⁃sis in children with acute lymphoblastic leukemia(ALL).Methods 48 children with ALL were selected as ALL cases in Shenzhen Children Hospital from January 2019 to August 2021.36 subjects excluding immunocompromised patients and those with infectious diseases by chest CT were enrolled in the control group at the same time.Patients with ALL were divid⁃ed into sepsis group(22 cases)and non⁃sepsis group(26cases)according to whether they had sepsis after chemotherapy.Retrospectively analyzed the chest CT data(ALL group including CT imagesbefore and after chemotherapy),vein blood rou⁃tine and T lymphocyte subsets results in 3 days during the following⁃up by CT of all the subjects.The independent sample t⁃test and paired⁃samples t test was used for measurement data and Pearsonχ^(2)was used for enumeration datain the compari⁃son between two groups.The ROC curve was used to analyze the diagnostic value of non⁃enhanced CT value of thymus in post⁃chemotherapy sepsis.Results There was no significant differencein CT value of thymus between the ALL groupbefore chemotherapy and the control group.After chemotherapy,the CT value of thymus in the sepsis group(6.30±27.80)HU was significantly lower than that in the non⁃sepsis group(41.90±20.73)HU(P<0.001).The CT value of thymus in the sepsis group after chemotherapy(6.30±27.80)HU was significantly lower than that before the chemotherapy(60.62±19.78)HU(P<0.001).There was no significant difference in CT value of thymus between patients in the non⁃sepsis group before and after chemotherapy.The area under the ROC curve(AUC)of non⁃enhanced CT value of thymus was 0.881.When the threshold value was 36.25 HU,the sensitivity and specificity of CT value in the diagnosis of sepsis and non-sepsis patients with ALL after chemotherapy was 69.2%and 95.5%,respectively.Conclusion The CT value of thymus can be regarded as a reference index of post⁃chemotherapy sepsis in children.The decrease of CT value of thymus indicates that the risk of post⁃chemotherapy sepsis would increase in ALL cases.