18F-FDG PET/CT联合常规影像学检查在直肠癌TNM分期中的价值

Value of 18F-FDG PET/CT combined with conventional imaging modalities in TNM staging of rectal cancer

目的:探讨18F-FDG PET/CT联合常规影像学检查在直肠癌肿瘤侵犯深度、区域淋巴结转移、远处脏器及淋巴结转移情况(TNM分期)及邻近结构侵犯评估中的价值。方法:回顾性选取2019年9月至2021年6月青岛大学附属青岛市中心医院收治的经病理证实的直肠癌患者54例[男28例、女26例,年龄(65.8±11.0)岁];患者在确诊前后2周内行18F-FDG PET/CT及常规影像学[直肠高分辨率MRI(HR-MRI)、胸部CT平扫、上腹部MRI或CT平扫+强化]检查。用18F-FDG PET/CT、常规影像学检查及两者联合对直肠癌进行TNM分期及邻近结构侵犯[环周切缘(CRM)、壁外血管侵犯(EMVI)、肛门括约肌复合体受累]评估,并与病理或最终临床随访结果对照。用χ^(2)检验比较单独18F-FDG PET/CT或常规影像学检查与联合检查的诊断效能差异。结果:联合检查评估T分期的准确性、评估N分期的灵敏度及准确性分别为96.30%(52/54)、98.65%(73/74)、93.91%(185/197),高于18F-FDG PET/CT的85.19%(46/54)、66.22%(49/74)、81.73%(161/197),差异有统计学意义(χ^(2)值:3.97、26.88、13.66,均P<0.05);评估N分期的特异性[91.06%(112/123)]及准确性高于常规影像学检查的相应指标[77.24%(95/123)、83.76%(165/197);χ^(2)值:8.81、10.23,均P<0.05];评估M分期的灵敏度及准确性[97.01%(65/67)、95.95%(71/74)]高于常规影像学组的相应指标[73.13%(49/67)、68.92%(51/74);χ^(2)值:15.05、18.66,均P<0.001]。联合检查评估CRM、EMVI的灵敏度分别为100%(22/22)和95.00%(19/20),准确性分别为98.15%(53/54)和96.30%(52/54),较18F-FDG PET/CT的54.55%(12/22)、74.07%(40/54)、30.00%(6/20)和74.07%(40/54)高(χ^(2)值:12.94、13.08、18.03、10.56,均P<0.01);评估EMVI的准确性也较常规影像学检查的高[85.19%(46/54);χ^(2)=3.97,P=0.046]。结论:18F-FDG PET/CT联合常规影像学检查有助于提高对直肠癌TNM分期及邻近结构侵犯的诊断效能。

Objective To investigate the value of 18F-FDG PET/CT combined with conventional imaging modalities in the evaluation of the depth of tumor invasion,regional lymph node metastasis,distant organ and lymph node metastasis(TNM staging),and the adjacent structure invasion of rectal cancer.Methods Fifty-four patients(28 males,26 females,age(65.8±11.0)years)with pathologically confirmed rectal cancer admitted to the Affiliated Qingdao Central Hospital of Qingdao University between September 2019 and June 2021 were retrospectively analyzed.18F-FDG PET/CT examination,conventional imaging modalities including high-resolution MRI(HR-MRI),chest CT plain scan,upper abdominal MRI or CT plain scan+enhanced examination were performed within 2 weeks before or after the rectal cancer being confirmed.The TNM staging and adjacent structural invasions including circumferential resection margin(CRM),extramural vascular invasion(EMVI),anal sphincter complex involvement were evaluated by 18F-FDG PET/CT and conventional imaging modalities separately or in combination,and those results based on imaging were compared with the pathological results or clinical follow-up results.χ^(2) test was used to compare the differences of diagnostic sensitivity,specificity and accuracy between the 18F-FDG PET/CT or conventional imaging modalities and combined examination.Results The accuracy for T staging and the sensitivity and accuracy for N staging of the combined examination were 96.30%(52/54),98.65%(73/74)and 93.91%(185/197),respectively,which were significantly higher than those of 18F-FDG PET/CT(85.19%(46/54),66.22%(49/74),81.73%(161/197);χ^(2) values:3.97,26.88,13.66,all P<0.05).The specificity(91.06%,112/123)and accuracy of the combined examination for N staging were higher than those of the conventional imaging modalities(77.24%(95/123),83.76%(165/197);χ^(2) values:8.81,10.23,both P<0.05).The sensitivity and accuracy of the combined examination for M staging were higher than those of the conventional imaging modalities(97.01%(65/67)vs 73.13%(49/67),95.95%(71/74)vs 68.92%(51/74);χ^(2) values:15.05,18.66,both P<0.001).The sensitivities of the combined examination in evaluating CRM and EMVI were 100%(22/22)and 95.00%(19/20),and the accuracies were 98.15%(53/54)and 96.30%(52/54),all of which were higher than those of 18F-FDG PET/CT(CRM:54.55%(12/22),74.07%(40/54);EVMI:30.00%(6/20),74.07%(40/54);χ^(2) values:12.94,13.08,18.03,10.56,all P<0.01).The accuracy of the combined examination in evaluating EMVI was higher than that of the conventional imaging modalities(85.19%(46/54);χ^(2)=3.97,P=0.046).Conclusion 18F-FDG PET/CT combined with conventional imaging modalities can improve the diagnostic efficacy for TNM staging and assessment of adjacent structural invasion in rectal cancer.