^(18)F-FDG PET/CT显像对胃癌治疗后临床再分期及治疗决策的影响

Impact of ^(18)F-FDG PET/CT on the Clinical Restaging and Therapeutic Regimens in Post-Treatment Patients with Gastric Carcinoma

目的探讨18氟标记的氟脱氧葡萄糖(18F-FDG)正电子发射计算机断层显像/电子计算机断层扫描(PET/CT)显像在胃癌治疗后随访中的价值,分析其对胃癌治疗后临床再分期及治疗决策的影响。方法选取我院收治的胃癌治疗后患者55例,分别于静脉注射18F-FDG后60 min及120 min行PET/CT早期及延迟显像。延迟显像于患者饮水使胃适度充盈后进行。必要时行增强CT检查。分别从肿瘤复发、淋巴结转移及淋巴结外转移3个方面评价18F-FDG PET/CT显像在胃癌治疗后随访中的价值,分析18F-FDG PET/CT显像对临床再分期及治疗决策的影响。分别测量胃癌复发与吻合口炎症早期及延迟显像最大标准化摄取值(SUVmax)及SUVmax变化率(△SUVmax%),评价饮水胃充盈后18F-FDG PET/CT延迟显像的价值。所有患者的诊断以病理组织学检查结果为金标准。采用SAS 9.13统计学软件进行统计分析。结果 (1)18F-FDG PET/CT诊断胃癌复发的准确性96.4%(53/55)高于CT(85.5%),诊断淋巴结转移的灵敏度(92.0%)、准确性(96.4%)、阴性预测值(93.8%)均高于CT(60.0%、81.8%、75.0%),诊断淋巴结外转移的灵敏度(81.8%)、准确性(90.9%)均高于CT(45.5%、76.4%),差异均有统计学意义(P<0.05)。(2)18F-FDG PET/CT显像使34.5%(19/55)的患者TNM分期发生改变,21.8%(12/55)的患者治疗方案改变。(3)胃癌复发患者及吻合口炎症患者△SUVmax%分别为(22.8±9.8)%、(8.6±13.3)%,差异有统计学意义(P<0.05)。结论18F-FDG PET/CT显像可早期探测胃癌复发、转移,将成为胃癌治疗后有效的监测手段;且18F-FDG PET/CT显像对临床再分期及合理治疗决策的制定具有重要指导作用;饮水胃充盈后18F-FDG PET/CT延迟显像有助于肿瘤复发与吻合口炎症的鉴别。

Objective To investigate the value of 18F - fluorodeoxyglucose positron emission tomography/computed tomography （18F- FDG PET/CT） in the follow -up of post -treatment patients with gastric cancer and to investigate the impact of 18F - FDG PET/CT on the clinical restaging and therapeutic regimens. Methods A retrospective study was conducted in 55 post -treatment patients with gastric cancer, 18F- FDG PET/CT scan was performed at 60 min （early phase） and 120 rain （delayed phase） after 18F - FDG administration, 18F - FDG PET/CT of delayed phase was undertaken after gastric filling with moder- ate water. If necessary, enhanced CT was also performed. The value of 18F - FDG PET/CT in the follow - up of post - treatment patients with gastric cancer was evaluated based on recurrence, lymph node metastases and lymph node external metastases respectively, and it was compared with CT. Meanwhile, the impact of 18 F - FDG PET/CT on the restaging and treatment decision was also analyzed in this study. Additionally, the maximum of standardized uptake value （SUVmax） of early and delayed phases in the anastomotic stoma was measured, and the percentage change of SUVmax （ △ SUVmax% ） was also calculated in this stud- y. Tumor recurrence and/or metastases were finally confirmed by pathology. Data was analyzed with SAS 9. 13. Results （ 1 ） The accuracy of 18F - FDG PET/CT in the diagnosis of gastric recurrence was 96.4% （53/55）, which was significantly higher than CT （85.5%） . In the detection of lymph node metastases, the sensitivity, accuracy and negative predictive value （NPV） of 18F-FDG PET/CT （92.0%, 96.4% and 93.8%） showed statistically significant differences compared with CT （60.0%,81.8% and 75.0% ） . In addition, the sensitivity and accuracy of 18F - FDG PET/CT in detecting lymph node external metastases were 81.8% and 90. 9%, significantly higher than CT （45.5%, 76. 4% ） . （2） 18F - FDG PET/CT changed the TNM stage in 34. 5% （19/55） cases, and the therapeutic strategies of 21.8% （ 12/55 ） cases were changed due to PET/CT findings. （3） ASUVmax% was （22. 8 ±9. 8）% and （8. 6 ± 13.3）% in gastric recurrence and the anastomotic inflammation with statistically significant differences between the two groups （P 〈 0. 05） . Conclusion is F - FDG PET/CT is a superior post - operative surveillance modality in the diagnosis of recurrence and metastases in post - treatment patients with gastric cancer compared with CT. 18F - FDG PET/CT has great impact on the clinical restaging and proper re - treatment regimens. 18F - FDG PET/ CT of delayed phase after gastric filling with water may be one of the best ways in discriminating the recurrence from the inflammation in anastomotic stoma.