Department of Medical Oncology, Dr. Lutfi Kirdar Kartal Education and Research Hospital, Istanbul, Turkey.
Eur J Nucl Med Mol Imaging. 2011 Jan;38(1):64-73. doi: 10.1007/s00259-010-1611-1. Epub 2010 Sep 14.
(18)F-fluorodeoxyglucose (FDG) PET/CT has been widely used for staging, re-staging and for monitoring therapy-induced changes and response to therapy in patients with various types of cancer, but its utilization for gastric cancer has been limited. The purpose of this study was to evaluate the clinical role of FDG PET/CT in the detection of gastric cancer recurrence as compared with diagnostic CT and to assess the impact of FDG PET/CT results on patients' treatment planning.
Thirty-four patients with suspected recurrent gastric cancer, who had previously undergone curative gastrectomy and lymph node dissection, were retrospectively analysed. The diagnostic CT and FDG PET/CT imaging were performed for all patients as clinically indicated. The results of FDG PET/CT were compared with the findings of the diagnostic CT. The changes in the clinical management of patients according to the results of FDG PET/CT were also evaluated.
FDG PET/CT was performed in 19 patients (55.9%) due to the suspicion of distant metastasis at diagnostic CT. The remaining 15 patients were suspected to have local recurrence at diagnostic CT (n = 4) or gastroscopy (n = 1) and due to an increase in tumour markers or clinical manifestations (n = 10). The FDG PET/CT result was positive in 23 patients (67.6%) and negative in 11 patients (32.4%). In total, 24 (70.6%) of the 34 patients had documented recurrent disease by histopathology in 7 (29.1%) and by clinical follow-up in 17 (70.9%), while 11 patients had no evidence of recurrent disease. FDG PET/CT correctly confirmed recurrent disease in 23 of the patients with recurrence and it was classified as true-positive in these patients. However, FDG PET/CT was false-negative in one patient but recurrent disease was confirmed by histopathology. The overall sensitivity, specificity, accuracy, positive and negative predictive values of FDG PET/CT were significantly superior to those of diagnostic CT (95.8 vs 62.5%, 100 vs 10%, 97 vs 47%, 100 vs 62.5% and 90.9 vs 10%, respectively, p = 0.012) in the detection of recurrent gastric cancer after initial surgery. The FDG PET/CT results changed the patients' management in 18 (52.9%) cases by leading to the use of previously unplanned treatment procedures in 9 (50%) patients and the avoidance of previously planned therapeutic procedures in 9 (50%) patients.
FDG PET/CT is a superior post-therapy surveillance modality for the diagnosis of recurrent gastric cancer compared with diagnostic CT imaging after initial surgery. In addition, integrated FDG PET/CT was specifically helpful in optimizing the treatment plan and it might play an important role in treatment stratification in the future.
（18）氟-脱氧葡萄糖（FDG）正电子发射断层扫描/计算机断层扫描（PET/CT）已广泛用于各种类型癌症患者的分期、再分期以及监测治疗引起的变化和对治疗的反应，但在胃癌中的应用受到限制。本研究旨在评估 FDG PET/CT 在检测胃癌复发方面的临床作用，与诊断 CT 相比，并评估 FDG PET/CT 结果对患者治疗计划的影响。
回顾性分析 34 例疑似复发性胃癌患者，这些患者均已接受根治性胃切除术和淋巴结清扫术。所有患者均根据临床需要进行诊断 CT 和 FDG PET/CT 影像学检查。将 FDG PET/CT 结果与诊断 CT 的结果进行比较。还评估了根据 FDG PET/CT 结果改变患者临床管理的情况。
19 名患者（55.9%）因诊断 CT 怀疑远处转移而进行 FDG PET/CT。其余 15 名患者因诊断 CT（n=4）或胃镜（n=1）怀疑局部复发，以及肿瘤标志物或临床表现增加（n=10）而怀疑局部复发。FDG PET/CT 结果阳性 23 例（67.6%），阴性 11 例（32.4%）。总共，34 例患者中的 24 例（70.6%）通过组织病理学证实有复发疾病，7 例（29.1%）和 17 例（70.9%）通过临床随访证实有复发疾病，而 11 例患者没有复发疾病的证据。FDG PET/CT 在 23 例有复发的患者中正确证实了复发疾病，在这些患者中，FDG PET/CT 被归类为真阳性。然而，FDG PET/CT 在一名患者中为假阴性，但通过组织病理学证实有复发疾病。FDG PET/CT 在检测初始手术后复发性胃癌方面的总体敏感性、特异性、准确性、阳性预测值和阴性预测值均明显优于诊断 CT（95.8%比 62.5%、100%比 10%、97%比 47%、100%比 62.5%和 90.9%比 10%，p=0.012）。FDG PET/CT 结果改变了 18 例（52.9%）患者的治疗管理，导致 9 例（50%）患者使用了先前未计划的治疗程序，9 例（50%）患者避免了先前计划的治疗程序。
与初始手术后的诊断 CT 成像相比，FDG PET/CT 是一种用于诊断复发性胃癌的术后治疗监测的更优方法。此外，整合 FDG PET/CT 特别有助于优化治疗计划，并且将来可能在治疗分层中发挥重要作用。
