Objectives: To evaluate the value of ⁶⁸Ga-DOTATATE and ¹⁸F-FDG PET/CT imaging in staging and treatment decision for gastroenteropancreatic neuroendocrine neoplasms (GEP-NEN).
Methods: This retrospective analysis was conducted in 49 patients with GEP-NEN undergoing 18F-FDG and 68Ga-DOTATATE PET/CT imaging at our hospital from August, 2020 to March, 2023, including 34 newly diagnosed patients and 15 patients with recurrence or metastasis after treatment. GEP-NEN were classified into G1, G2, and G3 neuroendocrine tumors (NET) and neuroendocrine carcinomas (NEC) based on pathological typing. The detection efficiency were classified into 4 patterns based on the number of positive tumor lesions detected by the two tracers: 68Ga-DOTATATE>18F-FDG (A); 68Ga-DOTATATE=18F-FDG (B); 68Ga-DOTATATE<18F-FDG (C); and complementation (D). The value of dual-modality imaging in staging and treatment decision were evaluated by visual analysis.
Results: In the 49 patients with GEP-NEN, 68Ga-DOTATATE PET/CT was superior to 18F-FDG PET/CT for detecting systemic tumor lesions (P<0.001) and more sensitive for detecting primary/recurrent lesions, lymph node metastasis, liver metastasis, and bone metastasis (P<0.05), while 18F-FDG PET/CT had higher detection rates for lung metastasis and peritoneal metastasis (P<0.05). In terms of the detection efficiency, Pattern A was found in 46.9% (23/49) patients, Pattern B in 38.8% (19/49), Pattern C in 12.2% (6/49), and Pattern D in 2.0% (1/49). The complementary value of ¹⁸F-FDG PET/CT to ⁶⁸Ga-DOTATATE PET/CT was 0% in G1 NET patients (0/13), 8.3% in G2 NET patients (2/24), 50% in G3 NET patients (3/6), and 33.3% in NEC patients (2/6). 12.2% (6/49) of the patients had their staging confirmed or changed due to additional lesions detected by ¹⁸F-FDG PET/CT imaging, resulting subsequently in establishment or adjustment of their treatment plans.
Conclusions: 68Ga-DOTATATE PET/CT imaging should be the primary choice for GEP-NEN patients. Additional ¹⁸F-FDG PET/CT imaging can potentially improve precision of staging and treatment decision-making for G2, G3 and NEC patients but provides virtually no clinical benefits for G1 NET patients.
目的: 探讨68Ga-DOTATATE与18F-FDG PET/CT显像在不同级别胃肠胰神经内分泌肿瘤（GEP-NEN）分期及治疗决策中的价值。方法: 回顾性分析2020年8月~2023年3月在南方医科大学南方医院行18F-FDG和68Ga-DOTATATE PET/CT显像的GEP-NEN患者49例，包括初诊患者34例，治疗后复发、转移患者15例。按病理分型将GEP-NEN分为G1、G2、G3神经内分泌瘤（NET）及神经内分泌癌（NEC）。依据同一患者双示踪剂阳性肿瘤病灶检出效能分为4种模式：68Ga-DOTATATE>18F-FDG（A）；68Ga-DOTATATE=18F-FDG（B）；68Ga-DOTATATE<18F-FDG（C）；互补（D）。分析评价双示踪联合显像在分期及治疗决策中的价值。结果: 68Ga-DOTATATE PET/CT对全身肿瘤病灶检出优于18F-FDG PET/CT（P<0.001）； 68Ga-DOTATATE显像在原发灶/复发灶、淋巴结转移、肝转移及骨转移的检出率更高（P<0.05），而18F-FDG PET/CT在肺转移和腹膜转移的检出率更高（P<0.05）。49例患者双示踪剂检出模式的比例为：模式A占46.9%（23/49），模式B占38.8%（19/49），模式C占12.2%（6/49），模式D占2.0%（1/49）。不同级别GEP-NEN患者18F-FDG PET/CT对68Ga-DOTATATE PET/CT的补充价值为：G1 NET患者为0%（0/13）、G2 NET患者为8.3%（2/24）、G3 NET患者为50%（3/6）及NEC患者为33.3%（2/6）。12.2%（6/49）患者因联合18F-FDG PET/CT显像额外发现病灶而确定或改变分期，从而确定或改变治疗方案。结论: GEP-NEN患者应首选68Ga-DOTATATE PET/CT显像。对于G1 NET患者，联合18F-FDG PET/CT显像对分期及治疗决策无帮助，对G2、G3、NEC患者，联合18F-FDG PET/CT显像提高了部分患者分期及治疗决策精准度。.
Keywords: X-ray computed; fluorodeoxyglucose F18; gallium radioisotope Ga68; neuroendocrine tumors; octreotide; positron emission tomography; somatostatin receptor; tomography.