Our purpose was to prospectively assess the distribution of NETPET scores in well-differentiated (WD) grade 2 and 3 gastroenteropancreatic (GEP) neuroendocrine tumors (NETs) and to determine the impact of the NETPET score on clinical management. Methods: This single-arm, institutional ethics review board–approved prospective study included 40 patients with histologically proven WD GEP NETs. ⁶⁸Ga-DOTATATE PET and ¹⁸F-FDG PET were performed within 21 d of each other. NETPET scores were evaluated qualitatively by 2 reviewers, with up to 10 marker lesions selected for each patient. The quantitative parameters that were evaluated included marker lesion SUV_max for each tracer; ¹⁸F-FDG/⁶⁸Ga-DOTATATE SUV_max ratios; functional tumor volume (FTV) and metabolic tumor volume (MTV) on ⁶⁸Ga-DOTATATE and ¹⁸F-FDG PET, respectively; and FTV/MTV ratios. The treatment plan before and after ¹⁸F-FDG PET was recorded. Results: There were 22 men and 18 women (mean age, 60.8 y) with grade 2 (n = 24) or grade 3 (n = 16) tumors and a mean Ki-67 index of 16.1%. NETPET scores of P0, P1, P2A, P2B, P3B, P4B, and P5 were documented in 2 (5%), 5 (12.5%), 5 (12.5%) 20 (50%), 2 (5%), 4 (10%), and 2 (5%) patients, respectively. No association was found between the SUV_max of target lesions on ⁶⁸Ga-DOTATATE and the SUV_max of target lesions on ¹⁸F-FDG PET (P = 0.505). ¹⁸F-FDG/⁶⁸Ga-DOTATATE SUV_max ratios were significantly lower for patients with low (P1–P2) primary NETPET scores than for those with high (P3–P5) primary NETPET scores (mean ± SD, 0.20 ± 0.13 and 1.68 ± 1.44, respectively; P < 0.001). MTV on ¹⁸F-FDG PET was significantly lower for low primary NETPET scores than for high ones (mean ± SD, 464 ± 601 cm³ and 66 ± 114 cm³, respectively; P = 0.005). A change in the type of management was observed in 42.5% of patients after ¹⁸F-FDG PET, with the most common being a change from systemic therapy to peptide receptor radionuclide therapy and from debulking surgery to systemic therapy. Conclusion: There was a heterogeneous distribution of NETPET scores in patients with WD grade 2 and 3 GEP NETs, with more than 1 in 5 patients having a high NETPET score and a frequent change in management after ¹⁸F-FDG PET. Quantitative parameters including ¹⁸F-FDG/⁶⁸Ga-DOTATATE SUV_max ratios in target lesions and FTV/MTV ratios can discriminate between patients with high and low NETPET scores.

我们的目的是前瞻性评估 NETPET 评分在高分化 （WD） 2 级和 3 级胃肠胰 （GEP） 神经内分泌肿瘤 （NETs） 中的分布，并确定 NETPET 评分对临床管理的影响。方法：这项经组织学证实的 WD GEP NET 患者的单臂、机构伦理审查委员会批准的前瞻性研究包括 40 名患者。⁶⁸Ga-DOTATATE PET 和 ¹⁸个 F-FDG PET 在 21 d 内进行。NETPET 评分由 2 名评价员定性评估，为每位患者选择最多 10 个标志病灶。评估的定量参数包括每个示踪剂的标志物病变 SUV_max;¹⁸F-FDG/⁶⁸Ga-DOTATATE SUV_最大比率;分别在 ⁶⁸个 Ga-DOTATATE 和 ¹⁸个 F-FDG PET 上显示功能性肿瘤体积 （FTV） 和代谢肿瘤体积 （MTV）;和 FTV/MTV 比率。记录 ¹⁸F-FDG PET 前后的治疗计划。结果：有 22 例男性和 18 例女性 （平均年龄，60.8 岁） 患有 2 级 （n = 24） 或 3 级 （n = 16） 肿瘤，平均 Ki-67 指数为 16.1%。2 例 （5%） 、 5 例 （12.5%） 、 5 例 （12.5%） 、 5 例 （12.5%） 、 20 例 （50%） 、 2 例 （5%） 、 4 例 （10%） 和 2 例 （5%） 患者的 NETPET 评分分别为 P0 、 P1 、 P2A 、 P2B 、 P3B 、 P4B 和 P5 。在 ⁶⁸个 Ga-DOTATATE 上目标病灶的 SUV_max 与 ¹⁸个 F-FDG PET 上目标病灶的 SUV_max 之间未发现关联 （P = 0.505）。¹⁸原发性 NETPET 评分低 （P1-P2） 的患者的 F-FDG/⁶⁸Ga-DOTATATE SUV_max 比率显著低于原发性 NETPET 评分高 （平均 ± SD，0.20 ± 0.13 和 1.68 ± 1。分别为 44 个;P < 0.001）。低原发性 NETPET 评分的 ¹⁸F-FDG PET 的 MTV 显着低于高 NETPET 评分 （平均 ± SD，分别为 464 ± 601 cm³ 和 66 ± 114 cm³;P = 0.005）。在 ¹⁸F-FDG PET 后，42.5% 的患者观察到管理类型的变化，最常见的是从全身治疗转变为肽受体放射性核素治疗，从减瘤手术转变为全身治疗。结论：WD 2 级和 3 级 GEP NETs 患者的 NETPET 评分分布异质性，超过 1/5 的患者 NETPET 评分较高，并且在 ¹⁸次 F-FDG PET 后频繁更换管理。定量参数包括目标病灶中的 ¹⁸F-FDG/⁶⁸Ga-DOTATATE SUV_max 比率和 FTV/MTV 比率，可以区分 NETPET 评分高和低的患者。