Gastrointestinal stromal tumors (GISTs) are the most common stromal tumors in the gastrointestinal tract. This study was designed to evaluate a gastrin-releasing peptide receptor antagonist PET tracer, [⁶⁸Ga]Ga-NOTA-RM26, and compare it with [¹⁸F]FDG PET/CT in the assessment of patients with GISTs. Methods: With institutional review board approval and informed consent, 30 patients with suspected or proven GISTs based on abdominal CT or gastroscopy were recruited. All patients underwent [⁶⁸Ga]Ga-NOTA-RM26 and [¹⁸F]FDG PET/CT scans. Pathology and other patient information were collected. Results: No radiopharmaceutical-related adverse events were observed in the patients. In total, 18 lesions in 16 patients were diagnosed as GIST, 3 patients were diagnosed with schwannoma, and 4 patients were diagnosed with leiomyoma. In 18 GISTs, the mean SUV_max of [⁶⁸Ga]Ga-NOTA-RM26 PET was significantly higher than that of [¹⁸F]FDG PET (17.07 ± 19.57 vs. 2.28 ± 1.65; P < 0.01), and [⁶⁸Ga]Ga-NOTA-RM26 PET/CT had a higher tumor detection rate than did [¹⁸F]FDG PET/CT (88.9% vs. 50%; P < 0.01). The uptake of [⁶⁸Ga]Ga-NOTA-RM26 in GISTs was significantly higher than that in 2 other benign tumors (leiomyoma or schwannoma) (17.07 ± 19.57 vs. 4.23 ± 1.77; P = 0.014). With the SUV_max cutoff value of 6.0, the sensitivity of ⁶⁸Ga-NOTA-RM26 PET/CT in diagnosing GISTs is 72% and the specificity is 85.7%. Conclusion: Compared with [¹⁸F]FDG PET/CT, [⁶⁸Ga]Ga-NOTA-RM26 PET/CT is a promising and effective imaging modality for the detection of GISTs.

胃肠道间质瘤 （GIST） 是胃肠道中最常见的间质瘤。本研究旨在评估胃泌素释放肽受体拮抗剂 PET 示踪剂 [⁶⁸Ga]Ga-NOTA-RM26，并将其与 [¹⁸F]FDG PET/CT 在评估 GIST 患者中进行比较。方法：经机构审查委员会批准和知情同意，招募了 30 例基于腹部 CT 或胃镜检查的疑似或确诊 GIST 患者。所有患者均接受了 [⁶⁸Ga]Ga-NOTA-RM26 和 [¹⁸F]FDG PET/CT 扫描。收集病理和其他患者信息。结果：在患者中未观察到放射性药物相关的不良事件。共有 16 例患者中 18 个病灶诊断为 GIST，3 例患者诊断为神经鞘瘤，4 例患者诊断为平滑肌瘤。在 18 个 GIST 中，[⁶⁸Ga]Ga-NOTA-RM26 PET 的平均 SUV_max 显著高于 [¹⁸F]FDG PET （17.07 ± 19.57 vs. 2.28 ± 1.65;P < 0.01），[⁶⁸Ga]Ga-NOTA-RM26 PET/CT 的肿瘤检出率高于 [¹⁸F]FDG PET/CT （88.9% vs. 50%;P < 0.01）。胃肠道间质瘤中 [⁶⁸Ga]Ga-NOTA-RM26 的摄取显著高于其他 2 种良性肿瘤（平滑肌瘤或神经鞘瘤）（17.07 ± 19.57 对 4.23 ± 1.77;P = 0.014）。SUV_最大临界值为 6.0,68 Ga-NOTA-RM26 PET/CT 诊断 GIST 的敏感性为 72%，特异性为 85.7%。结论：与 [¹⁸F]FDG PET/CT 相比，[⁶⁸Ga]Ga-NOTA-RM26 PET/CT 是一种有前途且有效的 GIST 检测成像方式。