Department of Radiation Oncology, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.
Heidelberg Institute of Radiation Oncology (HIRO), Heidelberg, Germany.
Eur J Nucl Med Mol Imaging. 2021 Nov;48(12):3918-3924. doi: 10.1007/s00259-021-05374-4. Epub 2021 May 21.
A high expression of fibroblast activation protein (FAP) was observed in multiple sarcomas, indicating an enormous potential for PET/CT using Ga-radiolabeled inhibitors of FAP (FAPI). Therefore, this retrospective study aimed to evaluate the role of the novel hybrid imaging probe for sarcomas as a first clinical evaluation.
A cohort of 15 patients underwent Ga-FAPI-PET/CT for staging or restaging. The acquisition of PET scans was performed 60 min after administration of 127 to 308 MBq of the tracer. The uptake of Ga-FAPI in malignant tissue as well as in healthy organs was quantified by standardized uptake values SUVmean and SUVmax.
Excellent tumor-to-background ratios (> 7) could be achieved due to low background activity and high SUVmax in primary tumors (median 7.16), local relapses (median 11.47), and metastases (median 6.29). The highest uptake was found for liposarcomas and high-grade disease (range 18.86-33.61). A high SUVmax (> 10) was observed for clinically more aggressive disease.
These preliminary findings suggest a high potential for the clinical use of Ga-FAPI-PET/CT for patients diagnosed with sarcoma.
成纤维细胞激活蛋白（FAP）在多种肉瘤中表达较高，这表明使用 Ga 放射性标记的 FAP（FAPI）抑制剂进行 PET/CT 具有巨大的潜力。因此，本回顾性研究旨在评估新型杂交成像探针在肉瘤中的作用，作为首次临床评估。
15 名患者接受了 Ga-FAPI-PET/CT 分期或重新分期。在给予 127 至 308MBq 示踪剂后 60 分钟进行 PET 扫描采集。通过标准化摄取值 SUVmean 和 SUVmax 来量化恶性组织和健康器官中 Ga-FAPI 的摄取。
由于原发性肿瘤（中位数 7.16）、局部复发（中位数 11.47）和转移（中位数 6.29）的背景活性低且 SUVmax 高，因此可以实现优异的肿瘤与背景比值（>7）。脂肪肉瘤和高级别疾病的摄取量最高（范围为 18.86-33.61）。高 SUVmax（>10）与临床侵袭性更高的疾病相关。
这些初步发现表明，Ga-FAPI-PET/CT 对诊断为肉瘤的患者具有很高的临床应用潜力。
