Department of Nuclear Medicine, Netherlands Cancer Institute, Amsterdam, The Netherlands.
Department of Medical Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands.
Eur J Nucl Med Mol Imaging. 2019 Mar;46(3):696-703. doi: 10.1007/s00259-018-4117-x. Epub 2018 Aug 10.
Somatostatin receptor imaging with PET is the standard of care for patients with a neuroendocrine tumour (NET). Since therapy and imaging with somatostatin analogues utilize the same receptor, current guidelines recommend withdrawing long-acting somatostatin analogues for 3-4 weeks prior to somatostatin receptor PET imaging. The aim of this study is to prospectively assess the effect of lanreotide use on the uptake of Ga-DOTATATE intra-individually 1 day prior to and 1 day post injection of lanreotide.
Thirty-four patients with metastatic and/or unresectable NET and currently on lanreotide therapy for at least 4 months were included in the study. A Ga-DOTATATE PET/CT scan was performed on the day before and the day after lanreotide injection. In each patient Ga-DOTATATE uptake (SUV, , ) was assessed in both tumour lesions and normal tissue. All scans were assessed by two blinded nuclear medicine physicians for visual analysis. Paired T-tests were performed to determine the differences between the scans.
Of the 34 patients included, 31 were available for analyses in which 190 tumour lesions were measured. Uptake of Ga-DOTATATE in tumour lesions was increased significantly after lanreotide, but decreased significantly in the liver, spleen, and thyroid gland resulting in a higher tumour-to-liver ratio.
Lanreotide injection prior to Ga-DOTATATE PET/CT does not result in decreased tumour uptake. In contrast, tumour uptake was increased, whereas the uptake in normal organs is decreased, leading to an increased tumour-to-liver ratio. However, these differences were small and not deemed clinically relevant. These results strongly suggest that discontinuation of lanreotide injections in the weeks prior to Ga-DOTATATE PET examinations is unnecessary and does not compromise nuclear medicine imaging results.
正电子发射断层扫描（PET）与生长抑素受体显像用于神经内分泌肿瘤（NET）患者的标准治疗。由于生长抑素类似物治疗和成像均利用相同的受体，因此目前的指南建议在进行生长抑素受体 PET 成像前，停止使用长效生长抑素类似物 3-4 周。本研究旨在前瞻性评估 1 天前和 1 天内注射兰瑞肽对镓-DOTATATE 摄取的影响。
本研究纳入了 34 例正在接受兰瑞肽治疗且至少已治疗 4 个月的转移性和/或不可切除 NET 患者。在兰瑞肽注射前一天和后一天进行 Ga-DOTATATE PET/CT 扫描。在每个患者中，均在肿瘤病变和正常组织中评估 Ga-DOTATATE 摄取（SUV， ）。所有扫描均由两位核医学医师进行盲法评估。采用配对 T 检验来确定两次扫描之间的差异。
在纳入的 34 例患者中，有 31 例可进行分析，其中 190 个肿瘤病变被测量。肿瘤病变中 Ga-DOTATATE 的摄取在兰瑞肽注射后显著增加，但在肝脏、脾脏和甲状腺中显著减少，导致肿瘤与肝脏的比值增加。
在 Ga-DOTATATE PET/CT 之前注射兰瑞肽不会导致肿瘤摄取减少。相反，肿瘤摄取增加，而正常器官的摄取减少，导致肿瘤与肝脏的比值增加。然而，这些差异很小，且不被认为具有临床意义。这些结果强烈表明，在 Ga-DOTATATE PET 检查前几周停止兰瑞肽注射是不必要的，并且不会影响核医学成像结果。
