关于体内可视化生长抑素受体阳性肿瘤的首次描述基于放射性碘（123 I）标记的生长抑素类似物（Krenning等，1989）。在随后的几年中，通过与二乙三胺五乙酸（DTPA）螯合的铟-111（111 In）标记的生长抑素类似物成功开发。随后，全球推广了111 In-OctreoScan。在未来几年，99mTc-Tektrotyde变得商业可用并且易于获得。在过去的十年中，随着正电子发射断层摄影（PET）成像的增加，生长抑素类似物已经标记了各种正电子放射性同位素，如镓-68（68Ga）和铜-64（64Cu）（Lewis等，1999年，Schottelius等，2004年，Gabriel等，2007年），例如68Ga-DOTATOC，68Ga-DOTATATE，68Ga-DOTANOC和68Cu-DOTATATE。与单光子发射断层摄影（SPECT）断层摄影相比，使用这些研究性化合物的闪烁显像在肿瘤部位检测方面显示出令人鼓舞的成像质量良好和灵敏度提高。此外，还开发了其他PET放射性药物，如18F-二羟基苯丙氨酸（18F-DOPA）和11C-标记的5-羟色胺代硝基酸（11C-5-HTP），在GEP-NETs的可视化方面取得了鼓舞人心的结果（Koopmans等，2008）。在在NETs的诊断和分期中成功引入SRS之后，下一个逻辑步骤是增加给药活性，以便放射性药物可以在无法手术和/或转移的NEN患者中引起肿瘤萎缩。因此，通过静脉注射高剂量的[111In-DTPA0]生长抑素进行了第一次肽受体放射性核素治疗（PRRT）（Krenning等，1994a）。为了在生长抑素受体阳性转移性疾病的治疗中取得重大进展，开发了亲和力更高的放射性标记生长抑素类似物以提高对生长抑素受体的亲和力。放射性同位素肽或PRRT的治疗是无法手术或转移的NETs管理中有希望的新治疗选择。所有基于111In、90Y和177Lu标记的生长抑素类似物的PRRT都可以实现症状控制。对于客观反应和持久反应时间而言，90Y-DOTATOC和177Lu-DOTATATE是最有希望的放射性药物。如果采取足够的肾脏保护措施并且遵守剂量限制，PRRT的副作用很少且轻微。在少数患者中，如果SRS无法识别神经内分泌疾病，MIBG显像和随后的131I-MBG治疗可能是另一种治疗选择。靶向α粒子治疗（TAT）已经成为PRRT中β发射体的替代治疗选择。与β发射体PRRT相比，α发射体在癌症治疗中使用具有两个优点。α粒子的短程作用范围仅为几个细胞直径（<0.1mm），使得可选择地消除目标癌细胞，同时保护周围健康组织。此外，与常规β发射体相比，更高的线性能量转移（LET）导致复杂的DNA双链和DNA簇断裂的形成，最终导致细胞死亡（Lassmann M等，《国际放射防护委员会年鉴》，2018）。可考虑用于转移性NEN治疗的可能放射性药物包括铈-225（225Ac）-DOTATATE和铋-213（213Bi）-DOTATOC。使用这两种放射性药物剂时有部分反应的证据，而且无明显的血液、肾脏或肝脏毒性。未来的研究应考虑长期随机对照试验，调查TAT（特别是225c-DOTATATE）在转移性NENs治疗中的作用。核医学在神经内分泌肿瘤（NETs）的成像和治疗中扮演着重要角色。生长抑素受体成像的新技术包括使用具有更高亲和力和不同亲和力状况的不同放射性标记的生长抑素类似物。在NETs的成像方面已经取得了相当大的进展，但要找到增加灵敏度、更好地定位原发和转移疾病的理想成像方法仍然是研究的最终目标。

The first description of the in vivo visualization of somatostatin receptor-positive tumors in patients was based on the use of a radioiodine (123I) labelled somatostatin analogue (Krenning et al. 1989). In the years that followed an Indium-111 (111In) labelled somatostatin analogue, chelated with diethylenetriaminepentaacetic acid (DTPA), was successfully developed. Subsequently, 111In-OctreoScan was introduced worldwide. In the years to come 99mTc-Tektrotyde became commercially available with easy access. In the last decade, with the increasing use of positron emission tomography (PET) imaging, somatostatin analogues have been labelled with various positron-emitting isotopes, such as Gallium-68 (68Ga) and Copper-64 (64Cu) (Lewis et al. 1999, Schottelius et al. 2004, Gabriel et al. 2007) e.g 68Ga-DOTATOC, 68Ga-DOTATATE 68Ga-DOTANOC and 68Cu-DOTATATE. Scintigraphy with these investigational compounds display encouraging good imaging quality amd improved sensitivity in tumor site detection compared with SPECT scintigraphy. Also, other PET radiopharmaceuticals were developed, such as 18F-dihydroxy-phenyl-alanine (18F-DOPA) and 11C-labelled 5-hydroxytryptophan (11C-5-HTP) with encouraging results in terms of visualization of GEP-NETs (Koopmans et al. 2008). After the successful introduction of SRS in the diagnosis and staging of NETs, the next logical step was to increase the administered activity so that the radiopharmaceutical can induce tumor shrinkage in patients who had inoperable and/or metastasized NENs. Therefore, the first peptide receptor radionuclide therapy (PRRT) was performed with high administered activity of [111In-DTPA0] octreotide (Krenning et al. 1994a). To make significant advancements in the treatment of somatostatin receptor-positive metastatic disease, more efficient radiolabelled somatostatin analogues were developed with higher affinity to the somatostatin receptor. Treatment with radiolabelled peptides or PRRT is a promising new therapeutic option in the management of inoperable or metastasized NETs. Symptomatic control can be achieved with all 111In-, 90Y- and 177Lu-labelled somatostatin analogue-based PRRT. For objective response and long-lasting duration of response, 90Y-DOTATOC and 177Lu-DOTATATE are the most promising radiopharmaceuticals. Side effects of PRRT are few and mild, if adequate kidney protective measures are taken and dose-limits are respected. In a minority of patients, when SRS fails to identify neuroendocrine disease, MIBG scintigraphy and subsequent 131I-MBG therapy might be an alternative treatment option. Targeted alpha-particle therapy (TAT) has emerged as an alternative treatment option to beta emitters in PRRT. The use of alpha emitters for cancer therapy has two advantages over beta emitter PRRT. The short range of alpha particles of only a few cell diameters (<0.1mm) allows for selective ablation of the target cancer cells, while sparing the surrounding healthy tissue. In addition, the higher linear energy transfer (LET), when compared to conventional beta emitters, results in the formation of complex DNA double-strand and DNA cluster breaks, which ultimately lead to cell death.(Lassmann M et al. Ann ICRP. 2018) Putative radiopharmaceuticals that can be considered for metastatic NEN treatment include Actinium-225 (225Ac)-DOTATATE and Bismuth-213 (213Bi)-DOTATOC. There was evidence of partial response using both radiopharmaceutical agents without significant hematological, renal, or hepatotoxicity. Future studies should consider longer term, randomized controlled trials investigating the role of TAT, in particular, 225c-DOTATATE, in the treatment of metastatic NENs. Nuclear medicine plays a pivotal role in the imaging and treatment of neuroendocrine tumors (NETs). New techniques in somatostatin receptor imaging include the use of different radiolabelled somatostatin analogues with higher affinity and different affinity profiles to the somatostatin receptor subtypes. Considerable advances have been made in the imaging of NETs, but to find the ideal imaging method with increased sensitivity and better topographic localization of the primary and metastatic disease remains the ultimate goal of research.