Wiseman G A, Kvols L K
Department of Diagnostic Radiology, Mayo Clinic, Rochester, MN 55905, USA.
Semin Nucl Med. 1995 Jul;25(3):272-8. doi: 10.1016/s0001-2998(95)80016-6.
The increased understanding of the neuroendocrine tumors at a cellular and molecular level has led to the development of new radiopharmaceuticals for imaging. Two of the imaging agents include 131I metaiodobenzylguanidine (131I-MIBG) and 111In-DTPA-D-Phe1-octreotide (111In-pentetreotide) each having specific localization in certain neuroendocrine tumors. The selective uptake of these radiopharmaceuticals by the tumor cells has generated interest in potential use for targeted radiotherapy for neuroendocrine tumors. 131I-MIBG has been used to treat patients with pheochromocytoma, neuroblastoma, carcinoid tumors, medullary thyroid carcinoma, and paragangliomas. The tumor responses have been variable with the most encouraging results being in patients with pheochromocytoma. The dose-limiting toxicity has been thrombocytopenia or granulocytopenia. 111In-pentetreotide has been used as therapy in only a few patients and has resulted in objective evidence of tumor responses. A therapeutic agent using a somatostatin analogue will most likely require radiolabeling with a beta- or possibly an alpha-emitting radionuclide to achieve significant and durable tumor responses.
在细胞和分子水平上对神经内分泌肿瘤认识的加深，促使了用于成像的新型放射性药物的开发。其中两种成像剂包括131I间碘苄胍（131I-MIBG）和111In-DTPA-D-苯丙氨酸1-奥曲肽（111In-喷替肽），它们在某些神经内分泌肿瘤中具有特定的定位。肿瘤细胞对这些放射性药物的选择性摄取引发了人们对其用于神经内分泌肿瘤靶向放疗潜在用途的兴趣。131I-MIBG已用于治疗嗜铬细胞瘤、神经母细胞瘤、类癌肿瘤、甲状腺髓样癌和副神经节瘤患者。肿瘤反应各不相同，最令人鼓舞的结果见于嗜铬细胞瘤患者。剂量限制性毒性为血小板减少或粒细胞减少。111In-喷替肽仅用于少数患者的治疗，并有肿瘤反应的客观证据。使用生长抑素类似物的治疗剂很可能需要用发射β射线或可能发射α射线的放射性核素进行放射性标记，以实现显著且持久的肿瘤反应。
