Hernandez M Carmen, Knox Susan J
Department of Radiation Oncology, Stanford University Medical Center, CA 94305, USA.
Semin Oncol. 2003 Dec;30(6 Suppl 17):6-10. doi: 10.1053/j.seminoncol.2003.10.005.
Radioimmunotherapy represents a significant advance over unlabeled immunotherapy for the treatment of patients with B-cell non-Hodgkin's lymphoma. The efficacy of radioimmunotherapeutic agents depends in large part on the basic biological effects associated with their components, monoclonal antibodies and radionuclides, separately and in combination. The radiobiological effects associated with yttrium 90-labeled ibritumomab tiuxetan (Zevalin; Biogen Idec Inc, Cambridge, MA) include the induction of apoptosis and cell-cycle redistribution (eg, arrest of cells in the G(2)/M phase of the cell cycle). Because of dose-rate effects, tumor cells may, in some cases, be more susceptible to the low-dose-rate radiation used in radioimmunotherapy than to the high-dose-rate radiation used in external beam radiotherapy. The efficacy of radioimmunotherapy may potentially be optimized through a variety of approaches, including the use of agents that increase the expression of certain tumor antigens (thus facilitating improved biodistribution of radiolabeled monoclonal antibodies) or that sensitize tumor cells to radiation.
放射免疫疗法相较于未标记的免疫疗法，在治疗B细胞非霍奇金淋巴瘤患者方面取得了重大进展。放射免疫治疗药物的疗效在很大程度上取决于与其成分（单克隆抗体和放射性核素）单独及联合相关的基本生物学效应。与钇90标记的替伊莫单抗（泽瓦林；百健艾迪公司，马萨诸塞州剑桥）相关的放射生物学效应包括诱导细胞凋亡和细胞周期重新分布（例如，使细胞停滞在细胞周期的G(2)/M期）。由于剂量率效应，在某些情况下，肿瘤细胞可能对放射免疫疗法中使用的低剂量率辐射比对外照射放疗中使用的高剂量率辐射更敏感。放射免疫疗法的疗效可能通过多种方法得到优化，包括使用能增加某些肿瘤抗原表达的药物（从而促进放射性标记单克隆抗体更好的生物分布）或使肿瘤细胞对辐射敏感的药物。
