Jacobs S A, Harrison A M, Swerdlow S H, Foon K A, Avril N, Vidnovic N, Joyce J, DeMonaco N, McCarty K S
University of Pittsburgh Medical Center, University of Pittsburgh Cancer Institute and UPMC Cancer Centers, PA 15232, USA.
Mol Imaging Biol. 2009 Jan-Feb;11(1):39-45. doi: 10.1007/s11307-008-0170-3. Epub 2008 Sep 5.
(90)Yttrium-ibritumomab-tiuxetan (Zevalin) is an effective treatment for relapsed or refractory low-grade, follicular, or transformed B-cell NHL. The purpose of this study is to assess whether tissue and cellular localization of (90)Y-ibritumomab-tiuxetan determined by autoradiography and radioactivity localized to tumor tissue might enhance our understanding of the mechanism of action of radioimmunotherapy.
Eight eligible patients had CD20+ NHL, a bulky peripheral lymph node, and were scheduled for (90)Y-ibritumomab-tiuxetan treatment. 2-Deoxy-2-[F-18]fluoro-D: -glucose-positron emission tomography/computed tomography (FDG-PET/CT) was performed prior to treatment and at 12 weeks after therapy for assessment of response. Bone marrow, lymph node, and blood samples were collected 114 +/- 3 h after 14.8 MBq/kg (90)Y-ibritumomab-tiuxetan and processed for histology, scintillation counting, and microscopic autoradiography.
Pericellular membrane localization of (90)Y-ibritumomab-tiuxetan to lymphoma cells was observed by autoradiography in the involved areas of lymph node with absence of significant localization in histologically normal sections of bone marrow. Pericellular radioactivity and the highest quantitative radioactivity were observed in lymph node samples of responding patients.
(90)Y-ibritumomab-tiuxetan localizes to the surface membrane of CD20+ lymphoma cells in affected lymph nodes. The patients with the highest quantitative concentration of radioactivity to the lymph node as determined by scintillation counting were observed to have a clinical and FDG-PET/CT response.
钇-伊布替膦酸（泽瓦林）是复发性或难治性低度、滤泡性或转化型B细胞非霍奇金淋巴瘤（NHL）的有效治疗方法。本研究的目的是评估通过放射自显影法测定的钇-伊布替膦酸的组织和细胞定位以及肿瘤组织中的放射性定位是否能增强我们对放射免疫治疗作用机制的理解。
8名符合条件的患者患有CD20+ NHL、一个肿大的外周淋巴结，并计划接受钇-伊布替膦酸治疗。在治疗前和治疗后12周进行2-脱氧-2-[F-18]氟-D-葡萄糖正电子发射断层扫描/计算机断层扫描（FDG-PET/CT）以评估反应。在给予14.8 MBq/kg钇-伊布替膦酸后114±3小时采集骨髓、淋巴结和血液样本，并进行组织学、闪烁计数和显微放射自显影处理。
通过放射自显影在淋巴结受累区域观察到钇-伊布替膦酸在淋巴瘤细胞的细胞膜周围定位，而在骨髓组织学正常切片中无明显定位。在有反应的患者的淋巴结样本中观察到细胞膜周围放射性和最高定量放射性。
钇-伊布替膦酸定位于受影响淋巴结中CD20+淋巴瘤细胞的表面膜。通过闪烁计数测定淋巴结放射性定量浓度最高的患者观察到有临床和FDG-PET/CT反应。
