Happ J, Baum R P, Frohn J, Weimer B, Halbsguth A, Lochner B, Brandhorst I, Hör G
Abteilung für Allgemeine Nuklearmedizin, Universität Frankfurt am Main, BRD.
Nuklearmedizin. 1987 Dec;26(6):258-62.
The present study was done in order to examine if the use of 111In-DTPA-labeled MAb fragments in place of 131I-labeled MAb fragments increases the sensitivity of tomographic immunoscintigraphy to reach the level of that of planar imaging techniques. In 11 patients with various primary tumors, local recurrences or metastases [colorectal carcinoma (n = 7), ovarian carcinoma (n = 2), papillary thyroid carcinoma (n = 1), undifferentiated carcinoma of the lung (n = 1)], immunoscintigraphy (IS) was carried out using 111In-DTPA-labeled F(ab')2 fragments of various MAbs (anti-CEA, OC 125, anti-hTG) and planar and tomographic imaging were compared intra-individually. By conventional diagnostic procedures, the presence of a tumor mass was confirmed (transmission computer tomography, ultrasound) or verified (131I whole-body scintigraphy, histology) in all cases. Immunoscintigraphy was positive in 9 out of 11 cases by ECT and in 10 out of 11 cases by planar imaging. When using 111In-labeled MAb fragments, intra-individual comparison of ECT and planar imaging resulted in a similar sensitivity. The increased sensitivity of ECT using this tracer in contrast to 131I-labeled MAb fragments may be attributed to the fact that the physical properties of 111In are much more suitable for the gamma cameras most commonly used (single detector, 3/8'' crystal); using 111In-labeled MAb fragments, count rates sufficient for ECT can be obtained within a reasonable acquisition time. This allows to combine IS with the advantages of ECT regarding tumour localization and prevention of artefacts due to superposition of background.
本研究旨在探讨使用¹¹¹In-DTPA标记的单克隆抗体片段替代¹³¹I标记的单克隆抗体片段是否能提高断层免疫闪烁显像的敏感性，使其达到平面显像技术的水平。对11例患有各种原发性肿瘤、局部复发或转移的患者[结肠直肠癌（n = 7）、卵巢癌（n = 2）、甲状腺乳头状癌（n = 1）、肺未分化癌（n = 1）]，使用¹¹¹In-DTPA标记的各种单克隆抗体（抗癌胚抗原、OC 125、抗人甲状腺球蛋白）的F(ab')₂片段进行免疫闪烁显像（IS），并对个体内的平面显像和断层显像进行比较。通过传统诊断程序，在所有病例中均证实（透射计算机断层扫描、超声）或验证（¹³¹I全身闪烁显像、组织学）存在肿瘤肿块。免疫闪烁显像在11例中有9例通过ECT呈阳性，11例中有10例通过平面显像呈阳性。使用¹¹¹In标记的单克隆抗体片段时，ECT和平面显像的个体内比较显示出相似的敏感性。与¹³¹I标记的单克隆抗体片段相比，使用这种示踪剂的ECT敏感性增加可能归因于¹¹¹In的物理性质更适合最常用的γ相机（单探测器，3/8英寸晶体）；使用¹¹¹In标记的单克隆抗体片段，可以在合理的采集时间内获得足以进行ECT的计数率。这使得可以将免疫闪烁显像与ECT在肿瘤定位方面的优势以及避免因背景叠加而产生伪影相结合。
