Mariani G, Cei A, Collecchi P, Baranowska-Kortylewicz J, Van den Abbeele A D, Di Luca L, Di Stefano R, Viacava P, Ferdeghini E M, Di Sacco S
CNR Institute of Clinical Physiology, University of Pisa, Italy.
J Nucl Med. 1993 Jul;34(7):1175-83.
Previous studies have demonstrated the tumor-targeting potential of radioiodinated 5-iodo-2'-deoxyuridine (IUdR) in experimental animal models following direct intratumoral or intracavitary administration. The aim of this study was to measure the tumor uptake and metabolic fate of 5-[125I]iodo-2'-deoxyuridine ([125I]UdR) in humans after a single intratumoral injection. Ten patients with colorectal cancer were injected intratumorally with [125I]UdR) (0.24-3.9 MBq) during endoscopy 24 hr before ablative surgery. Blood and urine samples were collected up to 72 hr after [125I]UdR injection. Following resection, the radioactivity in the tumor and the surrounding tissues was measured in a gamma counter, and microautoradiography was performed on semi-thin tissue sections to assess localization of the radiopharmaceutical at the cellular level. An average of 0.234% of the injected dose was present per gram of tumor (range 0.009-0.918, median value 0.147), and tumor-to-nontumor radioactivity incorporation ratios were high for colonic mucosa when the nontumor tissue was taken at 1 cm (mean 629, range 27-2391) and 15 cm (mean 2387, range 122-12674) from the injection site. Microautoradiography confirmed these high tumor-to-nontumor ratios and demonstrated localization of [125I]UdR in the tumor cell nuclei. These results suggest that radioiodinated IUdR might have potential as a tumor-targeting agent in humans, provided homogeneous intratumoral distribution of the radiopharmaceutical by a suitable route of loco-regional administration can be achieved.
先前的研究已证实在实验动物模型中，经瘤内直接注射或腔内给药后，放射性碘化5-碘-2'-脱氧尿苷（IUdR）具有肿瘤靶向潜力。本研究的目的是在单次瘤内注射后，测定5-[¹²⁵I]碘-2'-脱氧尿苷（[¹²⁵I]UdR）在人体中的肿瘤摄取和代谢命运。10例结直肠癌患者在消融手术前24小时的内镜检查期间瘤内注射[¹²⁵I]UdR（0.24 - 3.9 MBq）。在注射[¹²⁵I]UdR后长达72小时收集血液和尿液样本。切除后，在γ计数器中测量肿瘤及周围组织中的放射性，并对半薄组织切片进行微放射自显影，以评估放射性药物在细胞水平的定位。每克肿瘤平均存在0.234%的注射剂量（范围0.009 - 0.918，中位数0.147），当在距注射部位1厘米（平均629，范围27 - 2391）和15厘米（平均2387，范围122 - 12674）处采集非肿瘤组织时，结肠黏膜的肿瘤与非肿瘤放射性摄取比值较高。微放射自显影证实了这些高肿瘤与非肿瘤比值，并显示[¹²⁵I]UdR定位于肿瘤细胞核。这些结果表明，放射性碘化IUdR可能具有作为人体肿瘤靶向剂的潜力，前提是能够通过合适的局部区域给药途径实现放射性药物在瘤内的均匀分布。
