核素/红外二区双模特异SLN探针的构建及其靶向示踪机制的研究

前哨淋巴结（SLN）是原发肿瘤淋巴转移的第一站淋巴结，预测区域淋巴结转移的准确性高达95%。传统示踪剂多为非特异性显像剂，定位性差，使用要求高，临床推广有限。发展高空间分辨率、特异性肿瘤前哨淋巴结显影并进行示踪机制研究意义重大。本项目，在已有99mTc-Rit用于七千余例临床SLN探测基础上，以CD20为靶点，拟构建双模态特异性探针99mTc-Rituximab-CH1055，利用SPECT-CT/NIR-II技术实时、在体、分子水平探测前哨淋巴结。机制方面：该双模态探针本质是以受体定量的方式去阐述CD20抗原表达情况，有望能够揭示前哨淋巴结的特异性/非特异性摄取比例，为SLN特异性显像提供理论依据；临床转化方面：借助于SPECT-CT技术，有望进行深部肿瘤的SLN探测，并具有可引导术中探测和切除等显著优势，达到快速、无创检测多种肿瘤SLN的目的，改善患者生活质量。

Sentinel lymph node (SLN) is the first node or nodes in the lymphatic drainage of the primary tumor. The accuracy of the prediction of regional lymph node metastasis is as high as 95%, and less complications. Traditional tracers are mostly non-specific imaging agent and their poor localization restricts the further clinical application. The development of high spatial resolution/specific tumor SLN and mechanism analysis attracts researches great attention. We previously developed novel CD 20 antigen specific 99mTc-Rit which applied in more than 7000 cases SLN detection. Here we are aiming to build a dual-modality specific probe named 99mTc-Rituximab-CH1055, for real-time, in vivo, and molecular imaging of SLN using SPECT-CT/NIR-II technology. Mechanism: the dual-modality probe holds quantitative methods to describe CD20 antigen expression, is expected to be able to reveal the SLN specific /non-specific uptake ratio, and provide a theoretical basis for SLN specificity imaging; Clinical translation: with the SPECT-CT technology, it is expected to carry out deep tumor SLN detection and guide the intraoperative detection. In conclusion, the design of this new tracer intents to achieve a rapid and noninvasive detection of multiple tumor SLN, improve the quality of life of the patients.