Abstract 5615: Novel trop-2-targeted NIR-II fluorescence imaging technique for accurate determination of breast conserving surgery margin in vivo and human fresh tissue
Authors: Chen Weiling , Zhang YongQu , Zhang LiXin , Luo XiangJie , Zhu YuanYuan , Wang GuiMei , Zeng YunZhu , Wang JiaZheng , Li RongHui , Huang WenHe , Zhang GuoJun 
Published: April 2023

Abstract
Purpose Accurate evaluation of tumor boundaries in breast-conserving surgery is very important to reduce the second operation of patients.Near-infrared fluorescence imaging using molecular agents has shown promise for in situ imaging during resection.However, there are very effective probes that can be applied to clinical trials up to now. Here we developed a new technology that can quickly identify the tumor area both in vivo and the resected breast tissue during the operation and distinguish the tumor boundary.
Methods 1. Characterization and biosafety of the probe SG-ICG were performed.2. The targeting of the probe was verified by in vitro fluorescence co-localization and flow cytometry experiment and in vivo fluorescence imaging using tumor-bearing mouse model.3. Fluorescence image-guided surgery in spontaneous breast cancer transgenic mice and transplanted tumor model were to evaluated the specificity and sensitivity of guided tumor resection with the probe.4. The tumors and peritumoral muscle tissues of tumor-bearing mice were surgically removed and incubated with SG-ICG, and then imaged by a NIR-II fuorescence imaging system. 5. Six surgically removed breast tissues were incubated with the probe immediately after intraoperative resection and imaged to identify the tumor area. The accuracy of fuorescence imaging was confirmed by pathological diagnosis.
Results 1. SG-ICG was successfully synthesized with good dispersibility, stability with high intensity of NIR-II fluorescent imaging. 2. SG-ICG could specifically target high expression level of Trop-2 in breast cancer cell lines compared with IgG-ICG.3. SG-ICG was able to detected the MDA-MB-231-luc breast cell tumor-bearing mouse models with tumor-to-background ratios of ~4, correspondingly, nearly 2-fold NIR-II FL signal decrease was detected while blocked by unlabeled SG. 4. SG-ICG was able to detected the minimal residual lesions and the minimum detectable tumor diameter is about 1mm. The NIR-II fluorescence guidance facilitated more complete tumor resection, it has improved the relapse free survival rate, and effectively discriminates between benign and malignant breast tissues in spontaneous breast cancer transgenic mice (AUC= 0.9931; 95% CI: 0.9708, 1.0;P&lt;0.0001)..5. This new technology yielded more than 83.33% specifcity and 100% sensitivity in identifying the tumor area in the resected breast tissue.
Conclusions By using fuorescently labeled anti-human trop-2 antibody-drug conjugate to incubate freshly isolated tissues during surgery, the probes can quickly accumulate in breast cancer tissues, which can be used to quickly identify tumor areas in the resected breast tissues and distinguish tumor boundaries. This technology is expected to be used for rapid intraoperative pathological detection and margin determination.
Citation Format: Weiling Chen, YongQu Zhang, LiXin Zhang, XiangJie Luo, YuanYuan Zhu, GuiMei Wang, YunZhu Zeng, JiaZheng Wang, RongHui Li, WenHe Huang, GuoJun Zhang. Novel trop-2-targeted NIR-II fluorescence imaging technique for accurate determination of breast conserving surgery margin in vivo and human fresh tissue. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5615.