# TROP2-targeted NIR-II fluorescence imaging for visualizing surgical margins and metastatic sentinel lymph nodes in breast cancers

## TL;DR

This study introduces a TROP2-targeted imaging probe that helps surgeons quickly and accurately identify cancerous tissue and metastatic lymph nodes during breast cancer surgery.

## Contribution

A novel TROP2-targeted NIR-II fluorescence probe and rapid imaging method for intraoperative cancer margin and lymph node assessment in breast cancer.

## Key findings

- TTP-ICG specifically binds to TROP2-expressing tumors and metastatic lymph nodes in preclinical models.
- The RIIM method provides accurate intraoperative results within 8 minutes in 59 patients.
- The probe enables submillimeter visualization of metastatic sentinel lymph nodes and malignant tissues.

## Abstract

This study proposes a solution to the critical challenge of rapid and accurate intraoperative assessment of surgical margins and metastatic lymph nodes during early breast cancer surgery. We introduce a TROP2-targeted near-infrared (NIR-II) fluorescence probe, TROP2-targeting cyclic peptide (TTP)-ICG, which demonstrated high specificity for TROP2-expressing tumors and metastatic lymph nodes in preclinical models. Meanwhile, the TTP-ICG-based rapid incubation imaging method (RIIM) provides assessment results within 8 min, accurately distinguishing malignant from normal/fibroadenoma tissues and identifying metastatic lymph nodes in a cohort of 59 patients. This dual-capability technology offers transformative potential for fluorescence-guided surgery, improving oncologic outcomes by reducing positive margins and unnecessary lymph node procedures, thereby advancing precision breast cancer surgery.

In early breast cancer surgery (EBC), free margins significantly decrease local recurrence in breast-conserving surgery (BCS), while metastatic status of sentinel lymph node (SLN) impacts axillary management. However, intraoperative visualization of margins and metastatic SLNs (mSLNs) remains challenging. Here, we report a second-window near-infrared (NIR-II) fluorescence probe by conjugating ICG to TROP2-targeting cyclic peptide (TTP-ICG). Our results showed that TTP-ICG specifically binds to TROP2-expressing cells in vitro and identifies TROP2-positive tumors in vivo. In addition, TTP-ICG enabled efficient intraoperative evaluation of surgical margins and visualization of mSLNs at a submillimeter level in preclinical models. Additionally, we optimized the rapid incubation imaging method (RIIM) by shortening the procedure to less than 8 min, illustrating TTP-ICG’s high performance in distinguishing malignant from normal tissues/fibroadenoma lesions as well as detecting metastatic lymph nodes in a cohort of 59 patients. Thus, this TROP2-targeting probe demonstrates its significance for fluorescence imaging-guided surgery with dual applicability in EBC, providing translational potential for further clinical decision-making.