Improved ex vivo fluorescence imaging of human head and neck cancer using the peptide tracer TPP-IRDye800 targeting membrane-bound Hsp70 on tumor cells - Molecular Diagnostics

Sep 21, 2026

Surgical cure in head and neck squamous cell carcinoma depends on complete resection while sparing normal tissue, yet visual assessment can yield inadequate margins. This study evaluates TPP-IRDye800, a membrane Hsp70-targeting fluorescence-labelled peptide tracer, for real-time intraoperative tumor visualization. Flow cytometry and fluorescence microscopy assess mHsp70 binding and internalization, and tracer performance is compared with Cetuximab-IRDye680 against EGFR. Results show higher tumor-to-background and AUC values with improved tumor delineation and visualization of lymph node metastases, supported by clinical imaging hardware.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages11

Reading Time28 min

AccessFree to download

Background

Methods

Results

Conclusion

[www.nature.com/bjc](www.nature.com/bjc British)[ British](www.nature.com/bjc British) Journal of Cancer ARTICLE OPEN Molecular Diagnostics Improved ex vivo ﬂuorescence imaging of human head and neck cancer using the peptide tracer TPP-IRDye800 targeting membrane-bound Hsp70 on tumor cells Katharina L. K. Holzmann 1,2 ✉ , Johanna L. Wolf1,2, Stefan Stangl3, Philipp Lennartz2, Atsuko Kasajima4, Carolin Mogler4, Bernhard Haller5, Eva-Vanessa Ebert1, Daniel Jira1, Maren L. A. Lauterbach 1, Franziska von Meyer1, Leonhard Stark1, Leonie Mauch1, Benedikt Schmidl 1, Barbara Wollenberg 1, Gabriele Multhoff2,6 and Markus Wirth 1,6 © The Author(s) 2024 | | BACKGROUND: The primary goal of surgery in HNSCC is the complete resection of tumor cells with maximum preservation of normal tissue. The membrane Hsp70-targeting ﬂuorescence labelled peptide TPP-IRDye800 represents a promising tool for realtime intraoperative tumor visualization, enabling the detection of true tumor margins, critical isles of high-grade dysplasia and LN metastases.
METHODS: Membrane Hsp70 (mHsp70) expression on HNSCC cell lines and primary HNSCC was determined by ﬂow cytometry and ﬂuorescence microscopy using FITC-conjugated mAb cmHsp70.1 and TPP. TPP-IRDye800 was sprayed on freshly resected tumor material of immunohistochemically conﬁrmed HNSCC and LN metastases for tumor imaging. TBRs were compared using TPPIRDye800 and Cetuximab-IRDye680, recognizing EGFR.
RESULTS: mHsp70 expressing HNSCC cells speciﬁcally bind and internalize TPP in vitro. The TBR (2.56 ± 0.39) and AUC [0.98 CI, 0.95–1.00 vs. 0.91 CI, 0.85–0.97] of TPP-IRDye800 on primary HNSCC was signiﬁcantly higher than Cetuximab-IRDye680 (1.61 ± 0.39)(p = 0.0068) and TPP-IRDye800 provided a superior tumor delineation. Fluorescence imaging showed higher AUC values than a visual inspection by surgeons [0.97 CI, 0.94–1.00 vs. 0.92 CI, 0.88–0.97](p = 0.048) . LN metastases could be visualized using TPPIRDye800 Real-time tissue delineation was conﬁrmed using the clinically applied KARL-STORZ imaging system | | | --- | --- | --- | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | . .
CONCLUSION: TPP-IRDye800 is a promising ﬂuorescence imaging probe for HNSCC. | | | | | British Journal of Cancer (2024) 131:1814–1824; [https://doi.org/10.1038/s41416-024-02872-8](https://doi.org/10.1038/s41416-024-02872-8) | | | | | | BACKGROUND For the majority of solid tumors, including head and necksquamous cell carcinoma (HNSCC), resection is an elementary pillar for curative therapy. The aim of a successful cancer surgery is to localize and accurately delineate malignant from benign tissue to ensure cancer removal while minimizing damage to non-cancerous tissue. The importance of precise cancer surgery is evident, considering that incomplete tumor resection has a signiﬁcant negative impact on local and regional recurrence, distant metastases, and overall survival [1, 2] . Nevertheless, preservation of adjacent healthy tissue is particularly important for treatments in the head and neck region in order to keep functional and aesthetic impairments as low as possible. In daily clinical practice, surgeons mostly rely on visual inspection, manual palpation, and the analysis of frozen sections for a correct tissue differentiation [3] . The frequencies of inadequate resection margins reported in the literature are inconsistent and range from 30% up to 85%[4] . However, the unanimous conclusion from all studies is that the high rates of inadequate resection margins need to be improved [5] . A highly promising technology that has rapidly evolved over the last few years is real-time ﬂuorescence-guided tumor imaging [6] which can support surgical navigation by identifying true tumor margins and even molecular alterations in or close to the tumor border, such as high-grade dysplasia which may not be visible by the naked

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What was the study’s main conclusion?

TPP-IRDye800 is a promising fluorescence imaging probe for HNSCC, supporting real-time tissue delineation and tumor margin detection.

Sep 21, 2026

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