Dynamic optical contrast imaging for real-time delineation of tumor resection margins using head and neck cancer as a model

TL;DR

This paper presents a real-time, label-free optical imaging technique that uses autofluorescence lifetime measurements to accurately delineate tumor margins during head and neck cancer surgeries, potentially improving surgical outcomes.

Contribution

The study introduces a novel wide-field autofluorescence lifetime imaging system for intraoperative tumor margin detection in head and neck cancer, demonstrating high accuracy and rapid imaging capabilities.

Findings

Achieved 70 μm spatial resolution in tissue imaging.

Demonstrated 91.86% sensitivity and 84.38% specificity in tumor boundary delineation.

Enabled 2 seconds per frame imaging at a 50 mm working distance.

Abstract

Complete surgical resection of the tumor for Head and neck squamous cell carcinoma (HNSCC) remains challenging, given the devastating side effects of aggressive surgery and the anatomic proximity to vital structures. To address the clinical challenges, we introduce a wide-field, label-free imaging tool that can assist surgeons delineate tumor margins real-time. We assume that autofluorescence lifetime is a natural indicator of the health level of tissues, and ratio-metric measurement of the emission-decay state to the emission-peak state of excited fluorophores will enable rapid lifetime mapping of tissues. Here, we describe the principle, instrumentation, characterization of the imager and the intraoperative imaging of resected tissues from 13 patients undergoing head and neck cancer resection. 20 x 20 mm2 imaging takes 2 second/frame with a working distance of 50 mm, and characterization shows that the spatial resolution reached 70 {\mu}m and the least distinguishable fluorescence lifetime difference is 0.14 ns. Tissue imaging and Hematoxylin-Eosin stain slides comparison reveals its capability of delineating cancerous boundaries with submillimeter accuracy and a sensitivity of 91.86% and specificity of 84.38%.