“IEEE Transactions on Biomedical Engineering” August 2022, Vol. 69, No. 8, First Clinical Study: Application of Near-Infrared Window IIA/IIB Fluorescence Imaging in Precise Glioma Resection Surgery

Cao Caiguang, Jin Zeping, Shi Xiaojing, Zhang Zhe, Xiao Anqi, Yang Junying, Ji Nan, Tian Jie (IEEE Member), Hu Zhenhua (IEEE Senior Member)

Introduction

In the field of biomedical research, fluorescence imaging is attracting considerable attention due to its high sensitivity, high spatial resolution, real-time imaging capability, and ease of operation. This study explores the value of near-infrared window II (NIR-II, 1000-1700 nm) imaging technology in clinical applications to guide the resection of tumors in glioma surgery. The authors combined newly developed imaging equipment and intraoperative image fusion methods to enhance surgical accuracy, reduce intraoperative bleeding, and maximize tumor removal.

Source of Article

This study was conducted by Cao Caiguang, Jin Zeping, Shi Xiaojing, Zhang Zhe, Xiao Anqi, Yang Junying, Ji Nan, Tian Jie, and Hu Zhenhua. They are affiliated with the Key Laboratory of Molecular Imaging, Institute of Automation, Chinese Academy of Sciences, Beijing Municipal Key Laboratory of Molecular Imaging, National Key Laboratory of Complex System Management and Control, Beijing Tiantan Hospital Neurosurgery Department, Beijing National Clinical Research Center for Neurological Diseases, among other institutions. The research findings were published in the IEEE Transactions on Biomedical Engineering on January 19, 2022.

Detailed Description of Research Process

The study designed a multispectral fluorescence imaging device integrating NIR-I/II/IIA/IIB fluorescence imaging and developed corresponding intraoperative image fusion methods. A total of seven patients with grade III/IV gliomas participated in the study, which initially used enhanced magnetic resonance imaging (MRI) for pre-diagnostic analysis.

a) Development of Imaging Device and Intraoperative Image Fusion Methods

The research team designed and manufactured a multispectral imaging subsystem, which includes two fluorescence cameras—one for NIR-I imaging and another for NIR-II/IIA/IIB imaging. Additionally, the system is equipped with an 808 nm laser and matching excitation equipment to provide near-infrared illumination. The team also developed a method to quickly fuse intraoperative images. This method first uses a pre-trained U-net network to remove the background of vascular fluorescence images, followed by the Canny algorithm to refine the segmentation results and obtain precise vascular images.

b) Patient Recruitment and Characteristics

The study enrolled seven patients aged 18 to 75 with grade III/IV gliomas. Forty-eight hours before surgery, patients received intravenous injection of indocyanine green (ICG) for fluorescence labeling. During surgery, multispectral fluorescence images of the tumor site were obtained, and the developed image fusion method was used to merge the vascular and tumor fluorescence images to guide the surgery.

c) Clinical Protocol

One week before surgery, patients underwent enhanced MRI scans followed by ICG injection. During surgery, fluorescence images of the tumor site under different spectra were first acquired. Then, the flow process of ICG within the blood vessels was captured via intravenous injection, and finally, image fusion was performed according to the fused images to guide tumor resection.

d) Fluorescence Image and Statistical Analysis

ImageJ software was used to extract fluorescence intensity, Gaussian fitting was employed to calculate the apparent width of corresponding blood vessels, and the signal-to-background ratio (SBR) was defined to quantify the contrast of vessel fluorescence to the background.

Main Results of the Study

The multispectral imaging technology was successfully applied in clinical surgery for glioma resection, achieving high-resolution and high-contrast imaging effects. Compared to the control group, patients showed significantly reduced intraoperative bleeding. The results indicate that NIR-IIA/IIB imaging holds excellent clinical application prospects, particularly in improving surgical resection accuracy and reducing bleeding.

Significance and Value of the Study

The scientific value of this study lies in the pioneering application of NIR-IIA/IIB imaging technology in clinical surgery, demonstrating its superiority in precisely resecting gliomas. The practical value of this study lies in its ability to significantly reduce intraoperative bleeding in glioma surgery and maximize tumor removal, providing a reference for future related vascular surgeries.

Highlights of the Study

• The first clinical study employing NIR-IIA/IIB imaging technology on humans.
• Development of a multispectral imaging device integrating NIR-I/II/IIA/IIB fluorescence imaging.
• Advancement of intraoperative image fusion methods that swiftly and accurately merge intraoperative fluorescence images.
• The study showcases significant scientific value and potential clinical application in the precise resection of gliomas.