[The research team led by Professor Ki Hean Kim from POSTECH developed a fast and sensitive delineation method of brain tumor based on cellular imaging]

What makes brain tumor different from other tumors is that it grows inside of the skull. There is not enough space inside of the skull. When brain tumor grows, it causes brain pressure to increase which then causes symptoms such as headache and vomits. It can also cause malfunctions of the brain when a specific part of the brain is pressed. So, surgery to the brain requires opening of the skull to remove a tumor. In case of a malignant tumor which grows and spreads fast to other parts of the body, margins of the tumor are not clear. For optimal clinical outcomes after surgery, it is critical to remove tumors as much as possible while keeping normal tissues undamaged. Therefore, it is crucial to demarcate normal brain tissues and tumors for precise removal of tumors.

Prof. Ki Hean Kim and his student, Mr. Seunghun Lee of Mechanical Engineering and Integrative Biosciences and Biotechnology, POSTECH developed a real-time high-definition cellular imaging method that can differentiate between normal brain tissues and brain tumors in collaboration with Dr. Kyung Hwa Lee of Department of Pathology, Chonnam National University, Dr. Euiheon Chung of Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology, and Dr. Eui Hyun Kim of College of Medicine Neurosurgery, Yonsei University. This new method can be used for early diagnosis and surgical guide techniques via cytoarchitecture visualization which is promising for clinical applications such as early diagnosis of keratitis and removal of brain tumors that requires precise resection.

For a successful surgery of fatal brain tumors, it is required to demarcate brain tumors and normal brain tissues, however, there has not been a clinically applicable method. Current medical imaging methods including Magnetic Resonance Imaging, Computer Tomography, Wide-field Surgical Microscopy can provide information on the location of tumors but they all have difficulties in delineating tumor margins due to their low resolution. For real-time detection of tumor margin delineation, many different optical imaging methods have been developed, but they have problems such as low sensitivity, low imaging speed, and technical difficulty in endoscopy development.

To overcome these difficulties, the research team have been developing cellular imaging method for brain tumor detection and delineation by using an antibiotic, Moxifloxacin as a cell labeling agent. Since 2017 when they reported on the applicability of cellular imaging method for brain tumor detection and delineation published in Biomedical Optics Express, they have been working on ways to develop a high-speed method. The newly developed cellular imaging method demonstrates high-speed faster than 30 frames per second which makes possible to visualize brain cells. Also, this cellular imaging method is highly sensitive, compared to the existing methods.

The new cellular imaging method demarcates brain tumor and normal tissues by visualizing dense and irregular cell distribution in all tested specimens including a brain tumor mouse model and malignant brain tumor specimens from patients.

The team also developed algorithm that detects brain tumor and its boundaries separating from the normal tissues for automated analysis of the real-time cellular imaging method. By using this method, they plan to develop an endoscopy pen for brain tumor surgical guide.

Professor Ki Hean Kim commented with anticipation, “This new imaging method can be utilized for a precise brain tumor surgery and it is expected to increase success rate of surgery and decrease post-surgery side effects and complications. It is only tested with the mouse model and sample tissues from a patient but we will continuously put our efforts to develop it into clinical skills.”

The findings of this research are published on Journal of Biophotonics. The study was financially supported by the grant programs of National Research Foundation of Korea.