10157-BOT-1 DISCRIMINATION OF EPENDYMOMA AND MEDULLOBLASTOMA BY RAMAN SPECTROSCOPY
Yuki Kawamoto, Yoshiko Okita, Kenta Tenma, Kanji Nakagawa, Reina Utsugi, Koki Murakami, Hideki Kuroda, Tetsuro Tachi, Ryuichi Hirayama, Noriyuki Kijima, Naoki Kagawa, Katsumasa Fujita, Haruhiko Kishima- Surgery
- Oncology
- Neurology (clinical)
Abstract
Introduction
Ependymoma and medulloblastoma are difficult to diagnose by imaging and histology. Since the treatment strategies differ between the two, an accurate and prompt diagnosis is required. Raman spectroscopy can measure tissue-specific molecular vibrations. It shows extract biomolecular information characteristic of tumor tissue. We observed the tissues of ependymoma and medulloblastoma by Raman spectroscopy, and attempted to establish a new differentiation method.
Methods
The subjects were 13 patients with ependymoma and 5 patients with medulloblastoma who underwent resection from July 2017 to June 2023 at our institution. Their formalin-fixed paraffin-embedded (FFPE) section were observed by Raman spectroscopy. Raman spectra were collected using a line-illumination Raman microscopy developed at the department of Applied Physics, Osaka University. 532 nm excitation light was focused on the sample by an objective lens (Nikon 25x, NA1.1, CFI75). Excitation intensity and measurement time were 3 (mW/um2 ) and 5 seconds, respectively.
Results
We observed a Raman peak at 1240 cm-1 (Amide II3) that was significantly different in both ependymoma and medulloblastoma, and a similar tendency was observed for each specimen. It can suggest differences in amino acids, proteins, and lipids within tumor tissue.
Discussion and conclusion
We investigated whether it is possible to make a differential diagnosis between ependymoma and medulloblastoma using Raman spectroscopy. It was suggested that we can detect the molecular difference between the two using FFPE sections. Raman spectroscopy is a label-free measurement technique that does not require staining of biological samples, allowing simple and rapid evaluation. In the future, we plan to verify the validity of the differential method using specimens collected during surgery and frozen specimens.