News from Nanotechjapan

ライフ・医療

Optical biopsy for the immediate diagnosis of cancer without excision

 On July 23, 2020, Osaka University, Kyushu University, Nikon Corporation, and Japan Agency for Medical Research and Development (AMED) jointly announced that a research group of members from the above institutions has realized in vivo real-time three-dimensional observation of cervical tissues without formalin fixation or staining, by using biological imaging technology with a multiphoton excita-tion microscope. Details were published in Cancer Research by Professor Masaru Ishii at Osaka Univer-sity as  last author*.

 Cancer diagnosis requires a lengthy process of multiple analyses of tissue biopsies, impeding the quick and early detection of cancers. Since time is of the essence when it comes to cancer, the research group set a goal to provide a cancer diagnosis in real-time using the obtained tissues only, without further his-topathological preparation.

 To achieve their goal, the researchers focused on cervical cancer, the fourth most common type of can-cer in women. They obtained biopsies from healthy patients and patients with cervical cancer, and im-aged them with their multiphoton excitation microscope that uses near-infrared light to scan the tis-sues.  Fluorescent imaging signals excited by THG (Third Harmonic Generation) or SHG (Second Har-monic Generation) were observed to distinguish between cell nucleus and fibers around cells. With this three dimensional imaging technology and analyzing it using a machine learning algorithm, they were able to set up a quantitative approach to classify tissues into normal and cancerous based on nuclear shape.

 The results of R&D will be applied to medical devices to realize less invasive and more rapid and quantitative diagnosis of cancer tissues than conventional methods.

*Takahiro Matsui, Ryo Tamoto, Akio Iwasa, Masafumi Mimura, Seiji Taniguchi, Tetsuo Hasegawa, Ta-kao Sudo, Hiroki Mizuno, Junichi Kikuta, Ichiro Onoyama, Kaoru Okugawa, Mayu Shiomi, Shinya Matsuzaki, Eiichi Morii, Tadashi Kimura, Kiyoko Kato, Yasujiro Kiyota and Masaru Ishii, "Nonlinear optics with near-infrared excitation enable real-time quantitative diagnosis of human cervical cancers", Cancer Research, 2020, doi: 10.1158/0008-5472.CAN-20-0348; Published Online First July 23