PET Innovations for Earlier Diagnosis and Particle Therapy Imaging

Taiga Yamaya, PhD, is Team Leader of the Imaging Physics Team at the National Institute of Radiological Sciences (NIRS) in Japan. His research interests are next generation positron emission tomography (PET) instrumentations as well as the development of radiation detectors and image reconstruction algorithms. In Dr. Yamaya’s laboratory, using their core technologies for depth-of-interaction (DOI) measurement, a novel DOI detector “X'tal Cube” and a new equipment concept of “OpenPET” for joint PET - therapy imaging are being developed.
 

Abstract: Positron emission tomography (PET) plays important roles in cancer diagnosis, neuroimaging and molecular imaging research; but potential points remain for which big improvements could be made, including spatial resolution, sensitivity and manufacturing costs. Therefore, research on next generation PET technologies remains a hot topic worldwide. Depth-of-interaction (DOI) measurement in the radiation sensor will be a key technology needed to obtain any significant improvement in sensitivity while maintaining high spatial resolution. In this talk, we will review PET innovations being made at the National Institute of Radiological Sciences (NIRS)

OpenPET is our original idea to realize the world’s first open-type 3D PET scanner for PET-image guided particle therapy such as in situ dose verification and direct tumor tracking. The principal of dose verification for particle therapy is based on the measurement of positron emitters which are produced through fragmentation reactions caused by proton or ¹²C ion irradiation. Even with a full-ring geometry, the OpenPET has an open gap through which the treatment beam passes.

Life extension enabled by progressed cancer therapy is causing another issue, that of dementia. To satisfy a potential demand for brain molecular imaging, prototypes of brain-dedicated PET scanners have been developed. However all previous developments were based on a cylindrical geometry, which is not the most efficient for brain imaging. Making the detector ring as small as possible is essential in PET, because sensitivity can be increased with a limited number of detectors. Therefore, we developed the world’s first helmet-chin PET, in which DOI detectors are arranged to form a hemisphere, for compact, high-sensitivity, high-resolution, and low-cost brain PET imaging.