Introduction

Radiation exposure to the operator has been a serious problem in research and development of radioactive molecular probes for molecular imaging by PET. The objectives of our team are the development of automated systems including radionuclide production, treatment of target, radioisotope purification, molecular probe manufacturing, and quality control and dispensing, so as to reduce the operator's radiation exposure from radionuclides. Moreover, research is being performed on accuracy management of radioactivity-measuring instruments / machines such as ionization chamber, micro PET, etc. The results from this research will expand to benefit society.

Research Introduction

Research on radionuclide manufacturing
Besides ¹¹C, ¹³N, and ¹⁵O and ¹⁸F PET radionuclides, which have been used for clinical PET, other many useful PET radio nuclides such as ^61,62Cu, ³⁴mCl, ⁷⁶Br, ¹²⁴I are available for the development of new molecular probes.

Reliable systems for irradiation, handling of solid targets, and radioisotope purification, etc., are necessary to produce these radioisotopes with high yield. Production systems for ^34mCl and ^61,62Cu are available at NIRS. Moreover, an irradiation system for solid targets by vertical beam is now under development by our team to produce ⁷⁶Br and ¹²⁴I.

Development of multipurpose, synthetic devices
To avoid radiation exposure, molecular probes should be produced with an automatic synthesis device in a hot cell. Automated synthesis apparatuses developed in the past have been specialized for the production of a few radiopharmaceuticals. In our laboratory, a versatile synthesis apparatus was developed to produce a wide variety of molecular probes for molecular imaging.

Accuracy management of radioactivity measurement devices
It is very important to secure the reliability of obtained data by radioactivity measurements. For this purpose, the traceability of our ionization chamber (working standard) to the national standard was established using the short half-life PET nuclide of ¹⁸F. The accuracy of the measurement instruments in our laboratory can be maintained by cross-calibration with the working standard.

members