Clinical diagnostic system using a small cyclotron for medical use

Since a small cyclotron and a positron emission tomography (PET) scanner have been installed at the Kyoto University Hospital in 1983, a great deal of effort has been directed to the clinical application of the PET-cyclotron system. This paper outlines the experience with PET in the clinical setting, including the facility, equipments and staff involved, weekly schedule, typical clinical protocols, and some results from the patients. The system consists of small cyclotron for production of the short-lived positron emitting radionuclides, fully automated synthesis system for labeling various compounds, scanning for measurement of radioactivities, and data analysis system for calculating physiological parameters. A resolving cylinder target system with eight smaller cylinders is equipped for production of C-11, N-13, O-15, and F-18. Labeled compounds are quickly delivered to the PET scanner room by two systems--the continuous delivery system for the labeled gas and the rapid delivery system for the liquid compounds by compressed air. A PET scanner devoted for clinical studies is a multislice whole-body PET scanner. Ten PET studies are performed weekly on the average for measuring blood flow and oxygen and glucose metabolism in the brain, blood flow and glucose and fatty acid metabolism in the heart, blood flow and amino acid uptake in the pancreas, lung ventilation, and tumor glucose metabolism. The availability of PET-cyclotron system is still limited in view of cost. The previous clinical studies suggest the contribution of PET to the the understanding of the mechanism of disease pathophysiology. (N.K.)