|Budget Amount *help
¥1,400,000 (Direct Cost : ¥1,400,000)
Fiscal Year 1990 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 1989 : ¥900,000 (Direct Cost : ¥900,000)
Tumor uptake of L- [methyl-C-11] methionine (C-11-Met) was found to respond to radiotherapy more sensitively than does the tumor volume reduction and the extension of necrosis (JNM 30 ; 2012-16). In order to find the best tracer for monitoring tumor radiotherapy, metabolic tracers for tumor study representing glucose, amino acid and nucleic acid metabolisms ; 2-deoxy-2- [F-18] fluoro-D-glucose (F-18-FDG), L- [methyl-C-14] methionine (C-14-Met), [6-H-3] thymidine (H-3-Thd), and 2'-deoxy-5- [F-18] fluorouridine (F-18-FdUrd) ; and conventional [Ga-67] citrate (Ga-67) were compared using a same rattumor model AH109A with quadruple-tracer technique. Two combinations of quadruple-tracers each (F-18-FDG or F-18-FdUrd, C-14-Met, H-3-Thd and Ga-67) were used for comparison of 5 tracers in the time-course study frter 20 Gy single-dose irradiation and in the dose-dependency study 6 days arfer 5, 10, 15 and 20 Gy irradiation. Measurements of each radionuclide were performed using the differences of energy spectrum and half-life. F-18-FDG has advantage of its wide range of uptake change and steady response to radiotherapy. F-18-FdUrd showed rapid decrease but the range was narrow. Ga-67 cannot etect the tumor response esrly after treatment, but showed wide range of uptake change later. H-3-Thd and C-14-Met showed rapid responses and high sensitivity for monitoring the radiotherapy suggesting that C-11-Thd and C-11-Met seem to be ideal for the positron emission tomography study.