Standardization of I-131 using portable $4\pi\beta(LS)\mbox{-}\gamma$ coincidence detection system in OPBG hospital.

This project concerned the development at ENEA-INMRI of new $in situ 4\pi\beta(LS)\mbox{-}\gamma$ coincidence detection system (4PBLSG) for activity measurement of the short half-life radionuclides used in nuclear medicine. For the first time the portable 4PBLSG detector is used directly at the OPBG hospital in Vatican City, Italy, to measure the activity of I-131 and to calibrate the OPBG ionization chamber used for routine applications. The hardware of the new portable 4PBLSG detector was developed at ENEA-INMRI, in collaboration with Catania University and INFN, by implementing a gamma channel on the existing TDCR portable detector available at ENEA. A data analysis software was updated at CAEN in order to analyze the data recorded in list-mode by the new detector equipped with the CAEN desktop digitizer DT5720. The activity measurements for short half-life radionuclides used in nuclear medicine can be then computed. Two primary activity measurement ---TDCR and $4\pi\beta(LS)\mbox{-}\gamma$ coincidence--- methods were then used to determine the activity of I-131 in the OPBG hospital. The TDCR parameter is measured for I-131 standard solution using both CAEN and ENEA data analysis software.