A novel method for accurate and real-time quantification of radiopharmaceutical activity in automated dose dispensers

• Published in: Radiation effects and defects in solids 2024-09, Vol.179 (9-10), p.1478-1493
• Main Authors: Farasat, M., Pompignoli, L., Zagni, F., Scherer, U. W., Cirrone, G. A. P., Mostacci, Domiziano
• Format: Article
• Language: English
• Subjects: Algorithms; automatic radiopharmaceutical dose dispenser; Beta particles; Beta rays; Calibration; Data analysis; Dispensers; Drug dosages; Evolutionary algorithms; Gallium isotopes; Half-life; Ionization; Ionization chambers; Linearity; Monte Carlo simulation; Nuclear medicine; Performance evaluation; Radiation dosage; Radiation effects; Radiation shielding; Radioactive half-life; Radiochemical analysis; Radioisotopes; Real time; Run time (computers); scintillation detectors; Sensors; silicon photomultipliers
• ISSN: 1042-0150; 1029-4953
• DOI: 10.1080/10420150.2024.2347475

In recent years, there has been a rapid growth in new technologies within nuclear medicine and PET diagnostics, particularly in the field of radiopharmaceutical dose preparation. These advancements are driven by the integration of automatic algorithms into the process. This evolution has brought about significant improvements in the efficiency and accuracy of radiopharmaceutical dose preparation. These automatic algorithms utilize state-of-the-art technologies to streamline the process and ensure precise and tailored doses for patients. The integration of these advanced technologies has revolutionized the field, allowing for more effective and personalized treatment options in nuclear medicine and PET diagnostics. By employing automatic radiopharmaceutical dose dispensers (ARDDs), radiation exposure to technologists is minimized while also mitigating the risk of potential infections for patients. Ionization chambers are currently the most used detectors to measure the activity of radiopharmaceuticals in ARDDs. However, they present certain limitations, including size constraints. This study is part of an international endeavor to develop a new approach for evaluating radiopharmaceutical activity in an ARDD named KARl 100 . A new approach was used to develop a scintillation detector by linking a PVT detector to a SiPMs array consisting of four elements, each having an active surface of 6 × 6 mm with a bias voltage of 30 V. The detection system's amplified output was then fed to a single-channel analyzer called Enviro, developed by Tema Sinergie S.p.A in Italy. The counts per second (CPS) detected by the detector were studied using WinTAM software allowing for the radionuclide's activity concentration to be read out at run-time. Three widely used medical radioisotopes, 18 F, 11 C and 68 Ga, were used to evaluate the performance of the detector in terms of linearity and repeatability of the measurements. Half-life and linear response were evaluated over a wide range of activities with different decay schemes. Data analysis was conducted, resulting in half-lives of the 18 F, 11 C and 68 Ga radioisotopes of 109.75 ± 0.35, 20.62 ± 0.34 and 67.82 ± 0.25 min, respectively, with calculated deviations of 0.0167%, 1.00% and 0.29% from expected values. The linear response of the detector over the entire range of desired activity concentrations was confirmed after data correction for the detector dead time. Calibration of the detector combined with the dispenser system