Preliminary Dosimetry Study of 67Ga-AATS for Human Based on Biodistribution Data in Rats

• Main Authors: Hassan Yousefnia, Samaneh Zolghadri, Amir Reza Jalilian
• Format: Article
• Language: English
• Published: Mashhad University of Medical Sciences 2015-07-01
• Series: Iranian Journal of Medical Physics
• Subjects: Gallium-67; Radiation Dose; Dosimetry
• Online Access: http://ijmp.mums.ac.ir/pdf_4775_4cfda3851f12994f25573744c62f691c.html
• ISSN: 2252-0309; 2345-3672

Introduction Gallium-67 (67Ga) has been used as a radionuclide for imaging a variety of solid tumors since 1969. Since then use of various gallium-based radiotracers has been reported. Recently, 67Ga-labeled acetylacetate bis(thiosemicarbazones) (67Ga-AATS) complex with significant tumor accumulation and fast blood clearance has been employed. Materials and Methods In this study, the absorbed dose of 67Ga-AATS in each human organ was evaluated and compared with 67Ga-citrate as the most commonly used form of 67Ga in nuclear medicine. 67Ga was produced via 68Zn(p,2n)67Ga reaction at 30 MeV cyclotron. Moreover, 67Ga-AATS was produced by adding 50 µl of AATS to absolute ethanol (1 mg/ml) in a gallium-containing vial at 80-90 °C. The absorbed dose of each human organ was calculated, using RADAR method, based on biodistribution data in Wistar rats. Results According to the results, 67Ga-AATS was produced with radionuclidic and radiochemical purity higher than 99% and 93%, respectively. The highest absorbed dose was reported in the bone surface (0.401 mGy/MBq), whereas the whole-body absorbed dose was 0.092 mGy/MBq. Conclusion The absorbed dose of each human organ was comparable with the absorbed dose received by each organ after 67Ga-citrate injection. Considering this interesting finding and the significant tumor uptake, it seems that 67Ga-AATS can be used as an appropriate SPECT tracer.