title: A novel, self-shielded modular radiosynthesis system for fully automated preparation of PET and therapeutic radiopharmaceuticals.
abstract: OBJECTIVE
  With the vast development of theranostics and, recently, (68)Ga-radiolabeled molecules, there is also a need for novel, smaller, flexible, safe, and efficient modular automated synthesis systems in different clinical settings. The aim of our study was to determine the shielding properties of the modular self-shielded automated radiosynthesis box and determine its suitability for routine preparation of different radiopharmaceuticals to be used for diagnosis and therapy.
  
  
  METHODS
  To evaluate shielding properties, shielding factors were determined using two different radiation sources: (137)Cs and (68)Ga. The dose rates were measured at critical points at the surface and 1 m distance from the surface. Three different methods were used to concentrate and purify (68)Ga generator eluate. Performance of the system was tested by evaluating several radiolabeling applications using (68)Ga, (177)Lu, and (90)Y.
  
  
  RESULTS
  Dose rates measured at the surface did not exceed 9 μSv/h for (68)Ga and 20 μSv/h when using (137)Cs. On average, dose rates at the surface were reduced for factors of 1665 and 906, respectively. Different DOTA peptides were labeled successfully with (68)Ga with radiochemical purities more than 94% using three different radiolabeling methods. (177)Lu-DOTATATE and (90)Y-DOTATATE were synthesized reproducibly with a radiochemical purity of more than 99% and more than 97%, respectively.
  
  
  CONCLUSIONS
  A self-shielded radiosynthesis box is a unique solution for nuclear medicine departments that lack space for installation of standard automated synthesis systems set in large and heavy dedicated PET synthesis boxes. Shielding properties are sufficient for safe clinical use for both PET and β(-) radioisotopes. Because of its modular design and the simple adaptability of system parameters, the system can be used for the preparation of different clinically used radiopharmaceuticals and is also useful for research purposes.
authors.affiliation: aDepartment of Nuclear Medicine, University Medical Centre Ljubljana bFaculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia cEckert & Ziegler Eurotope GmbH, Berlin, Germany.
authors.forename: Marko
authors.initials: M
authors.lastname: Kroselj
authors.forename: Aljaz
authors.initials: A
authors.lastname: Socan
authors.forename: Katja
authors.initials: K
authors.lastname: Zaletel
authors.forename: Thorsten
authors.initials: T
authors.lastname: Dreger
authors.forename: Roger
authors.initials: R
authors.lastname: Knopp
authors.forename: Tanja
authors.initials: T
authors.lastname: Gmeiner
authors.forename: Petra
authors.initials: P
authors.lastname: Kolenc Peitl
mesh_terms: D001331:Automation; D006573:Heterocyclic Compounds, 1-Ring / Q000737:chemistry; D010455:Peptides / Q000737:chemistry; D049268:Positron-Emission Tomography; D011835:Radiation Protection / Q000295:instrumentation*; D011854:Radiochemistry / Q000295:instrumentation*; D011868:Radioisotopes / Q000737:chemistry; D019275:Radiopharmaceuticals / Q000138:chemical synthesis* / Q000627:therapeutic use*
chemical_list: D006573:Heterocyclic Compounds, 1-Ring; D010455:Peptides; D011868:Radioisotopes; D019275:Radiopharmaceuticals; C071349:1,4,7,10-tetraazacyclododecane- 1,4,7,10-tetraacetic acid