title: [Disposal of radioactive contaminated waste from Ga-68-PET - calculation of a clearance level for Ge-68].
abstract: Ga-68-labeled radiotracers, particularly used for the detection of neuroendocrine tumors by means of Ga-68-DOTA-TATE or -DOTA-TOC or for the diagnosis of prostate cancer by means of Ga-68-labeled antigens (Ga 68-PSMA), become increasingly important. In addition to the high sensitivity and specificity of these radiopharmaceuticals, the short-lived radionuclide Ga-68 offers almost ideal nuclear characteristics for use in PET. Ga-68 is obtained from a germanium-gallium-generator system, so that the availability of Ga-68-labeled radiotracers is independent of an on-site-cyclotron regardless of the short half-life of Ga-68 of about 68minutes. Regarding the disposal of the radioactively contaminated waste from the preparation of the radiopharmaceutical, the eluted Ga-68 has to be considered to be additionally contaminated with its parent nuclide Ge-68. Due to this production-related impurity in combination with the short half-life of Ga-68, the radioactive waste has to be considered to be contaminated with Ge-68 and Ga-68 in radioactive equilibrium (hereafter referred to as Ge-68+). As there are no clearance levels for Ge-68+ given in the German Radiation Protection Ordinance, this work presents a method to calculate the missing value basing on a recommendation of the German Radiation Protection Commission in combination with simple geometric models of practical radiation protection. Regarding the relevant exposure scenarios, a limit value for the unrestricted clearance of Ge-68+ of 0.4 Bq/g was determined.
authors.affiliation: Medizinische Hochschule Hannover, Stabsstelle Strahlenschutz und Abteilung Medizinische Physik - OE 0020, Carl-Neuberg-Str. 1, D-30625 Hannover, Deutschland. Electronic address: solle.alexander@mh-hannover.de.
authors.forename: Alexander
authors.initials: A
authors.lastname: Solle
authors.affiliation: Medizinische Hochschule Hannover, Stabsstelle Strahlenschutz und Abteilung Medizinische Physik - OE 0020, Carl-Neuberg-Str. 1, D-30625 Hannover, Deutschland.
authors.forename: Carsten
authors.initials: C
authors.lastname: Wanke
authors.affiliation: Medizinische Hochschule Hannover, Stabsstelle Strahlenschutz und Abteilung Medizinische Physik - OE 0020, Carl-Neuberg-Str. 1, D-30625 Hannover, Deutschland.
authors.forename: Lilli
authors.initials: L
authors.lastname: Geworski
mesh_terms: D005710:Gallium Radioisotopes; D006801:Humans; D049268:Positron-Emission Tomography; D011850:Radioactive Waste; D011868:Radioisotopes; D019275:Radiopharmaceuticals; D018505:Waste Management
chemical_list: D005710:Gallium Radioisotopes; D011850:Radioactive Waste; D011868:Radioisotopes; D019275:Radiopharmaceuticals
keywords: Ge-68+; Nuklearmedizin; Positron-Emission-Tomography; Positronenemissionstomographie; Uneingeschränkte Freigabe; Unrestricted clearance; nuclear medicine; radioactive contaminated waste; radioaktive Reststoffe