Tracing the path of the ⁶⁸Ga labeled radiopharmaceutical and predicting its possible outcome in a IQS ⁶⁸Ga fluidic labeling module

The IQS Ga⁶⁸ Fluidic Labeling module by ITG comprises a Ge⁶⁸-Ga⁶⁸ generator with synthesis unit and is a self-shielded unit.Once the fluidics are set up and the shielded lid is in place, the entire procedure has to be performed without any verification of whether the steps followed will result in expected product yield. This was the rationale for doing this study. Aim: To trace the path of the radioactivity by measuring the surface dose-rate over the self-shielded IQS Ga⁶⁸ Fluidic Labeling module by ITG. The IQS Ga⁶⁸ Fluidic Labeling module by ITG allows access through 3 openings to 5 important components (reactor, cartridge, generator, waste vial, product vial) in the preparation of the labeled product. The survey meter used was a Rotem Ramgene monitor. Readings were noted over four components; Reactor, Cartridge, Waste vial and Product vial. The survey meter was placed on the shielded lid above the reactor and the cartridge for the reactor and cartridge readings, respectively. Similarly separate readings were taken for the waste vial and the product vial by placing the survey meter on a stand in front of the respective vials. Readings were taken at each of the following steps: 1. Introduction of Ga⁶⁸ in the reactor. 2. Transfer of the labeled product to the cartridge with collection of unlabelled product in the waste vial. 3. Elution with ethanol and rinsing with saline of the cartridge with collection of the labeled product in the product vial. The pattern of the observed readings were recorded. For waste readings ranging from 1-20 mR /Hr the corresponding waste activity range was 0.15 - 2.43 mCi. For product readings ranging from 40-50 mR/ Hr the corresponding product range activity was 6.2-12 mCi. (See table). The use of a survey meter to trace the path of the Ga⁶⁸ labeled product in the shielded IQS Ga⁶⁸ Fluidic Labeling module by ITG, helped to optimize the procedure by allowing troubleshooting before the end of the procedure and by giving a rough estimate of the final available activity. (author)