Cyclotron produced F-18 radionuclide: O-18 enriched water validation of the INER TR30/15 Cyclotron in Taiwan

Learning Objectives Cyclotrons are currently used for the preparation of a wide variety of radionuclides that find application in positron emission tomography (PET) as well as in single photon emission computed tomography (SPECT). For F-18 radiopharmaceuticals, limits of impurities of unwanted radioisotopes are well-defined for labeling. Written procedures to document the operation of the cyclotron should ensure that all intended operating parameters will be followed. Most PET target materials, like O-18 enriched water, are not manufactured in PET centers. Therefore, it is essential that the PET center validate the quality of the target materials. Consequently, the O-18 enriched water quality specification should be adequately specified and appropriately validated.

Methods O-18 enriched water should be controlled in order to produce the radioisotope of required radionuclidic specifications. The raw materials (enriched water) used in F-18 production would be required to be of certain specifications with an acceptable range of enrichment, and the cyclotron beam energy clearly defined. We graph the curves for O-18(P,N)F-18, O-16(P,A)N-13, O-17(P,N)F-17 incident energy and reaction cross-section with different F-18, N-13, F-17 irradiation doses. The actual enrichment of O-18 enriched water can be calculated. Results The irradiation energy parameters derived from the above assessment are used in cyclotron irradiation to generate the best yield and the minimal other nuclides. The experimental irradiation parameters are as follows: 1. Irradiation energy: 2.5~29.5 MeV 2. Accelerated particle: proton 3. Beam current: 17~18 micro-A 4. Irradiation time: 1 hrs Conclusions It can be known the aforementioned curves for the O-18 enriched water proves to be predictive and controllable. Moreover, the irradiation products have consistent quality. Therefore, the present results have proved to possess industrial usefulness, novelty and progressiveness