664 Objectives: The ALCEO solid target system has been developed by Comecer for cyclotron production of 64Cu 89Zr, 123I and 124I. ALCEO Solid Target is composed by one irradiation unit (PTS), one dissolution/transfer unit (EDS/FDS) and one purification module (TADDEO PRF); all the units work automatically, avoiding any radiation exposures to operators. Many sites are already producing these radioisotopes with yields respectively of >2mCi/µAh (64Cu), >0.4mCi/µAh (89Zr and 123I), >0.1mCi/µAh (124I). The aim of this work was to expand the use of the ALCEO system to also produce 68Ga and 45Ti. Production and labelling results will be presented as well. Methods 68Zn was electroplated onto a target shuttle and irradiated (with a typical current from 10µA to 30µA) with 12.1 MeV protons to produce 68Ga. Irradiated target was dissolved in 10M HCl. The 68Ga was separated from the irradiated 68Zn using LN resin (TRISKEM), then labelled to PSMA and DOTATATE using an Eckert and Ziegler Modular-Lab eazy synthesis module. Natural scandium was irradiated with 12.1 MeV protons, with a typical current of 10µA to produce 45Ti. Irradiated target was dissolved by drop-by-drop 6M HCl. The 45Ti was separated from the irradiated scandium using ZR resin (TRISKEM), then labelled manually to DFO mesylate salt . Results 68Ga is produced with a saturation yield of 1330±590 MBq/µA (N=2), and was successfully labelled to PSMA and DOTATATE with 79.2% and 76.0% synthesis yields and 99.0% and 91.3% radiochemical purity respectively. 45Ti is produced with a saturation yield of 312 MBq/µA (N=1). It was not successfully labelled to PSMA and DOTATATE, however the labelling efficiency for DFO mesylate salt was 41%. Conclusions The Comecer ALCEO solid target system has been used successfully to produce 64Cu, 89Zr, 68Ga and 45Ti. The produced PET-isotopes have a very high radio-purity and chemical-purity and they can be used for radio-labeling processes. Future work includes optimisation of separation processes, and production of 203Pb and 44Sc.

The use of radioisotopes in nuclear medicine is essential for diagnosing and treating cancer. The optimization of their production is a key factor in maximizing the production yield and minimizing the associated costs. An efficient approach to this problem is the use of Monte Carlo simulations prior to experimentation. By predicting isotopes yields, one can study the isotope of interest expected activity for different energy ranges. One can also study the target contamination with other radioisotopes, especially undesired radioisotopes of the wanted chemical element which are difficult to separate from the irradiated target and might result in increasing the dose when delivering the radiopharmaceutical product to the patient. The aim of this work is to build and validate a Monte Carlo simulation platform using the GEANT4 toolkit to model the solid target system of the South Australian Health and Medical Research Institute (SAHMRI) GE Healthcare PETtrace cyclotron. It includes a GEANT4 Graphical User Interface (GUI) where the user can modify simulation parameters such as the energy, shape and current of the proton beam, the target geometry and material, the foil geometry and material and the time of irradiation. The paper describes the simulation and presents a comparison of simulated and experimental/theoretical yields for various nuclear reactions on an enriched nickel 64 target using the GEANT4 physics model QGSP_BIC_AllHP, a model recently developed to evaluate with high precision the interaction of protons with energies below 200MeV available in Geant4 version 10.1. The simulation yield of the (64)Ni(p,n)(64)Cu reaction was found to be 7.67±0.074 mCi·μA(-1) for a target energy range of 9-12MeV. Szelecsenyi et al. (1993) gives a theoretical yield of 6.71mCi·μA(-1) and an experimental yield of 6.38mCi·μA(-1). The (64)Ni(p,n)(64)Cu cross section obtained with the simulation was also verified against the yield predicted from the nuclear database TENDL and compared to experimental yield obtained from literature.

Treatment of low grade prostate cancer with permanent implant of radioactive seeds has become one of the most common brachytherapy procedures in use today. The implant procedure is usually performed with fluoroscopy image guidance to ensure that the seeds are deployed in the planned locations. In this situation the physician performing the transperineal implant is required to be close to the fluoroscopy unit and dose to the eye lens may be of concern. In 1991 the International Commission on Radiological Protection (ICRP) provided a recommended dose limit of 150 mSv yr(-1) for occupational exposures to the lens of the eye. With more long term follow-up data, this limit was revised in 2011 to 20 mSv yr(-1). With this revised limit in mind, we have investigated the dose to the lens of the eye received by physicians during prostate brachytherapy seed implantation. By making an approximation of annual workload, we have related the dose received to the annual background dose. Through clinical and phantom measurements with thermoluminescent dosimeters, it was found that the excess dose to the physician's eye lens received for a conservative estimate of annual workload was never greater than 100% of the annual background dose.