Amin, A. Barlow, R.J. Hoehr, C.M. Infantino, A. Lindsay, C. JACoW Geneva, Switzerland 978-3-95450-182-3 10.18429/JACoW-IPAC2017-THPVA130 English 4757-4760 THPVA130 Contribution to a conference proceedings 2017 2017-05 http://dx.doi.org/10.18429/JACoW-IPAC2017-THPVA130 http://jacow.org/ipac2017/papers/thpva130.pdf The Proton Therapy Facility in TRIUMF provides 74 MeV protons extracted from a 500 MeV H⁻ cyclotron for ocular melanoma treatments. During treatment, positron emitting radionuclides such as C-11, O-15 and N-13 are produced in patient tissue. Using PET scanners, the isotopic activity distribution can be measured for in-vivo range verification. A second cyclotron, the TR13, provides 13 MeV protons onto liquid targets for the production of PET radionuclides such as F-18, N-13 or Ga-68, for medical applications. The aim of this work was to validate Geant4 against FLUKA and experimental measurements for production of the above-mentioned isotopes using the two cyclotrons. The results show variable degrees of agreement. For proton therapy, the proton-range agreement was within 2 mm for C-11 activity, whereas N-13 disagreed. For liquid targets at the TR13 the average absolute deviation ratio between FLUKA and experiment was 1.9±2.8, whereas the average absolute deviation ratio between Geant4 and experiment was 0.6±0.4. This is due to the uncertainties present in experimentally determined reaction cross sections.