Technical Note: Defining cyclotron‐based clinical scanning proton machines in a FLUKA Monte Carlo system

摘要

PurposeCyclotron‐based pencil beam scanning (PBS) proton machines represent nowadays the majority and most affordable choice for proton therapy facilities, however, their representation in Monte Carlo (MC) codes is more complex than passively scattered proton system‐ or synchrotron‐based PBS machines. This is because degraders are used to decrease the energy from the cyclotron maximum energy to the desired energy, resulting in a unique spot size, divergence, and energy spread depending on the amount of degradation. This manuscript outlines a generalized methodology to characterize a cyclotron‐based PBS machine in a general‐purpose MC code. The code can then be used to generate clinically relevant plans starting from commercial TPS plans.