The INSIDE bimodal system for range monitoring in particle therapy toward clinical validation

INSIDE is an innovative bimodal imaging system in which the simultaneous detection of annihilation photons (with a PET scanner) and of secondary charged particles (with a tracker called dose profiler) provides a robust method of verification of the range of ions used in cancer treatments. The ultimate goal of the project is the development of an automatic procedure to control the particle range based on the comparison between data acquired during treatments and simulated data from treatment plans, in order to highlight in real time any discrepancies with respect to the expected plan. The procedure also allows comparing data obtained in subsequent sessions for a longitudinal monitoring of the treatment efficacy. Since 2016 the PET system has been installed at CNAO and the testing phase successfully concluded with the monitoring of two consecutive treatment sessions of a patient affected of lacrimal gland tumor. The dose profiler was tested at CNAO since the second half of 2017. In this paper we present the latest results and the upgrade of the INSIDE system required for its clinical validation. The trial will start in the next months with the acquisition and follow-up of 20 patients treated at CNAO for head and neck cancers.