METHOD AND APPARATUS FOR ACQUIRING POSITRON EMISSION TOMOGRAPHY DATA IN FULL BEAM HADRON THERAPY

摘要

Apparatus for acquiring positron emission tomography data when irradiating an object (20) with a hadron beam (B), the apparatus comprising a plurality of detectors (10) and a data processing system (12, 15). The data processing system (12, 15) is configured to process the detection data according to the following steps: a) determining a temporal distribution of the coincidence event rate acquired by the respective detector (10), b) sampling each spill interval with a sampling frequency of the order of magnitude of GHz to obtain a respective fine grained event rate distribution; c) for each spill interval: - c1) analysing frequencies of the fine grained event rate distribution to find an initial frequency value fo compatible with the radiofrequency signal of the hadron beam; - c2) from the initial frequency value, estimating period Ts of the micro-bunches and transforming time values of the coincidence events in the spill interval into values of phase relative to an arbitrary phase, based on the estimated period of the micro-bunches; and - c3) at each micro-bunch of the spill interval, executing filtering to remove coincidence events around a peak associated with background noise induced by the hadron beam and keep the remaining coincidence events of the micro-bunch.