Oreste ALLEGRINI 2019-2022 - Test and characterization of gamma cameras for medical applications

In a context where ion beam therapy techniques have experienced a rapid spread in medical practices during recent years, ion-range uncertainties are now well known to be a major concern. In order to fully take benet from the ballistic properties of ion beam therapy, collimated and Compton camera (CC) prototypes coupled with a beam tagging hodoscope are being developed within the CLaRyS collaboration (IP2I, CPPM, LPSC, CREATIS) to perform prompt gamma (PG) detection with TOF measurement.
An other promising eld of application of CC is the nuclear medicine where the SPECT modalities using collimated cameras are widely used. Indeed, Compton camera oers the possibility to detect a wide range of gamma-rays energy contrary to regular SPECT devices which are limited by the transparency of the collimator. Furthermore, CC can be used to detect gamma emissions from radiopharmaceuticals paving the way of targeted therapy control. The CLaRyS CC performances will be therefore also investigated in the context of these applications.
The collimated camera prototype is composed of an absorber made of BGO blocks and a scintillating bers hodoscope for which characterization studies have been performed by previous PhD students with a temporary data acquisition chain. A rst objective of this PhD project is to characterize the two detectors with the nal data acquisition chain. The interest of the time of flight information for background reduction mainly induced by neutrons will be then investigated.
A second major part of this PhD project consists in characterizing a first prototype of the CC scatterer composed of seven silicon detector before testing the CC prototype (using the same absorber as the collimated camera).
All these studies will be carried out along with Monte Carlo simulations in order to compare experimental data with theoretical expectations as well as providing some guidelines for further improvements.
Finally, image reconstruction including the determination of the gamma interaction sequences in the Compton camera will be thoroughly explored.