122: Development of a Time-Of-Flight Compton Camera for Online Control of Ion Therapy

Prompt-gamma monitoring in hadrontherapy: A review

“…The methods comprise filters, named distanceof-closest approach (DCA) and Compton line (CL) filter. Measurements with point sources of 22 Na, 137 Cs, 60 Co and the prototype described in [132] have been done. The purpose of the filters is to determine the initial gamma energy and to remove ''bad'' interactions from the data sample.…”

“…Small and large prototypes have been constructed, or are still under construction, which have a very large range of efficiencies, from ∼ 10 −8 up to ∼ 10 −4 . Still these cameras are facing several issues: i-the coincidence detection is perturbed by fortuitous events: as pointed out by Ortega et al [73], Ley [137] and recently by Rohling et al [138], the beam intensity needs to be reduced in order to minimize the probability of coincidence events generated by several ions incident during the camera time-resolution window, ii-the cost of a Compton camera device may not be much smaller than that of a PET system. However, Compton cameras should not be discarded, as reconstruction tools are rapidly evolving and may help solving the first issue, and as they may provide higher efficiency and spatial resolution, with 3D capability, than collimated devices.…”