Design of a new tracking device for on-line beam range monitor in carbon therapy
Charged particle therapy is a technique for cancer treatment that exploits hadron beams, mostly protons
and carbon ions. A critical issue is the monitoring of the beam range so to check the correct dose deposition
to the tumor and surrounding tissues. The design of a new tracking device for beam range real-time
monitoring in pencil beam carbon ion therapy is presented. The proposed device tracks secondary
charged particles produced by beam interactions in the patient tissue and exploits the correlation of
the charged particle emission profile with the spatial dose deposition and the Bragg peak position. The
detector, currently under construction, uses the information provided by 12 layers of scintillating fibers
followed by a plastic scintillator and a pixelated Lutetium Fine Silicate (LFS) crystal calorimeter. An algorithm
to account and correct for emission profile distortion due to charged secondaries absorption inside
the patient tissue is also proposed. Finally detector reconstruction efficiency for charged particle emission
profile is evaluated using a Monte Carlo simulation considering a quasi-realistic case of a nonhomogenous
phantom.