Feasibility study of proton beam therapy range monitoring by means of the J-PET tomograph
Supervisor: prof. Paweł Moskal
abstract
Defence year: 2017
The aim of this work was to determine amount of positron emitters produced in block made of poly methyl methacrylate (PMMA) during proton beam irradiation, check detection efficiency for registartion of annihilation gamma quanta with the plastic J-PET (Jagiellonian Positron Emission Tomography) tomograph and to find spatial resolution of such a scanner. Simulations were prepared using emph{GATE} software.\Obtained numbers of most significant for imaging isotopes: $^{15}$O, $^{11}$C and $^{10}$C for proton beam with energy 175 MeV that consists of 10$^6$ protons, are respectively 1.84 $cdot 10^4$, 4.47$cdot 10^4$, 4.69$cdot 10^3$. Efficiency for registration of gamma quanta by 2.5 cm thick layer of scintilation material used in J-PET scanner is at the level of 22.7\%. Spatial resolution of point source, that emits pairs of gamma quanta with energy 511 keV and is placed at the centre of two modules system (one module consists of ten plastic strips), was defined by point spread function (PSF) in three dimensions: $z$- along detector, $x$,$y$- transve$^3$rsal to detector. For a strip size $0.6cross 2.5cross 50$ cm and the distance between modules of 20 cm results are: PSF$_{z}=1.2$ cm, PSF$_{y}=3.7$ cm, PSF$_{x}=0.1$ cm and for a strip size $0.3cross 1cross 50$ cm and distance between modules of 20 cm results are: PSF$_{z}=1$ cm, PSF$_{y}=3.1$ cm, PSF$_{x}=0.1$ cm.
