An Analysis Scheme for 3D Visualization of Positron Emitting Radioisotopes Using Positron Emission Mammography System

Abstract

Proton range monitoring and verification is important to enhance the effectiveness of treatment by ensuring that the correct dose is delivered to the correct location. Upon proton irradiation, different positron emitting radioisotopes are produced by the inelastic nuclear interactions of protons with the target elements. Recently, it was reported that the 16O(p,2p2n)13N reaction has a relatively low threshold energy, and it could be potentially used for proton range verification. In the present work, we have proposed an analysis scheme (i.e., algorithm) for the extraction and three-dimensional visualization of positron emitting radioisotopes. The proposed step-by-step analysis scheme was tested using our own experimentally obtained dynamic data from a positron emission mammography (PEM) system (our developed PEMGRAPH system). The experimental irradiation was performed using an azimuthally varying field (AVF) cyclotron with a 80 MeV monoenergetic pencil-like beam. The 3D visualization showed promising results for proton-induced radioisotope distribution. The proposed scheme and developed tools would be useful for the extraction and 3D visualization of positron emitting radioisotopes and in turn for proton range monitoring and verification.

Development of PHITS graphical user interface for simulation of positron emitting radioisotopes production in common biological materials during proton therapy

“…The present GUI program has the ability to model homogenous phantoms with one seamless material definition for each simulation scenario. The main goal of this version of GUI program was to model homogenous phantoms that were being widely used in proton irradiation experiments, such as those for proton range verification prior to proton therapy [ 20 ]. The material composition, density and relevant references of these materials are shown in Table 1 .…”

A Feasibility Study on Proton Range Monitoring Using 13N Peak in Inhomogeneous Targets

“…Similar to our previous works on homogeneous targets [ 18 , 19 ], we have employed our previously developed SA technique to quantify the amount of produced 15 O, 11 C, and 13 N positron emitting radionuclides in the modelled target phantoms. The SA was initially developed for kinetic analysis of PET tracer [ 23 ].…”

“…The SA method was used to extract the positron emitting radionuclides ( 15 O, 11 C, and 13 N) from the obtained MC results. We refer interested readers to our previous work for a step-by-step scheme [ 19 ]. For the ordinary slab phantom, the SA technique was applied to the 40 frames (from 15 to 55 min; considering 15 min after proton irradiation).…”

“…Considering the low threshold and rather substantial yield of 13 N producing nuclear reaction, it was found to be useful for proton range monitoring and verification [ 17 ]. Previously, we have investigated the use of this nuclear reaction and the generated 13 N peak for proton range monitoring and verification in homogeneous targets both numerically [ 18 ] and experimentally [ 19 ]. In our previous works, we have also developed a spectral analysis (SA) approach to detect 13 N production from dynamic PET data and succeeded in rendering 13 N distribution proximal to the Bragg peak in homogenous phantom targets.…”

“…In the present work, we have extended our previously developed tools [ 18 , 19 ] for investigating the feasibility of using 13 N for proton range monitoring and verification in inhomogeneous target phantoms. The Particle and Heavy Ion Transport code System (PHITS) ( (accessed on 14 September 2022)) Monte Carlo (MC) package was used.…”