Range monitoring

Antoni Rucinski is leading NCBiR LIDER project titled PET technology for proton beam therapy range monitoring (link)

 

Project description

This project aims to study and perform pre-clinical tests and as a consequence to propose technological solution to monitor beam range in proton beam therapy. We aim to perform first world-wide simulations and experimental tests to assess feasibility of PET detector technique for proton beam therapy range monitoring. We will perform pre-clinical tests of developed technology with the purpose to implement it in proton beam therapy centre in Krakow and other centres abroad. The result of proposed study will be design of range monitoring detector prototype exploring PET technology.

Introduction

Physical and biological range uncertainties limit the clinical potential of Proton Beam Therapy (PBT). Our team study the feasibility of Jagiellonian-PET detector technology for proton beam therapy range monitoring by means of MC simulations of the β + activity induced in a phantom by proton beams and present preliminary results of PET image reconstruction. 

J-PET

A single detection unit of the J-PET scanner [15] consists of a 50 cm long and 6×24 mm2 intersection size scintillator strip. The light pulses produced in the strip by 511 keV back-to-back photons propagate to its edges where they are converted into electrical signals by photomultipliers (PMT). The interaction position of the photon with the detector is estimated from the time difference between the PMT signals located at the ends of the strip. A J-PET module consists of 13 scintillator strips read-out through a single front-end electronics and a FPGA-based DAQ system. More about J-PET you can find here: http://koza.if.uj.edu.pl/pet/

Current status

We performed comprehensive MC simulations using the GATE toolkit and reconstructions of 3D β+ activity distributions using the CASTOR software. We investigated single and multi-layer cylindrical and dual-head configurations of the J-PET modules that can be possibly applied for in-room range monitoring.

Here one can find preliminary results for one of the investigated setup configurations – a single layer J-PET barrel.

Fig. 1. Single layer modular J-PET barrel with isocentrically positioned PMMA phantom.

Fig. 2. The results of MC simulations. Top left: 2D distribution of dose deposited by 150 MeV proton beam in PMMA phantom; bottom left: β+ activity distribution detected in J-PET and reconstructed with CASTOR software; right: dose, β+ production in PMMA, reconstructed signal from β+ activity detected with J-PET.

The results show that the J-PET detector is feasible to acquire the β+ activity produced during proton therapy treatment and that the offline 3D reconstruction of PET activity images is possible using CASTOR toolkit. The characterization of J-PET sensitivity for proton beam range detection is currently an ongoing research activity.