A PET Prototype for “In-Beam” Monitoring of Proton Therapy (original) (raw)
Related papers
A PET Prototype for “In-Beam” Monitoring of Proton Therapy
IEEE Transactions on Nuclear Science, 2009
The in-beam PET is a novel PET application to image the β β β β + activity induced in biological tissues by hadronic therapeutic beams. Thanks to the correlation existing between beam-delivered dose profiles and beam-induced activity profiles, in vivo information about the effective ion paths can be extracted from the in-beam PET image. In-situ measurements, immediately after patient irradiation, are recommended in order to exploit the maximum statistics, by detecting the contribution provided by short lived isotopes. A compact, dedicated tomograph should then be developed for such an application, so as to be used in the treatment room.
Preliminary results of an in-beam PET prototype for proton therapy
Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment, 2008
Proton therapy can overcome the limitations of conventional radiotherapy due to the more selective energy deposition in depth and to the increased biological effectiveness. Verification of the delivered dose is desirable, but the complete stopping of the protons in patient prevents the application of electronic portal imaging methods that are used in conventional radiotherapy During proton therapy β+ emitters like 11C, 15O, 10C are generated in irradiated tissues by nuclear reactions. The measurement of the spatial distribution of this activity, immediately after patient irradiation, can lead to information on the effective delivered dose. First, results of a feasibility study of an in-beam PET for proton therapy are reported. The prototype is based on two planar heads with an active area of about 5×5 cm2. Each head is made up of a position sensitive photomultiplier coupled to a square matrix of same size of LYSO scintillating crystals (2×2×18 mm3 pixel dimensions). Four signals from each head are acquired through a dedicated electronic board that performs signal amplification and digitization. A 3D reconstruction of the activity distribution is calculated using an expectation maximization algorithm. To characterize the PET prototype, the detection efficiency and the spatial resolution were measured using a point-like radioactive source. The validation of the prototype was performed using 62 MeV protons at the CATANA beam line of INFN LNS and PMMA phantoms. Using the full energy proton beam and various range shifters, a good correlation between the position of the activity distal edge and the thickness of the beam range shifter was found along the axial direction.
Monitoring Proton Therapy Through In-Beam PET: An Experimental Phantom Study
IEEE Transactions on Radiation and Plasma Medical Sciences, 2019
In this work, we investigate the use of a PET system to monitor the proton therapy. The monitoring procedure is based on the comparison between the β+activity generated in the irradiated volume during the treatment, with the β+activity distribution obtained with Monte Carlo simulation. The dedicated PET system is a dual head detection system; each head is composed of nine scintillating LYSO crystal matrices read out independently with a custom modularized acquisition system. Our experimental data were acquired at the Cyclotron Centre Bronowice, Institute Nuclear Physics in Krakow, Poland and were simulated with the FLUKA Monte Carlo code. Homogeneous and heterogeneous plastic phantoms were irradiated with monoenergetic 130-MeV protons. The capabilities of our PET system to distinguish different irradiated materials were investigated, and the proton pencil beams were used as probes. Our focus was to analyze the activity width and the total activity event number in several cases. Irradiations were performed using either single pencil beams one at a time, or two pencil beams during the same data taking. The comparison of 1D activity profile for experimental data and MC simulation were always in good agreement showing that, the treatment quality assessment in proton therapy can be based on β+ activity measurements.
In-Beam Pet Monitoring Technique for Proton Therapy: Experimental Data and Monte Carlo Prediction
RAD Conference Proceedings, 2019
Charged particle therapy is a precise radiotherapy method for the treatment of solid tumors. This method can deliver conformal dose distributions minimizing damage to healthy tissues thanks to its characteristic dose profile. However, the steep dose profile of charged particle beams (due to the Bragg peak) can result in over-or under-dosage in critical regions. Monitoring the range of the charged particles is therefore highly desirable. In this study, we use a planar in-beam PET system for the range verification of pencil beams in proton therapy. The planar geometry of the DoPET system is advantageous because it can be used online, i.e., during treatment. In the particle therapy community, the Monte Carlo (MC) codes are widely used to evaluate the radiation transport and interaction with matter. For this reason, the FLUKA MC code was used to simulate the experimental conditions of irradiations performed at the Cyclotron Centre Bronowice (CCB) proton therapy center in Krakow (PL). 130MeV pencil beams were delivered on phantoms mimicking human tissues. Different acquisitions are analyzed and compared with the MC predictions. The image reconstruction for experimental data and simulation is based on the Maximum Likelihood Estimation Method (MLEM) algorithm. A special focus in the paper will be on the validation of the PET detector response for activity range verification.
Online proton therapy monitoring: clinical test of a Silicon-photodetector-based in-beam PET
Scientific reports, 2018
Particle therapy exploits the energy deposition pattern of hadron beams. The narrow Bragg Peak at the end of range is a major advantage but range uncertainties can cause severe damage and require online verification to maximise the effectiveness in clinics. In-beam Positron Emission Tomography (PET) is a non-invasive, promising in-vivo technique, which consists in the measurement of the β+ activity induced by beam-tissue interactions during treatment, and presents the highest correlation of the measured activity distribution with the deposited dose, since it is not much influenced by biological washout. Here we report the first clinical results obtained with a state-of-the-art in-beam PET scanner, with on-the-fly reconstruction of the activity distribution during irradiation. An automated time-resolved quantitative analysis was tested on a lacrimal gland carcinoma case, monitored during two consecutive treatment sessions. The 3D activity map was reconstructed every 10 s, with an ave...
Australasian Radiology, 2008
The International Commission on Radiation Units (ICRU) is concerned with the development of internationally acceptable recommendations regarding the quantities and units of radiation and radioactivity, measurement and application procedures, and the physical data needed for these procedures. Chaired by Andre Wambersie, the ICRU now presents Report 59, which specifically addresses the rationale for and the history of proton therapy. This report covers the production of proton beams for therapy, relevant quantities and units, proton interactions with matter, proton absorbed dose and beam monitoring and relative dosimetry. The report concludes with recommendations for the determination of absorbed dose in a phantom. A useful quality assurance example and a dosimetry worksheet are included in the Appendices. Some eight pages of references and tables of proton-stopping powers and ranges from 0.1 MeV to 300 MeV for a wide range of materials undoubtedly completes this important resource for proton therapy.
Characterization of an In-Beam PET Prototype for Proton Therapy With Different Target Compositions
IEEE Transactions on Nuclear Science, 2000
At the University of Pisa, the DoPET (Dosimetry with a Positron Emission Tomograph) project has focused on the development and characterization of an ad hoc, scalable, dual-head PET prototype for in-beam treatment planning verification of the proton therapy. In this paper we report the first results obtained with our current prototype, consisting of two opposing lutetium yttrium orthosilicate (LYSO) detectors, each one covering an area of 4.5 4.5 cm 2 . We measured the + -activation induced by 62 MeV proton beams at Catana facility (LNS, Catania, Italy) in several plastic phantoms. Experiments were performed to evaluate the possibility to extract accurate phantom geometrical information from the reconstructed PET images.
First tests for an online treatment monitoring system with in-beam PET for proton therapy
Journal of Instrumentation, 2015
PET imaging is a non-invasive technique for particle range verification in proton therapy. It is based on measuring the β + annihilations caused by nuclear interactions of the protons in the patient. In this work we present measurements for proton range verification in phantoms, performed at the CNAO particle therapy treatment center in Pavia, Italy, with our 10 x 10 cm 2 planar PET prototype DoPET. PMMA phantoms were irradiated with mono-energetic proton beams and clinical treatment plans, and PET data were acquired during and shortly after proton irradiation. We created 1-D profiles of the β + activity along the proton beam-axis, and evaluated the difference between the proximal rise and the distal fall-off position of the activity distribution. A good agreement with FLUKA Monte Carlo predictions was obtained. We also assessed the system response when the PMMA phantom contained an air cavity. The system was able to detect these cavities quickly after irradiation.
Feasibility of the J-PET to monitor range of therapeutic proton beams
arXiv (Cornell University), 2023
Objective: The aim of this work is to investigate the feasibility of the Jagiellonian Positron Emission Tomography (J-PET) scanner for intra-treatment proton beam range monitoring. Approach: The Monte Carlo simulation studies with GATE and PET image reconstruction with CASToR were performed in order to compare six J-PET scanner geometries (three dual-heads and three cylindrical). We simulated proton irradiation of a PMMA phantom with a Single Pencil Beam (SPB) and Spread-Out Bragg Peak (SOBP) of various ranges. The sensitivity and precision of each scanner were calculated, and considering the setup's cost-effectiveness, we indicated potentially optimal geometries for the J-PET scanner prototype dedicated to the proton beam range assessment. Main results: The investigations indicate that the double-layer cylindrical and triple-layer double-head configurations are the most promising for clinical application. We found that the scanner sensitivity is of the order of 10 −5 coincidences per primary proton, while the precision of the range assessment for both SPB and SOBP irradiation plans was found below 1 mm. Among the scanners with the same number of detector modules, the best results are found for the triple-layer dual-head geometry. Significance: We performed simulation studies demonstrating that the feasibility of the J-PET detector for PET-based proton beam therapy range monitoring is possible with reasonable sensitivity and precision enabling its pre-clinical tests in the clinical proton therapy environment. Considering the sensitivity, precision and costeffectiveness, the double-layer cylindrical and triple-layer dual-head J-PET geometry configurations seem promising for the future clinical application. Experimental tests are needed to confirm these findings.