Image Reconstruction for Range Verification in Particle Therapy: Institute of Medical Engineering

Image Reconstruction for Range Verification in Particle Therapy

In particle therapy, beams of energetic protons or certain ions are used to irradiate tumors or other types of diseased tissue. The interaction of therapeutic particle beams in matter is characterized by a very well-defined range, a high-dose deposition localized in a small region (the Bragg peak), and the steep dose gradient at the distal edge of the Bragg peak. On the other hand, these features imply that possible uncertainties in the determination of the particle range might have severe consequences, such as tumor underdosage, or the irradiation of healthy tissue.

To minimize the risks, it is necessary to quantify the actual dose deposition with high precision. For this purpose, verification methods aimed to determine the range of the particle beam are being investigated worldwide. Some of these methods are based in the detection of secondary radiation. For example, positron emitting nuclei are created along the beam path; their decay and subsequent annihilation of the emitted positrons give rise to two annihilation photons which can be detected using the same technology as in Positron Emission Tomography (PET). Another important effect is the excitation of nuclei along the particle path; these nuclei return to their ground state by emitting single gamma rays ("prompt-gammas"). Imaging techniques are being developed to use prompt-gammas to indirectly determine the particle range. One proposed technology is based on Compton cameras.

Grants

The project is financially supported by the German Research Foundation (DFG) under grant agreement no. 383681334.
The project is supported by the North German Supercomputing Alliance (Norddeutscher Verbund für Hoch- und Höchstleistungsrechnen – HLRN), project no.shp00028.

Cooperations

SiFi-CC collaboration
Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Torino, Italy

Publications

[ 2023 ] [ 2022 ] [ 2021 ] [ 2020 ] [ 2019 ] [ 2018 ]

2023 [ to top ]

Llosá, G. and Rafecas, M.: Hybrid PET/Compton-camera imaging: an imager for the next generation, The European Physical Journal Plus, 138(3), 214, 2023.
[ BibTeX ] [ URL ]

@article{llosa2023hybrid, author = {Llos{á}, Gabriela and Rafecas, Magdalena}, journal = {The European Physical Journal Plus}, keywords = {imt mermaid myown nuci nucirangeverification rafecasmagdalena}, number = 3, pages = 214, publisher = {Springer}, title = {Hybrid PET/Compton-camera imaging: an imager for the next generation}, volume = 138, year = 2023 }

2022 [ to top ]

Ferrero, V., Werner, J., Aglietta, M., Cerello, P., Fiorina, E., Gorgi, A., Vignati, A., Rafecas, M. and Pennazio, F.: The MERLINO project:characterization of LaBr3:Ce detectors for stopping power monitoring in proton therapy, Journal of Instrumentation, 17(11), C11013, 2022, DOI: 10.1088/1748-0221/17/11/C11013.
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@article{Ferrero_2022, abstract = {The MERLINO project is developing a multi-detector setup with the goal of evaluating the beam stopping power from Prompt-Gamma-Timing measurements in proton therapy. The detectors are based on the cerium-doped lanthanum bromide crystal, LaBr3:Ce, coupled to photo-multiplier tubes. The system characterization is ongoing and the first calibration measurements with two detectors showed 124 ps σ and σ E/E = 3% for the timing and energy resolution, respectively. The measured experimental parameters were then used to carry out a preliminary estimation of the stopping power. Results from the simulation of a 189 MeV proton beam impinging on an homogeneous phantom are presented for the optimisation of the MERLINO detector setup.}, author = {Ferrero, V. and Werner, J. and Aglietta, M. and Cerello, P. and Fiorina, E. and Gorgi, A. and Vignati, A. and Rafecas, M. and Pennazio, F.}, journal = {Journal of Instrumentation}, keywords = {NucI NucIRangeVerification RafecasMagdalena WernerJulius imt}, month = {nov}, number = 11, pages = {C11013}, publisher = {IOP Publishing}, title = {The MERLINO project:characterization of LaBr3:Ce detectors for stopping power monitoring in proton therapy}, volume = 17, year = 2022 }
Ferrero, V., Werner, J., Cerello, P., Fiorina, E., Vignati, A., Pennazio, F. and Rafecas, M.: Estimating the stopping power distribution during proton therapy: A proof of concept, Frontiers in Physics, 2022, DOI: 10.3389/fphy.2022.971767.
[ BibTeX ] [ URL ]

@article{ferrero2022estimating, abstract = {Objective. We introduce a new treatment verification technique to estimate the primary particle's stopping power from prompt gamma timing measurements in proton therapy. Approach. The starting point is the Spatio-temporal Emission Recostruction technique, which provides the time-depth distribution of the emitted prompt photons with a multiple Prompt-Gamma Timing detector setup based on Lanthanum Bromide crystals. A dedicated formalism based on an analytical approximation of the stopping power is developed to obtain the desired information. Its performance is evaluated in a proof of concept configuration via Monte Carlo simulations of monochromatic proton beams impinging on a homogeneous PMMA phantom. Main Results. Results indicate stopping power estimations as good as 3.8% with respect to NIST values, and range estimations within 0.3 cm (standard deviation), when considering 250 ps FWHM timing resolution. Significance. The current study shows, for the first time, the feasibility of evaluating the stopping power of primary beams with a technique that can be performed in-vivo, opening up new possibilities in the field of treatment verification and therapy optimization.}, author = {Ferrero, Veronica and Werner, Julius and Cerello, Piergiorgio and Fiorina, Elisa and Vignati, Anna and Pennazio, Francesco and Rafecas, Magdalena}, editor = {Vasquez Osorio, Eliana Maria}, journal = {Frontiers in Physics}, keywords = {NucI NucIRangeVerification RafecasMagdalena WernerJulius imt myown}, month = {sep}, publisher = {Frontiers}, title = {Estimating the stopping power distribution during proton therapy: A proof of concept}, type = {article}, year = 2022 }
Pennazio, F., Ferrero, V., D'Onghia, G., Garbolino, S., Fiorina, E., Villarreal, O. A. M., Milian, F. M., Monaco, V., Monti, V., Patera, A., Werner, J., Wheadon, R. and Rafecas, M.: Proton therapy monitoring: spatiotemporal emission reconstruction with prompt gamma timing and implementation with PET detectors, Physics in Medicine & Biology, 67(6), 065005, 2022, DOI: 10.1088/1361-6560/ac5765.
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@article{Pennazio_2022, author = {Pennazio, Francesco and Ferrero, Veronica and D'Onghia, Grazia and Garbolino, Sara and Fiorina, Elisa and Villarreal, Oscar Ariel Marti and Milian, Felix Mas and Monaco, Vincenzo and Monti, Valeria and Patera, Alessandra and Werner, Julius and Wheadon, Richard and Rafecas, Magdalena}, journal = {Physics in Medicine & Biology}, keywords = {NucIRangeVerification RafecasMagdalena WernerJulius imt myown}, month = {mar}, number = 6, pages = {065005}, publisher = {{IOP} Publishing}, title = {Proton therapy monitoring: spatiotemporal emission reconstruction with prompt gamma timing and implementation with {PET} detectors}, volume = 67, year = 2022 }

2021 [ to top ]

Rusiecka, K., Hetzel, R., Kasper, J., Kozani, M. K., Kohlhase, N., Kolodziej, M., Lalik, R., Magiera, A., Migdal, W., Rafecas, M., Stahl, A., Urbanevych, V., Wong, M. L. and Wro'nska, A.: A systematic study of LYSO:Ce, LuAG:Ce and GAGG:Ce scintillating fibers properties, Journal of Instrumentation, 16(11), P11006, 2021, DOI: 10.1088/1748-0221/16/11/p11006.
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@article{2021, author = {Rusiecka, K. and Hetzel, R. and Kasper, J. and Kozani, M. Kazemi and Kohlhase, N. and Ko{\l}odziej, M. and Lalik, R. and Magiera, A. and Migda{\l}, W. and Rafecas, M. and Stahl, A. and Urbanevych, V. and Wong, M.L. and Wro{{{\'n}}}ska, A.}, journal = {Journal of Instrumentation}, keywords = {CC Compton KohlhaseNadja NucI NucIRangeVerification RafecasMagdalena imt myown}, month = {nov}, number = 11, pages = {P11006}, publisher = {{IOP} Publishing}, title = {A systematic study of {LYSO}:Ce, {LuAG}:Ce and {GAGG}:Ce scintillating fibers properties}, volume = 16, year = 2021 }

2020 [ to top ]

Kohlhase, N., Stille, M., Bolke, A., Zvolský, M. and Rafecas, M.: Compton Camera Image Reconstruction with A-Priori Information from a Beam Tagging Hodoscope, In: 2020 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC), 1-4, 2020, DOI: 10.1109/NSS/MIC42677.2020.9507820.
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@inproceedings{9507820, abstract = {Compton cameras (CC) have been proposed for range monitoring in proton therapy. The goal is to detected the prompt-gamma (PG) radiation which emerges from the patient, and estimate the underlying activation distribution by using tomographic reconstruction algorithms. The reconstructed CC images are often affected by high levels of statistical noise and other artefacts. With the aim of improving the reconstructed images, here we study various approaches able to exploit a-priori information from a beam-tagging hodoscope. The latter provides an estimation about the beam spread and its direction, so that this information can be used before or during the reconstruction in different ways, e.g. to restrict the volume-of-response assigned to each event, or to design a novel penalty function for regularized image reconstruction. We have implemented several approaches using Monte Carlo simulated data. In particular, our penalized reconstruction led to a significant improvement of the image quality. The estimated distal edge was well resolved for all tested scenarios.}, author = {Kohlhase, Nadja and Stille, Maik and Bolke, Andreas and Zvolský, Milan and Rafecas, Magdalena}, booktitle = {2020 {IEEE} Nuclear Science Symposium and Medical Imaging Conference ({NSS}/{MIC})}, keywords = {BolkeAndreas CC Compton IMT KohlhaseNadja NucI NucIRangeVerification RafecasMagdalena Simulation StilleMaik ZvolskyMilan}, month = {oct}, pages = {1-4}, title = {Compton Camera Image Reconstruction with A-Priori Information from a Beam Tagging Hodoscope}, year = 2020 }
Kohlhase, N., Wegener, T., Schaar, M., Bolke, A., Etxebeste, A., Sarrut, D. and Rafecas, M.: Capability of MLEM and OE to Detect Range Shifts with a Compton Camera in Particle Therapy, IEEE Transactions on Radiation and Plasma Medical Sciences, 4(2), 233-242, 2020, DOI: 10.1109/TRPMS.2019.2937675.
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@article{8815866, abstract = {To identify range deviations by using Compton cameras (CC), tomographic image reconstruction of CC data is needed. Within this context, image reconstruction is usually performed using Maximum Likelihood Expectation Maximization (MLEM), and more recently, the Origin Ensemble (OE) algorithm. In this work, we investigate how MLEM and OE affect the precision and accuracy of estimated range deviations. In particular, we focus on the effects of data selection, statistical fluctuations, and artifact reduction. The use of external information of the beam path through a hodoscope was also explored. Additionally, two methods to calculate range deviations were tested. To this aim, realistic proton beams were simulated using GATE and data from single spots as well as from 7 contiguous spots of an energy layer were reconstructed. MLEM and OE reacted differently to the poor data statistics. In general, both algorithms were able to detect range shifts for single spots, particularly when multiple coincidences were also considered. Selection of events corresponding to the most relevant energy peaks decreased the identification performance due to the lower statistics. When data from several contiguous spots were jointly reconstructed, the accuracy of the results degraded significantly, and non-zero shifts were assigned when no shifts had occurred. The limited size of the cameras and the subsequent restriction in the orientation and aperture of detected cones, as well as in the number of detected events are major challenges. Future efforts should be devoted to noise regularization and compensation for data truncation.}, author = {{Kohlhase}, N. and {Wegener}, T. and {Schaar}, M. and {Bolke}, A. and {Etxebeste}, A. and {Sarrut}, D. and {Rafecas}, M.}, journal = {IEEE Transactions on Radiation and Plasma Medical Sciences}, keywords = {BolkeAndreas KohlhaseNadja NucI NucIRangeVerification RafecasMagdalena SchaarMoritz imt}, month = {March}, number = 2, pages = {233-242}, title = {Capability of MLEM and OE to Detect Range Shifts with a Compton Camera in Particle Therapy}, volume = 4, year = 2020 }

2019 [ to top ]

Kohlhase, N., Wegener, T., Schaar, M., Bolke, A. and Rafecas, M.: Bildrekonstruktion von Compton-Kamera Daten unter Verwendung eines Hodoskops für die Reichweitenverifikation in der Partikeltherapie, In: 50. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik (DGMP) - Abstractband, 317, 2019.
[ BibTeX ] [ URL ]

@inproceedings{kohlhase2019bildrekonstruktion, author = {Kohlhase, N and Wegener, T and Schaar, M and Bolke, A and Rafecas, M}, booktitle = {50. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik (DGMP) - Abstractband}, editor = {Gromoll, Christian and Wegner, Niels}, keywords = {BolkeAndreas KohlhaseNadja NucI NucIRangeVerification RafecasMagdalena SchaarMoritz imt}, organization = {Deutsche Gesellschaft für Medizinische Physik}, pages = 317, title = {Bildrekonstruktion von Compton-Kamera Daten unter Verwendung eines Hodoskops für die Reichweitenverifikation in der Partikeltherapie}, year = 2019 }
Wegener, T., Kohlhase, N., Schaar, M., Bolke, A. and Rafecas, M.: Stochastic behavior of the Origin-Ensemble Algorithm – effect on ange verification in proton therapy using Compton-Cameras, In: 50. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik (DGMP) - Abstractband, 240, 2019.
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@inproceedings{wegener2019stochastic, author = {Wegener, T and Kohlhase, N and Schaar, M and Bolke, A and Rafecas, M}, booktitle = {50. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik (DGMP) - Abstractband}, editor = {Gromoll, Christian and Wegner, Niels}, keywords = {BolkeAndreas KohlhaseNadja NucI NucIRangeVerification RafecasMagdalena SchaarMoritz imt}, organization = {Deutsche Gesellschaft für Medizinische Physik}, pages = 240, title = {Stochastic behavior of the Origin-Ensemble Algorithm – effect on ange verification in proton therapy using Compton-Cameras}, year = 2019 }
Ferrero, V., Pennazio, F., Cerello, P., Fiorina, E., Garbolino, S., Monaco, V., Wheadon, R. and Rafecas, M.: Evaluation of in-beam PET treatment verification in proton therapy with different reconstruction methods, IEEE Transactions on Radiation and Plasma Medical Sciences, 2019, DOI: 10.1109/TRPMS.2019.2942713.
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@article{8845670, abstract = {In-beam PET monitoring can provide early treatment assessment in proton therapy. However, open ring configurations and low positron emitter production yields degrade image quality, hampering the assessment accuracy. To achieve the highest precision for range monitoring, it is compulsory to mitigate image noise and compensate for data truncation. The goal of this work is to study the performance of state-of-the-art algorithms for in-beam PET image reconstruction, by evaluating the impact of the system response model and assessing the accuracy of range measurements. The approaches investigated here were Maximum-A-Posteriori algorithms combined with Total-Variation and Median-Root Priors. Maximum-Likelihood-Expectation-Maximization was used as reference. To compute the system matrix, different models were compared: a precise Monte Carlo model, and Single-Ray Tracing with and without Gaussian blurring in image space. The proposed methods were tested on simulations of Spread-Out-Bragg-Peaks delivered on phantoms. The I3PET scanner geometry was used as a case study. After image post-processing, the explored methods delivered similar results. Our work demonstrates the feasibility and reliability of using a simple and fast reconstruction method to perform range evaluations, given the correct image post-processing.}, author = {{Ferrero}, V. and {Pennazio}, F. and {Cerello}, P. and {Fiorina}, E. and {Garbolino}, S. and {Monaco}, V. and {Wheadon}, R. and {Rafecas}, M.}, journal = {IEEE Transactions on Radiation and Plasma Medical Sciences}, keywords = {NucI NucIRangeVerification RafecasMagdalena imt myown}, title = {Evaluation of in-beam PET treatment verification in proton therapy with different reconstruction methods}, year = 2019 }

2018 [ to top ]

Ferrero, V., Cerello, P., Fiorina, E., Monaco, V., Rafecas, M., Wheadon, R. and Pennazio, F.: Innovation in online hadrontherapy monitoring: An in-beam PET and prompt-gamma-timing combined device, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2018, DOI: 10.1016/j.nima.2018.08.065.
[ BibTeX ] [ URL ]

@article{ferrero2018innovation, author = {Ferrero, V. and Cerello, P. and Fiorina, E. and Monaco, V. and Rafecas, M. and Wheadon, R. and Pennazio, F.}, journal = {Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment}, keywords = {NucI NucIRangeVerification RafecasMagdalena imt}, title = {Innovation in online hadrontherapy monitoring: An in-beam PET and prompt-gamma-timing combined device}, year = 2018 }