Compact Method for Proton Range Verification Based on Coaxial Prompt Gamma-Ray Monitoring: A Theoretical Study

Range uncertainties in proton therapy hamper treatment precision. Prompt gamma-rays were suggested 16 years ago for real-time range verification, and have already shown promising results in clinical studies with collimated cameras. Simultaneously, alternative imaging concepts without collimation are investigated to reduce the footprint and price of current prototypes. In this paper, a compact range verification method is presented. It monitors prompt gamma-rays with a single scintillation detector positioned coaxially to the beam and behind the patient. Thanks to the solid angle effect, proton range deviations can be derived from changes in the number of gamma-rays detected per proton, provided that the number of incident protons is well known. A theoretical background is formulated and the requirements for a future proof-of-principle experiment are identified. The potential benefits and disadvantages of the method are discussed, and the prospects and potential obstacles for its use during patient treatments are assessed. The final milestone is to monitor proton range differences in clinical cases with a statistical precision of 1 mm, a material cost of 25000 USD and a weight below 10 kg. This technique could facilitate the widespread application of in vivo range verification in proton therapy and eventually the improvement of treatment quality.

[1]  Steffen Greilich,et al.  Dual-energy CT based proton range prediction in head and pelvic tumor patients. , 2017, Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology.

[2]  Wolfgang Enghardt,et al.  Detection systems for range monitoring in proton therapy: Needs and challenges , 2020 .

[3]  M Goitein,et al.  The relative costs of proton and X-ray radiation therapy. , 2003, Clinical oncology (Royal College of Radiologists (Great Britain)).

[4]  W. Enghardt,et al.  Prompt Gamma Rays Detected With a BGO Block Compton Camera Reveal Range Deviations of Therapeutic Proton Beams , 2017, IEEE Transactions on Radiation and Plasma Medical Sciences.

[5]  Thomas Bortfeld,et al.  A full-scale clinical prototype for proton range verification using prompt gamma-ray spectroscopy , 2018, Physics in medicine and biology.

[6]  M. Rovituso,et al.  Prompt-γ production of 220 MeV/u 12C ions interacting with a PMMA target , 2015 .

[7]  Christian Richter,et al.  Inter-centre variability of CT-based stopping-power prediction in particle therapy: Survey-based evaluation , 2018, Physics and imaging in radiation oncology.

[8]  Wayne D Newhauser,et al.  The physics of proton therapy , 2015, Physics in medicine and biology.

[9]  Wolfgang Enghardt,et al.  Processing of prompt gamma-ray timing data for proton range measurements at a clinical beam delivery , 2019, Physics in medicine and biology.

[10]  K Parodi,et al.  Ionoacoustic characterization of the proton Bragg peak with submillimeter accuracy. , 2015, Medical physics.

[11]  G Janssens,et al.  Prompt gamma imaging of proton pencil beams at clinical dose rate , 2014, Physics in medicine and biology.

[12]  J. Kiener,et al.  Shape and angular distribution of the 4.439-MeV γ -ray line from proton inelastic scattering off C12 , 2017, Physical Review C.

[13]  W Enghardt,et al.  Characterization of the microbunch time structure of proton pencil beams at a clinical treatment facility , 2016, Physics in medicine and biology.

[14]  Mauro Testa,et al.  Charged particle therapy, ion range verification, prompt radiation , 2010 .

[15]  Steve B. Jiang,et al.  Anatomic feature-based registration for patient set-up in head and neck cancer radiotherapy , 2005, Physics in medicine and biology.

[16]  Joao Seco,et al.  Energy- and time-resolved detection of prompt gamma-rays for proton range verification , 2013, Physics in medicine and biology.

[17]  Christian Richter,et al.  Correction of Geometrical Effects of a Knife-Edge Slit Camera for Prompt Gamma-Based Range Verification in Proton Therapy , 2018, Instruments.

[18]  Wolfgang Enghardt,et al.  Compton Camera and Prompt Gamma Ray Timing: Two Methods for In Vivo Range Assessment in Proton Therapy , 2016, Front. Oncol..

[19]  N. Pietralla,et al.  High count rate γ-ray spectroscopy with LaBr3:Ce scintillation detectors , 2012, 1202.6495.

[20]  I Rinaldi,et al.  Absolute prompt-gamma yield measurements for ion beam therapy monitoring , 2015, Physics in medicine and biology.

[21]  Ilker Meric,et al.  A Monte Carlo feasibility study for neutron based real-time range verification in proton therapy , 2019, Scientific Reports.

[22]  Dennis R. Schaart,et al.  Optimization of the Signal-to-Background Ratio in Prompt Gamma Imaging Using Energy and Shifting Time-of-Flight Discrimination: Experiments With a Scanning Parallel-Slit Collimator , 2018, IEEE Transactions on Radiation and Plasma Medical Sciences.

[23]  宋朝晖,et al.  Study of neutron radiation effect in LaBr3 scintillator , 2015 .

[24]  G. G. Shute,et al.  Angular correlations for 12C(p, p′γ)12C: (II). Overlapping resonances and the missing 52− level in 13N , 1966 .

[25]  Christian Richter,et al.  Sensitivity of a prompt-gamma slit-camera to detect range shifts for proton treatment verification. , 2017, Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology.

[26]  Timothy C Y Chan,et al.  Accounting for range uncertainties in the optimization of intensity modulated proton therapy , 2007, Physics in medicine and biology.

[27]  Ugo Amaldi,et al.  Radiotherapy with beams of carbon ions , 2005 .

[28]  Gang Li,et al.  Study of neutron radiation effect in LaBr 3 scintillator , 2015 .

[29]  Pedro Andreo,et al.  On the clinical spatial resolution achievable with protons and heavier charged particle radiotherapy beams , 2009, Physics in medicine and biology.

[30]  John T. Conway,et al.  Analytical solution for the solid angle subtended at any point by an ellipse via a point source radiation vector potential , 2010 .

[31]  Yong Kong,et al.  Experiment and modeling of scintillation photon-counting and current measurement for PMT gain stabilization , 2015 .

[32]  Carlo Fiorini,et al.  First clinical application of a prompt gamma based in vivo proton range verification system. , 2016, Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology.

[33]  S Beddar,et al.  3D prompt gamma imaging for proton beam range verification , 2018, Physics in medicine and biology.

[34]  Joao Seco,et al.  Simulation of prompt gamma-ray emission during proton radiotherapy , 2012, Physics in medicine and biology.

[35]  Sam Beddar,et al.  Study of the Angular Dependence of a Prompt Gamma Detector Response during Proton Radiation Therapy , 2014 .

[36]  Denis Dauvergne,et al.  Prompt-gamma monitoring in hadrontherapy: A review , 2018 .

[37]  S. Peterson,et al.  Evaluation of proton inelastic reaction models in Geant4 for prompt gamma production during proton radiotherapy , 2015, Physics in medicine and biology.

[38]  Steffen Greilich,et al.  Evaluation of Stopping-Power Prediction by Dual- and Single-Energy Computed Tomography in an Anthropomorphic Ground-Truth Phantom. , 2018, International journal of radiation oncology, biology, physics.

[39]  J. Glodo,et al.  CeBr3-PrBr3 scintillators , 2007, 2007 IEEE Nuclear Science Symposium Conference Record.

[40]  S. Saramad,et al.  Pile-up correction algorithm based on successive integration for high count rate medical imaging and radiation spectroscopy , 2018, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment.

[41]  A. Kraan,et al.  Range Verification Methods in Particle Therapy: Underlying Physics and Monte Carlo Modeling , 2015, Front. Oncol..

[42]  Annika Jakobi,et al.  Clinical Feasibility of Single-Source Dual-spiral 4D Dual-Energy CT for Proton Treatment Planning Within the Thoracic Region. , 2018, International journal of radiation oncology, biology, physics.

[43]  Valery A. Shelyuto.  Exact analytic results for the solid angle in systems with axial symmetry , 1989 .

[44]  Mikael Karlsson,et al.  Number of patients potentially eligible for proton therapy , 2005, Acta oncologica.

[45]  Wolfgang Enghardt,et al.  Range assessment in particle therapy based on prompt γ-ray timing measurements , 2014, Physics in medicine and biology.

[46]  Wolfgang Enghardt,et al.  Clinical Implementation of Dual-energy CT for Proton Treatment Planning on Pseudo-monoenergetic CT scans. , 2017, International journal of radiation oncology, biology, physics.

[47]  Thomas Bortfeld,et al.  Three ways to make proton therapy affordable , 2017, Nature.

[48]  F. Diblen,et al.  Beam-on imaging of short-lived positron emitters during proton therapy , 2017, Physics in medicine and biology.

[49]  Yunhe Xie,et al.  Prompt Gamma Imaging for In Vivo Range Verification of Pencil Beam Scanning Proton Therapy. , 2017, International journal of radiation oncology, biology, physics.

[50]  D. Caruge,et al.  Recent Developments in Geant4 , 2014, ICS 2014.

[51]  P. Busca,et al.  89 PROMPT GAMMA IMAGING WITH A SLIT CAMERA FOR REAL TIME RANGE CONTROL IN PROTON THERAPY , 2012 .

[52]  Katia Parodi,et al.  Time-of-flight neutron rejection to improve prompt gamma imaging for proton range verification: a simulation study , 2012, Physics in medicine and biology.

[53]  M. J. Berger.  ESTAR, PSTAR, and ASTAR: Computer programs for calculating stopping-power and range tables for electrons, protons, and helium ions , 1992 .

[54]  Katia Parodi,et al.  In-beam PET measurements of β+ radioactivity induced by proton beams , 2002 .

[55]  H Paganetti,et al.  TOPAS: an innovative proton Monte Carlo platform for research and clinical applications. , 2012, Medical physics.

[56]  Katia Parodi,et al.  Imaging particle beams for cancer treatment , 2015 .

[57]  Antony Lomax,et al.  In vivo proton range verification: a review , 2013, Physics in medicine and biology.

[58]  Philippe Lambin,et al.  How costly is particle therapy? Cost analysis of external beam radiotherapy with carbon-ions, protons and photons. , 2010, Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology.

[59]  Katia Parodi,et al.  In vivo range verification in particle therapy. , 2018, Medical physics.

[60]  A. Lomax,et al.  Is it necessary to plan with safety margins for actively scanned proton therapy? , 2011, Physics in medicine and biology.

[61]  Yong Hou,et al.  The evolution of proton beam therapy: Current and future status. , 2017, Molecular and clinical oncology.

[62]  Fernando,et al.  Nuclear methods for real-time range verification in proton therapy based on prompt gamma-ray imaging , 2015 .

[63]  Wolfgang Enghardt,et al.  Range Verification in Proton Therapy by Prompt Gamma-Ray Timing (PGT): Steps towards Clinical Implementation , 2017, 2017 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC).

[64]  Marlen Priegnitz,et al.  Analytical computation of prompt gamma ray emission and detection for proton range verification , 2015, Physics in medicine and biology.

[65]  Joao Seco,et al.  Proton range verification through prompt gamma-ray spectroscopy , 2014, Physics in medicine and biology.

[66]  Sam Beddar,et al.  Detecting prompt gamma emission during proton therapy: the effects of detector size and distance from the patient , 2014, Physics in medicine and biology.

[67]  Denis Dauvergne,et al.  A cost-effective monitoring technique in particle therapy via uncollimated prompt gamma peak integration , 2017 .

[68]  Jacobus Maarten Schippers,et al.  Miniaturizing Proton Therapy: A Technical Challenge With Unclear Clinical Impact. , 2016, International journal of radiation oncology, biology, physics.

[69]  W Enghardt,et al.  Requirements for a Compton camera for in vivo range verification of proton therapy , 2017, Physics in medicine and biology.

[70]  Giuseppe Gorini,et al.  Response of LaBr3(Ce) scintillators to 14 MeV fusion neutrons , 2015 .

[71]  Alexander Gerbershagen,et al.  New horizons in particle therapy systems , 2018, Medical physics.

[72]  G Janssens,et al.  Impact of machine log-files uncertainties on the quality assurance of proton pencil beam scanning treatment delivery , 2019, Physics in medicine and biology.

[73]  Wolfgang Enghardt,et al.  Comparison of LSO and BGO block detectors for prompt gamma imaging in ion beam therapy , 2015 .

[74]  Susanna Guatelli,et al.  Characterization of prompt gamma-ray emission with respect to the Bragg peak for proton beam range verification: A Monte Carlo study. , 2017, Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics.

[75]  J. H. Hubbell,et al.  XCOM : Photon Cross Sections Database , 2005 .

[76]  Bruce Bradtmiller,et al.  Head-and-Face Anthropometric Survey of U.S. Respirator Users , 2005, Journal of occupational and environmental hygiene.

[77]  D. M. Van Patter,et al.  COMPOUND INELASTIC NUCLEON AND GAMMA-RAY ANGULAR DISTRIBUTIONS FOR EVEN-AND ODD-MASS NUCLEI , 1966 .

[78]  Thomas Bortfeld,et al.  Reassessment of the Necessity of the Proton Gantry: Analysis of Beam Orientations From 4332 Treatments at the Massachusetts General Hospital Proton Center Over the Past 10 Years. , 2016, International journal of radiation oncology, biology, physics.

[79]  Dennis R Schaart,et al.  Correlations between the shifts in prompt gamma emission profiles and the changes in daily target coverage during simulated pencil beam scanning proton therapy , 2019, Physics in medicine and biology.

[80]  D Dauvergne,et al.  Assessment and improvements of Geant4 hadronic models in the context of prompt-gamma hadrontherapy monitoring , 2014, Physics in medicine and biology.

[81]  P. Busca,et al.  Prompt gamma imaging with a slit camera for real-time range control in proton therapy , 2012, 2012 IEEE Nuclear Science Symposium and Medical Imaging Conference Record (NSS/MIC).

[82]  Wolfgang Enghardt,et al.  First test of the prompt gamma ray timing method with heterogeneous targets at a clinical proton therapy facility , 2015, Physics in medicine and biology.