1
|
Lundberg M, Meijers A, Souris K, Deffet S, Weber DC, Lomax A, Knopf A. Technical note: development of a simulation framework, enabling the investigation of locally tuned single energy proton radiography. Biomed Phys Eng Express 2024; 10:027002. [PMID: 38241732 DOI: 10.1088/2057-1976/ad20a8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 01/19/2024] [Indexed: 01/21/2024]
Abstract
Range uncertainties remain a limitation for the confined dose distribution that proton therapy can offer. The uncertainty stems from the ambiguity when translating CT Hounsfield Units (HU) into proton stopping powers. Proton Radiography (PR) can be used to verify the proton range. Specifically, PR can be used as a quality-control tool for CBCT-based synthetic CTs. An essential part of the work illustrating the potential of PR has been conducted using multi-layer ionization chamber (MLIC) detectors and mono-energetic PR. Due to the dimensions of commercially available MLICs, clinical adoption is cumbersome. Here, we present a simulation framework exploring locally-tuned single energy (LTSE) proton radiography and corresponding potential compact PR detector designs. Based on a planning CT data set, the presented framework models the water equivalent thickness. Subsequently, it analyses the proton energies required to pass through the geometry within a defined ROI. In the final step, an LTSE PR is simulated using the MCsquare Monte Carlo code. In an anatomical head phantom, we illustrate that LTSE PR allows for a significantly shorter longitudinal dimension of MLICs. We compared PR simulations for two exemplary 30 × 30 mm2proton fields passing the phantom at a 90° angle at an anterior and a posterior location in an iso-centric setup. The longitudinal distance over which all spots per field range out is significantly reduced for LTSE PR compared to mono-energetic PR. In addition, we illustrate the difference in shape of integral depth dose (IDD) when using constrained PR energies. Finally, we demonstrate the accordance of simulated and experimentally acquired IDDs for an LTSE PR acquisition. As the next steps, the framework will be used to investigate the sensitivity of LTSE PR to various sources of errors. Furthermore, we will use the framework to systematically explore the dimensions of an optimized MLIC design for daily clinical use.
Collapse
Affiliation(s)
- Måns Lundberg
- Institute for Medical Engineering and Medical Informatics, School of Life Science FHNW, Muttenz, Switzerland
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
| | - Arturs Meijers
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
| | - Kevin Souris
- Ion Beam Applications SA, Louvain-La-Neuve, Belgium
| | | | - Damien C Weber
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
- Department of Radiation Oncology, University Hospital of Zürich, Zürich, Switzerland
- Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Antony Lomax
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
- Department of Physics, ETH Zurich, Zurich, Switzerland
| | - Antje Knopf
- Institute for Medical Engineering and Medical Informatics, School of Life Science FHNW, Muttenz, Switzerland
| |
Collapse
|
2
|
Li X, Bellotti R, Meier G, Bachtiary B, Weber D, Lomax A, Buhmann J, Zhang Y. Uncertainty-aware MR-based CT synthesis for robust proton therapy planning of brain tumour. Radiother Oncol 2024; 191:110056. [PMID: 38104781 DOI: 10.1016/j.radonc.2023.110056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 12/06/2023] [Accepted: 12/08/2023] [Indexed: 12/19/2023]
Abstract
BACKGROUND AND PURPOSE Deep learning techniques excel in MR-based CT synthesis, but missing uncertainty prediction limits its clinical use in proton therapy. We developed an uncertainty-aware framework and evaluated its efficiency in robust proton planning. MATERIALS AND METHODS A conditional generative-adversarial network was trained on 64 brain tumour patients with paired MR-CT images to generate synthetic CTs (sCT) from combined T1-T2 MRs of three orthogonal planes. A Bayesian neural network predicts Laplacian distributions for all voxels with parameters (μ, b). A robust proton plan was optimized using three sCTs of μ and μ±b. The dosimetric differences between the plan from sCT (sPlan) and the recalculated plan (rPlan) on planning CT (pCT) were quantified for each patient. The uncertainty-aware robust plan was compared to conventional robust (global ± 3 %) and non-robust plans. RESULTS In 8-fold cross-validation, sCT-pCT image differences (Mean-Absolute-Error) were 80.84 ± 9.84HU (body), 35.78 ± 6.07HU (soft tissues) and 221.88 ± 31.69HU (bones), with Dice scores of 90.33 ± 2.43 %, 95.13 ± 0.80 %, and 85.53 ± 4.16 %, respectively. The uncertainty distribution positively correlated with absolute prediction error (Correlation Coefficient: 0.62 ± 0.01). The uncertainty-conditioned robust optimisation improved the rPlan-sPlan agreement, e.g., D95 absolute difference (CTV) was 1.10 ± 1.24 % compared to conventional (1.64 ± 2.71 %) and non-robust (2.08 ± 2.96 %) optimisation. This trend was consistent across all target and organs-at-risk indexes. CONCLUSION The enhanced framework incorporates 3D uncertainty prediction and generates high-quality sCTs from MR images. The framework also facilitates conditioned robust optimisation, bolstering proton plan robustness against network prediction errors. The innovative feature of uncertainty visualisation and robust analyses contribute to evaluating sCT clinical utility for individual patients.
Collapse
Affiliation(s)
- Xia Li
- Center for Proton Therapy, Paul Scherrer Institut, Switzerland; Department of Computer Science, ETH Zurich, Switzerland
| | - Renato Bellotti
- Center for Proton Therapy, Paul Scherrer Institut, Switzerland; Department of Physics, ETH Zurich, Switzerland
| | - Gabriel Meier
- Center for Proton Therapy, Paul Scherrer Institut, Switzerland
| | | | - Damien Weber
- Center for Proton Therapy, Paul Scherrer Institut, Switzerland; Department of Radiation Oncology, University Hospital of Zurich, Switzerland; Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, Switzerland
| | - Antony Lomax
- Center for Proton Therapy, Paul Scherrer Institut, Switzerland; Department of Physics, ETH Zurich, Switzerland
| | | | - Ye Zhang
- Center for Proton Therapy, Paul Scherrer Institut, Switzerland.
| |
Collapse
|
3
|
Peters N, Taasti VT, Ackermann B, Bolsi A, Dahlgren CV, Ellerbrock M, Fracchiolla F, Gomà C, Góra J, Lopes PC, Rinaldi I, Salvo K, Tarp IS, Vai A, Bortfeld T, Lomax A, Richter C, Wohlfahrt P. Response to "Letter regarding Consensus guide on CT-based prediction of stopping-power ratio using a Hounsfield look-up table for proton therapy". Radiother Oncol 2024; 190:109961. [PMID: 37871749 DOI: 10.1016/j.radonc.2023.109961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Accepted: 09/21/2023] [Indexed: 10/25/2023]
Affiliation(s)
- Nils Peters
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Germany; Massachusetts General Hospital and Harvard Medical School, Department of Radiation Oncology, Boston, MA, USA.
| | - Vicki Trier Taasti
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, the Netherlands.
| | - Benjamin Ackermann
- Heidelberg Ion-Beam Therapy Center (HIT), Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
| | - Alessandra Bolsi
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
| | | | - Malte Ellerbrock
- Heidelberg Ion-Beam Therapy Center (HIT), Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
| | - Francesco Fracchiolla
- Azienda Provinciale per i Servizi Sanitari (APSS) Protontherapy Department, Trento, Italy
| | - Carles Gomà
- Department of Radiation Oncology, Hospital Clínic de Barcelona, Barcelona, Spain
| | - Joanna Góra
- MedAustron Ion Therapy Center, Wiener Neustadt, Austria
| | | | - Ilaria Rinaldi
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, the Netherlands
| | - Koen Salvo
- AZ Sint-Maarten, Department of Radiotherapy, Mechelen, Belgium
| | - Ivanka Sojat Tarp
- Aarhus University Hospital, Danish Center for Particle Therapy, Aarhus, Denmark
| | - Alessandro Vai
- Radiotherapy Department, Center for National Oncological Hadrontherapy (CNAO), 27100 Pavia, Italy
| | - Thomas Bortfeld
- Massachusetts General Hospital and Harvard Medical School, Department of Radiation Oncology, Boston, MA, USA
| | - Antony Lomax
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
| | - Christian Richter
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Germany; Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany; Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany; German Cancer Consortium (DKTK), Partner Site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Patrick Wohlfahrt
- Massachusetts General Hospital and Harvard Medical School, Department of Radiation Oncology, Boston, MA, USA
| |
Collapse
|
4
|
Smolders A, Lomax A, Weber DC, Albertini F. Deep learning based uncertainty prediction of deformable image registration for contour propagation and dose accumulation in online adaptive radiotherapy. Phys Med Biol 2023; 68:245027. [PMID: 37820691 DOI: 10.1088/1361-6560/ad0282] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 10/11/2023] [Indexed: 10/13/2023]
Abstract
Objective.Online adaptive radiotherapy aims to fully leverage the advantages of highly conformal therapy by reducing anatomical and set-up uncertainty, thereby alleviating the need for robust treatments. This requires extensive automation, among which is the use of deformable image registration (DIR) for contour propagation and dose accumulation. However, inconsistencies in DIR solutions between different algorithms have caused distrust, hampering its direct clinical use. This work aims to enable the clinical use of DIR by developing deep learning methods to predict DIR uncertainty and propagating it into clinically usable metrics.Approach.Supervised and unsupervised neural networks were trained to predict the Gaussian uncertainty of a given deformable vector field (DVF). Since both methods rely on different assumptions, their predictions differ and were further merged into a combined model. The resulting normally distributed DVFs can be directly sampled to propagate the uncertainty into contour and accumulated dose uncertainty.Main results.The unsupervised and combined models can accurately predict the uncertainty in the manually annotated landmarks on the DIRLAB dataset. Furthermore, for 5 patients with lung cancer, the propagation of the predicted DVF uncertainty into contour uncertainty yielded for both methods anexpected calibration errorof less than 3%. Additionally, theprobabilisticly accumulated dose volume histograms(DVH) encompass well the accumulated proton therapy doses using 5 different DIR algorithms. It was additionally shown that the unsupervised model can be used for different DIR algorithms without the need for retraining.Significance.Our work presents first-of-a-kind deep learning methods to predict the uncertainty of the DIR process. The methods are fast, yield high-quality uncertainty estimates and are useable for different algorithms and applications. This allows clinics to use DIR uncertainty in their workflows without the need to change their DIR implementation.
Collapse
Affiliation(s)
- A Smolders
- Paul Scherrer Institute, Center for Proton Therapy, Switzerland
- Department of Physics, ETH Zurich, Switzerland
| | - A Lomax
- Paul Scherrer Institute, Center for Proton Therapy, Switzerland
- Department of Physics, ETH Zurich, Switzerland
| | - D C Weber
- Paul Scherrer Institute, Center for Proton Therapy, Switzerland
- Department of Radiation Oncology, University Hospital Zurich, Switzerland
- Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, Switzerland
| | - F Albertini
- Paul Scherrer Institute, Center for Proton Therapy, Switzerland
| |
Collapse
|
5
|
Via R, Bryjova K, Pica A, Baroni G, Lomax A, Weber DC, Fattori G, Hrbacek J. Multi-camera optical tracking and fringe pattern analysis for eye surface profilometry in ocular proton therapy. Phys Imaging Radiat Oncol 2023; 28:100517. [PMID: 38026085 PMCID: PMC10679530 DOI: 10.1016/j.phro.2023.100517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 11/13/2023] [Accepted: 11/13/2023] [Indexed: 12/01/2023] Open
Abstract
Background and purpose An optical tracking system for high-precision measurement of eye position and orientation during proton irradiation of intraocular tumors was designed. The system performed three-dimensional (3D) topography of the anterior eye segment using fringe pattern analysis based on Fourier Transform Method (FTM). Materials and methods The system consisted of four optical cameras and two projectors. The design and modifications to the FTM pipeline were optimized for the realization of a reliable measurement system. Of note, phase-to-physical coordinate mapping was achieved through the combination of stereo triangulation and fringe pattern analysis. A comprehensive pre-clinical validation was carried out. Then, the system was set to acquire the eye surface of patients undergoing proton therapy. Topographies of the eye were compared to manual contouring on MRI. Results Pre-clinical results demonstrated that 3D topography could achieve sub-millimetric accuracy (median:0.58 mm) and precision (RMSE:0.61 mm) in the clinical setup. The absolute median discrepancy between MRI and FTM-based anterior eye segment surface reconstruction was 0.43 mm (IQR:0.65 mm). Conclusions The system complied with the requirement of precision and accuracy for image guidance in ocular proton therapy radiation and is expected to be clinically tested soon to evaluate its performance against the current standard.
Collapse
Affiliation(s)
- Riccardo Via
- Center for Proton Therapy, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
| | - Katarina Bryjova
- Center for Proton Therapy, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
| | - Alessia Pica
- Center for Proton Therapy, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
| | - Guido Baroni
- Dipartimento di Elettronica Informazione e Bioingegneria, Politecnico di Milano, Milano 20133, Italy
| | - Antony Lomax
- Center for Proton Therapy, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
| | - Damien Charles Weber
- Center for Proton Therapy, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
- Department of Radiation Oncology, University Hospital of Zürich, Switzerland
- Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, Switzerland
| | - Giovanni Fattori
- Center for Proton Therapy, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
| | - Jan Hrbacek
- Center for Proton Therapy, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
| |
Collapse
|
6
|
Smolders A, Choulilitsa E, Czerska K, Bizzocchi N, Krcek R, Lomax A, Weber DC, Albertini F. Dosimetric comparison of autocontouring techniques for online adaptive proton therapy. Phys Med Biol 2023; 68:175006. [PMID: 37385266 DOI: 10.1088/1361-6560/ace307] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 06/29/2023] [Indexed: 07/01/2023]
Abstract
Objective.Anatomical and daily set-up uncertainties impede high precision delivery of proton therapy. With online adaptation, the daily plan is reoptimized on an image taken shortly before the treatment, reducing these uncertainties and, hence, allowing a more accurate delivery. This reoptimization requires target and organs-at-risk (OAR) contours on the daily image, which need to be delineated automatically since manual contouring is too slow. Whereas multiple methods for autocontouring exist, none of them are fully accurate, which affects the daily dose. This work aims to quantify the magnitude of this dosimetric effect for four contouring techniques.Approach.Plans reoptimized on automatic contours are compared with plans reoptimized on manual contours. The methods include rigid and deformable registration (DIR), deep-learning based segmentation and patient-specific segmentation.Main results.It was found that independently of the contouring method, the dosimetric influence of usingautomaticOARcontoursis small (<5% prescribed dose in most cases), with DIR yielding the best results. Contrarily, the dosimetric effect of using theautomatic target contourwas larger (>5% prescribed dose in most cases), indicating that manual verification of that contour remains necessary. However, when compared to non-adaptive therapy, the dose differences caused by automatically contouring the target were small and target coverage was improved, especially for DIR.Significance.The results show that manual adjustment of OARs is rarely necessary and that several autocontouring techniques are directly usable. Contrarily, manual adjustment of the target is important. This allows prioritizing tasks during time-critical online adaptive proton therapy and therefore supports its further clinical implementation.
Collapse
Affiliation(s)
- A Smolders
- Paul Scherrer Institute, Center for Proton Therapy, Switzerland
- Department of Physics, ETH Zurich, Switzerland
| | - E Choulilitsa
- Paul Scherrer Institute, Center for Proton Therapy, Switzerland
- Department of Physics, ETH Zurich, Switzerland
| | - K Czerska
- Paul Scherrer Institute, Center for Proton Therapy, Switzerland
| | - N Bizzocchi
- Paul Scherrer Institute, Center for Proton Therapy, Switzerland
| | - R Krcek
- Paul Scherrer Institute, Center for Proton Therapy, Switzerland
- Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, Switzerland
| | - A Lomax
- Paul Scherrer Institute, Center for Proton Therapy, Switzerland
- Department of Physics, ETH Zurich, Switzerland
| | - D C Weber
- Paul Scherrer Institute, Center for Proton Therapy, Switzerland
- Department of Radiation Oncology, University Hospital Zurich, Switzerland
- Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, Switzerland
| | - F Albertini
- Paul Scherrer Institute, Center for Proton Therapy, Switzerland
| |
Collapse
|
7
|
Peters N, Trier Taasti V, Ackermann B, Bolsi A, Vallhagen Dahlgren C, Ellerbrock M, Fracchiolla F, Gomà C, Góra J, Cambraia Lopes P, Rinaldi I, Salvo K, Sojat Tarp I, Vai A, Bortfeld T, Lomax A, Richter C, Wohlfahrt P. Consensus guide on CT-based prediction of stopping-power ratio using a Hounsfield look-up table for proton therapy. Radiother Oncol 2023; 184:109675. [PMID: 37084884 DOI: 10.1016/j.radonc.2023.109675] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 03/08/2023] [Accepted: 04/10/2023] [Indexed: 04/23/2023]
Abstract
BACKGROUND AND PURPOSE Studies have shown large variations in stopping-power ratio (SPR) prediction from computed tomography (CT) across European proton centres. To standardise this process, a step-by-step guide on specifying a Hounsfield look-up table (HLUT) is presented here. MATERIALS AND METHODS The HLUT specification process is divided into six steps: Phantom setup, CT acquisition, CT number extraction, SPR determination, HLUT specification, and HLUT validation. Appropriate CT phantoms have a head- and body-sized part, with tissue-equivalent inserts in regard to X-ray and proton interactions. CT numbers are extracted from a region-of-interest covering the inner 70% of each insert in-plane and several axial CT slices in scan direction. For optimal HLUT specification, the SPR of phantom inserts is measured in a proton beam and the SPR of tabulated human tissues is computed stoichiometrically at 100 MeV. Including both phantom inserts and tabulated human tissues increases HLUT stability. Piecewise linear regressions are performed between CT numbers and SPRs for four tissue groups (lung, adipose, soft tissue, and bone) and then connected with straight lines. Finally, a thorough but simple validation is performed. RESULTS The best practices and individual challenges are explained comprehensively for each step. A well-defined strategy for specifying the connection points between the individual line segments of the HLUT is presented. The guide was tested exemplarily on three CT scanners from different vendors, proving its feasibility. CONCLUSION The presented step-by-step guide for CT-based HLUT specification with recommendations and examples can contribute to reduce inter-centre variations in SPR prediction.
Collapse
Affiliation(s)
- Nils Peters
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Germany; Massachusetts General Hospital and Harvard Medical School, Department of Radiation Oncology, Boston, MA, USA.
| | - Vicki Trier Taasti
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands.
| | - Benjamin Ackermann
- Heidelberg Ion-Beam Therapy Center (HIT), Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
| | - Alessandra Bolsi
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
| | | | - Malte Ellerbrock
- Heidelberg Ion-Beam Therapy Center (HIT), Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
| | - Francesco Fracchiolla
- Azienda Provinciale per i Servizi Sanitari (APSS) Protontherapy Department, Trento, Italy
| | - Carles Gomà
- Department of Radiation Oncology, Hospital Clínic de Barcelona, Barcelona, Spain
| | - Joanna Góra
- MedAustron Ion Therapy Center, Wiener Neustadt, Austria
| | | | - Ilaria Rinaldi
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Koen Salvo
- AZ Sint-Maarten, Department of Radiotherapy, Mechelen, Belgium
| | - Ivanka Sojat Tarp
- Aarhus University Hospital, Danish Center for Particle Therapy, Aarhus, Denmark
| | - Alessandro Vai
- Radiotherapy Department, Center for National Oncological Hadrontherapy (CNAO), 27100 Pavia, Italy
| | - Thomas Bortfeld
- Massachusetts General Hospital and Harvard Medical School, Department of Radiation Oncology, Boston, MA, USA
| | - Antony Lomax
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
| | - Christian Richter
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Germany; Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany; Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany; German Cancer Consortium (DKTK), partner site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Patrick Wohlfahrt
- Massachusetts General Hospital and Harvard Medical School, Department of Radiation Oncology, Boston, MA, USA
| |
Collapse
|
8
|
Ables S, Bennett A, Vanner S, Lomax A, Reed D. A272 EVIDENCE OF SEX DIFFERENCES IMPACTING PAIN SIGNALING BY LUMINAL MEDIATORS IN IRRITABLE BOWEL SYNDROME. J Can Assoc Gastroenterol 2023. [PMCID: PMC9991243 DOI: 10.1093/jcag/gwac036.272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/09/2023] Open
Abstract
Background Irritable bowel syndrome (IBS) is more than twice as common in women and female patients report more severe abdominal pain. This suggests that sex-specific mechanisms may contribute to the pathophysiology of IBS. Many IBS patients have altered gut microbiota and luminal meditators, implicating the gut microbiota in abdominal pain. These luminal mediators can alter excitability of visceral nociceptors, thus potentially contributing to abdominal pain in IBS. Furthermore, in a subset of IBS patients a low FODMAP diet (LFD) reduces the effect of luminal mediators on pain sensing neurons. The LFD may improve abdominal pain at greater rates in women, and numerous putative mechanisms contributing to abdominal pain in IBS are susceptible to sex-specific mediators. However, it is unknown whether luminal mediators have similar effects on visceral pain signaling in both males and females. We hypothesize that luminal mediators will cause greater differences in neuronal excitability and pain signaling in female mice due to sex-specific factors. Purpose To determine whether FS from IBS patients (IBS FS) affects nociceptors from female mice more than nociceptors from male mice. Method Neurons from dorsal root ganglia from male and female mice were incubated overnight in media containing fecal supernatant (FS) from IBS patients (N=2 females) before and after the LFD, or healthy controls (HC, N=1 female and 1 male). Ratiometric Ca2+ imaging with FURA-2-AM was employed to quantify TRPV1 channel sensitization following application of capsaicin (100nM for 1 minute) as a measure of neuronal excitability. Data was analyzed using chi-squared test as well as two-way and mixed-effects model ANOVA as appropriate, followed by Sidak’s multiple comparisons test. Result(s) IBS FS caused a 177% larger Ca2+ influx in response to capsaicin compared to HC FS in female mice (p=0.0148, N=6-7 mice, neurons=43-49). In male mice, IBS FS increased Ca2+ influx by only 13% compared to HC FS (p=0.79, N=5 mice, neurons=28-35). In female mice, 117% more neurons responded to capsaicin after incubation with IBS FS versus HC FS (p=0.0004), while in male mice, only 17% more neurons responded following incubation with IBS FS (p=0.46). Finally, FS from the same IBS patients following a LFD reduced neuronal Ca2+ influx by 39% compared to IBS FS in female mice (p=0.0434, N=4-6 mice, neurons=18-49). In male mice, LFD FS reduced Ca2+ influx by 11% versus IBS FS (p=0.98, N=5 mice, neurons=28-35). Conclusion(s) Nociceptive neurons from female mice are more sensitive to the pro-nociceptive effects of FS from IBS patients, as well as a reduction of these excitatory effects following the LFD. This suggests a potential role of sex hormones in pain signaling in IBS. Disclosure of Interest None Declared
Collapse
Affiliation(s)
- S Ables
- Queen's University, Kingston, Canada
| | - A Bennett
- Queen's University, Kingston, Canada
| | - S Vanner
- Queen's University, Kingston, Canada
| | - A Lomax
- Queen's University, Kingston, Canada
| | - D Reed
- Queen's University, Kingston, Canada
| |
Collapse
|
9
|
Wood H, Alward T, Abu Omar A, Guzman-Rodriguez M, Vanner S, Reed D, Lomax A. A17 EVIDENCE OF PROTEASE-MEDIATED PRO-NOCICEPTIVE EFFECTS OF FECAL SUPERNATANTS FROM CROHN'S DISEASE PATIENTS. J Can Assoc Gastroenterol 2023. [PMCID: PMC9991284 DOI: 10.1093/jcag/gwac036.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/09/2023] Open
Abstract
Background Abdominal pain is a debilitating symptom of Crohn’s disease (CD). Despite the current treatment options for this disease, abdominal pain is an unresolved problem that commonly persists in the absence of active inflammation. This suggests that something other than inflammation is driving the pain during the quiescent phase. We have previously reported that microbial proteases can directly modulate the excitability of dorsal root ganglia (DRG) neurons, many of which are pain-sensing. We hypothesize that luminal proteases of CD patients are contributing to their abdominal pain. Purpose Determine whether luminal mediators in CD fecal samples induce changes in pain signalling. Method The effects of patient (active CD [n = 3] and healthy volunteer (HV) [n = 3]) fecal supernatant (FS) samples on pain-sensing neurons were assessed using ex-vivo single unit afferent nerve recordings from mouse colons. Each sample was tested in colonic preparations from a least 5 mice. To further examine cellular mechanisms, DRG neurons were isolated and incubated overnight in media containing CD FS or HV FS media. Changes in neuronal excitability were recorded by determining the rheobase (lower rheobase=increased excitability) using patch clamp recordings (n ≥ 9 DRG neurons/group). Protease inhibitors were applied in both bioassays to determine whether these inhibited the excitatory effect of FS. Lastly, total proteolytic activity in the CD and HV fecal samples was calculated using a casein colorimetric protease detection assay. Result(s) FS from HV had no effect on afferent nerve excitability (p = 0.8920). FS from active CD patients increased action potential discharge from colonic afferent nerves by 85% (p<0.0001) and selectively increased the activation of high-threshold units, which are putative nociceptors, by 44% (p=0.0074). A protease inhibitor cocktail (1:1000) and protease-activated receptor (PAR)-2 antagonist GB83 (10µM) both blocked the excitatory effects of CD FS (p<0.05). Overnight incubation with CD FS also had an excitatory effect on DRG neurons compared to HV FS (rheobase decreased by 46%, p<0.05). The effect of CD FS was blocked by GB83 (10µM) (p<0.001) and a serine protease inhibitor (FUT175; 100µM) (p<0.05) independently, but the activity was not blocked by E64 (30nM) a cysteine protease inhibitor. A 200-fold increase (p<0.0001) in total proteolytic activity was found in CD FS compared to HV FS. Conclusion(s) Luminal serine proteases, but not cysteine proteases, appear to be driving nociceptive signalling in CD patients. This provides insight into the generation of pain in CD patients and may be a potential target to mitigate this action. Further research is required to elucidate whether these pro-nociceptive proteases are of bacterial or host origin and their effects in the quiescent phase. Disclosure of Interest None Declared
Collapse
Affiliation(s)
- H Wood
- Gastrointestinal Diseases Research Unit, Queen's University, Kingston, Canada
| | - T Alward
- Gastrointestinal Diseases Research Unit, Queen's University, Kingston, Canada
| | - A Abu Omar
- Gastrointestinal Diseases Research Unit, Queen's University, Kingston, Canada
| | - M Guzman-Rodriguez
- Gastrointestinal Diseases Research Unit, Queen's University, Kingston, Canada
| | - S Vanner
- Gastrointestinal Diseases Research Unit, Queen's University, Kingston, Canada
| | - D Reed
- Gastrointestinal Diseases Research Unit, Queen's University, Kingston, Canada
| | - A Lomax
- Gastrointestinal Diseases Research Unit, Queen's University, Kingston, Canada
| |
Collapse
|
10
|
Bennett A, Baker C, Guzman-Rodriguez M, Jimenez-Vargas N, Vanner S, Reed D, Lomax A. A278 SEX DIFFERENCES IN THE EFFECT OF THE MICROBIOTA FROM IRRITABLE BOWEL SYNDROME PATIENTS ON ABDOMINAL PAIN. J Can Assoc Gastroenterol 2023. [PMCID: PMC9991273 DOI: 10.1093/jcag/gwac036.278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/09/2023] Open
Abstract
Background Irritable bowel syndrome (IBS) is a chronic abdominal pain disorder that affects women twice as often as men. The gut microbiota has been implicated as a key player in the modulation of abdominal pain in IBS. Given this, we hypothesised that the production of pro-nociceptive mediators within the gut lumen are increased in females, and this contributes to the female predominance of IBS. Purpose Compare the effects of FS from male and female IBS patients on abdominal pain pathways and identify the impact of female mouse estrous cycle on abdominal pain. Method Fecal supernatants (FS) were perfused through murine colonic preparations while performing extracellular colonic afferent nerve recordings to measure changes in action potential frequency in response to colonic distension. Phase of estrous cycle in female mice was determined through vaginal swabs. FS from male and female IBS patients reporting low, moderate, and high levels of abdominal pain were used. Result(s) FS from female IBS patients (N=6) increased afferent nerve discharge (p < 0.05) whereas FS from male IBS patients has no effect (N=4). However, single unit analysis of nociceptive axons revealed that male IBS FS increased nociceptor activity in female mice taken during the proestrus/estrus stage (p < 0.05), but not female mice taken during the metestrus/diestrus stage or male mice. Further investigation found that IBS FS from female patients with high abdominal pain (N=6), but not patients with moderate (N=5) or low pain (N=3), increased visceral afferent nerve discharge by 70%. Single unit analysis of nociceptive axons showed that their activation was increased by almost 50% following FS perfusion from high abdominal pain patients only (p < 0.05). Histamine concentrations and proteolytic activity are increased in FS from female IBS patients with high abdominal pain compared to male IBS patients. Conclusion(s) This work suggests that luminal mediators that impact abdominal pain are increased in female IBS patients compared to male IBS patients, and females appear to be more sensitive to their pro-nociceptive effects. Together, these sex differences may contribute to the female predominance of IBS. Disclosure of Interest None Declared
Collapse
Affiliation(s)
- A Bennett
- Department of Biomedical and Molecular Sciences
| | - C Baker
- Department of Biomedical and Molecular Sciences
| | | | | | - S Vanner
- Department of Medicine, Queen's University, Kingston, Canada
| | - D Reed
- Department of Medicine, Queen's University, Kingston, Canada
| | - A Lomax
- Department of Biomedical and Molecular Sciences
| |
Collapse
|
11
|
Via R, Fattori G, Pica A, Paganelli C, Lomax A, Schalenbourg A, Weber DC, Baroni G, Hrbacek J. Response to "Letter to the Editor of Radiotherapy and Oncology regarding the paper titled "MRI and FUNDUS image fusion for improved ocular biometry in Ocular Proton Therapy" by Via et al.". Radiother Oncol 2022; 176:252. [PMID: 35988774 DOI: 10.1016/j.radonc.2022.08.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 08/15/2022] [Indexed: 12/14/2022]
Affiliation(s)
- Riccardo Via
- Paul Scherrer Institut (PSI), Center for Proton Therapy, 5232 Villigen PSI, Switzerland.
| | - Giovanni Fattori
- Paul Scherrer Institut (PSI), Center for Proton Therapy, 5232 Villigen PSI, Switzerland
| | - Alessia Pica
- Paul Scherrer Institut (PSI), Center for Proton Therapy, 5232 Villigen PSI, Switzerland
| | - Chiara Paganelli
- Dipartimento di Elettronica Informazione e Bioingegneria, Politecnico di Milano, Milano 20133, Italy
| | - Antony Lomax
- Paul Scherrer Institut (PSI), Center for Proton Therapy, 5232 Villigen PSI, Switzerland
| | - Ann Schalenbourg
- Department of Ophthalmology, University of Lausanne, Jules-Gonin Eye Hospital, FAA, Lausanne, Switzerland
| | - Damien Charles Weber
- Paul Scherrer Institut (PSI), Center for Proton Therapy, 5232 Villigen PSI, Switzerland; Department of Radiation Oncology, University Hospital Zurich, Rämistrasse 100, 8091 Zurich, Switzerland; Department of Radiation Oncology, University Hospital Bern, Freiburgstrasse 18, 3010 Bern, Switzerland
| | - Guido Baroni
- Dipartimento di Elettronica Informazione e Bioingegneria, Politecnico di Milano, Milano 20133, Italy
| | - Jan Hrbacek
- Paul Scherrer Institut (PSI), Center for Proton Therapy, 5232 Villigen PSI, Switzerland
| |
Collapse
|
12
|
Sarrut D, Arbor N, Baudier T, Borys D, Etxebeste A, Fuchs H, Gajewski J, Grevillot L, Jan S, Kagadis GC, Kang HG, Kirov A, Kochebina O, Krzemien W, Lomax A, Papadimitroulas P, Pommranz C, Roncali E, Rucinski A, Winterhalter C, Maigne L. The OpenGATE ecosystem for Monte Carlo simulation in medical physics. Phys Med Biol 2022; 67. [DOI: 10.1088/1361-6560/ac8c83] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 08/24/2022] [Indexed: 11/12/2022]
Abstract
Abstract
This paper reviews the ecosystem of GATE, an open-source Monte Carlo toolkit for medical physics. Based on the shoulders of Geant4, the principal modules (geometry, physics, scorers) are described with brief descriptions of some key concepts (Volume, Actors, Digitizer). The main source code repositories are detailed together with the automated compilation and tests processes (Continuous Integration). We then described how the OpenGATE collaboration managed the collaborative development of about one hundred developers during almost 20 years. The impact of GATE on medical physics and cancer research is then summarized, and examples of a few key applications are given. Finally, future development perspectives are indicated.
Collapse
|
13
|
Via R, Pica A, Antonioli L, Paganelli C, Fattori G, Spaccapaniccia C, Lomax A, Weber DC, Schalenbourg A, Baroni G, Hrbacek J. MRI and FUNDUS image fusion for improved ocular biometry in Ocular Proton Therapy. Radiother Oncol 2022; 174:16-22. [PMID: 35788353 DOI: 10.1016/j.radonc.2022.06.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 05/06/2022] [Accepted: 06/24/2022] [Indexed: 12/14/2022]
Abstract
INTRODUCTION Ocular biometry in Ocular Proton Therapy (OPT) currently relies on a generic geometrical eye model built by referencing surgically implanted markers. An alternative approach based on image fusion of volumetric Magnetic Resonance Imaging (MRI) and panoramic fundus photography was investigated. MATERIALS AND METHODS Eighteen non-consecutive uveal melanoma (UM) patients, who consented for an MRI and had their tumour base visible on panoramic fundus photography, were included in this comparative analysis. Through generating digitally-reconstructed projections from MRI images using the Lambert azimuthal equal-area projection, 2D-3D image fusion between fundus photography and an eye model delineated on MRI scans was achieved and allowed for a novel definition of the target base (MRI + FCTV). MRI + FCTV was compared with MRI-only delineation (MRIGTV) and the conventional (EyePlan) target definition (EPCTV). RESULTS The combined use of fundus photography and MRI to define tumour volumes reduced the average discrepancies by almost 65% with respect to the MRI only tumour definitions when comparing with the conventionally planned EPCTV. With the proposed method, shallow sub-retinal tumour infiltration, otherwise invisible on MRI, can be included in the target volume definition. Moreover, a novel definition of the fovea location improves the accuracy and personalisation of the 3D eye model. CONCLUSION MRI and fundus image fusion overcomes some of the limitations of ophthalmological MRI for tumour volume definition in OPT. This novel eye tumour modelling method might improve treatment planning personalisation, allowing to better anticipate which patients could benefit from prophylactic treatment protocols for radiation induced maculopathy.
Collapse
Affiliation(s)
- Riccardo Via
- Paul Scherrer Institut (PSI), Center for Proton Therapy, 5232 Villigen PSI, Switzerland.
| | - Alessia Pica
- Paul Scherrer Institut (PSI), Center for Proton Therapy, 5232 Villigen PSI, Switzerland
| | - Luca Antonioli
- Dipartimento di Elettronica Informazione e Bioingegneria, Politecnico di Milano, Milano 20133, Italy
| | - Chiara Paganelli
- Dipartimento di Elettronica Informazione e Bioingegneria, Politecnico di Milano, Milano 20133, Italy
| | - Giovanni Fattori
- Paul Scherrer Institut (PSI), Center for Proton Therapy, 5232 Villigen PSI, Switzerland
| | - Chiara Spaccapaniccia
- Paul Scherrer Institut (PSI), Center for Proton Therapy, 5232 Villigen PSI, Switzerland
| | - Antony Lomax
- Paul Scherrer Institut (PSI), Center for Proton Therapy, 5232 Villigen PSI, Switzerland
| | - Damien Charles Weber
- Paul Scherrer Institut (PSI), Center for Proton Therapy, 5232 Villigen PSI, Switzerland; Department of Radiation Oncology, University Hospital Zurich, Rämistrasse 100, 8091 Zurich, Switzerland; Department of Radiation Oncology, University Hospital Bern, Freiburgstrasse 18, 3010, Bern, Switzerland
| | - Ann Schalenbourg
- Department of Ophthalmology, University of Lausanne, Jules-Gonin Eye Hospital, FAA, Lausanne, Switzerland
| | - Guido Baroni
- Department of Radiation Oncology, University Hospital Bern, Freiburgstrasse 18, 3010, Bern, Switzerland
| | - Jan Hrbacek
- Paul Scherrer Institut (PSI), Center for Proton Therapy, 5232 Villigen PSI, Switzerland
| |
Collapse
|
14
|
Bachmann N, Vazquez M, Bolsi A, Pachigolla S, De Angelis C, Ahlhelm F, Lomax A, Pica A, Weber DC. RONC-02. Clinical outcome after craniospinal irradiation with pencil beam scanning proton therapy for children and young adults/adolescents with brain tumors. Neuro Oncol 2022. [PMCID: PMC9164887 DOI: 10.1093/neuonc/noac079.656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
BACKGROUND: Craniospinal irradiation (CSI) is an essential treatment component to achieve cure for some brain tumors in children and young adults/adolescents (C-AYAs). Multimodal treatment approaches are however associated with treatment-related late toxicities in these developing patients. Pencil beam scanning proton therapy (PBSPT) allows for a minimization of dose delivered to organs at risk and the brain integral dose and, thus, potentially also a reduction of radiation-induced adverse events. We report the clinical outcome and toxicity rates after CSI for C-AYAs treated with PBSPT. METHODS: We reviewed 71 C-AYAs with a median age of 7.4 years (1.7 – 21.3) who received CSI with PBSPT. Medullobastoma (n=42, 59%) and ependymoma (n=8, 11%) were the most common histologies. Thirty-four (48%) patients presented with metastatic disease at diagnosis. Sixteen (23%) patients were treated for tumor recurrence/progression and 9 (13%) patients underwent re-irradiation. Median prescribed total dose was 54 GyRBE (18 – 60.4) and median craniospinal dose 24 GyRBE (18 – 36.8). Toxicities were recorded according to CTCAE v5.0. RESULTS: With a median follow-up time of 24 months (2 – 195), 12 (17%) patients died due to progressive disease. Eight (11%) patients experienced local failure and 15 (21%) distant failure after PBSPT. Estimated 2-year OS, LC and DC was 86.9%, 86.0% and 80.4%, respectively. Grade 3 acute toxicity (thrombocytopenia, neutropenia, nausea) was observed in 5 (7%) patients. Late grade 3 toxicities (stroke, cataract and CNS necrosis) were observed in 3 (4%) patients, 8, 9 and 16 months after PBSPT, respectively. One (1%) patient developed grade 4 CNS necrosis 8 months after CSI. Late grade ≥3 toxicity free rate was 92.3% at 2 years. No radiation-induced secondary cancer was observed. CONCLUSION: Excellent tumor and brain/spinal distant control and a low late grade ≥3 toxicity rate after CSI were observed in our cohort of C-AYAs treated with PBSPT.
Collapse
Affiliation(s)
- Nicolas Bachmann
- Paul Scherrer Institute , Villigen , Switzerland
- University Hospital Inselspital , Bern , Switzerland
| | | | | | | | | | | | - Antony Lomax
- Paul Scherrer Institute , Villigen , Switzerland
| | - Alessia Pica
- Paul Scherrer Institute , Villigen , Switzerland
| | - Damien Charles Weber
- Paul Scherrer Institute , Villigen , Switzerland
- University Hospital Inselspital , Bern , Switzerland
| |
Collapse
|
15
|
Guo M, Batin E, Bolsi A, Safai S, Weber D, Lomax A, Chen Z, Zhang Y. PD-0402 Impact of CBCT-based patient positioning uncertainty due to the ROI/DOF selection for proton therapy. Radiother Oncol 2022. [DOI: 10.1016/s0167-8140(22)02837-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
16
|
Makkar S, Béguin M, Dissertori G, Flock J, Fuentes C, Gajewski J, Hrbacek J, McNamara K, Ritzer C, Rucinski A, Weber D, Lomax A, Winterhalter C. PO-1602 Image reconstruction using the PETITION PET scanner aimed at biologically guided proton therapy. Radiother Oncol 2022. [DOI: 10.1016/s0167-8140(22)03566-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
17
|
Zhang Y, Vatterodt N, Duetschler A, Safai S, Weber D, Lomax A. OC-0039 Improving 4D optimized Pencil Beam Scanned proton plan robustness using motion guided dose delivery. Radiother Oncol 2022. [DOI: 10.1016/s0167-8140(22)02458-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
18
|
Calais E, Symithe S, Monfret T, Delouis B, Lomax A, Courboulex F, Ampuero JP, Lara PE, Bletery Q, Chèze J, Peix F, Deschamps A, de Lépinay B, Raimbault B, Jolivet R, Paul S, St Fleur S, Boisson D, Fukushima Y, Duputel Z, Xu L, Meng L. Citizen seismology helps decipher the 2021 Haiti earthquake. Science 2022; 376:283-287. [PMID: 35271301 DOI: 10.1126/science.abn1045] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The August 14, Mw7.2, Nippes earthquake in Haiti occurred within the same fault zone as its devastating, Mw7.0, 2010 predecessor but struck the country when field access was limited by insecurity and conventional seismometers from the national network were inoperative. A network of citizen seismometers installed in 2019 provided near-field data critical to rapidly understand the mechanism of the mainshock and monitor its aftershock sequence. Their real-time data define two aftershock clusters that coincide with two areas of coseismic slip derived from inversions of conventional seismological and geodetic data. Machine learning applied to data from the citizen seismometer closest to the mainshock allows us to forecast aftershocks as accurately as with the network-derived catalog. This shows the utility of citizen science contributing to the understanding of a major earthquake.
Collapse
Affiliation(s)
- E Calais
- Département de Géosciences, École Normale Supérieure, CNRS UMR 8538, PSL Université, Paris, France.,Université Côte d'Azur, Institut de Recherche pour le Développement, Centre National de la Recherche Scientifique, Observatoire de la Côte d'Azur, Géoazur, Valbonne, France.,CARIBACT Joint Research Laboratory, Université d'État d'Haïti, Université Côte d'Azur, Institut de Recherche pour le Développement, Port-au-Prince, Haïti.,Institut Universitaire de France, Paris, France
| | - S Symithe
- CARIBACT Joint Research Laboratory, Université d'État d'Haïti, Université Côte d'Azur, Institut de Recherche pour le Développement, Port-au-Prince, Haïti.,URGéo, Faculté des Sciences, Université d'État d'Haïti, Port-au-Prince, Haïti
| | - T Monfret
- Université Côte d'Azur, Institut de Recherche pour le Développement, Centre National de la Recherche Scientifique, Observatoire de la Côte d'Azur, Géoazur, Valbonne, France.,CARIBACT Joint Research Laboratory, Université d'État d'Haïti, Université Côte d'Azur, Institut de Recherche pour le Développement, Port-au-Prince, Haïti.,Barcelona Center for Subsurface Imaging, Institut de Ciències del Mar (ICM), CSIC, Barcelona, Spain
| | - B Delouis
- Université Côte d'Azur, Institut de Recherche pour le Développement, Centre National de la Recherche Scientifique, Observatoire de la Côte d'Azur, Géoazur, Valbonne, France.,CARIBACT Joint Research Laboratory, Université d'État d'Haïti, Université Côte d'Azur, Institut de Recherche pour le Développement, Port-au-Prince, Haïti
| | - A Lomax
- ALomax Scientific, Mouans Sartoux, France
| | - F Courboulex
- Université Côte d'Azur, Institut de Recherche pour le Développement, Centre National de la Recherche Scientifique, Observatoire de la Côte d'Azur, Géoazur, Valbonne, France.,CARIBACT Joint Research Laboratory, Université d'État d'Haïti, Université Côte d'Azur, Institut de Recherche pour le Développement, Port-au-Prince, Haïti
| | - J P Ampuero
- Université Côte d'Azur, Institut de Recherche pour le Développement, Centre National de la Recherche Scientifique, Observatoire de la Côte d'Azur, Géoazur, Valbonne, France.,CARIBACT Joint Research Laboratory, Université d'État d'Haïti, Université Côte d'Azur, Institut de Recherche pour le Développement, Port-au-Prince, Haïti
| | - P E Lara
- Université Côte d'Azur, Institut de Recherche pour le Développement, Centre National de la Recherche Scientifique, Observatoire de la Côte d'Azur, Géoazur, Valbonne, France.,Instituto Geofísico del Perú, Lima, Perú
| | - Q Bletery
- Université Côte d'Azur, Institut de Recherche pour le Développement, Centre National de la Recherche Scientifique, Observatoire de la Côte d'Azur, Géoazur, Valbonne, France.,CARIBACT Joint Research Laboratory, Université d'État d'Haïti, Université Côte d'Azur, Institut de Recherche pour le Développement, Port-au-Prince, Haïti
| | - J Chèze
- Université Côte d'Azur, Institut de Recherche pour le Développement, Centre National de la Recherche Scientifique, Observatoire de la Côte d'Azur, Géoazur, Valbonne, France.,CARIBACT Joint Research Laboratory, Université d'État d'Haïti, Université Côte d'Azur, Institut de Recherche pour le Développement, Port-au-Prince, Haïti
| | - F Peix
- Université Côte d'Azur, Institut de Recherche pour le Développement, Centre National de la Recherche Scientifique, Observatoire de la Côte d'Azur, Géoazur, Valbonne, France.,CARIBACT Joint Research Laboratory, Université d'État d'Haïti, Université Côte d'Azur, Institut de Recherche pour le Développement, Port-au-Prince, Haïti
| | - A Deschamps
- Université Côte d'Azur, Institut de Recherche pour le Développement, Centre National de la Recherche Scientifique, Observatoire de la Côte d'Azur, Géoazur, Valbonne, France.,CARIBACT Joint Research Laboratory, Université d'État d'Haïti, Université Côte d'Azur, Institut de Recherche pour le Développement, Port-au-Prince, Haïti
| | - B de Lépinay
- Université Côte d'Azur, Institut de Recherche pour le Développement, Centre National de la Recherche Scientifique, Observatoire de la Côte d'Azur, Géoazur, Valbonne, France.,CARIBACT Joint Research Laboratory, Université d'État d'Haïti, Université Côte d'Azur, Institut de Recherche pour le Développement, Port-au-Prince, Haïti
| | - B Raimbault
- Département de Géosciences, École Normale Supérieure, CNRS UMR 8538, PSL Université, Paris, France
| | - R Jolivet
- Département de Géosciences, École Normale Supérieure, CNRS UMR 8538, PSL Université, Paris, France.,Institut Universitaire de France, Paris, France
| | - S Paul
- Université Côte d'Azur, Institut de Recherche pour le Développement, Centre National de la Recherche Scientifique, Observatoire de la Côte d'Azur, Géoazur, Valbonne, France.,CARIBACT Joint Research Laboratory, Université d'État d'Haïti, Université Côte d'Azur, Institut de Recherche pour le Développement, Port-au-Prince, Haïti.,URGéo, Faculté des Sciences, Université d'État d'Haïti, Port-au-Prince, Haïti
| | - S St Fleur
- CARIBACT Joint Research Laboratory, Université d'État d'Haïti, Université Côte d'Azur, Institut de Recherche pour le Développement, Port-au-Prince, Haïti.,URGéo, Faculté des Sciences, Université d'État d'Haïti, Port-au-Prince, Haïti
| | - D Boisson
- CARIBACT Joint Research Laboratory, Université d'État d'Haïti, Université Côte d'Azur, Institut de Recherche pour le Développement, Port-au-Prince, Haïti.,URGéo, Faculté des Sciences, Université d'État d'Haïti, Port-au-Prince, Haïti
| | - Y Fukushima
- International Research Institute of Disaster Science, Tohoku University, Sendai, Japan
| | - Z Duputel
- Observatoire Volcanologique du Piton de la Fournaise, Université de Paris, Institut de Physique du Globe de Paris, CNRS, Paris, France
| | - L Xu
- Department of Earth, Planetary and Space Sciences, University of California, Los Angeles, CA, USA
| | - L Meng
- Department of Earth, Planetary and Space Sciences, University of California, Los Angeles, CA, USA
| |
Collapse
|
19
|
Köthe A, Feuvret L, Safai S, Lomax A, Weber D, Fattori G. Multi-Institutional Analysis of Risk and Predictive Factors of Radiation Induced Optic Neuropathy Associated With Proton Therapy of Skull-Base Tumors. Int J Radiat Oncol Biol Phys 2021. [DOI: 10.1016/j.ijrobp.2021.07.1570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
20
|
Nenoff L, Köthe A, Matter M, Amaya E, Josipovic M, Knopf A, Persson G, Ribeiro C, Safai S, Visser S, Walser M, Weber D, Zhang Y, Lomax A, Fattori G, Albertini F. TCP and NTCP Calculations Based on Treatment Doses Instead of Planned Doses for Daily Adaptive Proton Therapy of Lung Cancer. Int J Radiat Oncol Biol Phys 2021. [DOI: 10.1016/j.ijrobp.2021.07.568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
21
|
Marc L, Fabiano S, Wahl N, Linsenmeier C, Lomax A, Unkelbach J. PO-1905 Combined proton-photon treatment for breast cancer using a fixed proton beamline. Radiother Oncol 2021. [DOI: 10.1016/s0167-8140(21)08356-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
22
|
Nesteruk K, Bobić M, Lalonde A, Lee H, Sharp G, Verburg J, Winey B, Lomax A, Paganetti H. PO-1564 CT on rails versus in-room CBCT for online daily adaptive proton therapy. Radiother Oncol 2021. [DOI: 10.1016/s0167-8140(21)08015-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
23
|
Peters N, Wohlfahrt P, Dahlgren CV, de Marzi L, Ellerbrock M, Fracchiolla F, Free J, Gomà C, Góra J, Jensen MF, Kajdrowicz T, Mackay R, Molinelli S, Rinaldi I, Rompokos V, Siewert D, van der Tol P, Vermeren X, Nyström H, Lomax A, Richter C. Experimental assessment of inter-centre variation in stopping-power and range prediction in particle therapy. Radiother Oncol 2021; 163:7-13. [PMID: 34329653 DOI: 10.1016/j.radonc.2021.07.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 07/01/2021] [Accepted: 07/19/2021] [Indexed: 12/13/2022]
Abstract
PURPOSE Experimental assessment of inter-centre variation and absolute accuracy of stopping-power-ratio (SPR) prediction within 17 particle therapy centres of the European Particle Therapy Network. MATERIAL AND METHODS A head and body phantom with seventeen tissue-equivalent materials were scanned consecutively at the participating centres using their individual clinical CT scan protocol and translated into SPR with their in-house CT-number-to-SPR conversion. Inter-centre variation and absolute accuracy in SPR prediction were quantified for three tissue groups: lung, soft tissues and bones. The integral effect on range prediction for typical clinical beams traversing different tissues was determined for representative beam paths for the treatment of primary brain tumours as well as lung and prostate cancer. RESULTS An inter-centre variation in SPR prediction (2σ) of 8.7%, 6.3% and 1.5% relative to water was determined for bone, lung and soft-tissue surrogates in the head setup, respectively. Slightly smaller variations were observed in the body phantom (6.2%, 3.1%, 1.3%). This translated into inter-centre variation of integral range prediction (2σ) of 2.9%, 2.6% and 1.3% for typical beam paths of prostate-, lung- and primary brain-tumour treatments, respectively. The absolute error in range exceeded 2% in every fourth participating centre. The consideration of beam hardening and the execution of an independent HLUT validation had a positive effect, on average. CONCLUSION The large inter-centre variations in SPR and range prediction justify the currently clinically used margins accounting for range uncertainty, which are of the same magnitude as the inter-centre variation. This study underlines the necessity of higher standardisation in CT-number-to-SPR conversion.
Collapse
Affiliation(s)
- Nils Peters
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany; Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany.
| | - Patrick Wohlfahrt
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany; Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany
| | | | - Ludovic de Marzi
- Institut Curie, PSL Research University, University Paris Saclay, LITO, Orsay, France; Institut Curie, PSL Research University, Radiation Oncology Department, Proton Therapy Centre, Centre Universitaire, Orsay, France
| | - Malte Ellerbrock
- Heidelberg Ion-Beam Therapy Center (HIT), Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
| | | | - Jeffrey Free
- University of Groningen, University Medical Center Groningen, Department of Radiation Oncology, Groningen, The Netherlands
| | - Carles Gomà
- KU Leuven, Department of Oncology, Laboratory of Experimental Radiotherapy, Leuven, Belgium
| | - Joanna Góra
- EBG Medaustron GmbH, Wiener Neustadt, Austria
| | | | - Tomasz Kajdrowicz
- Institute of Nuclear Physics - Polish Academy of Sciences, Krakow, Poland
| | - Ranald Mackay
- University of Manchester - Faculty of Life Sciences, Manchester, United Kingdom
| | | | - Ilaria Rinaldi
- Department of Radiation Oncology (Maastro), GROW School for Oncology, Maastricht University Medical Centre, Maastricht, The Netherlands
| | | | | | | | - Xavier Vermeren
- Westdeutsches Protonentherapiezentrum Essen, Universitätsklinkum Essen, Germany
| | | | | | - Christian Richter
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany; Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany; Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Germany; German Cancer Consortium (DKTK), partner site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany
| |
Collapse
|
24
|
Winterhalter C, Togno M, Nesteruk KP, Emert F, Psoroulas S, Vidal M, Meer D, Weber DC, Lomax A, Safai S. Faraday cup for commissioning and quality assurance for proton pencil beam scanning beams at conventional and ultra-high dose rates. Phys Med Biol 2021; 66. [PMID: 33906166 DOI: 10.1088/1361-6560/abfbf2] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 04/27/2021] [Indexed: 11/11/2022]
Abstract
Recently, proton therapy treatments delivered with ultra-high dose rates have been of high scientific interest, and the Faraday cup (FC) is a promising dosimetry tool for such experiments. Different institutes use different FC designs, and either a high voltage guard ring, or the combination of an electric and a magnetic field is employed to minimize the effect of secondary electrons. The authors first investigate these different approaches for beam energies of 70, 150, 230 and 250 MeV, magnetic fields between 0 and 24 mT and voltages between -1000 and 1000 V. When applying a magnetic field, the measured signal is independent of the guard ring voltage, indicating that this setting minimizes the effect of secondary electrons on the reading of the FC. Without magnetic field, applying the negative voltage however decreases the signal by an energy dependent factor up to 1.3% for the lowest energy tested and 0.4% for the highest energy, showing an energy dependent response. Next, the study demonstrates the application of the FC up to ultra-high dose rates. FC measurements with cyclotron currents up to 800 nA (dose rates of up to approximately 1000 Gy s-1) show that the FC is indeed dose rate independent. Then, the FC is applied to commission the primary gantry monitor for high dose rates. Finally, short-term reproducibility of the monitor calibration is quantified within single days, showing a standard deviation of 0.1% (one sigma). In conclusion, the FC is a promising, dose rate independent tool for dosimetry up to ultra-high dose rates. Caution is however necessary when using a FC without magnetic field, as a guard ring with high voltage alone can introduce an energy dependent signal offset.
Collapse
Affiliation(s)
- C Winterhalter
- Centre for Proton Therapy, Paul Scherrer Institute, Switzerland.,Physics Department, ETH Zurich, Switzerland
| | - M Togno
- Centre for Proton Therapy, Paul Scherrer Institute, Switzerland
| | - K P Nesteruk
- Centre for Proton Therapy, Paul Scherrer Institute, Switzerland
| | - F Emert
- Centre for Proton Therapy, Paul Scherrer Institute, Switzerland
| | - S Psoroulas
- Centre for Proton Therapy, Paul Scherrer Institute, Switzerland
| | - M Vidal
- Institut Mediterraneen de Protontherapie, Centre Antoine Lacassagne, Nice, France
| | - D Meer
- Centre for Proton Therapy, Paul Scherrer Institute, Switzerland
| | - D C Weber
- Centre for Proton Therapy, Paul Scherrer Institute, Switzerland.,Radiation Oncology Department of the University Hospital of Bern, Switzerland.,Radiation Oncology Department of the University Hospital of Zürich, Switzerland
| | - A Lomax
- Centre for Proton Therapy, Paul Scherrer Institute, Switzerland.,Physics Department, ETH Zurich, Switzerland
| | - S Safai
- Centre for Proton Therapy, Paul Scherrer Institute, Switzerland
| |
Collapse
|
25
|
Via R, Hennings F, Pica A, Fattori G, Beer J, Peroni M, Baroni G, Lomax A, Weber DC, Hrbacek J. Potential and pitfalls of 1.5T MRI imaging for target volume definition in ocular proton therapy. Radiother Oncol 2021; 154:53-59. [DOI: 10.1016/j.radonc.2020.08.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 08/25/2020] [Accepted: 08/26/2020] [Indexed: 12/13/2022]
|
26
|
Basler L, Poel R, Schröder C, Bolsi A, Lomax A, Tanadini-Lang S, Guckenberger M, Weber DC. Dosimetric analysis of local failures in skull-base chordoma and chondrosarcoma following pencil beam scanning proton therapy. Radiat Oncol 2020; 15:266. [PMID: 33198810 PMCID: PMC7670611 DOI: 10.1186/s13014-020-01711-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 11/06/2020] [Indexed: 12/04/2022] Open
Abstract
Background Despite combined modality treatment involving surgery and radiotherapy, a relevant proportion of skull-base chordoma and chondrosarcoma patients develop a local recurrence (LR). This study aims to analyze patterns of recurrence and correlate LR with a detailed dosimetric analysis. Methods 222 patients were treated with proton radiotherapy for chordoma (n = 151) and chondrosarcoma (n = 71) at the PSI between 1998 and 2012. All patients underwent surgery, followed by pencil-beam scanning proton therapy to a mean dose of 72.5 ± 2.2GyRBE. A retrospective patterns of recurrence analysis was performed: LR were contoured on follow-up MRI, registered with planning-imaging and the overlap with initial target structures (GTV, PTVhigh-dose, PTVlow-dose) was calculated. DVH parameters of planning structures and recurrences were calculated and correlated with LR using univariate and multivariate cox regression. Results After a median follow-up of 50 months, 35 (16%) LR were observed. Follow-up MRI imaging was available for 27 (77%) of these recurring patients. Only one (3.7%) recurrence was located completely outside the initial PTV (surgical pathway recurrence). The mean proportions of LR covered by the initial target structures were 48% (range 0–86%) for the GTV, 70% (range 0–100%) for PTVhigh and 83% (range 0–100%) for PTVlow. In the univariate analysis, the following DVH parameters were significantly associated with LR: GTV(V < 66GyRBE, p = 0.01), GTV(volume, p = 0.02), PTVhigh(max, p = 0.02), PTVhigh(V < 66GyRBE, p = 0.03), PTVhigh(V < 59GyRBE, p = 0.02), PTVhigh(volume, p = 0.01) and GTV(D95, p = 0.05). In the multivariate analysis, only histology (chordoma vs. chondrosarcoma, p = 0.01), PTVhigh(volume, p = 0.05) and GTV(V < 66GyRBE, p = 0.02) were independent prognostic factors for LR. Conclusion This study identified DVH parameters, which are associated with the risk of local recurrence after proton therapy using pencil-beam scanning for patients with skull-base chordoma and chondrosarcoma.
Collapse
Affiliation(s)
- Lucas Basler
- Center for Proton Therapy, Paul Scherrer Institute, ETH Domain, Forschungsstrasse 111, 5232, Villigen, Switzerland.
| | - Robert Poel
- Center for Proton Therapy, Paul Scherrer Institute, ETH Domain, Forschungsstrasse 111, 5232, Villigen, Switzerland
| | - Christina Schröder
- Center for Proton Therapy, Paul Scherrer Institute, ETH Domain, Forschungsstrasse 111, 5232, Villigen, Switzerland
| | - Alessandra Bolsi
- Center for Proton Therapy, Paul Scherrer Institute, ETH Domain, Forschungsstrasse 111, 5232, Villigen, Switzerland
| | - Antony Lomax
- Center for Proton Therapy, Paul Scherrer Institute, ETH Domain, Forschungsstrasse 111, 5232, Villigen, Switzerland
| | - Stephanie Tanadini-Lang
- Department of Radiation Oncology, University Hospital Zürich, University of Zurich, Zurich, Switzerland
| | - Matthias Guckenberger
- Department of Radiation Oncology, University Hospital Zürich, University of Zurich, Zurich, Switzerland
| | - Damien C Weber
- Center for Proton Therapy, Paul Scherrer Institute, ETH Domain, Forschungsstrasse 111, 5232, Villigen, Switzerland.,Department of Radiation Oncology, University Hospital Zürich, University of Zurich, Zurich, Switzerland.,Department of Radiation Oncology, University Hospital Bern, University of Bern, Bern, Switzerland
| |
Collapse
|
27
|
De Angelis C, Albertini F, Weber D, Walser M, Lomax A, Bolsi A. OC-0702: Is there a correlation between robustness and tumor control for skull base proton PBS treatments? Radiother Oncol 2020. [DOI: 10.1016/s0167-8140(21)00724-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
28
|
Basler L, Schanne D, Schroeder C, De Angelis C, Hrbacek J, Lomax A, Balermpas P, Weber D. Induced Leukopenia In Head And Neck Cancer Patients Treated With Proton Or Photon Radiotherapy. Int J Radiat Oncol Biol Phys 2020. [DOI: 10.1016/j.ijrobp.2020.07.372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
29
|
Colvill E, Safai S, Bieri O, Kozerke S, Weber D, Lomax A, Fattori G. PO-1687: Regional lung motion amplitude and variability assessment from a 4DMRI dataset. Radiother Oncol 2020. [DOI: 10.1016/s0167-8140(21)01705-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
30
|
Colvill E, Krieger M, Bosshard P, Steinacher P, Rohrer Schnidrig BA, Parkel T, Stergiou I, Zhang Y, Peroni M, Safai S, Weber DC, Lomax A, Fattori G. Anthropomorphic phantom for deformable lung and liver CT and MR imaging for radiotherapy. Phys Med Biol 2020; 65:07NT02. [PMID: 32045898 DOI: 10.1088/1361-6560/ab7508] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In this study, a functioning and ventilated anthropomorphic phantom was further enhanced for the purpose of CT and MR imaging of the lung and liver. A deformable lung, including respiratory tract was 3D printed. Within the lung's inner structures is a solid region shaped from a patient's lung tumour and six nitro-glycerine capsules as reference landmarks. The full internal mesh was coated, and the tumour filled, with polyorganosiloxane based gel. A moulded liver was created with an external casing of silicon filled with polyorganosiloxane gel and flexible plastic internal structures. The liver, fitted to the inferior portion of the right lung, moves along with the lung's ventilation. In the contralateral side, a cavity is designed to host a dosimeter, whose motion is correlated to the lung pressure. A 4DCT of the phantom was performed along with static and 4D T1 weighted MR images. The CT Hounsfield units (HU) for the flexible 3D printed material were -600-100 HU (lung and liver structures), for the polyorganosiloxane gel 30-120 HU (lung coating and liver filling) and for the silicon 650-800 HU (liver casing). The MR image intensity units were 0-40, 210-280 and 80-130, respectively. The maximum range of motion in the 4D imaging for the superior lung was 1-3.5 mm and 3.5-8 mm in the inferior portion. The liver motion was 5.5-8.0 mm at the tip and 5.7-10.0 mm at the dome. No measurable drift in motion was observed over a 2 h session and motion was reproducible over three different sessions for sin2(t), sin4(t) and a patient-like breathing curve with the interquartile range of amplitudes for all breathing cycles within 0.5 mm. The addition of features within the lung and of a deformable liver will allow the phantom to be used for imaging studies such as validation of 4DMRI and pseudo CT methods.
Collapse
Affiliation(s)
- Emma Colvill
- Paul Scherrer Institute, Center for Proton Therapy, Villigen, Switzerland. Author to whom any correspondence should be addressed
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Via R, Hennings F, Fattori G, Pica A, Lomax A, Weber DC, Baroni G, Hrbacek J. Technical Note: Benchmarking automated eye tracking and human detection for motion monitoring in ocular proton therapy. Med Phys 2020; 47:2237-2241. [PMID: 32037578 DOI: 10.1002/mp.14087] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 01/17/2020] [Accepted: 02/03/2020] [Indexed: 11/06/2022] Open
Abstract
PURPOSE Ocular proton therapy is an effective therapeutic option for patients affected with uveal melanomas. An optical eye-tracking system (ETS) aiming at noninvasive motion monitoring was developed and tested in a clinical scenario. MATERIALS AND METHODS The ETS estimates eye position and orientation at 25 frames per second using the three-dimensional position of pupil and cornea curvature centers identified, in the treatment room, through stereoscopic optical imaging and infrared eye illumination. Its capabilities for automatic detection of eye motion were retrospectively evaluated on 60 treatment fractions. Then, the ETS performance was benchmarked against the clinical standard based on visual control and manual beam interruption. RESULTS Eye-tracking system detected eye position successfully in 97% of all available frames. Eye-tracking system-based eye monitoring during therapy guarantees quicker response to involuntary eye motions than manual beam interruptions and avoids unnecessary beam interruptions. CONCLUSIONS Eye-tracking system shows promise for on-line monitoring of eye motion. Its introduction in the clinical workflow will guarantee a swifter treatment course for the patient and the clinical personnel.
Collapse
Affiliation(s)
- Riccardo Via
- Paul Scherrer Institut (PSI), Center for Proton Therapy, 5232, Villigen PSI, Switzerland
| | - Fabian Hennings
- Paul Scherrer Institut (PSI), Center for Proton Therapy, 5232, Villigen PSI, Switzerland
| | - Giovanni Fattori
- Paul Scherrer Institut (PSI), Center for Proton Therapy, 5232, Villigen PSI, Switzerland
| | - Alessia Pica
- Paul Scherrer Institut (PSI), Center for Proton Therapy, 5232, Villigen PSI, Switzerland
| | - Antony Lomax
- Paul Scherrer Institut (PSI), Center for Proton Therapy, 5232, Villigen PSI, Switzerland
| | - Damien Charles Weber
- Paul Scherrer Institut (PSI), Center for Proton Therapy, 5232, Villigen PSI, Switzerland.,Department of Radiation Oncology, University Hospital Zurich, Rämistrasse 100, 8091, Zurich, Switzerland.,Department of Radiation Oncology, University Hospital Bern, Freiburgstrasse 18, 3010, Bern, Switzerland
| | - Guido Baroni
- Dipartimento di Elettronica Informazione e Bioingegneria, Politecnico di Milano, Milano, 20133, Italy
| | - Jan Hrbacek
- Paul Scherrer Institut (PSI), Center for Proton Therapy, 5232, Villigen PSI, Switzerland
| |
Collapse
|
32
|
Albertini F, Matter M, Nenoff L, Zhang Y, Lomax A. Online daily adaptive proton therapy. Br J Radiol 2020; 93:20190594. [PMID: 31647313 PMCID: PMC7066958 DOI: 10.1259/bjr.20190594] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 10/15/2019] [Accepted: 10/22/2019] [Indexed: 12/11/2022] Open
Abstract
It is recognized that the use of a single plan calculated on an image acquired some time before the treatment is generally insufficient to accurately represent the daily dose to the target and to the organs at risk. This is particularly true for protons, due to the physical finite range. Although this characteristic enables the generation of steep dose gradients, which is essential for highly conformal radiotherapy, it also tightens the dependency of the delivered dose to the range accuracy. In particular, the use of an outdated patient anatomy is one of the most significant sources of range inaccuracy, thus affecting the quality of the planned dose distribution. A plan should be ideally adapted as soon as anatomical variations occur, ideally online. In this review, we describe in detail the different steps of the adaptive workflow and discuss the challenges and corresponding state-of-the art developments in particular for an online adaptive strategy.
Collapse
Affiliation(s)
| | | | | | - Ye Zhang
- Paul Scherrer Institute, Center for Proton Therapy, Switzerland
| | | |
Collapse
|
33
|
Dominietto M, Kole A, Pica A, Ahlhelm F, Lomax A, Safai S, Weber D. Deep Learning Based on Radiomics Features Dataset to Predict the Outcome of Skull-Base Chordomas Patients Treated with Pencil Beam Scanning Proton Therapy. Int J Radiat Oncol Biol Phys 2019. [DOI: 10.1016/j.ijrobp.2019.06.2168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
34
|
Winterhalter C, Meier G, Oxley D, Weber D, Lomax A, Safai S. PO-0931 Application of a thin, energy-layer specific multi-leaf collimator for proton pencil beam scanning. Radiother Oncol 2019. [DOI: 10.1016/s0167-8140(19)31351-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
35
|
Winterhalter C, Zepter S, Shim S, Meier G, Bolsi A, Fredh A, Hrbacek J, Oxley D, Zhang Y, Weber DC, Lomax A, Safai S. Evaluation of the ray-casting analytical algorithm for pencil beam scanning proton therapy. Phys Med Biol 2019; 64:065021. [PMID: 30641496 DOI: 10.1088/1361-6560/aafe58] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
For pencil beam scanned (PBS) proton therapy, analytical dose calculation engines are still typically used for the optimisation process, and often for the final evaluation of the plan. Recently however, the suitability of analytical calculations for planning PBS treatments has been questioned. Conceptually, the two main approaches for these analytical dose calculations are the ray-casting (RC) and the pencil-beam (PB) method. In this study, we compare dose distributions and dosimetric indices, calculated on both the clinical dose calculation grid and as a function of dose grid resolution, to Monte Carlo (MC) calculations. The analysis is done using a comprehensive set of clinical plans which represent a wide choice of treatment sites. When analysing dose difference histograms for relative treatment plans, pencil beam calculations with double grid resolution perform best, with on average 97.7%/91.9% (RC), 97.9%/92.7% (RC, double grid resolution), 97.6%/91.0% (PB) and 98.6%/94.0% (PB, double grid resolution) of voxels agreeing within ±5%/± 3% between the analytical and the MC calculations. Even though these point-to-point dose comparison shows differences between analytical and MC calculations, for all algorithms, clinically relevant dosimetric indices agree within ±4% for the PTV and within ±5% for critical organs. While the clinical agreement depends on the treatment site, there is no substantial difference of indices between the different algorithms. The pencil-beam approach however comes at a higher computational cost than the ray-casting calculation. In conclusion, we would recommend using the ray-casting algorithm for fast dose optimization and subsequently combine it with one MC calculation to scale the absolute dose and assure the quality of the treatment plan.
Collapse
Affiliation(s)
- Carla Winterhalter
- Centre for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland. Department of Physics, ETH Zurich, Zurich, Switzerland
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Pelak M, Walser M, Bachtiary B, Bolsi A, Hrbacek J, Lomax A, Kliebsch U, Pica A, Weber D. PO-162 Patient outcome of pencil beam-scanning proton therapy in Head and Neck adenoid cystic carcinoma. Radiother Oncol 2019. [DOI: 10.1016/s0167-8140(19)30328-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
37
|
Lomax A. What will the medical physics of proton therapy look like 10 yr from now? A personal view. Med Phys 2018; 45:e984-e993. [DOI: 10.1002/mp.13206] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 07/29/2018] [Accepted: 08/31/2018] [Indexed: 11/06/2022] Open
Affiliation(s)
- Antony Lomax
- Centre for Proton Therapy Paul Scherrer Institute 5232 Villigen Aargau Switzerland
| |
Collapse
|
38
|
Winterhalter C, Fura E, Tian Y, Aitkenhead A, Bolsi A, Dieterle M, Fredh A, Meier G, Oxley D, Siewert D, Weber DC, Lomax A, Safai S. Validating a Monte Carlo approach to absolute dose quality assurance for proton pencil beam scanning. ACTA ACUST UNITED AC 2018; 63:175001. [DOI: 10.1088/1361-6560/aad3ae] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
39
|
Fredh A, Comiskey P, Dillon S, Mayor A, Weber DC, Lomax A. [P158] Analysis of different overlap of patched spot scanned proton fields. Phys Med 2018. [DOI: 10.1016/j.ejmp.2018.06.460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
|
40
|
Klimpki G, Zhang Y, Fattori G, Psoroulas S, Weber DC, Lomax A, Meer D. The impact of pencil beam scanning techniques on the effectiveness and efficiency of rescanning moving targets. ACTA ACUST UNITED AC 2018; 63:145006. [DOI: 10.1088/1361-6560/aacd27] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
41
|
Géli L, Henry P, Grall C, Tary JB, Lomax A, Batsi E, Riboulot V, Cros E, Gürbüz C, Işık SE, Sengör AMC, Le Pichon X, Ruffine L, Dupré S, Thomas Y, Kalafat D, Bayrakci G, Coutellier Q, Regnier T, Westbrook G, Saritas H, Çifçi G, Çağatay MN, Özeren MS, Görür N, Tryon M, Bohnhoff M, Gasperini L, Klingelhoefer F, Scalabrin C, Augustin JM, Embriaco D, Marinaro G, Frugoni F, Monna S, Etiope G, Favali P, Bécel A. Gas and seismicity within the Istanbul seismic gap. Sci Rep 2018; 8:6819. [PMID: 29717139 PMCID: PMC5931589 DOI: 10.1038/s41598-018-23536-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 03/06/2018] [Indexed: 11/13/2022] Open
Abstract
Understanding micro-seismicity is a critical question for earthquake hazard assessment. Since the devastating earthquakes of Izmit and Duzce in 1999, the seismicity along the submerged section of North Anatolian Fault within the Sea of Marmara (comprising the “Istanbul seismic gap”) has been extensively studied in order to infer its mechanical behaviour (creeping vs locked). So far, the seismicity has been interpreted only in terms of being tectonic-driven, although the Main Marmara Fault (MMF) is known to strike across multiple hydrocarbon gas sources. Here, we show that a large number of the aftershocks that followed the M 5.1 earthquake of July, 25th 2011 in the western Sea of Marmara, occurred within a zone of gas overpressuring in the 1.5–5 km depth range, from where pressurized gas is expected to migrate along the MMF, up to the surface sediment layers. Hence, gas-related processes should also be considered for a complete interpretation of the micro-seismicity (~M < 3) within the Istanbul offshore domain.
Collapse
Affiliation(s)
- L Géli
- Ifremer, Département Ressources Physiques et Ecosystèmes de fond de Mer (REM), Plouzané, F-29280, France.
| | - P Henry
- CEREGE, Aix Marseille Univ., CNRS, IRD, INRA, Coll. France, Aix-Marseille, France
| | - C Grall
- CEREGE, Aix Marseille Univ., CNRS, IRD, INRA, Coll. France, Aix-Marseille, France.,Lamont-Doherty Earth Observatory, Palisades, NY, USA
| | - J-B Tary
- Ifremer, Département Ressources Physiques et Ecosystèmes de fond de Mer (REM), Plouzané, F-29280, France.,Universidad de los Andes, Bogotà, Colombia
| | - A Lomax
- ALomax Scientific, 06370, Mouans-Sartoux, France
| | - E Batsi
- Ifremer, Département Ressources Physiques et Ecosystèmes de fond de Mer (REM), Plouzané, F-29280, France
| | - V Riboulot
- Ifremer, Département Ressources Physiques et Ecosystèmes de fond de Mer (REM), Plouzané, F-29280, France
| | - E Cros
- Ifremer, Département Ressources Physiques et Ecosystèmes de fond de Mer (REM), Plouzané, F-29280, France
| | - C Gürbüz
- Kandilli Observatory and Earthquake Research Institute, Boğaziçi University, Istanbul, Turkey
| | - S E Işık
- Kandilli Observatory and Earthquake Research Institute, Boğaziçi University, Istanbul, Turkey
| | | | - X Le Pichon
- CEREGE, Aix Marseille Univ., CNRS, IRD, INRA, Coll. France, Aix-Marseille, France
| | - L Ruffine
- Ifremer, Département Ressources Physiques et Ecosystèmes de fond de Mer (REM), Plouzané, F-29280, France
| | - S Dupré
- Ifremer, Département Ressources Physiques et Ecosystèmes de fond de Mer (REM), Plouzané, F-29280, France
| | - Y Thomas
- Ifremer, Département Ressources Physiques et Ecosystèmes de fond de Mer (REM), Plouzané, F-29280, France
| | - D Kalafat
- Kandilli Observatory and Earthquake Research Institute, Boğaziçi University, Istanbul, Turkey
| | - G Bayrakci
- Ifremer, Département Ressources Physiques et Ecosystèmes de fond de Mer (REM), Plouzané, F-29280, France.,Ocean and Earth Science, National Oceanography Centre, Southampton, UK
| | - Q Coutellier
- Ifremer, Département Ressources Physiques et Ecosystèmes de fond de Mer (REM), Plouzané, F-29280, France
| | - T Regnier
- Ifremer, Département Ressources Physiques et Ecosystèmes de fond de Mer (REM), Plouzané, F-29280, France
| | - G Westbrook
- Ifremer, Département Ressources Physiques et Ecosystèmes de fond de Mer (REM), Plouzané, F-29280, France.,School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - H Saritas
- Mineral Research & Exploration General Directorate, MTA, Ankara, Turkey.,Institute for Marine Science and Technology, Dokuz Eyiul Universitesi, Izmir, Turkey
| | - G Çifçi
- Institute for Marine Science and Technology, Dokuz Eyiul Universitesi, Izmir, Turkey
| | - M N Çağatay
- Istanbul Technical University, Istanbul, Turkey
| | - M S Özeren
- Istanbul Technical University, Istanbul, Turkey
| | - N Görür
- Istanbul Technical University, Istanbul, Turkey
| | - M Tryon
- Ocean and Earth Science, National Oceanography Centre, Southampton, UK
| | - M Bohnhoff
- Helmholtz-Centre Potsdam German Centre for Geosciences GFZ, Section 4.2 Geomechanics and Rheology, Telegrafenberg, 14473, Potsdam, Germany.,Freie Universität Berlin, Department of Earth Sciences, Malteser Strasse 74-100, 12249, Berlin, Germany
| | - L Gasperini
- Institute of Marine Science, ISMAR-CNR, Bologna, Italy
| | - F Klingelhoefer
- Ifremer, Département Ressources Physiques et Ecosystèmes de fond de Mer (REM), Plouzané, F-29280, France
| | - C Scalabrin
- Ifremer, Département Ressources Physiques et Ecosystèmes de fond de Mer (REM), Plouzané, F-29280, France
| | - J-M Augustin
- Ifremer, Département Ressources Physiques et Ecosystèmes de fond de Mer (REM), Plouzané, F-29280, France
| | - D Embriaco
- Istituto Nazionale di Geofisica e Vulcanologia, INGV, Roma, Italy
| | - G Marinaro
- Istituto Nazionale di Geofisica e Vulcanologia, INGV, Roma, Italy
| | - F Frugoni
- Istituto Nazionale di Geofisica e Vulcanologia, INGV, Roma, Italy
| | - S Monna
- Istituto Nazionale di Geofisica e Vulcanologia, INGV, Roma, Italy
| | - G Etiope
- Istituto Nazionale di Geofisica e Vulcanologia, INGV, Roma, Italy.,Faculty of Environmental Science and Engineering, Babes-Bolyai University, Cluj-Napoca, Romania
| | - P Favali
- Istituto Nazionale di Geofisica e Vulcanologia, INGV, Roma, Italy
| | - A Bécel
- Lamont-Doherty Earth Observatory, Palisades, NY, USA
| |
Collapse
|
42
|
Snider JW, Schneider RA, Poelma-Tap D, Stieb S, Murray FR, Placidi L, Albertini F, Lomax A, Bolsi A, Kliebsch U, Malyapa R, Weber DC. Long-Term Outcomes and Prognostic Factors After Pencil-Beam Scanning Proton Radiation Therapy for Spinal Chordomas: A Large, Single-Institution Cohort. Int J Radiat Oncol Biol Phys 2018; 101:226-233. [DOI: 10.1016/j.ijrobp.2018.01.060] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 12/22/2017] [Accepted: 01/16/2018] [Indexed: 01/24/2023]
|
43
|
Delaney A, Dong L, Mascia A, Zou W, Zhang Y, Yin L, Hrbacek J, Lomax A, Slotman B, Dahele M, Verbakel W. OC-0304: Using a single knowledge-based proton planning model to create automated plans for different centers. Radiother Oncol 2018. [DOI: 10.1016/s0167-8140(18)30614-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
|
44
|
Fredh A, Winterhalter C, Fura E, Bolsi A, Safai S, Weber D, Lomax A. EP-1815: Comparison of independent Monte Carlo calculations with measurements of spot scanned proton fields. Radiother Oncol 2018. [DOI: 10.1016/s0167-8140(18)32124-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
|
45
|
Rosas S, Belosi M, Bizzocchi N, Morach P, Zepter S, Weber D, Lomax A, Hrbacek J. EP-2186: An analysis of the clinical performance of Eclipse for PBS proton therapy treatment planning. Radiother Oncol 2018. [DOI: 10.1016/s0167-8140(18)32495-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
|
46
|
Placidi L, Pica A, Ahllhelm F, Walser M, Lomax A, Bolsi A, Weber D. EP-1958: LET evaluation for pediatric craniopharyngioma with cerebral vasculopathies after PBS proton therapy. Radiother Oncol 2018. [DOI: 10.1016/s0167-8140(18)32267-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
|
47
|
Via R, Hennings F, Fattori G, Fassi A, Pica A, Lomax A, Weber DC, Baroni G, Hrbacek J. Noninvasive eye localization in ocular proton therapy through optical eye tracking: A proof of concept. Med Phys 2018; 45:2186-2194. [DOI: 10.1002/mp.12841] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 01/16/2018] [Accepted: 02/17/2018] [Indexed: 11/05/2022] Open
Affiliation(s)
- Riccardo Via
- Dipartimento di Elettronica, Informazione e Bioingegneria; Politecnico di Milano; Milano 20133 Italy
| | - Fabian Hennings
- Center for Proton Therapy; Paul Scherrer Institut; Villigen PSI 5232 Switzerland
| | - Giovanni Fattori
- Center for Proton Therapy; Paul Scherrer Institut; Villigen PSI 5232 Switzerland
| | - Aurora Fassi
- Dipartimento di Elettronica, Informazione e Bioingegneria; Politecnico di Milano; Milano 20133 Italy
| | - Alessia Pica
- Center for Proton Therapy; Paul Scherrer Institut; Villigen PSI 5232 Switzerland
| | - Antony Lomax
- Center for Proton Therapy; Paul Scherrer Institut; Villigen PSI 5232 Switzerland
- Department of Physics; ETH-Hönggerberg; Zurich 8093 Switzerland
| | - Damien Charles Weber
- Center for Proton Therapy; Paul Scherrer Institut; Villigen PSI 5232 Switzerland
- Radiation Oncology Department; Inselspital Universitätsspital Bern; Bern 3010 Switzerland
| | - Guido Baroni
- Dipartimento di Elettronica, Informazione e Bioingegneria; Politecnico di Milano; Milano 20133 Italy
- CNAO Centro Nazionale di Adroterapia Oncologica; Pavia 27100 Italy
| | - Jan Hrbacek
- Center for Proton Therapy; Paul Scherrer Institut; Villigen PSI 5232 Switzerland
| |
Collapse
|
48
|
Winterhalter C, Lomax A, Oxley D, Weber DC, Safai S. A study of lateral fall-off (penumbra) optimisation for pencil beam scanning (PBS) proton therapy. Phys Med Biol 2018; 63:025022. [PMID: 29324441 DOI: 10.1088/1361-6560/aaa2ad] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The lateral fall-off is crucial for sparing organs at risk in proton therapy. It is therefore of high importance to minimize the penumbra for pencil beam scanning (PBS). Three optimisation approaches are investigated: edge-collimated uniformly weighted spots (collimation), pencil beam optimisation of uncollimated pencil beams (edge-enhancement) and the optimisation of edge collimated pencil beams (collimated edge-enhancement). To deliver energies below 70 MeV, these strategies are evaluated in combination with the following pre-absorber methods: field specific fixed thickness pre-absorption (fixed), range specific, fixed thickness pre-absorption (automatic) and range specific, variable thickness pre-absorption (variable). All techniques are evaluated by Monte Carlo simulated square fields in a water tank. For a typical air gap of 10 cm, without pre-absorber collimation reduces the penumbra only for water equivalent ranges between 4-11 cm by up to 2.2 mm. The sharpest lateral fall-off is achieved through collimated edge-enhancement, which lowers the penumbra down to 2.8 mm. When using a pre-absorber, the sharpest fall-offs are obtained when combining collimated edge-enhancement with a variable pre-absorber. For edge-enhancement and large air gaps, it is crucial to minimize the amount of material in the beam. For small air gaps however, the superior phase space of higher energetic beams can be employed when more material is used. In conclusion, collimated edge-enhancement combined with the variable pre-absorber is the recommended setting to minimize the lateral penumbra for PBS. Without collimator, it would be favourable to use a variable pre-absorber for large air gaps and an automatic pre-absorber for small air gaps.
Collapse
Affiliation(s)
- C Winterhalter
- Centre for Proton Therapy, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | | | | | | | | |
Collapse
|
49
|
Klimpki G, Psoroulas S, Bula C, Rechsteiner U, Eichin M, Weber DC, Lomax A, Meer D. A beam monitoring and validation system for continuous line scanning in proton therapy. ACTA ACUST UNITED AC 2017; 62:6126-6143. [DOI: 10.1088/1361-6560/aa772e] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
50
|
Belosi M, Van der Meer R, Garcia de Acilu Laa P, Bolsi A, Weber D, Lomax A. OC-0230: Treatment log files as a tool to identify inaccuracies in scanned proton beam delivery and planning. Radiother Oncol 2017. [DOI: 10.1016/s0167-8140(17)30673-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|