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Bennett LC, Hyer DE, Vu J, Patwardhan K, Erhart K, Gutierrez AN, Pons E, Jensen E, Ubau M, Zapata J, Wroe A, Wake K, Nelson NP, Culberson WS, Smith BR, Hill PM, Flynn RT. Patient-specific quality assurance of dynamically-collimated proton therapy treatment plans. Med Phys 2024. [PMID: 38977285 DOI: 10.1002/mp.17295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 05/16/2024] [Accepted: 06/10/2024] [Indexed: 07/10/2024] Open
Abstract
BACKGROUND The dynamic collimation system (DCS) provides energy layer-specific collimation for pencil beam scanning (PBS) proton therapy using two pairs of orthogonal nickel trimmer blades. While excellent measurement-to-calculation agreement has been demonstrated for simple cube-shaped DCS-trimmed dose distributions, no comparison of measurement and dose calculation has been made for patient-specific treatment plans. PURPOSE To validate a patient-specific quality assurance (PSQA) process for DCS-trimmed PBS treatment plans and evaluate the agreement between measured and calculated dose distributions. METHODS Three intracranial patient cases were considered. Standard uncollimated PBS and DCS-collimated treatment plans were generated for each patient using the Astroid treatment planning system (TPS). Plans were recalculated in a water phantom and delivered at the Miami Cancer Institute (MCI) using an Ion Beam Applications (IBA) dedicated nozzle system and prototype DCS. Planar dose measurements were acquired at two depths within low-gradient regions of the target volume using an IBA MatriXX ion chamber array. RESULTS Measured and calculated dose distributions were compared using 2D gamma analysis with 3%/3 mm criteria and low dose threshold of 10% of the maximum dose. Median gamma pass rates across all plans and measurement depths were 99.0% (PBS) and 98.3% (DCS), with a minimum gamma pass rate of 88.5% (PBS) and 91.2% (DCS). CONCLUSIONS The PSQA process has been validated and experimentally verified for DCS-collimated PBS. Dosimetric agreement between the measured and calculated doses was demonstrated to be similar for DCS-collimated PBS to that achievable with noncollimated PBS.
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Affiliation(s)
- Laura C Bennett
- Roy J. Carver Department of Biomedical Engineering, University of Iowa, 5601 Seamans Center for the Engineering Arts and Sciences, Iowa City, Iowa, USA
| | - Daniel E Hyer
- Department of Radiation Oncology, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - Justin Vu
- Roy J. Carver Department of Biomedical Engineering, University of Iowa, 5601 Seamans Center for the Engineering Arts and Sciences, Iowa City, Iowa, USA
| | - Kaustubh Patwardhan
- Department of Radiation Oncology, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | | | - Alonso N Gutierrez
- Department of Radiation Oncology, Miami Cancer Institute, Baptist Health South Florida, Miami, Florida, USA
| | - Eduardo Pons
- Department of Radiation Oncology, Miami Cancer Institute, Baptist Health South Florida, Miami, Florida, USA
| | - Eric Jensen
- Ion Beam Applications S.A., R&D Proton Therapy, Louvain-La-Neuve, Belgium
| | - Manual Ubau
- Ion Beam Applications S.A., R&D Proton Therapy, Louvain-La-Neuve, Belgium
| | - Julio Zapata
- Ion Beam Applications S.A., R&D Proton Therapy, Louvain-La-Neuve, Belgium
| | - Andrew Wroe
- Department of Radiation Oncology, Miami Cancer Institute, Baptist Health South Florida, Miami, Florida, USA
| | - Karsten Wake
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin, USA
| | - Nicholas P Nelson
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin, USA
- Department of Radiation Oncology, Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah, USA
| | - Wesley S Culberson
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin, USA
| | - Blake R Smith
- Department of Radiation Oncology, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - Patrick M Hill
- Department of Human Oncology, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin, USA
| | - Ryan T Flynn
- Department of Radiation Oncology, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
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Feng H, Holmes JM, Vora SA, Stoker JB, Bues M, Wong WW, Sio TS, Foote RL, Patel SH, Shen J, Liu W. Modelling small block aperture in an in-house developed GPU-accelerated Monte Carlo-based dose engine for pencil beam scanning proton therapy. Phys Med Biol 2024; 69:10.1088/1361-6560/ad0b64. [PMID: 37944480 PMCID: PMC11009986 DOI: 10.1088/1361-6560/ad0b64] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 11/09/2023] [Indexed: 11/12/2023]
Abstract
Purpose. To enhance an in-house graphic-processing-unit accelerated virtual particle (VP)-based Monte Carlo (MC) proton dose engine (VPMC) to model aperture blocks in both dose calculation and optimization for pencil beam scanning proton therapy (PBSPT)-based stereotactic radiosurgery (SRS).Methods and materials. A module to simulate VPs passing through patient-specific aperture blocks was developed and integrated in VPMC based on simulation results of realistic particles (primary protons and their secondaries). To validate the aperture block module, VPMC was first validated by an opensource MC code, MCsquare, in eight water phantom simulations with 3 cm thick brass apertures: four were with aperture openings of 1, 2, 3, and 4 cm without a range shifter, while the other four were with same aperture opening configurations with a range shifter of 45 mm water equivalent thickness. Then, VPMC was benchmarked with MCsquare and RayStation MC for 10 patients with small targets (average volume 8.4 c.c. with range of 0.4-43.3 c.c.). Finally, 3 typical patients were selected for robust optimization with aperture blocks using VPMC.Results. In the water phantoms, 3D gamma passing rate (2%/2 mm/10%) between VPMC and MCsquare was 99.71 ± 0.23%. In the patient geometries, 3D gamma passing rates (3%/2 mm/10%) between VPMC/MCsquare and RayStation MC were 97.79 ± 2.21%/97.78 ± 1.97%, respectively. Meanwhile, the calculation time was drastically decreased from 112.45 ± 114.08 s (MCsquare) to 8.20 ± 6.42 s (VPMC) with the same statistical uncertainties of ~0.5%. The robustly optimized plans met all the dose-volume-constraints (DVCs) for the targets and OARs per our institutional protocols. The mean calculation time for 13 influence matrices in robust optimization by VPMC was 41.6 s and the subsequent on-the-fly 'trial-and-error' optimization procedure took only 71.4 s on average for the selected three patients.Conclusion. VPMC has been successfully enhanced to model aperture blocks in dose calculation and optimization for the PBSPT-based SRS.
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Affiliation(s)
- Hongying Feng
- College of Mechanical and Power Engineering, China Three Gorges University, Yichang, Hubei 443002, People’s Republic of China
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ 85054, United States of America
- Department of Radiation Oncology, Guangzhou Concord Cancer Center, Guangzhou, Guangdong, 510555, People’s Republic of China
| | - Jason M Holmes
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ 85054, United States of America
| | - Sujay A Vora
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ 85054, United States of America
| | - Joshua B Stoker
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ 85054, United States of America
| | - Martin Bues
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ 85054, United States of America
| | - William W Wong
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ 85054, United States of America
| | - Terence S Sio
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ 85054, United States of America
| | - Robert L Foote
- Department of Radiation Oncology, Mayo Clinic, Rochester, MN 55902, United States of America
| | - Samir H Patel
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ 85054, United States of America
| | - Jiajian Shen
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ 85054, United States of America
| | - Wei Liu
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ 85054, United States of America
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Actis O, Mayor A, Meer D, Rechsteiner U, Bolsi A, Lomax AJ, Weber DC. A bi-directional beam-line energy ramping for efficient patient treatment with scanned proton therapy. Phys Med Biol 2023; 68:175001. [PMID: 37506707 DOI: 10.1088/1361-6560/acebb2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 07/28/2023] [Indexed: 07/30/2023]
Abstract
Objective.The treatment of mobile tumours using Pencil Beam Scanning (PBS) has become more prevalent in the last decade. However, to achieve the same beam delivery quality as for static tumours, treatments have to be combined with motion mitigation techniques, not limited but including, breath hold, gating and re-scanning, which typically prolong treatment time. In this article we present a novel method of bi-directional energy modulation and demonstrate our initial experience in improvement of treatment efficiency. Approach.At Paul Scherrer Institute Gantry 2 mobile tumours are treated by combining PBS with gating and volumetric re-scanning (VR), where the target volume is irradiated multiple times. Initial implementation of VR used only descending beam energies, creating a substantial dead time due to the beam-line initialization (ramping) before each re-scan. In 2019 we commissioned an energy meandering strategy that allows us to avoid beam line ramping in-between energy series while maintaining beam delivery quality.Main results.The measured beam parameters difference for both energy sequence are in the order of the typical daily variations: 0.2 mm in beam position and 0.2 mm in range. Using machine log files, we performed point-to-point dose difference calculations between original and new applications where we observed dose differences of less than 2%. After three years of operation employing bi-directional energy modulation, we have analysed the individual beam delivery time for 181 patients and have compared this to simulations of the timing behaviour assuming uni-directional energy sequence application. Depending on treatment complexity, we obtained plan delivery time reductions of up to 55%, with a median time gain of 17% for all types of treatments.Significance. Bi-directional energy modulation can help improving patient treatment efficiency by reducing delivery times especially for complex and specialised irradiations. It could be implemented in many existing facilities without significant additional hardware upgrades.
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Affiliation(s)
- Oxana Actis
- Center for Proton Therapy, Paul Scherrer Institut, Switzerland
| | - Alexandre Mayor
- Center for Proton Therapy, Paul Scherrer Institut, Switzerland
| | - David Meer
- Center for Proton Therapy, Paul Scherrer Institut, Switzerland
| | - Urs Rechsteiner
- Center for Proton Therapy, Paul Scherrer Institut, Switzerland
| | | | - Antony John Lomax
- Center for Proton Therapy, Paul Scherrer Institut, Switzerland
- ETH Zurich, Switzerland
| | - Damien Charles Weber
- Center for Proton Therapy, Paul Scherrer Institut, Switzerland
- University Hospital Zurich, Switzerland
- University Hospital Bern, University of Bern, Switzerland
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4
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Feng H, Holmes JM, Vora SA, Stoker JB, Bues M, Wong WW, Sio TS, Foote RL, Patel SH, Shen J, Liu W. Modelling small block aperture in an in-house developed GPU-accelerated Monte Carlo-based dose engine for pencil beam scanning proton therapy. ARXIV 2023:arXiv:2307.01416v1. [PMID: 37461414 PMCID: PMC10350098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Subscribe] [Scholar Register] [Indexed: 07/22/2023]
Abstract
Purpose To enhance an in-house graphic-processing-unit (GPU) accelerated virtual particle (VP)-based Monte Carlo (MC) proton dose engine (VPMC) to model aperture blocks in both dose calculation and optimization for pencil beam scanning proton therapy (PBSPT)-based stereotactic radiosurgery (SRS). Methods and Materials A module to simulate VPs passing through patient-specific aperture blocks was developed and integrated in VPMC based on simulation results of realistic particles (primary protons and their secondaries). To validate the aperture block module, VPMC was first validated by an opensource MC code, MCsquare, in eight water phantom simulations with 3cm thick brass apertures: four were with aperture openings of 1, 2, 3, and 4cm without a range shifter, while the other four were with same aperture opening configurations with a range shifter of 45mm water equivalent thickness. Then, VPMC was benchmarked with MCsquare and RayStation MC for 10 patients with small targets (average volume 8.4 cc with range of 0.4 - 43.3 cc). Finally, 3 typical patients were selected for robust optimization with aperture blocks using VPMC. Results In the water phantoms, 3D gamma passing rate (2%/2mm/10%) between VPMC and MCsquare was 99.71±0.23%. In the patient geometries, 3D gamma passing rates (3%/2mm/10%) between VPMC/MCsquare and RayStation MC were 97.79±2.21%/97.78±1.97%, respectively. Meanwhile, the calculation time was drastically decreased from 112.45±114.08 seconds (MCsquare) to 8.20±6.42 seconds (VPMC) with the same statistical uncertainties of ~0.5%. The robustly optimized plans met all the dose-volume-constraints (DVCs) for the targets and OARs per our institutional protocols. The mean calculation time for 13 influence matrices in robust optimization by VPMC was 41.6 seconds and the subsequent on-the-fly "trial-and-error" optimization procedure took only 71.4 seconds on average for the selected three patients. Conclusion VPMC has been successfully enhanced to model aperture blocks in dose calculation and optimization for the PBSPT-based SRS.
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Affiliation(s)
- Hongying Feng
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ 85054, USA
| | - Jason M. Holmes
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ 85054, USA
| | | | | | - Martin Bues
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ 85054, USA
| | | | - Terence S. Sio
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ 85054, USA
| | - Robert L. Foote
- Department of Radiation Oncology, Mayo Clinic, Rochester, MN 55902, USA
| | - Samir H. Patel
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ 85054, USA
| | - Jiajian Shen
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ 85054, USA
| | - Wei Liu
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ 85054, USA
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5
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Miyata J, Tominaga Y, Kondo K, Sonoda Y, Hanazawa H, Sakai M, Itasaka S, Oita M, Kuroda M. Dosimetric comparison of pencil beam scanning proton therapy with or without multi-leaf collimator versus volumetric-modulated arc therapy for treatment of malignant glioma. Med Dosim 2023; 48:105-112. [PMID: 36914455 DOI: 10.1016/j.meddos.2023.01.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 01/24/2023] [Accepted: 01/26/2023] [Indexed: 03/14/2023]
Abstract
This study aimed to examine the dosimetric effect of intensity-modulated proton therapy (IMPT) with a multi-leaf collimator (MLC) in treating malignant glioma. We compared the dose distribution of IMPT with or without MLC (IMPTMLC+ or IMPTMLC-, respectively) using pencil beam scanning and volumetric-modulated arc therapy (VMAT) in simultaneous integrated boost (SIB) plans for 16 patients with malignant gliomas. High- and low-risk target volumes were assessed using D2%, V90%, V95%, homogeneity index (HI), and conformity index (CI). Organs at risk (OARs) were evaluated using the average dose (Dmean) and D2%. Furthermore, the dose to the normal brain was evaluated using from V5Gy to V40Gy at 5 Gy intervals. There were no significant differences among all techniques regarding V90%, V95%, and CI for the targets. HI and D2% for IMPTMLC+ and IMPTMLC- were significantly superior to those for VMAT (p < 0.01). The Dmean and D2% of all OARs for IMPTMLC+ were equivalent or superior to those of other techniques. Regarding the normal brain, there was no significant difference in V40Gy among all techniques whereas V5Gy to V35Gy in IMPTMLC+ were significantly smaller than those in IMPTMLC- (with differences ranging from 0.45% to 4.80%, p < 0.05) and VMAT (with differences ranging from 6.85% to 57.94%, p < 0.01). IMPTMLC+ could reduce the dose to OARs, while maintaining target coverage compared to IMPTMLC- and VMAT in treating malignant glioma.
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Affiliation(s)
- Junya Miyata
- Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University, Okayama, Okayama, Japan; Department of Radiological Technology, Kurashiki Central Hospital, Kurashiki, Okayama, Japan
| | - Yuki Tominaga
- Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University, Okayama, Okayama, Japan; Department of Radiotherapy, Medical Co. Hakuhokai, Osaka Proton Therapy Clinic, Osaka, Osaka, Japan
| | - Kazuto Kondo
- Department of Radiological Technology, Kurashiki Central Hospital, Kurashiki, Okayama, Japan
| | - Yasuaki Sonoda
- Department of Radiological Technology, Kurashiki Central Hospital, Kurashiki, Okayama, Japan
| | - Hideki Hanazawa
- Department of Radiation Oncology, Kurashiki Central Hospital, Kurashiki, Okayama, Japan
| | - Mami Sakai
- Department of Radiation Oncology, Kurashiki Central Hospital, Kurashiki, Okayama, Japan
| | - Satoshi Itasaka
- Department of Radiation Oncology, Kurashiki Central Hospital, Kurashiki, Okayama, Japan
| | - Masataka Oita
- Faculty of Interdisciplinary Science and Engineering in Health Systems, Okayama University, Okayama, Okayama, Japan.
| | - Masahiro Kuroda
- Graduate School of Health Sciences, Okayama University, Okayama, Okayama, Japan
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6
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Nelson NP, Culberson WS, Hyer DE, Geoghegan TJ, Patwardhan KA, Smith BR, Flynn RT, Yu J, Gutiérrez AN, Hill PM. Dosimetric delivery validation of dynamically collimated pencil beam scanning proton therapy. Phys Med Biol 2023; 68:055003. [PMID: 36706460 PMCID: PMC9940016 DOI: 10.1088/1361-6560/acb6cd] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 01/27/2023] [Indexed: 01/28/2023]
Abstract
Objective. Pencil beam scanning (PBS) proton therapy target dose conformity can be improved with energy layer-specific collimation. One such collimator is the dynamic collimation system (DCS), which consists of four nickel trimmer blades that intercept the scanning beam as it approaches the lateral extent of the target. While the dosimetric benefits of the DCS have been demonstrated through computational treatment planning studies, there has yet to be experimental verification of these benefits for composite multi-energy layer fields. The objective of this work is to dosimetrically characterize and experimentally validate the delivery of dynamically collimated proton therapy with the DCS equipped to a clinical PBS system.Approach. Optimized single field, uniform dose treatment plans for 3 × 3 × 3 cm3target volumes were generated using Monte Carlo dose calculations with depths ranging from 5 to 15 cm, trimmer-to-surface distances ranging from 5 to 18.15 cm, with and without a 4 cm thick polyethylene range shifter. Treatment plans were then delivered to a water phantom using a prototype DCS and an IBA dedicated nozzle system and measured with a Zebra multilayer ionization chamber, a MatriXX PT ionization chamber array, and Gafchromic™ EBT3 film.Main results. For measurements made within the SOBPs, average 2D gamma pass rates exceeded 98.5% for the MatriXX PT and 96.5% for film at the 2%/2 mm criterion across all measured uncollimated and collimated plans, respectively. For verification of the penumbra width reduction with collimation, film agreed with Monte Carlo with differences within 0.3 mm on average compared to 0.9 mm for the MatriXX PT.Significance. We have experimentally verified the delivery of DCS-collimated fields using a clinical PBS system and commonly available dosimeters and have also identified potential weaknesses for dosimeters subject to steep dose gradients.
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Affiliation(s)
- Nicholas P Nelson
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin—Madison, 1111 Highland Avenue, Madison, WI, 53705, United States of America,Author to whom any correspondence should be addressed
| | - Wesley S Culberson
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin—Madison, 1111 Highland Avenue, Madison, WI, 53705, United States of America
| | - Daniel E Hyer
- Department of Radiation Oncology, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, IA, 52242, United States of America
| | - Theodore J Geoghegan
- Department of Radiation Oncology, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, IA, 52242, United States of America
| | - Kaustubh A Patwardhan
- Department of Radiation Oncology, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, IA, 52242, United States of America
| | - Blake R Smith
- Department of Radiation Oncology, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, IA, 52242, United States of America
| | - Ryan T Flynn
- Department of Radiation Oncology, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, IA, 52242, United States of America
| | - Jen Yu
- Department of Radiation Oncology, Miami Cancer Institute, Baptist Health South Florida, 8900 N. Kendall Drive, Miami, FL, 33176, United States of America
| | - Alonso N Gutiérrez
- Department of Radiation Oncology, Miami Cancer Institute, Baptist Health South Florida, 8900 N. Kendall Drive, Miami, FL, 33176, United States of America
| | - Patrick M Hill
- Department of Human Oncology, School of Medicine and Public Health, University of Wisconsin—Madison, 600 Highland Avenue, Madison, WI, 53792, United States of America
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Rädler M, Buizza G, Kawula M, Palaniappan P, Gianoli C, Baroni G, Paganelli C, Parodi K, Riboldi M. Impact of secondary particles on the magnetic field generated by a proton pencil beam: a finite-element analysis based on Geant4-DNA simulations. Med Phys 2023; 50:1000-1018. [PMID: 36346042 DOI: 10.1002/mp.16062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 09/22/2022] [Accepted: 09/27/2022] [Indexed: 11/11/2022] Open
Abstract
PURPOSE To investigate the static magnetic field generated by a proton pencil beam as a candidate for range verification by means of Monte Carlo simulations, thereby improving upon existing analytical calculations. We focus on the impact of statistical current fluctuations and secondary protons and electrons. METHODS We considered a pulsed beam (10 μ ${\umu}$ s pulse duration) during the duty cycle with a peak beam current of 0.2 μ $\umu$ A and an initial energy of 100 MeV. We ran Geant4-DNA Monte Carlo simulations of a proton pencil beam in water and extracted independent particle phase spaces. We calculated longitudinal and radial current density of protons and electrons, serving as an input for a magnetic field estimation based on a finite element analysis in a cylindrical geometry. We made sure to allow for non-solenoidal current densities as is the case of a stopping proton beam. RESULTS The rising proton charge density toward the range is not perturbed by energy straggling and only lowered through nuclear reactions by up to 15%, leading to an approximately constant longitudinal current. Their relative low density however (at most 0.37 protons/mm3 for the 0.2 μ ${\umu}$ A current and a beam cross-section of 2.5 mm), gives rise to considerable current density fluctuations. The radial proton current resulting from lateral scattering and being two orders of magnitude weaker than the longitudinal current is subject to even stronger fluctuations. Secondary electrons with energies above 10 eV, that far outnumber the primary protons, reduce the primary proton current by only 10% due to their largely isotropic flow. A small fraction of electrons (<1%), undergoing head-on collisions, constitutes the relevant electron current. In the far-field, both contributions to the magnetic field strength (longitudinal and lateral) are independent of the beam spot size. We also find that the nuclear reaction-related losses cause a shift of 1.3 mm to the magnetic field profile relative to the actual range, which is further enlarged to 2.4 mm by the electron current (at a distance of ρ = 50 $\rho =50$ mm away from the central beam axis). For ρ > 45 $\rho >45$ mm, the shift increases linearly. While the current density variations cause significant magnetic field uncertainty close to the central beam axis with a relative standard deviation (RSD) close to 100%, they average out at a distance of 10 cm, where the RSD of the total magnetic field drops below 2%. CONCLUSIONS With the small influence of the secondary electrons together with the low RSD, our analysis encourages an experimental detection of the magnetic field through sensitive instrumentation, such as optical magnetometry or SQUIDs.
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Affiliation(s)
- Martin Rädler
- Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Giulia Buizza
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Piazza Leonardo da Vinci, Milan, Italy
| | - Maria Kawula
- Department of Radiation Oncology, LMU Hospital, Munich, Germany
| | - Prasannakumar Palaniappan
- Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Chiara Gianoli
- Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Guido Baroni
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Piazza Leonardo da Vinci, Milan, Italy
| | - Chiara Paganelli
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Piazza Leonardo da Vinci, Milan, Italy
| | - Katia Parodi
- Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Marco Riboldi
- Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität München, Munich, Germany
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8
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Chang S, Liu G, Zhao L, Zheng W, Yan D, Chen P, Li X, Yang K, Deraniyagala R, Stevens C, Grills I, Chinnaiyan P, Li X, Ding X. Redefine the Role of Spot-Scanning Proton Beam Therapy for the Single Brain Metastasis Stereotactic Radiosurgery. Front Oncol 2022; 12:804036. [PMID: 35664795 PMCID: PMC9160604 DOI: 10.3389/fonc.2022.804036] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 04/14/2022] [Indexed: 12/30/2022] Open
Abstract
Purpose To explore the role of using Pencil Beam Scanning (PBS) proton beam therapy in single lesion brain stereotactic radiosurgery (SRS), we developed and validated a dosimetric in silico model to assist in the selection of an optimal treatment approach among the conventional Volumetric Modulated Arc Therapy (VMAT), Intensity Modulated Proton Therapy (IMPT) and Spot-scanning Proton Arc (SPArc). Material and Methods A patient’s head CT data set was used as an in silico model. A series of targets (volume range from 0.3 cc to 33.03 cc) were inserted in the deep central and peripheral region, simulating targets with different sizes and locations. Three planning groups: IMPT, VMAT, and SPArc were created for dosimetric comparison purposes and a decision tree was built based on this in silico model. Nine patients with single brain metastases were retrospectively selected for validation. Multiple dosimetric metrics were analyzed to assess the plan quality, such as dose Conformity Index (CI) (ratio of the target volume to 100% prescription isodose volume); R50 (ratio of 50% prescription isodose volume to the target volume); V12Gy (volume of brain tissue minus GTV receiving 12 Gy), and mean dose of the normal brain. Normal tissue complication probability (NTCP) of brain radionecrosis (RN) was calculated using the Lyman-Kutcher-Burman (LKB) model and total treatment delivery time was calculated. Six physicians from different institutions participated in the blind survey to evaluate the plan quality and rank their choices. Results The study showed that SPArc has a dosimetric advantage in the V12Gy and R50 with target volumes > 9.00 cc compared to VMAT and IMPT. A significant clinical benefit can be found in deep centrally located lesions larger than 20.00 cc using SPArc because of the superior dose conformity and mean dose reduction in healthy brain tissue. Nine retrospective clinical cases and the blind survey showed good agreement with the in silico dosimetric model and decision tree. Additionally, SPArc significantly reduced the treatment delivery time compared to VMAT (SPArc 184.46 ± 59.51s vs. VMAT: 1574.78 ± 213.65s). Conclusion The study demonstrated the feasibility of using Proton beam therapy for single brain metastasis patients utilizing the SPArc technique. At the current stage of technological development, VMAT remains the current standard modality of choice for single lesion brain SRS. The in silico dosimetric model and decision tree presented here could be used as a practical clinical decision tool to assist the selection of the optimal treatment modality among VMAT, IMPT, and SPArc in centers that have both photon and proton capabilities.
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Affiliation(s)
- Sheng Chang
- Department of Radiation Oncology, Renmin Hospital, Wuhan University, Wuhan, China
- Department of Radiation Oncology, Beaumont Health System, Royal Oak, MI, United States
| | - Gang Liu
- Department of Radiation Oncology, Beaumont Health System, Royal Oak, MI, United States
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Lewei Zhao
- Department of Radiation Oncology, Beaumont Health System, Royal Oak, MI, United States
| | - Weili Zheng
- Department of Radiation Oncology, Beaumont Health System, Royal Oak, MI, United States
| | - Di Yan
- Department of Radiation Oncology, Beaumont Health System, Royal Oak, MI, United States
| | - Peter Chen
- Department of Radiation Oncology, Beaumont Health System, Royal Oak, MI, United States
| | - Xiangpan Li
- Department of Radiation Oncology, Renmin Hospital, Wuhan University, Wuhan, China
| | - Kunyu Yang
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Rohan Deraniyagala
- Department of Radiation Oncology, Beaumont Health System, Royal Oak, MI, United States
| | - Craig Stevens
- Department of Radiation Oncology, Beaumont Health System, Royal Oak, MI, United States
| | - Inga Grills
- Department of Radiation Oncology, Beaumont Health System, Royal Oak, MI, United States
| | - Prakash Chinnaiyan
- Department of Radiation Oncology, Beaumont Health System, Royal Oak, MI, United States
| | - Xiaoqiang Li
- Department of Radiation Oncology, Beaumont Health System, Royal Oak, MI, United States
| | - Xuanfeng Ding
- Department of Radiation Oncology, Beaumont Health System, Royal Oak, MI, United States
- *Correspondence: Xuanfeng Ding,
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9
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Holmes J, Shen J, Shan J, Patrick CL, Wong WW, Foote RL, Patel SH, Bues M, Liu W. Technical Note: Evaluation and 2nd check of a commercial Monte Carlo dose engine for small-field apertures in pencil beam scanning proton therapy. Med Phys 2022; 49:3497-3506. [PMID: 35305269 DOI: 10.1002/mp.15604] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 02/19/2022] [Accepted: 03/02/2022] [Indexed: 11/10/2022] Open
Abstract
PURPOSE To evaluate the accuracy of the RayStation Monte Carlo dose engine (RayStation MC) in modeling small-field block apertures in proton pencil beam scanning. Furthermore, we evaluate the suitability of MCsquare as a 2nd check for RayStation MC. METHODS We have enhanced MCsquare to model block apertures. To test the accuracy of both RayStation MC and the newly enhanced MCsquare, we compare the dose predictions of each to in-water dose measurements obtained using diode detectors and radiochromic film. Nine brass apertures with openings of 1, 2, 3, 4, and 5 cm and either 2 cm or 4 cm thickness were used in the irradiation of a water phantom. Two measurement setups were used, one with a range shifter and 119.7 MeV proton beam energy and the other with no range shifter and 147 MeV proton beam energy. To further test the validity of RayStation MC and MCsquare in modeling block apertures and to evaluate MCsquare as a 2nd check tool, ten small-field (average target volume 8.3 cm3 ) patient treatment plans were calculated by each dose engine followed by a statistical comparison. RESULTS Comparing to the absolute dose measurements in water, RayStation MC differed by 1.2% ± 1.0% while MCsquare differed by -1.8% ± 3.7% in the plateau region of a pristine Bragg peak. Compared to the in-water film measurements, RayStation MC and MCsquare both performed well with an average 2D-3D gamma passing rate of 99.4% and 99.7% (3%/3mm) respectively. A t-test comparing the agreement with the film measurements between RayStation MC and MCsquare suggested that the relative spatial dose distributions calculated by MCsquare and RayStation MC were statistically indistinguishable. Directly comparing the dose calculations between MCsquare and RayStation MC over ten patients resulted in an average 3D-3D gamma passing rates of 98.5% (3%/3mm) and 94.1% (2%/2mm) respectively. CONCLUSION The validity of RayStation MC algorithm for use with patient-specific apertures has been expanded to include small apertures. MCsquare has been enhanced to model apertures and was found to be an adequate 2nd check of RayStation MC in this scenario. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Jason Holmes
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, 85054, USA
| | - Jiajian Shen
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, 85054, USA
| | - Jie Shan
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, 85054, USA
| | | | - William W Wong
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, 85054, USA
| | - Robert L Foote
- Department of Radiation Oncology, Mayo Clinic, Rochester, MN, 55902, USA
| | - Samir H Patel
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, 85054, USA
| | - Martin Bues
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, 85054, USA
| | - Wei Liu
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, 85054, USA
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10
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ur Rehman M, Zeidan OA, Willoughby T, Meeks SL, Kelly P, Erhart K. Dosimetric Comparison of Various Spot Placement Techniques in Proton Pencil Beam Scanning. Int J Part Ther 2022; 9:54-63. [PMID: 35774494 PMCID: PMC9238129 DOI: 10.14338/ijpt-21-00022.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 11/30/2021] [Indexed: 11/30/2022] Open
Abstract
Purpose To present quantitative dosimetric evaluations of five proton pencil beam spot placement techniques. Materials and Methods The spot placement techniques that were investigated include two grid-based (rectilinear grid and hexagonal grid, both commonly available in commercial planning systems) and three boundary-contoured (concentric contours, hybrid, and optimized) techniques. Treatment plans were created for two different target volumes, one spherical and one conical. An optimal set of planning parameters was defined for all treatment plans and the impact of spot placement techniques on the plan quality was evaluated in terms of lateral/distal dose falloff, normal tissue sparing, conformity and homogeneity of dose distributions, as well as total number of spots used. Results The results of this work highlight that for grid-based spot placement techniques, the dose conformity is dependent on target cross-sectional shape perpendicular to beam direction, which changes for each energy layer. This variable conformity problem is mitigated by using boundary contoured spot placement techniques. However, in the case of concentric contours, the conformity is improved but at the cost of decreased homogeneity inside the target. Hybrid and optimized spot placement techniques, which use contoured spots at the boundary and gridlike interior spot patterns, provide more uniform dose distributions inside the target volume while maintaining the improved dose conformity. The optimized spot placement technique improved target coverage, homogeneity of dose, and minimal number of spots. The dependence of these results on spot size is also presented for both target shapes. Conclusion This work illustrates that boundary-contoured spot placement techniques offer marked improvement in dosimetry metrics when compared to commercially available grid-based techniques for a range of proton scanned beam spot sizes.
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11
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Rana S, Rosenfeld AB. Small spot size versus large spot size: Effect on plan quality for lung cancer in pencil beam scanning proton therapy. J Appl Clin Med Phys 2022; 23:e13512. [PMID: 34989458 PMCID: PMC8833272 DOI: 10.1002/acm2.13512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Revised: 11/26/2021] [Accepted: 12/10/2021] [Indexed: 11/09/2022] Open
Abstract
Purpose The purpose of the current study was to evaluate the impact of spot size on the interplay effect, plan robustness, and dose to the organs at risk for lung cancer plans in pencil beam scanning (PBS) proton therapy Methods The current retrospective study included 13 lung cancer patients. For each patient, small spot (∼3 mm) plans and large spot (∼8 mm) plans were generated. The Monte Carlo algorithm was used for both robust plan optimization and final dose calculations. Each plan was normalized, such that 99% of the clinical target volume (CTV) received 99% of the prescription dose. Interplay effect was evaluated for treatment delivery starting in two different breathing phases (T0 and T50). Plan robustness was investigated for 12 perturbed scenarios, which combined the isocenter shift and range uncertainty. The nominal and worst‐case scenario (WCS) results were recorded for each treatment plan. Equivalent uniform dose (EUD) and normal tissue complication probability (NTCP) were evaluated for the total lung, heart, and esophagus. Results In comparison to large spot plans, the WCS values of small spot plans at CTV D95%, D96%, D97%, D98%, and D99% were higher with the average differences of 2.2% (range, 0.3%–3.7%), 2.3% (range, 0.5%–4.0%), 2.6% (range, 0.6%–4.4%), 2.7% (range, 0.9%–5.2%), and 2.7% (range, 0.3%–6.0%), respectively. The nominal and WCS mean dose and EUD for the esophagus, heart, and total lung were higher in large spot plans. The difference in NTCP between large spot and small spot plans was up to 1.9% for the total lung, up to 0.3% for the heart, and up to 32.8% for the esophagus. For robustness acceptance criteria of CTV D95% ≥ 98% of the prescription dose, seven small spot plans had all 12 perturbed scenarios meeting the criteria, whereas, for 13 large spot plans, there were ≥2 scenarios failing to meet the criteria. Interplay results showed that, on average, the target coverage in large spot plans was higher by 1.5% and 0.4% in non‐volumetric and volumetric repainting plans, respectively. Conclusion For robustly optimized PBS lung cancer plans in our study, a small spot machine resulted in a more robust CTV against the setup and range errors when compared to a large spot machine. In the absence of volumetric repainting, large spot PBS lung plans were more robust against the interplay effect. The use of a volumetric repainting technique in both small and large spot PBS lung plans led to comparable interplay target coverage.
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Affiliation(s)
- Suresh Rana
- Department of Medical Physics, The Oklahoma Proton Center, Oklahoma City, Oklahoma, USA.,Department of Radiation Oncology, Boca Raton Regional Hospital, Lynn Cancer Institute, Baptist Health South Florida, Boca Raton, Florida, USA.,Department of Radiation Oncology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida, USA.,Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
| | - Anatoly B Rosenfeld
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
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12
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Normal Tissue Complication Probability Modelling for Toxicity Prediction and Patient Selection in Proton Beam Therapy to the Central Nervous System: A Literature Review. Clin Oncol (R Coll Radiol) 2022; 34:e225-e237. [DOI: 10.1016/j.clon.2021.12.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 11/22/2021] [Accepted: 12/21/2021] [Indexed: 11/22/2022]
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13
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Yap J, De Franco A, Sheehy S. Future Developments in Charged Particle Therapy: Improving Beam Delivery for Efficiency and Efficacy. Front Oncol 2021; 11:780025. [PMID: 34956897 PMCID: PMC8697351 DOI: 10.3389/fonc.2021.780025] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 11/16/2021] [Indexed: 01/09/2023] Open
Abstract
The physical and clinical benefits of charged particle therapy (CPT) are well recognized. However, the availability of CPT and complete exploitation of dosimetric advantages are still limited by high facility costs and technological challenges. There are extensive ongoing efforts to improve upon these, which will lead to greater accessibility, superior delivery, and therefore better treatment outcomes. Yet, the issue of cost remains a primary hurdle as utility of CPT is largely driven by the affordability, complexity and performance of current technology. Modern delivery techniques are necessary but limited by extended treatment times. Several of these aspects can be addressed by developments in the beam delivery system (BDS) which determines the overall shaping and timing capabilities enabling high quality treatments. The energy layer switching time (ELST) is a limiting constraint of the BDS and a determinant of the beam delivery time (BDT), along with the accelerator and other factors. This review evaluates the delivery process in detail, presenting the limitations and developments for the BDS and related accelerator technology, toward decreasing the BDT. As extended BDT impacts motion and has dosimetric implications for treatment, we discuss avenues to minimize the ELST and overview the clinical benefits and feasibility of a large energy acceptance BDS. These developments support the possibility of advanced modalities and faster delivery for a greater range of treatment indications which could also further reduce costs. Further work to realize methodologies such as volumetric rescanning, FLASH, arc, multi-ion and online image guided therapies are discussed. In this review we examine how increased treatment efficiency and efficacy could be achieved with improvements in beam delivery and how this could lead to faster and higher quality treatments for the future of CPT.
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Affiliation(s)
- Jacinta Yap
- School of Physics, University of Melbourne, Melbourne, VIC, Australia
| | - Andrea De Franco
- IFMIF Accelerator Development Group, Rokkasho Fusion Institute, National Institutes for Quantum Science and Technology, Aomori, Japan
| | - Suzie Sheehy
- School of Physics, University of Melbourne, Melbourne, VIC, Australia
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14
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Lin B, Fu S, Lin Y, Rotondo RL, Huang W, Li HH, Chen RC, Gao H. An adaptive spot placement method on Cartesian grid for pencil beam scanning proton therapy. Phys Med Biol 2021; 66:10.1088/1361-6560/ac3b65. [PMID: 34798620 PMCID: PMC9311299 DOI: 10.1088/1361-6560/ac3b65] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 11/19/2021] [Indexed: 11/11/2022]
Abstract
Pencil beam scanning proton radiotherapy (RT) offers flexible proton spot placement near treatment targets for delivering tumoricidal radiation dose to tumor targets while sparing organs-at-risk. Currently the spot placement is mostly based on a non-adaptive sampling (NS) strategy on a Cartesian grid. However, the spot density or spacing during NS is a constant for the Cartesian grid that is independent of the geometry of tumor targets, and thus can be suboptimal in terms of plan quality (e.g. target dose conformality) and delivery efficiency (e.g. number of spots). This work develops an adaptive sampling (AS) spot placement method on the Cartesian grid that fully accounts for the geometry of tumor targets. Compared with NS, AS places (1) a relatively fine grid of spots at the boundary of tumor targets to account for the geometry of tumor targets and treatment uncertainties (setup and range uncertainty) for improving dose conformality, and (2) a relatively coarse grid of spots in the interior of tumor targets to reduce the number of spots for improving delivery efficiency and robustness to the minimum-minitor-unit (MMU) constraint. The results demonstrate that (1) AS achieved comparable plan quality with NS for regular MMU and substantially improved plan quality from NS for large MMU, using merely about 10% of spots from NS, where AS was derived from the same Cartesian grid as NS; (2) on the other hand, with similar number of spots, AS had better plan quality than NS consistently for regular and large MMU.
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Affiliation(s)
- Bowen Lin
- School of Mathematics, Shandong University, Jinan, People's Republic of China
| | - Shujun Fu
- School of Mathematics, Shandong University, Jinan, People's Republic of China
| | - Yuting Lin
- Department of Radiation Oncology, University of Kansas Medical Center, Kansas City, United States of America
| | - Ronny L Rotondo
- Department of Radiation Oncology, University of Kansas Medical Center, Kansas City, United States of America
| | - Weizhang Huang
- Department of Mathematics, University of Kansas, Lawrence, United States of America
| | - Harold H Li
- Department of Radiation Oncology, University of Kansas Medical Center, Kansas City, United States of America
| | - Ronald C Chen
- Department of Radiation Oncology, University of Kansas Medical Center, Kansas City, United States of America
| | - Hao Gao
- Department of Radiation Oncology, University of Kansas Medical Center, Kansas City, United States of America
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15
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Righetto R, Fellin F, Scartoni D, Amichetti M, Schwarz M, Amelio D, Farace P. Is it beneficial to use apertures in proton radiosurgery with a scanning beam? A dosimetric comparison in neurinoma and meningioma patients. J Appl Clin Med Phys 2021; 23:e13459. [PMID: 34751499 PMCID: PMC8833271 DOI: 10.1002/acm2.13459] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 10/07/2021] [Accepted: 10/08/2021] [Indexed: 11/10/2022] Open
Abstract
PURPOSE To assess the dosimetric advantages of apertures in intracranial single fraction proton radiosurgery. MATERIALS AND METHODS Six neuroma and 10 meningioma patients were investigated. For each patient, six plans were computed, with two spot spacing and three aperture settings (no apertures, 5 and 8 mm margin between aperture and clinical target volume [CTV]). All plans were optimized on the CTV with the same beam arrangement and the same single-field robust optimization (2 mm setup errors, 3.5% range uncertainties). Robustness analysis was performed with 0.5 and 1.0 mm systematic setup errors and 3.5% range uncertainties. CTV coverage in the perturbed scenarios and healthy brain tissue sparing in the surrounding of the CTV were compared. RESULTS Meningiomas were larger and at a shallow depth than neuromas. In neuromas, spot spacing did not affect OAR doses or the robustness of CTV coverage and the apertures reduced brain dose without any significant impact on CTV robustness. In meningiomas, smaller spot spacing produced a reduction in brain V5Gy and improved robustness of CTV coverage; in addition, an 8 mm margin aperture reduced low and medium brain tissue doses without affecting robustness in the 0.5 mm perturbed scenario. A 5 mm margin aperture caused a reduction of plan robustness. CONCLUSION The optimal use of apertures is a trade-off between sparing of low and medium dose to the healthy brain and robustness of target coverage, also depending on size and depth of the lesion.
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Affiliation(s)
- Roberto Righetto
- Proton Therapy Unit, S. Chiara Hospital-Azienda Provinciale per I Servizi Sanitari (APSS), Trento, Italy
| | - Francesco Fellin
- Proton Therapy Unit, S. Chiara Hospital-Azienda Provinciale per I Servizi Sanitari (APSS), Trento, Italy
| | - Daniele Scartoni
- Proton Therapy Unit, S. Chiara Hospital-Azienda Provinciale per I Servizi Sanitari (APSS), Trento, Italy
| | - Maurizio Amichetti
- Proton Therapy Unit, S. Chiara Hospital-Azienda Provinciale per I Servizi Sanitari (APSS), Trento, Italy
| | - Marco Schwarz
- Proton Therapy Unit, S. Chiara Hospital-Azienda Provinciale per I Servizi Sanitari (APSS), Trento, Italy.,Trento Institute for Fundamental Physics and Applications (TIFPA), National Institute for Nuclear Physics, (INFN), Povo, Italy
| | - Dante Amelio
- Proton Therapy Unit, S. Chiara Hospital-Azienda Provinciale per I Servizi Sanitari (APSS), Trento, Italy
| | - Paolo Farace
- Proton Therapy Unit, S. Chiara Hospital-Azienda Provinciale per I Servizi Sanitari (APSS), Trento, Italy
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16
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Fukumitsu N, Yamashita T, Mima M, Demizu Y, Suzuki T, Soejima T. Dose distribution effects of spot-scanning proton beam therapy equipped with a multi-leaf collimator for pediatric brain tumors. Oncol Lett 2021; 22:635. [PMID: 34295382 PMCID: PMC8273856 DOI: 10.3892/ol.2021.12896] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 06/15/2021] [Indexed: 11/06/2022] Open
Abstract
The present study simulated the effect of spot-scanning proton beam therapy (PBT) performed using a device equipped with a multi-leaf collimator (MLC) to calculate the dose distribution. Simulation studies using 18 pediatric patients with brain tumors in the posterior fossa were performed. Treatment plans were created for the MLC at different stages: Fully open (initial plan), fully closed to allow an irradiated area extending to 15 mm from the clinical target volume (CTV) (15-mm plan), or closing only the leaves where an organ at risk (OAR) overlapped with a border at 10 or 5 mm from the CTV (10- and 5-mm plans, respectively). The mean dose values for the brainstem, cervical cord, brain and cochlea in all MLC closure plans decreased as the MLC was closed (P=9.9×10−10, P=1.3×10−17, P=2.1×10−16 and P=2.0×10−5, respectively). The maximum dose (Dmax) values of the cervical cord and cochlea in all MLC closure plans were also decreased as the MLC was closed (P=3.0×10−4 and P=1.1×10−5, respectively). The dose to the CTV was almost unchanged. In 10 patients, the Dmax of the brain in all MLC-closure plans was higher than that of the initial plan, but the maximum increase was only 0.8 gray relative biological effectiveness [Gy(RBE)]. In conclusion, the existing MLC installed in the treatment device can be used to decrease the OAR dose significantly using spot-scanning PBT without a large capital investment. The dose from the scattered particles was small.
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Affiliation(s)
- Nobuyoshi Fukumitsu
- Department of Radiation Oncology, Kobe Proton Center, Kobe, Hyōgo 650-0047, Japan
| | - Tomohiro Yamashita
- Division of Medical Physics, Kobe Proton Center, Kobe, Hyōgo 650-0047, Japan
| | - Masayuki Mima
- Department of Radiation Oncology, Kobe Proton Center, Kobe, Hyōgo 650-0047, Japan
| | - Yusuke Demizu
- Department of Radiation Oncology, Kobe Proton Center, Kobe, Hyōgo 650-0047, Japan
| | - Takeshi Suzuki
- Department of Anesthesiology, Kobe Proton Center, Kobe, Hyōgo 650-0047, Japan
| | - Toshinori Soejima
- Department of Radiation Oncology, Kobe Proton Center, Kobe, Hyōgo 650-0047, Japan
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17
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Hyer DE, Bennett LC, Geoghegan TJ, Bues M, Smith BR. Innovations and the Use of Collimators in the Delivery of Pencil Beam Scanning Proton Therapy. Int J Part Ther 2021; 8:73-83. [PMID: 34285937 PMCID: PMC8270095 DOI: 10.14338/ijpt-20-00039.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 10/19/2020] [Indexed: 12/29/2022] Open
Abstract
Purpose The development of collimating technologies has become a recent focus in pencil beam scanning (PBS) proton therapy to improve the target conformity and healthy tissue sparing through field-specific or energy-layer–specific collimation. Given the growing popularity of collimators for low-energy treatments, the purpose of this work was to summarize the recent literature that has focused on the efficacy of collimators for PBS and highlight the development of clinical and preclinical collimators. Materials and Methods The collimators presented in this work were organized into 3 categories: per-field apertures, multileaf collimators (MLCs), and sliding-bar collimators. For each case, the system design and planning methodologies are summarized and intercompared from their existing literature. Energy-specific collimation is still a new paradigm in PBS and the 2 specific collimators tailored toward PBS are presented including the dynamic collimation system (DCS) and the Mevion Adaptive Aperture. Results Collimation during PBS can improve the target conformity and associated healthy tissue and critical structure avoidance. Between energy-specific collimators and static apertures, static apertures have the poorest dose conformity owing to collimating only the largest projection of a target in the beam's eye view but still provide an improvement over uncollimated treatments. While an external collimator increases secondary neutron production, the benefit of collimating the primary beam appears to outweigh the risk. The greatest benefit has been observed for low- energy treatment sites. Conclusion The consensus from current literature supports the use of external collimators in PBS under certain conditions, namely low-energy treatments or where the nominal spot size is large. While many recent studies paint a supportive picture, it is also important to understand the limitations of collimation in PBS that are specific to each collimator type. The emergence and paradigm of energy-specific collimation holds many promises for PBS proton therapy.
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Affiliation(s)
- Daniel E Hyer
- Department of Radiation Oncology, University of Iowa, Iowa City, IA, USA
| | - Laura C Bennett
- Department of Radiation Oncology, University of Iowa, Iowa City, IA, USA
| | | | - Martin Bues
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, AZ, USA
| | - Blake R Smith
- Department of Radiation Oncology, University of Iowa, Iowa City, IA, USA
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18
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Spiotto MT, McGovern SL, Gunn GB, Grosshans D, McAleer MF, Frank SJ, Paulino AC. Proton Radiotherapy to Reduce Late Complications in Childhood Head and Neck Cancers. Int J Part Ther 2021; 8:155-167. [PMID: 34285943 PMCID: PMC8270100 DOI: 10.14338/ijpt-20-00069.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Accepted: 12/07/2020] [Indexed: 11/21/2022] Open
Abstract
In most childhood head and neck cancers, radiotherapy is an essential component of treatment; however, it can be associated with problematic long-term complications. Proton beam therapy is accepted as a preferred radiation modality in pediatric cancers to minimize the late radiation side effects. Given that childhood cancers are a rare and heterogeneous disease, the support for proton therapy comes from risk modeling and a limited number of cohort series. Here, we discuss the role of proton radiotherapy in pediatric head and neck cancers with a focus on reducing radiation toxicities. First, we compare the efficacy and expected toxicities in proton and photon radiotherapy for childhood cancers. Second, we review the benefit of proton radiotherapy in reducing acute and late radiation toxicities, including risks for secondary cancers, craniofacial development, vision, and cognition. Finally, we review the cost effectiveness for proton radiotherapy in pediatric head and neck cancers. This review highlights the benefits of particle radiotherapy for pediatric head and neck cancers to improve the quality of life in cancer survivors, to reduce radiation morbidities, and to maximize efficient health care use.
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Affiliation(s)
- Michael T Spiotto
- Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Susan L McGovern
- Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - G Brandon Gunn
- Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - David Grosshans
- Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Mary Frances McAleer
- Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Steven J Frank
- Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Arnold C Paulino
- Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX, USA
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19
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Feng H, Shan J, Ashman JB, Rule WG, Bhangoo RS, Yu NY, Chiang J, Fatyga M, Wong WW, Schild SE, Sio TT, Liu W. Technical Note: 4D robust optimization in small spot intensity-modulated proton therapy (IMPT) for distal esophageal carcinoma. Med Phys 2021; 48:4636-4647. [PMID: 34058026 DOI: 10.1002/mp.15003] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 05/18/2021] [Accepted: 05/19/2021] [Indexed: 12/24/2022] Open
Abstract
PURPOSE To compare the dosimetric performances of small-spot three-dimensional (3D) and four-dimensional (4D) robustly optimized intensity-modulated proton (IMPT) plans in the presence of uncertainties and interplay effect simultaneously for distal esophageal carcinoma. METHOD AND MATERIALS Thirteen (13) patients were selected and re-planned with small-spot ( σ ~ 2-6 mm) 3D and 4D robust optimization in IMPT, respectively. The internal clinical target volumes (CTVhigh3d , CTVlow3d ) were used in 3D robust optimization. Different CTVs (CTVhigh4d , CTVlow4d ) were generated by subtracting an inner margin of the motion amplitudes in three cardinal directions from the internal CTVs and used in 4D robust optimization. All patients were prescribed the same dose to CTVs (50 Gy[RBE] for CTVhigh3d /CTVhigh4d and 45 Gy[RBE] for CTVlow3d /CTVlow4d ). Dose-volume histogram (DVH) indices were calculated to assess plan quality. Comprehensive plan robustness evaluations that consisted of 300 perturbed scenarios (10 different motion patterns to consider irregular motion (sampled from a Gaussian distribution) and 30 different uncertainties scenarios (sampled from a 4D uniform distribution) combined), were performed to quantify robustness to uncertainties and interplay effect simultaneously. Wilcoxon signed-rank test was used for statistical analysis. RESULTS Compared to 3D robustly optimized plans, 4D robustly optimized plans had statistically improved target coverage and better sparing of lungs and heart (heart Dmean , P = 0.001; heart V30Gy[RBE] , P = 0.001) in the nominal scenario. 4D robustly optimized plans had better robustness in target dose coverage (CTVhigh4d V100% , P = 0.002) and the protection of lungs and heart (heart Dmean , P = 0.001; heart V30Gy[RBE] , P = 0.001) when uncertainties and interplay effect were considered simultaneously. CONCLUSIONS Even with small spots in IMPT, 4D robust optimization outperformed 3D robust optimization in terms of normal tissue protection and robustness to uncertainties and interplay effect simultaneously. Our findings support the use of 4D robust optimization to treat distal esophageal carcinoma with small spots in IMPT.
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Affiliation(s)
- Hongying Feng
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, 85054, USA
| | - Jie Shan
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, 85054, USA
| | - Jonathan B Ashman
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, 85054, USA
| | - William G Rule
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, 85054, USA
| | - Ronik S Bhangoo
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, 85054, USA
| | - Nathan Y Yu
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, 85054, USA
| | - Jennifer Chiang
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, 85054, USA
| | - Mirek Fatyga
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, 85054, USA
| | - William W Wong
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, 85054, USA
| | - Steven E Schild
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, 85054, USA
| | - Terence T Sio
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, 85054, USA
| | - Wei Liu
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, 85054, USA
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20
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Willoughby TR, Boczkowski A, Meeks SL, Bova FJ, Zeidan OA, Erhart K, Kelly P. Design and characterization of a prototype tertiary device for proton beam stereotactic radiosurgery. Biomed Phys Eng Express 2021; 7. [PMID: 34087816 DOI: 10.1088/2057-1976/ac086b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 06/04/2021] [Indexed: 11/12/2022]
Abstract
Though potentially beneficial, proton beam stereotactic radiosurgery has not been adopted widely secondary to the technical challenge of safely delivering multiple focused beams of proton radiation. In this study, we describe the design and characterization of a proton beam stereotactic radiosurgery system that can be adopted by existing passive scattering systems. This system utilizes a helmet-like device in which patient-specific brass apertures required for final beam collimation are positioned on a scaffold that is separate from the treatment gantry. The proton snout is then fitted with a generic aperture to focus the primary proton beam onto the patient specific apertures that are in the helmet-like device. The patient-specific apertures can all be placed at the start of the treatment, thus treatment with multiple beams can be accomplished without the delay of switching the apertures. In this report we describe a prototype design of this collimation system and dosimetric testing to verify efficacy. Subsequently, we describe a custom 3D printing of a prototype device and report on overall localization accuracy using Winston-Lutz tests. Our results show that it is possible to develop an add-on device for proton beam radiosurgery that is safe and efficient and capable of wide adoption on existing proton delivery systems.
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Affiliation(s)
- T R Willoughby
- Department of Radiation Oncology, Orlando Health Cancer Institute, Orlando, FL, United States of America
| | - A Boczkowski
- Department of Neurosurgery, University of Florida, Gainesville, FL, United States of America
| | - S L Meeks
- Department of Radiation Oncology, Orlando Health Cancer Institute, Orlando, FL, United States of America
| | - F J Bova
- Department of Neurosurgery, University of Florida, Gainesville, FL, United States of America
| | - O A Zeidan
- Department of Radiation Oncology, Orlando Health Cancer Institute, Orlando, FL, United States of America
| | - K Erhart
- DotDecimal, Sanford, FL, United States of America
| | - P Kelly
- Department of Radiation Oncology, Orlando Health Cancer Institute, Orlando, FL, United States of America
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21
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Bäumer C, Plaude S, Khalil DA, Geismar D, Kramer PH, Kröninger K, Nitsch C, Wulff J, Timmermann B. Clinical Implementation of Proton Therapy Using Pencil-Beam Scanning Delivery Combined With Static Apertures. Front Oncol 2021; 11:599018. [PMID: 34055596 PMCID: PMC8149965 DOI: 10.3389/fonc.2021.599018] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 04/06/2021] [Indexed: 11/13/2022] Open
Abstract
Proton therapy makes use of the favorable depth-dose distribution with its characteristic Bragg peak to spare normal tissue distal of the target volume. A steep dose gradient would be desired in lateral dimensions, too. The widespread spot scanning delivery technique is based, however, on pencil-beams with in-air spot full-widths-at-half-maximum of typically 1 cm or more. This hampers the sparing of organs-at-risk if small-scale structures adjacent to the target volume are concerned. The trimming of spot scanning fields with collimating apertures constitutes a simple measure to increase the transversal dose gradient. The current study describes the clinical implementation of brass apertures in conjunction with the pencil-beam scanning delivery mode at a horizontal, clinical treatment head based on commercial hardware and software components. Furthermore, clinical cases, which comprised craniopharyngiomas, re-irradiations and ocular tumors, were evaluated. The dosimetric benefits of 31 treatment plans using apertures were compared to the corresponding plans without aperture. Furthermore, an overview of the radiation protection aspects is given. Regarding the results, robust optimization considering range and setup uncertainties was combined with apertures. The treatment plan optimizations followed a single-field uniform dose or a restricted multi-field optimization approach. Robustness evaluation was expanded to account for possible deviations of the center of the pencil-beam delivery and the mechanical center of the aperture holder. Supplementary apertures improved the conformity index on average by 15.3%. The volume of the dose gradient surrounding the PTV (evaluated between 80 and 20% dose levels) was decreased on average by 17.6%. The mean dose of the hippocampi could be reduced on average by 2.9 GyRBE. In particular cases the apertures facilitated a sparing of an organ-at-risk, e.g. the eye lens or the brainstem. For six craniopharyngioma cases the inclusion of apertures led to a reduction of the mean dose of 1.5 GyRBE (13%) for the brain and 3.1 GyRBE (16%) for the hippocampi.
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Affiliation(s)
- Christian Bäumer
- West German Proton Therapy Centre Essen, Essen, Germany
- West German Cancer Center (WTZ), University Hospital Essen, Essen, Germany
- German Cancer Consortium (DKTK), Heidelberg, Germany
- Faculty of Physics, TU Dortmund University, Dortmund, Germany
| | - Sandija Plaude
- West German Proton Therapy Centre Essen, Essen, Germany
- West German Cancer Center (WTZ), University Hospital Essen, Essen, Germany
| | - Dalia Ahmad Khalil
- West German Proton Therapy Centre Essen, Essen, Germany
- West German Cancer Center (WTZ), University Hospital Essen, Essen, Germany
- Department of Particle Therapy, University Hospital Essen, Essen, Germany
| | - Dirk Geismar
- West German Proton Therapy Centre Essen, Essen, Germany
- West German Cancer Center (WTZ), University Hospital Essen, Essen, Germany
- German Cancer Consortium (DKTK), Heidelberg, Germany
- Department of Particle Therapy, University Hospital Essen, Essen, Germany
| | - Paul-Heinz Kramer
- West German Proton Therapy Centre Essen, Essen, Germany
- West German Cancer Center (WTZ), University Hospital Essen, Essen, Germany
| | - Kevin Kröninger
- Faculty of Physics, TU Dortmund University, Dortmund, Germany
| | | | - Jörg Wulff
- West German Proton Therapy Centre Essen, Essen, Germany
- West German Cancer Center (WTZ), University Hospital Essen, Essen, Germany
| | - Beate Timmermann
- West German Proton Therapy Centre Essen, Essen, Germany
- West German Cancer Center (WTZ), University Hospital Essen, Essen, Germany
- German Cancer Consortium (DKTK), Heidelberg, Germany
- Department of Particle Therapy, University Hospital Essen, Essen, Germany
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22
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Indelicato DJ, Rotondo RL, Mailhot Vega RB, Holtzman AL, Looi WS, Morris CG, Sandler ES, Aldana PR, Bradley JA. Local Control After Proton Therapy for Pediatric Chordoma. Int J Radiat Oncol Biol Phys 2021; 109:1406-1413. [PMID: 33253819 DOI: 10.1016/j.ijrobp.2020.11.051] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 11/10/2020] [Accepted: 11/18/2020] [Indexed: 11/20/2022]
Abstract
PURPOSE Due to the location and high dose required for disease control, pediatric chordomas are theoretically well-suited for treatment with proton therapy, but their low incidence limits the clinical outcome data available in the literature. We sought to report the efficacy and toxicity of proton therapy among a single-institution cohort. METHODS AND MATERIALS Between 2008 and 2019, 29 patients with a median age of 14.8 years (range, 3.8-21.8) received passive-scattered proton therapy for nonmetastatic chordoma. No patient received prior irradiation. Twenty-four tumors arose in the clivus/cervical spine region and 5 in the lumbosacral spine. Twenty-six tumors demonstrated classic well-differentiated histology and 3 were dedifferentiated or not otherwise specified. Approximately half of the tumors underwent specialized testing: 14 were brachyury-positive and 10 retained INI-1. Three patients had locally recurrent tumors after surgery alone (n = 2) or surgery + chemotherapy (n = 1), and 17 patients had gross disease at the time of radiation. The median radiation dose was 73.8 Gy relative biological effectivness (range, 69-75.6). RESULTS With a median follow-up of 4.3 years (range, 1.0-10.7), the 5-year estimates of local control, progression-free survival, and overall survival rates were 85%, 82%, and 86%, respectively. No disease progression was observed beyond 3 years. Excluding 3 patients with dedifferentiated/not-otherwise-specified chordoma, the 5-year local control, progression-free survival, and overall survival rates were 92%, 92%, and 91%, respectively. Serious toxicities included 3 patients with hardware failure or related infection requiring revision surgery, 2 patients with hormone deficiency, and 2 patients with Eustachian tube dysfunction causing chronic otitis media. No patient experienced brain stem injury, myelopathy, vision loss, or hearing loss after radiation. CONCLUSIONS In pediatric patients with chordoma, proton therapy is associated with a low risk of serious toxicity and high efficacy, particularly in well-differentiated tumors. Complete resection may be unnecessary for local control, and destabilizing operations requiring instrumentation may result in additional complications after therapy.
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Affiliation(s)
- Daniel J Indelicato
- Department of Radiation Oncology, University of Florida College of Medicine, Jacksonville, Florida.
| | - Ronny L Rotondo
- Department of Radiation Oncology, University of Kansas, Kansas City, Kansas
| | - Raymond B Mailhot Vega
- Department of Radiation Oncology, University of Florida College of Medicine, Jacksonville, Florida
| | - Adam L Holtzman
- Department of Radiation Oncology, University of Florida College of Medicine, Jacksonville, Florida
| | - Wen S Looi
- Department of Radiation Oncology, University of Florida College of Medicine, Jacksonville, Florida
| | - Christopher G Morris
- Department of Radiation Oncology, University of Florida College of Medicine, Jacksonville, Florida
| | - Eric S Sandler
- Department of Pediatrics, Nemours Childrens Specialty Clinic, Jacksonville, Florida
| | - Philipp R Aldana
- Department of Neurosurgery, University of Florida College of Medicine, Jacksonville, Florida
| | - Julie A Bradley
- Department of Radiation Oncology, University of Florida College of Medicine, Jacksonville, Florida
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23
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Boczkowski A, Kelly P, Meeks SL, Erhart K, Bova FJ, Willoughby TR. Proton vs Hyperarc™ radiosurgery: A planning comparison. J Appl Clin Med Phys 2020; 21:96-108. [PMID: 33151014 PMCID: PMC7769415 DOI: 10.1002/acm2.13075] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 09/24/2020] [Accepted: 09/29/2020] [Indexed: 11/29/2022] Open
Abstract
For many patients, stereotactic radiosurgery (SRS) offers a minimally invasive, curative option when surgical techniques are not possible. To date, the literature supporting the efficacy and safety of SRS treatment techniques uses photon beams. However, with the number of proton therapy facilities exponentially growing and the favorable physical properties of proton beam radiation therapy, there is an opportunity to develop proton therapy techniques for SRS. The goal of this paper is to determine the ability of clinical proton treatment planning systems to model small field dosimetry accurately and to compare various planning metrics used to evaluate photon SRS to determine the optimum beam configurations and settings for proton SRS (PSRS) treatment plans. Once established, these plan settings were used to perform a planning comparison on a variety of different SRS cases and compare SRS metrics between the PSRS plans and HyperArc™ (VMAT) SRS plans.
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Affiliation(s)
- A. Boczkowski
- Department of NeurosurgeryUniversity of FloridaGainesvilleFLUSA
| | - P. Kelly
- UF Health Cancer Center–Orlando HealthOrlandoFLUSA
| | - S. L. Meeks
- UF Health Cancer Center–Orlando HealthOrlandoFLUSA
| | | | - F. J. Bova
- Department of NeurosurgeryUniversity of FloridaGainesvilleFLUSA
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24
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Rana S, Storey M, Manthala Padannayil N, Shamurailatpam DS, Bennouna J, George J, Chang J. Investigating the utilization of beam-specific apertures for the intensity-modulated proton therapy (IMPT) head and neck cancer plans. Med Dosim 2020; 46:e7-e11. [PMID: 33246881 DOI: 10.1016/j.meddos.2020.10.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 10/11/2020] [Accepted: 10/28/2020] [Indexed: 12/16/2022]
Abstract
Intensity-modulated proton therapy (IMPT) planning for the head and neck (HN) cancer often requires the use of the range shifter, which can increase the lateral penumbrae of the pencil proton beam in the patient, thus leading to an increase in unnecessary dose to the organs at risks (OARs) in proximity to the target volumes. The primary goal of the current study was to investigate the dosimetric benefits of utilizing beam-specific apertures for the IMPT HN cancer plans. The current retrospective study included computed tomography datasets of 10 unilateral HN cancer patients. The clinical target volume (CTV) was divided into low-risk CTV1 and high-risk CTV2. Total dose prescriptions to the CTV1 and CTV2 were 54 Gy(RBE) and 70 Gy(RBE), respectively, with a fractional dose of 2 Gy(RBE). All treatment plans were robustly optimized (patient setup uncertainty = 3 mm; range uncertainty = 3.5%) on the CTVs. For each patient, 2 sets of plans were generated: (1) without beam-specific aperture (WOBSA), and (2) with beam-specific aperture (WBSA). Specifically, both the WOBSA and WBSA of the given patient used identical beam angles, air gap, optimization structures, optimization constraints, and optimization settings. Target coverage and homogeneity index were comparable in both the WOBSA and WBSA plans with no statistical significance (p > 0.05). On average, the mean dose in WBSA plans was reduced by 12.1%, 2.9%, 3.0%, 3.8%, and 5.2% for the larynx, oral cavity, parotids, superior pharyngeal constrictor muscle, and inferior pharyngeal constrictor muscle, respectively. The dosimetric results of the OARs were found to be statistically significant (p < 0.05). The use of the beam-specific apertures did not deteriorate the coverage and homogeneity in the target volume and allowed for a reduction in mean dose to the OARs with an average difference up to 12.1%.
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Affiliation(s)
- Suresh Rana
- Department of Medical Physics, Oklahoma Proton Center, Oklahoma City, OK 73142, USA; Department of Radiation Oncology, Miami Cancer Institute, Baptist Health South Florida, Miami, FL, USA; Department of Radiation Oncology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA.
| | - Mark Storey
- Department of Radiation Oncology, Oklahoma Proton Center, Oklahoma City, OK 73142, USA
| | | | | | - Jaafar Bennouna
- Department of Radiation Oncology, Miami Cancer Institute, Baptist Health South Florida, Miami, FL, USA
| | - Jerry George
- Department of Radiation Oncology, Miami Cancer Institute, Baptist Health South Florida, Miami, FL, USA
| | - John Chang
- Department of Radiation Oncology, Oklahoma Proton Center, Oklahoma City, OK 73142, USA
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25
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Rana S, Rosenfeld AB. Parametrization of in-air spot size as a function of energy and air gap for the ProteusPLUS pencil beam scanning proton therapy system. Radiol Phys Technol 2020; 13:392-397. [PMID: 33038003 DOI: 10.1007/s12194-020-00589-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 09/24/2020] [Accepted: 09/26/2020] [Indexed: 02/04/2023]
Abstract
The purpose of this study was to parametrize the in-air one sigma spot size for various energies and air gaps in pencil beam scanning (PBS) proton therapy. The current study included range shifters with a water equivalent thickness (WET) of 40 mm (RS40) and 75 mm (RS75). For RS40, the spot sizes were measured for energies ranging from 80 to 225 MeV in increments of 2.5 MeV, whereas the air gap was varied from 5 to 25 cm in increments of 2.5 cm. For RS75, the spot sizes were measured for energies ranging from 120 to 225 MeV in increments of 2.5 MeV, whereas the air gap was varied from 5 to 35 cm in increments of 2.5 cm. For both RS40 and RS75, all measurements (n = 1090) were acquired at the isocenter using a Lynx 2D scintillation detector. For RS40, the spot sizes increased from 3.1 mm to 10.4 mm, whereas the variation in spot sizes for RS75 ranged from 3.3 mm to 13.1 mm. For each range shifter, an analytical equation demonstrating the relationship of the spot size with the proton energy and air gap was obtained. The best parametrization results were obtained with the 3rd degree polynomial fits of the energy and air gap parameters. The average difference between the modeled and measured spot sizes was 0.0 ± 0.1 mm (range, - 0.24-0.21 mm) for RS40, and 0.0 ± 0.1 mm (range, - 0.23-0.15 mm) for RS75. In conclusion, the analytical model agrees within ± 0.25 mm of the measured spot sizes on a ProteusPLUS PBS proton system with a PBS dedicated nozzle.
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Affiliation(s)
- Suresh Rana
- Department of Radiation Oncology, Miami Cancer Institute, Baptist Health South Florida, Miami, FL, USA. .,Department of Radiation Oncology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA. .,Department of Medical Physics, The Oklahoma Proton Center, Oklahoma City, OK, USA.
| | - Anatoly B Rosenfeld
- Centre for Medical Radiation Physics (CMRP), University of Wollongong, Wollongong, NSW, Australia
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26
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Bäcker CM, Bäumer C, Gerhardt M, Ibisi S, Kröninger K, Nitsch C, Weingarten J, Timmermann B. Evaluation of the activation of brass apertures in proton therapy using gamma-ray spectrometry and Monte Carlo simulations. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2020; 40:848-860. [PMID: 32575092 DOI: 10.1088/1361-6498/ab9f42] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Collimating apertures are used in proton therapy to laterally conform treatment fields to the target volume. While this is a standard technique in passive spreading treatment heads, patient-specific apertures can supplement pencil-beam scanning (PBS) techniques to sharpen the lateral dose fall-off. A radiation protection issue is that proton-induced nuclear reactions can lead to the formation of radionuclides in the apertures. In the experiments of the current study, cylindrical, thick brass targets were irradiated with quasi-monoenergetic proton fields of 100.0 MeV and of 226.7 MeV in PBS mode. The radioactivation of these two brass samples was characterised with a low-level gamma-ray spectrometer. The activation products were scored in a Monte Carlo simulation, too, and compared with the experimental activities. For the high-energy field, 63Zn, 60Cu, and 61Cu were the most important short-lived isotopes regarding the measured specific activity. After irradiation with the 100.0 MeV field, 62Cu, 63Zn, and 60Cu had the highest activity. Regarding long-lived isotopes, which determine the storage time of the used apertures, the isotopes 57Co, 65Zn, 54Mn, 56Co had the largest contribution to the activity. The relative difference of activities between simulation and experiment was typically between 10%-20% for short-lived nuclides and were up to a factor of five larger for long-lived nuclides. Summarising experiments and simulations for both incident proton energies, 62Cu was the most important detected residual nucleus regardless if specific activity or equivalent dose is considered.
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Affiliation(s)
- Claus Maximilian Bäcker
- West German Proton Therapy Centre Essen (WPE), Am Mühlenbach 1, Essen, Germany. University Hospital Essen, Hufelandstr. 55, Essen, Germany. West German Cancer Center (WTZ), Hufelandstr. 55, Essen, Germany. Technische Universität Dortmund, Otto-Hahn-Str. 4a, Dortmund, Germany
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27
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Mara E, Clausen M, Khachonkham S, Deycmar S, Pessy C, Dörr W, Kuess P, Georg D, Gruber S. Investigating the impact of alpha/beta and LET d on relative biological effectiveness in scanned proton beams: An in vitro study based on human cell lines. Med Phys 2020; 47:3691-3702. [PMID: 32347564 PMCID: PMC7496287 DOI: 10.1002/mp.14212] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 04/03/2020] [Accepted: 04/13/2020] [Indexed: 12/15/2022] Open
Abstract
PURPOSE A relative biological effectiveness (RBE) of 1.1 is commonly used in clinical proton therapy, irrespective of tissue type and depth. This in vitro study was conducted to quantify the RBE of scanned protons as a function of the dose-averaged linear energy transfer (LETd ) and the sensitivity factor (α/ß)X . Additionally, three phenomenological models (McNamara, Rørvik, and Jones) and one mechanistic model (repair-misrepair-fixation, RMF) were applied to the experimentally derived data. METHODS Four human cell lines (FaDu, HaCat, Du145, SKMel) with differential (α/ß)X ratios were irradiated in a custom-designed irradiation setup with doses between 0 and 6 Gy at proximal, central, and distal positions of a 80 mm spread-out Bragg peak (SOBP) centered at 80 mm (setup A: proton energies 66.5-135.6 MeV) and 155 mm (setup B: proton energies 127.2-185.9 MeV) depth, respectively. LETd values at the respective cell positions were derived from Monte Carlo simulations performed with the treatment planning system (TPS, RayStation). Dosimetric measurements were conducted to verify dose homogeneity and dose delivery accuracy. RBE values were derived for doses that resulted in 90 % (RBE90 ) and 10 % (RBE10 ) of cell survival, and survival after a 0.5 Gy dose (RBE0.5Gy ), 2 Gy dose (RBE2Gy ), and 6 Gy dose (RBE6Gy ). RESULTS LETd values at sample positions were 1.9, 2.1, 2.5, 2.8, 4.1, and 4.5 keV/µm. For the cell lines with high (α/ß)X ratios (FaDu, HaCat), the LETd did not impact on the RBE. For low (α/ß)X cell lines (Du145, SKMel), LQ-derived survival curves indicated a clear correlation of LETd and RBE. RBE90 values up to 2.9 and RBE10 values between 1.4 and 1.8 were obtained. Model-derived RBE predictions slightly overestimated the RBE for the high (α/ß)X cell lines, although all models except the Jones model provided RBE values within the experimental uncertainty. For low (α/ß)X cell lines, no agreement was found between experiments and model predictions, that is, all models underestimated the measured RBE. CONCLUSIONS The sensitivity parameter (α/ß)X was observed to be a major influencing factor for the RBE of protons and its sensitivity toward LETd changes. RBE prediction models are applicable for high (α/ß)X cell lines but do not estimate RBE values with sufficient accuracy in low (α/ß)X cell lines.
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Affiliation(s)
- Elisabeth Mara
- Department of Radiation Oncology/Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Vienna, Austria.,University of Applied Science, Wiener Neustadt, Austria
| | - Monika Clausen
- Department of Radiation Oncology/Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Vienna, Austria
| | - Suphalak Khachonkham
- Department of Radiation Oncology/Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Vienna, Austria.,Division of Radiation Therapy, Department of Diagnostic and Therapeutic Radiology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Simon Deycmar
- Laboratory of Applied Radiobiology, Department of Radiation Oncology, University Hospital Zürich, Zürich, Switzerland
| | - Clara Pessy
- Department of Radiation Oncology/Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Vienna, Austria
| | - Wolfgang Dörr
- Department of Radiation Oncology/Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Vienna, Austria
| | - Peter Kuess
- Department of Radiation Oncology/Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Vienna, Austria.,EBG MedAustron GmbH, Wiener Neustadt, Austria
| | - Dietmar Georg
- Department of Radiation Oncology/Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Vienna, Austria.,EBG MedAustron GmbH, Wiener Neustadt, Austria
| | - Sylvia Gruber
- Department of Radiation Oncology/Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Vienna, Austria.,EBG MedAustron GmbH, Wiener Neustadt, Austria
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28
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Su Z, Indelicato DJ, Mailhot RB, Bradley JA. Impact of different treatment techniques for pediatric Ewing sarcoma of the chest wall: IMRT, 3DCPT, and IMPT with/without beam aperture. J Appl Clin Med Phys 2020; 21:100-107. [PMID: 32268008 PMCID: PMC7324690 DOI: 10.1002/acm2.12870] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Revised: 03/08/2020] [Accepted: 03/11/2020] [Indexed: 12/25/2022] Open
Abstract
Purpose To evaluate the dosimetric differences between photon intensity‐modulated radiation therapy (IMRT) plans, 3D conformal proton therapy (3DCPT), and intensity‐modulated proton therapy (IMPT) plans and to investigate the dosimetric impact of different beam spot size and beam apertures in IMPT for pediatric Ewing sarcoma of the chest wall. Methods and Materials Six proton pediatric patients with Ewing sarcoma in the upper, middle, and lower thoracic spine regions as well as upper lumbar spine region were treated with 3DCPT and retrospectively planned with photon IMRT and IMPT nozzles of different beam spot sizes with/without beam apertures. The plan dose distributions were compared both on target conformity and homogeneity, and on organs‐at‐risk (OARs) sparing using QUANTEC metrics of the lung, heart, liver, and kidney. The total integral doses of healthy tissue of all plans were also evaluated. Results Target conformity and homogeneity indices are generally better for the IMPT plans with beam aperture. Doses to the lung, heart, and liver for all patients are substantially lower with the 3DPT and IMPT plans than those of IMRT plans. In the IMPT plans with large spot without beam aperture, some OAR doses are higher than those of 3DCPT plans. The integral dose of each photon IMRT plan ranged from 2 to 4.3 times of proton plans. Conclusion Compared to IMRT, proton therapy delivers significant lower dose to almost all OARs and much lower healthy tissue integral dose. Compared to 3DCPT, IMPT with small beam spot size or using beam aperture has better dose conformity to the target.
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Affiliation(s)
- Zhong Su
- Department of Radiation Oncology, University of Florida, Gainesville, FL, USA.,University of Florida Health Proton Therapy Institute, Jacksonville, FL, USA
| | - Daniel J Indelicato
- Department of Radiation Oncology, University of Florida, Gainesville, FL, USA.,University of Florida Health Proton Therapy Institute, Jacksonville, FL, USA
| | - Raymond B Mailhot
- Department of Radiation Oncology, University of Florida, Gainesville, FL, USA.,University of Florida Health Proton Therapy Institute, Jacksonville, FL, USA
| | - Julie A Bradley
- Department of Radiation Oncology, University of Florida, Gainesville, FL, USA.,University of Florida Health Proton Therapy Institute, Jacksonville, FL, USA
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29
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Ur Rehman M, Erhart K, Kielbasa J, Meeks SL, Li Z, Willoughby T, Ramakrishna N, Stephenson K, Rahman TS, Kelly P, Zeidan O. An optimized approach for robust spot placement in proton pencil beam scanning. Phys Med Biol 2019; 64:235016. [PMID: 31618722 DOI: 10.1088/1361-6560/ab4e78] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Maintaining a sharp lateral dose falloff in pencil beam scanning (PBS) proton therapy is crucial for sparing organs at risk (OARs), especially when they are in close proximity to the target volume. The most common approach to improve lateral dose falloff is through the use of physical beam shaping devices, such as brass apertures or collimator based systems. A recently proposed approach focuses on proton beam spot placements, moving away from traditional grid-based placements to concentric-contours based schemes. This improves lateral dose falloff in two ways: (1) by better conforming all spots to the tumor boundary and (2) allowing for 'edge enhancement', where boundary spots deliver higher fluence than more central spots, thereby creating a steeper lateral dose falloff. However, these benefits come at the expense of maintaining uniformity of spot distribution inside the target volume. In this work we have developed a new optimized spot placement scheme that provides robust spot distributions inside the target. This approach achieves the boundary conformity of a concentric-contours based approach and uses a fast-iterative method to distribute the interior spots in a highly uniform fashion in an attempt to improve both the lateral dose falloff and uniformity. Furthermore, we quantified the impact of this new approach through direct comparison with grid, contour, and hybrid spot placements schemes, showing improvements for this new approach. The results were validated in homogeneous medium for two different target shapes having concave and convex geometry.
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Affiliation(s)
- Mahboob Ur Rehman
- University of Central Florida, Orlando, FL, United States of America
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Sugiyama S, Katsui K, Tominaga Y, Waki T, Katayama N, Matsuzaki H, Kariya S, Kuroda M, Nishizaki K, Kanazawa S. Dose distribution of intensity-modulated proton therapy with and without a multi-leaf collimator for the treatment of maxillary sinus cancer: a comparative effectiveness study. Radiat Oncol 2019; 14:209. [PMID: 31752928 PMCID: PMC6873663 DOI: 10.1186/s13014-019-1405-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 10/24/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Severe complications, such as eye damage and dysfunciton of salivary glands, have been reported after radiotherapy among patients with head and neck cancer. Complications such as visual impairment have also been reported after proton therapy with pencil beam scanning (PBS). In the case of PBS, collimation can sharpen the penumbra towards surrounding normal tissue in the low energy region of the proton beam. In the current study, we examined how much the dose to the normal tissue was reduced by when intensity-modulated proton therapy (IMPT) was performed using a multi-leaf collimator (MLC) for patients with maxillary sinus cancer. METHODS Computed tomography findings of 26 consecutive patients who received photon therapy at Okayama University Hospital were used in this study. We compared D2% of the region of interest (ROI; ROI-D2%) and the mean dose of ROI (ROI-mean) with and without the use of an MLC. The organs at risk (OARs) were the posterior retina, lacrimal gland, eyeball, and parotid gland. IMPT was performed for all patients. The spot size was approximately 5-6 mm at the isocenter. The collimator margin was calculated by enlarging the maximum outline of the target from the beam's eye view and setting the margin to 6 mm. All plans were optimized with the same parameters. RESULTS The mean of ROI-D2% for the ipsilateral optic nerve was significantly reduced by 0.48 Gy, and the mean of ROI-mean for the ipsilateral optic nerve was significantly reduced by 1.04 Gy. The mean of ROI-mean to the optic chiasm was significantly reduced by 0.70 Gy. The dose to most OARs and the planning at risk volumes were also reduced. CONCLUSIONS Compared with the plan involving IMPT without an MLC, in the dose plan involving IMPT using an MLC for maxillary sinus cancer, the dose to the optic nerve and optic chiasm were significantly reduced, as measured by the ROI-D2% and the ROI-mean. These findings demonstrate that the use of an MLC during IMPT for maxillary sinus cancer may be useful for preserving vision and preventing complications.
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Affiliation(s)
- Soichi Sugiyama
- Departments of Radiology, Dentistry and Pharmaceutical Science, Okayama University Graduate School of Medicine, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan.,Department of Radiology, Tsuyama Chuo Hospital, Tusyama, Okayama, 708-0841, Japan
| | - Kuniaki Katsui
- Departments of Proton Beam Therapy, Dentistry and Pharmaceutical Science, Okayama University Graduate School of Medicine, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan.
| | - Yuki Tominaga
- Department of Radiation Technology, Tsuyama Chuo Hospital, Tusyama, Okayama, 708-0841, Japan
| | - Takahiro Waki
- Department of Radiology, Tsuyama Chuo Hospital, Tusyama, Okayama, 708-0841, Japan
| | - Norihisa Katayama
- Departments of Radiology, Okayama University Hospital, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan
| | - Hidenobu Matsuzaki
- Departments of Oral Diagnosis and Dentomaxillofacial Radiology, Okayama University Hospital, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan
| | - Shin Kariya
- Departments of Otolaryngology-Head and Neck Surgery, Dentistry and Pharmaceutical Science, Okayama University Graduate School of Medicine, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan
| | - Masahiro Kuroda
- Department of Radiological Technology, Graduate School of Health Sciences, Okayama University, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan
| | - Kazunori Nishizaki
- Departments of Otolaryngology-Head and Neck Surgery, Dentistry and Pharmaceutical Science, Okayama University Graduate School of Medicine, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan
| | - Susumu Kanazawa
- Departments of Radiology, Dentistry and Pharmaceutical Science, Okayama University Graduate School of Medicine, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan
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Iwata H, Toshito T, Hayashi K, Yamada M, Omachi C, Nakajima K, Hattori Y, Hashimoto S, Kuroda Y, Okumura Y, Mizoe JE, Ogino H, Shibamoto Y. Proton therapy for non-squamous cell carcinoma of the head and neck: planning comparison and toxicity. JOURNAL OF RADIATION RESEARCH 2019; 60:612-621. [PMID: 31147697 PMCID: PMC6805978 DOI: 10.1093/jrr/rrz036] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 04/16/2019] [Indexed: 05/20/2023]
Abstract
To investigate optimal treatment planning using proton beams for non-squamous cell carcinoma of the head and neck (NSCHN), the dose distributions of plans involving pencil beam scanning (PBS) with or without a patient-specific aperture system (PSAS), passive-scattering proton therapy (PSPT) and X-ray intensity-modulated radiotherapy (IMRT) were compared. As clinical results, toxicities of PBS with PSAS, including changes in quality of life, were reported. Between April 2014 and August 2016, a total of 30 patients were treated using PBS with PSAS. In 20 patients selected at random, the dose distributions of PBS with or without the PSAS, PSPT and IMRT plans were compared. Neutron exposure by proton therapy was calculated using a Monte Carlo simulation. Toxicities were scored according to CTCAE ver. 4.0. Patients completed EORTC quality of life survey forms (QLQ-C30 and QLQ-HN35) before and 0-12 months after proton therapy. The 95% conformity number of PBS with the PSAS plan was the best, and significant differences were detected among the four plans (P < 0.05, Bonferroni tests). Neutron generation by PSAS was ~1.1-fold higher, but was within an acceptable level. No grade 3 or higher acute dermatitis was observed. Pain, appetite loss and increased weight loss were more likely at the end of treatment, but recovered by the 3 month follow-up and returned to the pretreatment level at the 12 month follow-up. PBS with PSAS reduced the penumbra and improved dose conformity in the planning target volume. PBS with PSAS was tolerated well for NSCHN.
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Affiliation(s)
- Hiromitsu Iwata
- Department of Radiation Oncology, Nagoya Proton Therapy Center, Nagoya City West Medical Center, 1-1-1 Hirate-cho, Kita-ku, Nagoya, Japan
- Department of Radiology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Japan
- Corresponding author: Department of Radiation Oncology, Nagoya Proton Therapy Center, Nagoya City West Medical Center, 1-1-1 Hirate-cho, Kita-ku, Nagoya, 462-8508 Japan. Tel: +81 52-991-8577; Fax: +81 52-991-8599; E-mail:
| | - Toshiyuki Toshito
- Department of Proton Therapy Physics, Nagoya Proton Therapy Center, Nagoya City West Medical Center, 1-1-1 Hirate-cho, Kita-ku, Nagoya, Japan
| | - Kensuke Hayashi
- Department of Proton Therapy Technology, Nagoya Proton Therapy Center, Nagoya City West Medical Center, 1-1-1 Hirate-cho, Kita-ku, Nagoya, Japan
| | - Maho Yamada
- Department of Radiation Therapy, Nagoya City West Medical Center, 1-1-1 Hirate-cho, Kita-ku, Nagoya, Japan
| | - Chihiro Omachi
- Department of Proton Therapy Physics, Nagoya Proton Therapy Center, Nagoya City West Medical Center, 1-1-1 Hirate-cho, Kita-ku, Nagoya, Japan
| | - Koichiro Nakajima
- Department of Radiation Oncology, Nagoya Proton Therapy Center, Nagoya City West Medical Center, 1-1-1 Hirate-cho, Kita-ku, Nagoya, Japan
- Department of Radiology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Japan
| | - Yukiko Hattori
- Department of Radiation Oncology, Nagoya Proton Therapy Center, Nagoya City West Medical Center, 1-1-1 Hirate-cho, Kita-ku, Nagoya, Japan
| | - Shingo Hashimoto
- Department of Radiation Oncology, Nagoya Proton Therapy Center, Nagoya City West Medical Center, 1-1-1 Hirate-cho, Kita-ku, Nagoya, Japan
| | - Yo Kuroda
- Department of Otorhinolaryngology, Nagoya City West Medical Center, 1-1-1 Hirate-cho, Kita-ku, Nagoya, Japan
| | - Yoshihide Okumura
- Department of Oral and Maxillofacial Surgery, Nagoya City West Medical Center, 1-1-1 Hirate-cho, Kita-ku, Nagoya, Japan
| | - Jun-etsu Mizoe
- Department of Radiation Oncology, Nagoya Proton Therapy Center, Nagoya City West Medical Center, 1-1-1 Hirate-cho, Kita-ku, Nagoya, Japan
- Osaka Heavy Ion Therapy Center, 3-1-10 Otemae, chuo-ku, Osaka, Japan
| | - Hiroyuki Ogino
- Department of Radiation Oncology, Nagoya Proton Therapy Center, Nagoya City West Medical Center, 1-1-1 Hirate-cho, Kita-ku, Nagoya, Japan
- Department of Radiology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Japan
| | - Yuta Shibamoto
- Department of Radiology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Japan
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Smith BR, Hyer DE, Flynn RT, Hill PM, Culberson WS. Trimmer sequencing time minimization during dynamically collimated proton therapy using a colony of cooperating agents. Phys Med Biol 2019; 64:205025. [PMID: 31484170 DOI: 10.1088/1361-6560/ab416d] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The dynamic collimation system (DCS) can be combined with pencil beam scanning proton therapy to deliver highly conformal treatment plans with unique collimation at each energy layer. This energy layer-specific collimation is accomplished through the synchronized motion of four trimmer blades that intercept the proton beam near the target boundary in the beam's eye view. However, the corresponding treatment deliveries come at the cost of additional treatment time since the translational speed of the trimmer is slower than the scanning speed of the proton pencil beam. In an attempt to minimize the additional trimmer sequencing time of each field while still maintaining a high degree of conformity, a novel process utilizing ant colony optimization (ACO) methods was created to determine the most efficient route of trimmer sequencing and beamlet scanning patterns for a collective set of collimated proton beamlets. The ACO process was integrated within an in-house treatment planning system optimizer to determine the beam scanning and DCS trimmer sequencing patterns and compared against an analytical approximation of the trimmer sequencing time should a contour-like scanning approach be assumed instead. Due to the stochastic nature of ACO, parameters where determined so that they could ensure good convergence and an efficient optimization of trimmer sequencing that was faster than an analytical contour-like trimmer sequencing. The optimization process was tested using a set of three intracranial treatment plans which were planned using a custom research treatment planning system and were successfully optimized to reduce the additional trimmer sequencing time to approximately 60 s per treatment field while maintaining a high degree of target conformity. Thus, the novel use of ACO techniques within a treatment planning algorithm has been demonstrated to effectively determine collimation sequencing patterns for a DCS in order to minimize the additional treatment time required for trimmer movement during treatment.
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Affiliation(s)
- Blake R Smith
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53705. Author to whom correspondence should be addressed
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Liu C, Yu NY, Shan J, Bhangoo RS, Daniels TB, Chiang JS, Ding X, Lara P, Patrick CL, Archuleta JP, DeWees T, Hu Y, Schild SE, Bues M, Sio TT, Liu W. Technical Note: Treatment planning system (TPS) approximations matter - comparing intensity-modulated proton therapy (IMPT) plan quality and robustness between a commercial and an in-house developed TPS for nonsmall cell lung cancer (NSCLC). Med Phys 2019; 46:4755-4762. [PMID: 31498885 DOI: 10.1002/mp.13809] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 08/29/2019] [Accepted: 08/29/2019] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Approximate dose calculation methods were used in the nominal dose distribution and the perturbed dose distributions due to uncertainties in a commercial treatment planning system (CTPS) for robust optimization in intensity-modulated proton therapy (IMPT). We aimed to investigate whether the approximations influence plan quality, robustness, and interplay effect of the resulting IMPT plans for the treatment of locally advanced lung cancer patients. MATERIALS AND METHODS Ten consecutively treated locally advanced nonsmall cell lung cancer (NSCLC) patients were selected. Two IMPT plans were created for each patient using our in-house developed TPS, named "Solo," and also the CTPS, EclipseTM (Varian Medical Systems, Palo Alto, CA, USA), respectively. The plans were designed to deliver prescription doses to internal target volumes (ITV) drawn by a physician on averaged four-dimensional computed tomography (4D-CT). Solo plans were imported back to CTPS, and recalculated in CTPS for fair comparison. Both plans were further verified for each patient by recalculating doses in the inhalation and exhalation phases to ensure that all plans met clinical requirements. Plan robustness was quantified on all phases using dose-volume-histograms (DVH) indices in the worst-case scenario. The interplay effect was evaluated for every plan using an in-house developed software, which randomized starting phases of each field per fraction and accumulated dose in the exhalation phase based on the patient's breathing motion pattern and the proton spot delivery in a time-dependent fashion. DVH indices were compared using Wilcoxon rank-sum test. RESULTS Compared to the plans generated using CTPS on the averaged CT, Solo plans had significantly better target dose coverage and homogeneity (normalized by the prescription dose) in the worst-case scenario [ITV D95% : 98.04% vs 96.28%, Solo vs CTPS, P = 0.020; ITV D5% -D95% : 7.20% vs 9.03%, P = 0.049] while all DVH indices were comparable in the nominal scenario. On the inhalation phase, Solo plans had better target dose coverage and cord Dmax in the nominal scenario [ITV D95% : 99.36% vs 98.45%, Solo vs CTPS, P = 0.014; cord Dmax : 20.07 vs 23.71 Gy(RBE), P = 0.027] with better target coverage and cord Dmax in the worst-case scenario [ITV D95% : 97.89% vs 96.47%, Solo vs CTPS, P = 0.037; cord Dmax : 24.57 vs 28.14 Gy(RBE), P = 0.037]. On the exhalation phase, similar phenomena were observed in the nominal scenario [ITV D95% : 99.63% vs 98.87%, Solo vs CTPS, P = 0.037; cord Dmax : 19.67 vs 23.66 Gy(RBE), P = 0.039] and in the worst-case scenario [ITV D95% : 98.20% vs 96.74%, Solo vs CTPS, P = 0.027; cord Dmax : 23.47 vs 27.93 Gy(RBE), P = 0.027]. In terms of interplay effect, plans generated by Solo had significantly better target dose coverage and homogeneity, less hot spots, and lower esophageal Dmean , and cord Dmax [ITV D95% : 101.81% vs 98.68%, Solo vs CTPS, P = 0.002; ITV D5% -D95% : 2.94% vs 7.51%, P = 0.002; cord Dmax : 18.87 vs 22.29 Gy(RBE), P = 0.014]. CONCLUSIONS Solo-generated IMPT plans provide improved cord sparing, better target robustness in all considered phases, and reduced interplay effect compared with CTPS. Consequently, the approximation methods currently used in commercial TPS programs may have space for improvement in generating optimal IMPT plans for patient cases with locally advanced lung cancer.
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Affiliation(s)
- Chenbin Liu
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, 85054, USA
| | - Nathan Y Yu
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, 85054, USA
| | - Jie Shan
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, 85054, USA
| | - Ronik S Bhangoo
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, 85054, USA
| | - Thomas B Daniels
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, 85054, USA
| | - Jennifer S Chiang
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, 85054, USA
| | - Xiaoning Ding
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, 85054, USA
| | - Pedro Lara
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, 85054, USA
| | | | - James P Archuleta
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, 85054, USA
| | - Todd DeWees
- Division of Biostatistics, Mayo Clinic, Phoenix, AZ, 85054, USA
| | - Yanle Hu
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, 85054, USA
| | - Steven E Schild
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, 85054, USA
| | - Martin Bues
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, 85054, USA
| | - Terence T Sio
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, 85054, USA
| | - Wei Liu
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, 85054, USA
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Bäumer C, Fuentes C, Janson M, Matic A, Timmermann B, Wulff J. Stereotactical fields applied in proton spot scanning mode with range shifter and collimating aperture. ACTA ACUST UNITED AC 2019; 64:155003. [DOI: 10.1088/1361-6560/ab2ae7] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Liu C, Bhangoo RS, Sio TT, Yu NY, Shan J, Chiang JS, Ding JX, Rule WG, Korte S, Lara P, Ding X, Bues M, Hu Y, DeWees T, Ashman JB, Liu W. Dosimetric comparison of distal esophageal carcinoma plans for patients treated with small-spot intensity-modulated proton versus volumetric-modulated arc therapies. J Appl Clin Med Phys 2019; 20:15-27. [PMID: 31112371 PMCID: PMC6612702 DOI: 10.1002/acm2.12623] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2019] [Revised: 04/24/2019] [Accepted: 05/02/2019] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Esophageal carcinoma is the eighth most common cancer in the world. Volumetric-modulated arc therapy (VMAT) is widely used to treat distal esophageal carcinoma due to high conformality to the target and good sparing of organs at risk (OAR). It is not clear if small-spot intensity-modulated proton therapy (IMPT) demonstrates a dosimetric advantage over VMAT. In this study, we compared dosimetric performance of VMAT and small-spot IMPT for distal esophageal carcinoma in terms of plan quality, plan robustness, and interplay effects. METHODS 35 distal esophageal carcinoma patients were retrospectively reviewed; 19 patients received small-spot IMPT and the remaining 16 of them received VMAT. Both plans were generated by delivering prescription doses to clinical target volumes (CTVs) on phase-averaged 4D-CT's. The dose-volume-histogram (DVH) band method was used to quantify plan robustness. Software was developed to evaluate interplay effects with randomized starting phases for each field per fraction. DVH indices were compared using Wilcoxon rank-sum test. For fair comparison, all the treatment plans were normalized to have the same CTVhigh D95% in the nominal scenario relative to the prescription dose. RESULTS In the nominal scenario, small-spot IMPT delivered statistically significantly lower liver Dmean and V30Gy[RBE] , lung Dmean , heart Dmean compared with VMAT. CTVhigh dose homogeneity and protection of other OARs were comparable between the two treatments. In terms of plan robustness, the IMPT and VMAT plans were comparable for kidney V18Gy[RBE] , liver V30Gy[RBE] , stomach V45Gy[RBE] , lung Dmean , V5Gy[RBE] , and V20Gy[RBE] , cord Dmax and D 0.03 c m 3 , liver Dmean , heart V20Gy[RBE] , and V30Gy[RBE] , but IMPT was significantly worse for CTVhigh D95% , D 2 c m 3 , and D5% -D95% , CTVlow D95% , heart Dmean , and V40Gy[RBE] , requiring careful and experienced adjustments during the planning process and robustness considerations. The small-spot IMPT plans still met the standard clinical requirements after interplay effects were considered. CONCLUSIONS Small-spot IMPT decreases doses to heart, liver, and total lung compared to VMAT as well as achieves clinically acceptable plan robustness. Our study supports the use of small-spot IMPT for the treatment of distal esophageal carcinoma.
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Affiliation(s)
- Chenbin Liu
- Department of Radiation OncologyMayo ClinicPhoenixAZ85054USA
| | | | - Terence T. Sio
- Department of Radiation OncologyMayo ClinicPhoenixAZ85054USA
| | - Nathan Y. Yu
- Department of Radiation OncologyMayo ClinicPhoenixAZ85054USA
| | - Jie Shan
- Department of Radiation OncologyMayo ClinicPhoenixAZ85054USA
| | | | - Julia X. Ding
- Department of Radiation OncologyMayo ClinicPhoenixAZ85054USA
| | - William G. Rule
- Department of Radiation OncologyMayo ClinicPhoenixAZ85054USA
| | - Shawn Korte
- Department of Radiation OncologyMayo ClinicPhoenixAZ85054USA
| | - Pedro Lara
- Department of Radiation OncologyMayo ClinicPhoenixAZ85054USA
| | - Xiaoning Ding
- Department of Radiation OncologyMayo ClinicPhoenixAZ85054USA
| | - Martin Bues
- Department of Radiation OncologyMayo ClinicPhoenixAZ85054USA
| | - Yanle Hu
- Department of Radiation OncologyMayo ClinicPhoenixAZ85054USA
| | - Todd DeWees
- Division of BiostatisticsMayo ClinicPhoenixAZ85054USA
| | | | - Wei Liu
- Department of Radiation OncologyMayo ClinicPhoenixAZ85054USA
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Ueno K, Matsuura T, Hirayama S, Takao S, Ueda H, Matsuo Y, Yoshimura T, Umegaki K. Physical and biological impacts of collimator-scattered protons in spot-scanning proton therapy. J Appl Clin Med Phys 2019; 20:48-57. [PMID: 31237090 PMCID: PMC6612695 DOI: 10.1002/acm2.12653] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Revised: 05/01/2019] [Accepted: 05/04/2019] [Indexed: 11/29/2022] Open
Abstract
To improve the penumbra of low‐energy beams used in spot‐scanning proton therapy, various collimation systems have been proposed and used in clinics. In this paper, focused on patient‐specific brass collimators, the collimator‐scattered protons' physical and biological effects were investigated. The Geant4 Monte Carlo code was used to model the collimators mounted on the scanning nozzle of the Hokkaido University Hospital. A systematic survey was performed in water phantom with various‐sized rectangular targets; range (5–20 cm), spread‐out Bragg peak (SOBP) (5–10 cm), and field size (2 × 2–16 × 16 cm2). It revealed that both the range and SOBP dependences of the physical dose increase had similar trends to passive scattering methods, that is, it increased largely with the range and slightly with the SOBP. The physical impact was maximized at the surface (3%–22% for the tested geometries) and decreased with depth. In contrast, the field size (FS) dependence differed from that observed in passive scattering: the increase was high for both small and large FSs. This may be attributed to the different phase‐space shapes at the target boundary between the two dose delivery methods. Next, the biological impact was estimated based on the increase in dose‐averaged linear energy transfer (LETd) and relative biological effectiveness (RBE). The LETd of the collimator‐scattered protons were several keV/μm higher than that of unscattered ones; however, since this large increase was observed only at the positions receiving a small scattered dose, the overall LETd increase was negligible. As a consequence, the RBE increase did not exceed 0.05. Finally, the effects on patient geometries were estimated by testing two patient plans, and a negligible RBE increase (0.9% at most in the critical organs at surface) was observed in both cases. Therefore, the impact of collimator‐scattered protons is almost entirely attributed to the physical dose increase, while the RBE increase is negligible.
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Affiliation(s)
- Koki Ueno
- Graduate School of Biomedical Science and Engineering, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Taeko Matsuura
- Faculty of Engineering, Hokkaido University, Sapporo, Hokkaido, Japan.,Proton Beam Therapy Center, Hokkaido University Hospital, Sapporo, Hokkaido, Japan.,Global Station for Quantum Medical Science and Engineering, Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Sapporo, Japan
| | - Shusuke Hirayama
- Graduate School of Biomedical Science and Engineering, Hokkaido University, Sapporo, Hokkaido, Japan.,Proton Beam Therapy Center, Hokkaido University Hospital, Sapporo, Hokkaido, Japan
| | - Seishin Takao
- Proton Beam Therapy Center, Hokkaido University Hospital, Sapporo, Hokkaido, Japan
| | - Hideaki Ueda
- Faculty of Engineering, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Yuto Matsuo
- Proton Beam Therapy Center, Hokkaido University Hospital, Sapporo, Hokkaido, Japan
| | - Takaaki Yoshimura
- Proton Beam Therapy Center, Hokkaido University Hospital, Sapporo, Hokkaido, Japan
| | - Kikuo Umegaki
- Faculty of Engineering, Hokkaido University, Sapporo, Hokkaido, Japan.,Proton Beam Therapy Center, Hokkaido University Hospital, Sapporo, Hokkaido, Japan.,Global Station for Quantum Medical Science and Engineering, Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Sapporo, Japan
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Rana S, Bennouna J, Samuel EJJ, Gutierrez AN. Development and long-term stability of a comprehensive daily QA program for a modern pencil beam scanning (PBS) proton therapy delivery system. J Appl Clin Med Phys 2019; 20:29-44. [PMID: 30920146 PMCID: PMC6448164 DOI: 10.1002/acm2.12556] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 12/16/2018] [Accepted: 01/22/2019] [Indexed: 11/08/2022] Open
Abstract
PURPOSE The main purpose of this study is to demonstrate the clinical implementation of a comprehensive pencil beam scanning (PBS) daily quality assurance (QA) program involving a number of novel QA devices including the Sphinx/Lynx/parallel-plate (PPC05) ion chamber and HexaCheck/multiple imaging modality isocentricity (MIMI) imaging phantoms. Additionally, the study highlights the importance of testing the connectivity among oncology information system (OIS), beam delivery/imaging systems, and patient position system at a proton center with multi-vendor equipment and software. METHODS For dosimetry, a daily QA plan with spot map of four different energies (106, 145, 172, and 221 MeV) is delivered on the delivery system through the OIS. The delivery assesses the dose output, field homogeneity, beam coincidence, beam energy, width, distal-fall-off (DFO), and spot characteristics - for example, position, size, and skewness. As a part of mechanical and imaging QA, a treatment plan with the MIMI phantom serving as the patient is transferred from OIS to imaging system. The HexaCheck/MIMI phantoms are used to assess daily laser accuracy, imaging isocenter accuracy, image registration accuracy, and six-dimensional (6D) positional correction accuracy for the kV imaging system and robotic couch. RESULTS The daily QA results presented herein are based on 202 daily sets of measurements over a period of 10 months. Total time to perform daily QA tasks at our center is under 30 min. The relative difference (Δrel ) of daily measurements with respect to baseline was within ± 1% for field homogeneity, ±0.5 mm for range, width and DFO, ±1 mm for spots positions, ±10% for in-air spot sigma, ±0.5 spot skewness, and ±1 mm for beam coincidence (except 1 case: Δrel = 1.3 mm). The average Δrel in dose output was -0.2% (range: -1.1% to 1.5%). For 6D IGRT QA, the average absolute difference (Δabs ) was ≤0.6 ± 0.4 mm for translational and ≤0.5° for rotational shifts. CONCLUSION The use of novel QA devices such as the Sphinx in conjunction with the Lynx, PPC05 ion chamber, HexaCheck/MIMI phantoms, and myQA software was shown to provide a comprehensive and efficient method for performing daily QA of a number of system parameters for a modern proton PBS-dedicated treatment delivery unit.
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Affiliation(s)
- Suresh Rana
- Department of Radiation Oncology, Miami Cancer Institute, Baptist Health South Florida, Miami, FL, USA.,Department of Radiation Oncology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA.,Department of Physics, School of Advanced Sciences, VIT University, Vellore, India
| | - Jaafar Bennouna
- Department of Radiation Oncology, Miami Cancer Institute, Baptist Health South Florida, Miami, FL, USA.,Department of Radiation Oncology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA
| | | | - Alonso N Gutierrez
- Department of Radiation Oncology, Miami Cancer Institute, Baptist Health South Florida, Miami, FL, USA.,Department of Radiation Oncology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA
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Winterhalter C, Meier G, Oxley D, Weber DC, Lomax AJ, Safai S. Contour scanning, multi-leaf collimation and the combination thereof for proton pencil beam scanning. Phys Med Biol 2018; 64:015002. [PMID: 30523928 DOI: 10.1088/1361-6560/aaf2e8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In proton therapy, the lateral fall-off is often used to spare critical organs. It is therefore crucial to improve the penumbra for proton pencil beam scanning. However, previous work has shown that collimation may not be necessary for depths of >15 cm in water. As such, in this work we investigate the effectiveness of a thin multi leaf collimator (just thick enough to completely stop protons with ranges of <15 cm in water) for energy layer specific collimation in patient geometries, when applied in combination with both grid and contour scanned PBS proton therapy. For this, an analytical model of collimated beam shapes, based solely on data available in the treatment planning system, has been included in the optimization, with the resulting optimised plans then being recalculated using Monte Carlo in order to most accurately simulate the full physics effects of the collimator. For grid based scanning, energy specific collimation has been found to reduce the V30 outside the PTV by 19.8% for an example patient when compared to the same pencil beam placement without collimation. V30 could be even reduced by a further 5.6% when combining collimation and contour scanning. In addition, mixed plans, consisting of contour scanning for deep fields (max range >15 cm WER) and collimated contour scanning for superficial fields (<15 cm), have been created for four patients, by which V30 could be reduced by 0.8% to 8.0% and the mean dose to the brain stem by 1.5% to 3.3%. Target dose homogeneity however is not substantially different when compared to the best un-collimated scenario. In conclusion, we demonstrate the potential advantages of a thin, multi leaf collimator in combination with contour scanning for energy layer specific collimation in PBS proton therapy.
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Affiliation(s)
- Carla Winterhalter
- Centre for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland. Physics Department, ETH Zürich, Zürich, Switzerland
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Pfeiler T, Ahmad Khalil D, Ayadi M, Bäumer C, Blanck O, Chan M, Engwall E, Geismar D, Peters S, Plaude S, Spaan B, Timmermann B, Wulff J. Motion effects in proton treatments of hepatocellular carcinoma-4D robustly optimised pencil beam scanning plans versus double scattering plans. Phys Med Biol 2018; 63:235006. [PMID: 30468685 DOI: 10.1088/1361-6560/aaecfc] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Pencil beam scanning (PBS) proton therapy enables better dose conformality for complex anatomical geometries than passive proton scattering techniques, but is more susceptible to organ motion. This becomes an issue when treating moving tumours in the thorax or abdomen. Novel four-dimensional treatment planning approaches have been developed to increase the robustness of PBS plans against motion. However, their efficacy still needs to be examined by means of 4D dynamically accumulated dose (4DDD) analyses. This study investigates the potential use of 4D robust optimisation to maintain sufficient target coverage in the presence of organ motion, while sparing surrounding healthy tissue, for hepatocellular carcinoma (HCC). The liver is particularly suited to study motion interplay effects since the treatment region exhibits smaller density gradients and more homogeneous tissue than targets in the thorax, making it less prone to range errors. A facility-specific beam time model, developed and experimentally validated previously, was used for the clinical evaluation. 4DDD analyses of eleven target volumes did not show a significant improvement of the target coverage using 4D robust optimisation, but a reduction of the dose to close-by organs at risk. Interplay effects were averaged out for the applied fractionation scheme of 15 fractions. Contrary to PBS, passive double scattering (DS) plans yielded homogeneous 4DDD dose distributions in a single fraction. But, in some cases, they exceeded organ at risk dose limits, which were only satisfied in PBS. The average normal liver dose could be decreased by almost 6% compared to non-robustly optimised PBS plans and by 16% compared to DS plans when implementing 4D robust optimisation. Except for some very small tumours with large motion amplitudes, 4D robustly optimised PBS plans were found to be clinically acceptable even without supplementary motion mitigation techniques.
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Affiliation(s)
- Tina Pfeiler
- West German Proton Therapy Centre Essen (WPE), Essen, Germany. West German Cancer Centre (WTZ), Essen, Germany. TU Dortmund University, Experimental Physics 5, Dortmund, Germany. Department of Particle Therapy, University Hospital Essen, Essen, Germany. Author to whom any correspondence should be addressed
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Liu C, Sio TT, Deng W, Shan J, Daniels TB, Rule WG, Lara PR, Korte SM, Shen J, Ding X, Schild SE, Bues M, Liu W. Small-spot intensity-modulated proton therapy and volumetric-modulated arc therapies for patients with locally advanced non-small-cell lung cancer: A dosimetric comparative study. J Appl Clin Med Phys 2018; 19:140-148. [PMID: 30328674 PMCID: PMC6236833 DOI: 10.1002/acm2.12459] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Revised: 08/29/2018] [Accepted: 08/30/2018] [Indexed: 12/25/2022] Open
Abstract
Purpose To compare dosimetric performance of volumetric‐modulated arc therapy (VMAT) and small‐spot intensity‐modulated proton therapy for stage III non‐small‐cell lung cancer (NSCLC). Methods and Materials A total of 24 NSCLC patients were retrospectively reviewed; 12 patients received intensity‐modulated proton therapy (IMPT) and the remaining 12 received VMAT. Both plans were generated by delivering prescription doses to clinical target volumes (CTV) on averaged 4D‐CTs. The dose‐volume‐histograms (DVH) band method was used to quantify plan robustness. Software was developed to evaluate interplay effects with randomized starting phases of each field per fraction. DVH indices were compared using Wilcoxon rank sum test. Results Compared with VMAT, IMPT delivered significantly lower cord Dmax, heart Dmean, and lung V5 Gy[RBE] with comparable CTV dose homogeneity, and protection of other OARs. In terms of plan robustness, the IMPT plans were statistically better than VMAT plans in heart Dmean, but were statistically worse in CTV dose coverage, cord Dmax, lung Dmean, and V5 Gy[RBE]. Other DVH indices were comparable. The IMPT plans still met the standard clinical requirements with interplay effects considered. Conclusions Small‐spot IMPT improves cord, heart, and lung sparing compared to VMAT and achieves clinically acceptable plan robustness at least for the patients included in this study with motion amplitude less than 11 mm. Our study supports the usage of IMPT to treat some lung cancer patients.
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Affiliation(s)
- Chenbin Liu
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, USA
| | - Terence T Sio
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, USA
| | - Wei Deng
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, USA
| | - Jie Shan
- Department of Biomedical Informatics, Arizona State University, Tempe, AZ, USA
| | | | - William G Rule
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, USA
| | - Pedro R Lara
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, USA
| | - Shawn M Korte
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, USA
| | - Jiajian Shen
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, USA
| | - Xiaoning Ding
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, USA
| | - Steven E Schild
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, USA
| | - Martin Bues
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, USA
| | - Wei Liu
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, USA
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Farr JB, Moskvin V, Lukose RC, Tuomanen S, Tsiamas P, Yao W. Development, commissioning, and evaluation of a new intensity modulated minibeam proton therapy system. Med Phys 2018; 45:4227-4237. [PMID: 30009481 DOI: 10.1002/mp.13093] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 07/02/2018] [Accepted: 07/10/2018] [Indexed: 11/10/2022] Open
Abstract
PURPOSE To invent, design, construct, and commission an intensity modulated minibeam proton therapy system (IMMPT) without the need for physical collimation and to compare its resulting conformity to a conventional IMPT system. METHODS A proton therapy system (Hitachi, Ltd, Hitachi City, Japan; Model: Probeat-V) was specially modified to produce scanned minibeams without collimation. We performed integral depth dose acquisitions and calibrations using a large diameter parallel-plate ionization chamber in a scanning water phantom (PTW, Freiburg, Germany; Models: Bragg Peak ionization chamber, MP3-P). Spot size and shape was measured using radiochromic film (Ashland Advanced Materials, Bridgewater NJ; Type: EBT3), and a synthetic diamond diode type scanned point by point in air (PTW Models: MicroDiamond, MP3-P). The measured data were used as inputs to generate a Monte Carlo-based model for a commercial radiotherapy planning system (TPS) (Varian Medical Systems, Inc., Palo Alto, CA; Model: Eclipse v13.7.15). The regular ProBeat-V system (sigma ~2.5 mm) TPS model was available for comparison. A simulated base of skull case with small and medium targets proximal to brainstem was planned for both systems and compared. RESULTS The spot sigma is determined to be 1.4 mm at 221 MeV at the isocenter and below 1 mm at proximal distances. Integral depth doses were indistinguishable from the standard spot commissioning data. The TPS fit the spot profiles closely, giving a residual error maximum of 2.5% in the spot penumbra tails (below 5% of maximum) from the commissioned energies 69.4 to 221.3 MeV. The resulting IMMPT plans were more conformal than the IMPT plans due to a sharper dose gradient (90-10%) 1.5 mm smaller for the small target, and 1.3 mm for the large target, at a representative central axial water equivalent depth of 7 cm. CONCLUSIONS We developed, implemented, and tested a new IMMPT system. The initial results look promising in cases where treatments can benefit from additional dose sparing to neighboring sensitive structures.
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Affiliation(s)
- J B Farr
- Department of Radiation Oncology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105-2794, USA
| | - V Moskvin
- Department of Radiation Oncology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105-2794, USA
| | - R C Lukose
- Department of Radiation Oncology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105-2794, USA
| | - S Tuomanen
- Department of Radiation Oncology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105-2794, USA
| | - P Tsiamas
- Department of Radiation Oncology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105-2794, USA
| | - W Yao
- Department of Radiation Oncology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105-2794, USA
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Bäumer C, Janson M, Timmermann B, Wulff J. Collimated proton pencil-beam scanning for superficial targets: impact of the order of range shifter and aperture. ACTA ACUST UNITED AC 2018; 63:085020. [DOI: 10.1088/1361-6560/aab79c] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Liu C, Schild SE, Chang JY, Liao Z, Korte S, Shen J, Ding X, Hu Y, Kang Y, Keole SR, Sio TT, Wong WW, Sahoo N, Bues M, Liu W. Impact of Spot Size and Spacing on the Quality of Robustly Optimized Intensity Modulated Proton Therapy Plans for Lung Cancer. Int J Radiat Oncol Biol Phys 2018; 101:479-489. [PMID: 29550033 DOI: 10.1016/j.ijrobp.2018.02.009] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 01/31/2018] [Accepted: 02/05/2018] [Indexed: 12/19/2022]
Abstract
PURPOSE To investigate how spot size and spacing affect plan quality, robustness, and interplay effects of robustly optimized intensity modulated proton therapy (IMPT) for lung cancer. METHODS AND MATERIALS Two robustly optimized IMPT plans were created for 10 lung cancer patients: first by a large-spot machine with in-air energy-dependent large spot size at isocenter (σ: 6-15 mm) and spacing (1.3 σ), and second by a small-spot machine with in-air energy-dependent small spot size (σ: 2-6 mm) and spacing (5 mm). Both plans were generated by optimizing radiation dose to internal target volume on averaged 4-dimensional computed tomography scans using an in-house-developed IMPT planning system. The dose-volume histograms band method was used to evaluate plan robustness. Dose evaluation software was developed to model time-dependent spot delivery to incorporate interplay effects with randomized starting phases for each field per fraction. Patient anatomy voxels were mapped phase-to-phase via deformable image registration, and doses were scored using in-house-developed software. Dose-volume histogram indices, including internal target volume dose coverage, homogeneity, and organs at risk (OARs) sparing, were compared using the Wilcoxon signed-rank test. RESULTS Compared with the large-spot machine, the small-spot machine resulted in significantly lower heart and esophagus mean doses, with comparable target dose coverage, homogeneity, and protection of other OARs. Plan robustness was comparable for targets and most OARs. With interplay effects considered, significantly lower heart and esophagus mean doses with comparable target dose coverage and homogeneity were observed using smaller spots. CONCLUSIONS Robust optimization with a small spot-machine significantly improves heart and esophagus sparing, with comparable plan robustness and interplay effects compared with robust optimization with a large-spot machine. A small-spot machine uses a larger number of spots to cover the same tumors compared with a large-spot machine, which gives the planning system more freedom to compensate for the higher sensitivity to uncertainties and interplay effects for lung cancer treatments.
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Affiliation(s)
- Chenbin Liu
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, Arizona
| | - Steven E Schild
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, Arizona
| | - Joe Y Chang
- Department of Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas
| | - Zhongxing Liao
- Department of Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas
| | - Shawn Korte
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, Arizona
| | - Jiajian Shen
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, Arizona
| | - Xiaoning Ding
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, Arizona
| | - Yanle Hu
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, Arizona
| | - Yixiu Kang
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, Arizona
| | - Sameer R Keole
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, Arizona
| | - Terence T Sio
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, Arizona
| | - William W Wong
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, Arizona
| | - Narayan Sahoo
- Department of Radiation Physics, The University of Texas M. D. Anderson Cancer Center, Houston, Texas
| | - Martin Bues
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, Arizona
| | - Wei Liu
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, Arizona.
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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] [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.
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Affiliation(s)
- C Winterhalter
- Centre for Proton Therapy, Paul Scherrer Institute, 5232 Villigen, Switzerland
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Kraan AC, Depauw N, Clasie B, Giunta M, Madden T, Kooy HM. Effects of spot parameters in pencil beam scanning treatment planning. Med Phys 2017; 45:60-73. [DOI: 10.1002/mp.12675] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 11/07/2017] [Accepted: 11/07/2017] [Indexed: 11/10/2022] Open
Affiliation(s)
- Aafke Christine Kraan
- Applications of Detectors and Accelerators to Medicine (ADAM) SA; Geneva Switzerland
- Istituto Nazionale di Fisica Nucleare; Sezione di Pisa Italy
| | - Nicolas Depauw
- Department of Physics; Massachusetts General Hospital; Boston USA
| | - Ben Clasie
- Department of Physics; Massachusetts General Hospital; Boston USA
| | - Marina Giunta
- Applications of Detectors and Accelerators to Medicine (ADAM) SA; Geneva Switzerland
| | - Tom Madden
- Department of Physics; Massachusetts General Hospital; Boston USA
| | - Hanne M. Kooy
- Department of Physics; Massachusetts General Hospital; Boston USA
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Yasui K, Toshito T, Omachi C, Hayashi K, Tanaka K, Asai K, Shimomura A, Muramatsu R, Hayashi N. Evaluation of dosimetric advantages of using patient-specific aperture system with intensity-modulated proton therapy for the shallow depth tumor. J Appl Clin Med Phys 2017; 19:132-137. [PMID: 29178546 PMCID: PMC5768032 DOI: 10.1002/acm2.12231] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 09/22/2017] [Accepted: 10/23/2017] [Indexed: 11/11/2022] Open
Abstract
In this study, we evaluate dosimetric advantages of using patient-specific aperture system with intensity-modulated proton therapy (IMPT) for head and neck tumors at the shallow depth. We used four types of patient-specific aperture system (PSAS) to irradiate shallow regions less than 4 g/cm2 with a sharp lateral penumbra. Ten head and neck IMPT plans with or without aperture were optimized separately with the same 95% prescription dose and same dose constraint for organs at risk (OARs). The plans were compared using dose volume histograms (DVHs), dose distributions, and some dose indexes such as volume receiving 50% of the prescribed dose (V50 ), mean or maximum dose (Dmean and Dmax ) to the OARs. All examples verified in this study had decreased V50 and OAR doses. Average, maximum, and minimum relative reductions of V50 were 15.4%, 38.9%, and 1.0%, respectively. Dmax and Dmean of OARs were decreased by 0.3% to 25.7% and by 1.0% to 46.3%, respectively. The plans with the aperture over more than half of the field showed decreased V50 or OAR dose by more than 10%. The dosimetric advantage of patient-specific apertures with IMPT was clarified in many cases. The PSAS has some dosimetric advantages for clinical use, and in some cases, it enables to fulfill dose constraints.
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Affiliation(s)
- Keisuke Yasui
- Nagoya Proton Therapy Center, Nagoya City West Medical Center, Nagoya, Japan.,School of Health Sciences, Faculty of Radiological Technology, Fujita Health University, Toyoake, Japan
| | - Toshiyuki Toshito
- Nagoya Proton Therapy Center, Nagoya City West Medical Center, Nagoya, Japan
| | - Chihiro Omachi
- Nagoya Proton Therapy Center, Nagoya City West Medical Center, Nagoya, Japan
| | - Kensuke Hayashi
- Nagoya Proton Therapy Center, Nagoya City West Medical Center, Nagoya, Japan
| | - Kenichiro Tanaka
- Nagoya Proton Therapy Center, Nagoya City West Medical Center, Nagoya, Japan
| | - Kumiko Asai
- Nagoya Proton Therapy Center, Nagoya City West Medical Center, Nagoya, Japan
| | - Akira Shimomura
- Nagoya Proton Therapy Center, Nagoya City West Medical Center, Nagoya, Japan
| | - Rie Muramatsu
- Nagoya Proton Therapy Center, Nagoya City West Medical Center, Nagoya, Japan
| | - Naoki Hayashi
- School of Health Sciences, Faculty of Radiological Technology, Fujita Health University, Toyoake, Japan
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Grosshans DR, Mohan R, Gondi V, Shih HA, Mahajan A, Brown PD. The role of image-guided intensity modulated proton therapy in glioma. Neuro Oncol 2017; 19:ii30-ii37. [PMID: 28380636 DOI: 10.1093/neuonc/nox002] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Gliomas represent a broad spectrum of disease with life-expectancy outcomes ranging from months to decades. As our understanding of the molecular profiles of gliomas expands rapidly, practitioners are now better able to identify patients with favorable versus nonfavorable prognoses. Radiation therapy plays a key role in glioma treatment, improving disease control and oftentimes survival. However, for survivors, either long-term or short-term, radiation-induced cognitive impairments may negatively impact their quality of life. For patients with both favorable and unfavorable prognoses, intensity modulated proton therapy (IMPT) may offer significant, yet unproven benefits. IMPT is the newest and most advanced proton delivery technique, one with substantial benefits compared with historical proton techniques. IMPT allows practitioners to maximize the physical benefits of protons, increasing normal tissue sparing and reducing the potential for adverse effects. For more aggressive tumors, the dose conformality and normal tissue sparing afforded by IMPT may also allow for dose escalation to target volumes. However, in order to truly maximize the clinical potential of IMPT, the field of radiation oncology must not only implement the most advanced technologies, but also understand and capitalize on the unique biologic aspects of proton therapy.
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Affiliation(s)
- David R Grosshans
- Departments of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Radhe Mohan
- Department of Surgical Oncology, New Hope Medical Centre, Kilpauk, Chennai, Tamil Nadu, India
| | - Vinai Gondi
- Northwestern Medicine Chicago Proton Center, Warrenville, Illinois, USA
| | - Helen A Shih
- Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Anita Mahajan
- Departments of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Paul D Brown
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota, USA
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Farace P, Bizzocchi N, Righetto R, Fellin F, Fracchiolla F, Lorentini S, Widesott L, Algranati C, Rombi B, Vennarini S, Amichetti M, Schwarz M. Supine craniospinal irradiation in pediatric patients by proton pencil beam scanning. Radiother Oncol 2017; 123:112-118. [DOI: 10.1016/j.radonc.2017.02.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 01/19/2017] [Accepted: 02/12/2017] [Indexed: 10/20/2022]
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Pollard JM, Wen Z, Sadagopan R, Wang J, Ibbott GS. The future of image-guided radiotherapy will be MR guided. Br J Radiol 2017; 90:20160667. [PMID: 28256898 DOI: 10.1259/bjr.20160667] [Citation(s) in RCA: 132] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Advances in image-guided radiotherapy (RT) have allowed for dose escalation and more precise radiation treatment delivery. Each decade brings new imaging technologies to help improve RT patient setup. Currently, the most frequently used method of three-dimensional pre-treatment image verification is performed with cone beam CT. However, more recent developments have provided RT with the ability to have on-board MRI coupled to the teleradiotherapy unit. This latest tool for treating cancer is known as MR-guided RT. Several varieties of these units have been designed and installed in centres across the globe. Their prevalence, history, advantages and disadvantages are discussed in this review article. In preparation for the next generation of image-guided RT, this review also covers where MR-guided RT might be heading in the near future.
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Affiliation(s)
| | - Zhifei Wen
- UT MD Anderson Cancer Center, Houston, TX, USA
| | | | - Jihong Wang
- UT MD Anderson Cancer Center, Houston, TX, USA
| | | |
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