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Lin Y, Zhang W, Prezado Y, Traneus E, Johnson D, Li W, Gan GN, Chen RC, Gao H. Towards Clinical Proton Minibeam Radiation Therapy (pMBRT): Development of Clinical pMBRT System Prototype and pMBRT-Specific Treatment Planning Method. Int J Radiat Oncol Biol Phys 2023; 117:S38. [PMID: 37784487 DOI: 10.1016/j.ijrobp.2023.06.307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) Proton minibeam radiation therapy (pMBRT) is an emerging spatially fractionated RT (SFRT) modality that can provide very high therapeutic index compared to conventional radiotherapy methods and clinically-available SFRT methods (GRID and LATTICE). The biological data collected thus far encourage the preparation of clinical trials in pMBRT. This work is to facilitate the clinical translation of pMBRT by developing (1) the first clinical pMBRT system prototype worldwide, readily available for both small-animal biology studies and large-animal pMBRT trials; (2) pMBRT-specific treatment planning method with peak-valley dose ratio (PVDR) optimization capability for large animal and patient pMBRT trials, which is currently unavailable. MATERIALS/METHODS The pMBRT system is based on clinically-used pencil-beam-scanning proton machine equipped with large-field clinical-size pMBRT collimator, pMBRT-dedicated treatment planning system, and KV/CBCT imaging guidance. The multi-slit brass collimator has 10 × 10 cm field size, 0.4mm width per slit and 4 mm center-to-center distance. The divergence of slits is tailed to the divergence of the proton beam. A unique universal collimator design is implemented, so that we can keep the outer fitting to the snout and conveniently inter-change collimators as needed. The pMBRT-specific treatment planning method jointly optimizes PVDR and dose objectives, to meet a minimal PVDR threshold and maximize PVDR, to avoid the situations where meeting dose objectives can compromise PVDR when PVDR were not optimized. In addition, the survival fraction for organs at risk is also optimized. The dose calculation engine is based on the Monte Carlo method using TOPAS. The optimization algorithm utilizes total variation and L1 sparsity regularization to maximize PVDR and iterative convex relaxation method to solve the optimization problem. RESULTS Monte Carlo simulations via TOPAS were performed to design this large-field multi-slit collimator, using the beam structure and the beam data specific to our proton system, with mean dose rate of 8 Gy/min under clinical condition with the collimator in place. The feasibility of using this pMBRT system for small-animal studies has been demonstrated, with customized 3D printed holder for immobilizing small animals, on-board KV imaging system for accurate small-animal positioning, and the GAFchromic film for verifying radiation dose and PVDR. On the other hand, the efficacy of pMBRT-specific treatment planning method (with PVDR optimization capability) to improve PVDR has been demonstrated using retrospective patient planning studies in comparison with standard proton treatment planning method (without PVDR optimization capability). CONCLUSION The initial development of a clinical pMBRT system prototype and pMBRT-specific treatment planning method of PVDR optimization capability has been completed with ongoing efforts to make this system ready for large-animal pMBRT studies.
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Affiliation(s)
- Y Lin
- Department of Radiation Oncology, University of Kansas Medical Center, Kansas City, KS
| | - W Zhang
- Department of Radiation Oncology, University of Kansas Medical Center, Kansas City, KS
| | | | - E Traneus
- RaySearch Laboratories AB, Stockholm, Sweden
| | - D Johnson
- Department of Radiation Oncology, University of Kansas Medical Center, Kansas City, KS
| | - W Li
- Department of Radiation Oncology, University of Kansas Medical Center, Kansas City, KS
| | - G N Gan
- Department of Radiation Oncology, University of Kansas Medical Center, Kansas City, KS
| | - R C Chen
- Department of Radiation Oncology, University of Kansas Medical Center, Kansas City, KS
| | - H Gao
- Department of Radiation Oncology, University of Kansas Medical Center, Kansas City, KS
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Zhang W, Traneus E, Lin Y, Gan GN, Chen RC, Gao H. Virtual-Collimator Based Spatial Dose Modulation for Proton GRID Therapy. Int J Radiat Oncol Biol Phys 2023; 117:e747. [PMID: 37786164 DOI: 10.1016/j.ijrobp.2023.06.2287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) Compared to conventional proton therapy, the proton GRID therapy can substantially improve normal tissue protection (with the delivery of spatially-modulated peak-valley dose pattern to normal tissues) while maintaining the tumor control efficacy (with the delivery of uniform dose pattern to tumor targets). The realization of proton GRID often relies on the use of physical collimators to shape the spatial dose distribution. However, the physical collimator may increase neutron dose, decrease delivery efficiency, and limit the freedom for patient positioning. Here we propose a virtual-collimator (VC) method for proton GRID. This new approach can generate peak-to-valley pattern with high peak-to-valley dose ratio (PVDR), without using a physical collimator. MATERIALS/METHODS The principle behind the VC method to modulate the spatial dose distribution consists of two major steps: (1) the primary beam is essentially halved, i.e., the beamlets are interleaved, so that the organ-at-risk (OAR) plane has the peak-valley dose pattern, while the target plane also has the valley dose; (2) the complementary beam is added with half complementary beamlets to fill in the previously valley-dose positions at the target plane, so that the target dose is uniform, while on the other hand, the complementary beam is angled slightly from the primary beam, so that the OAR still has the peak-valley dose pattern. Moreover, on top of VC, we also utilize sparsity regularization method using total variation and L1 sparsity (TVL1) to further jointly optimize PVDR and dose objectives, namely VC-TVL1. RESULTS VC and VC-TVL1 were validated in comparison with conventional proton GRID treatment planning method via IMPT ("CONV") and TVL1-based proton GRID treatment planning method without VC ("TVL1"), for a prostate case with single-beam (270° only) or two-beam (90° and 270°) scenarios. As shown in the table, the results show that VC can indeed modulate spatial dose with higher PVDR than CONV or even TVL1. VC had higher spatial modulation frequency with smaller peak-to-peak distance than TVL1. Moreover, VC+TVL1, as the synergy of VC and TVL1, further improved PVDR from VC or TVL1 alone. CONCLUSION A new way to deliver proton GRID therapy without a physical collimator is developed using the VC method. The VC method can be synergized with TVL1 optimization algorithm to further jointly optimize PVDR and dose objectives.
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Affiliation(s)
- W Zhang
- Department of Radiation Oncology, University of Kansas Medical Center, Kansas City, KS
| | - E Traneus
- RaySearch Laboratories AB, Stockholm, Sweden
| | - Y Lin
- Department of Radiation Oncology, University of Kansas Medical Center, Kansas City, KS
| | - G N Gan
- Department of Radiation Oncology, University of Kansas Medical Center, Kansas City, KS
| | - R C Chen
- Department of Radiation Oncology, University of Kansas Medical Center, Kansas City, KS
| | - H Gao
- Department of Radiation Oncology, University of Kansas Medical Center, Kansas City, KS
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Pietsch J, Piplack N, Berthold J, Khamfongkhruea C, Thiele J, Hölscher T, Traneus E, Janssens E, Smeets J, Stützer K, Löck S, Richter C. OC-0620 Prompt-gamma imaging for prostate cancer proton therapy: CNN-based detection of anatomical changes. Radiother Oncol 2022. [DOI: 10.1016/s0167-8140(22)02642-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Böhlen T, Germond JF, Traneus E, Desorgher L, Vozenin MC, Bourhis J, Bailat C, Bochud F, Moeckli R. FLASH Modalities Track (Oral Presentations) CAN UHDR VHEE DEVICES WITH ONLY A FEW FIXED BEAMS PROVIDE COMPETITIVE TREATMENT PLANS COMPARED TO VMAT? Phys Med 2022. [DOI: 10.1016/s1120-1797(22)01514-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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Traneus E. FLASH in the Clinic Track (Oral Presentations) COMBINING PROTON CONFORMAL FLASH WITH TARGET LET OR RBE DOSE MAXIMIZATION: BEST OF TWO WORLDS? Phys Med 2022. [DOI: 10.1016/s1120-1797(22)01467-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Järvinen L, Tenhunen M, Myllykangas M, Persson M, Traneus E, Sjöberg O, Ekström P. PO-1620: Reconstruction of intra-fractional real-time prostate movement and its effect on dose distribution. Radiother Oncol 2020. [DOI: 10.1016/s0167-8140(21)01638-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Ödén J, Eriksson K, Traneus E, Dasu A, Nyström PW, Toma-Dasu I. OC-0699: Relative biological effectiveness in proton therapy: accounting for variability and uncertainties. Radiother Oncol 2020. [DOI: 10.1016/s0167-8140(21)00721-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Bauer J, Bahn E, Harrabi S, Herfarth K, Traneus E, Debus J, Alber M. PO-1456: Normal Tissue Risk Avoidance Dose Painting vs Conventional Planning for Proton Brain Irradiation. Radiother Oncol 2020. [DOI: 10.1016/s0167-8140(21)01474-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Pinto M, Kröniger K, Bauer J, Nilsson R, Traneus E, Parodi K. A filtering approach for PET and PG predictions in a proton treatment planning system. Phys Med Biol 2020; 65:095014. [PMID: 32191932 DOI: 10.1088/1361-6560/ab8146] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Positron emission tomography (PET) and prompt gamma (PG) detection are promising proton therapy monitoring modalities. Fast calculation of the expected distributions is desirable for comparison to measurements and to develop/train algorithms for automatic treatment error detection. A filtering formalism was used for positron-emitter predictions and adapted to allow for its use for the beamline of any proton therapy centre. A novel approach based on a filtering formalism was developed for the prediction of energy-resolved PG distributions for arbitrary tissues. The method estimates PG yields and their energy spectra in the entire treatment field. Both approaches were implemented in a research version of the RayStation treatment planning system. The method was validated against PET monitoring data and Monte Carlo simulations for four patients treated with scanned proton beams. Longitudinal shifts between profiles from analytical and Monte Carlo calculations were within -1.7 and 0.9 mm, with maximum standard deviation of 0.9 mm and 1.1 mm, for positron-emitters and PG shifts, respectively. Normalized mean absolute errors were within 1.2 and 5.3%. When comparing measured and predicted PET data, the same more complex case yielded an average shift of 3 mm, while all other cases were below absolute average shifts of 1.1 mm. Normalized mean absolute errors were below 7.2% for all cases. A novel solution to predict positron-emitter and PG distributions in a treatment planning system is proposed, enabling calculation times of only a few seconds to minutes for entire patient cases, which is suitable for integration in daily clinical routine.
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Affiliation(s)
- M Pinto
- Department for Medical Physics, Ludwig-Maximilians-Universität München, Garching, Germany
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Chiavassa S, Nilsson R, Clément-Colmou K, Potiron V, Delpon G, Traneus E. Validation of the analytical irradiator model and Monte Carlo dose engine in the small animal irradiation treatment planning system µ-RayStation 8B. Phys Med Biol 2020; 65:035006. [PMID: 31829982 DOI: 10.1088/1361-6560/ab6155] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Dose calculation in preclinical context with a clinical level of accuracy is a challenge due to the small animal scale and the medium photon energy range. In this work, we evaluate the effectiveness and accuracy of an analytical irradiator model combined with Monte Carlo (MC) calculations in the irradiated volume to calculate the dose delivered by a modern small animal irradiator. A model of the XRAD225Cx was created in µ-RayStation 8B, a preclinical treatment planning system, allowing arc and static beams for seven cylindrical collimators. Calculations with the µ-RayStation MC dose engine were compared with EBT3 measurements in water for all static beams and with a validated GATE model in water, heterogeneous media and a mouse CT. The GATE model is a complete MC representation of the XRAD225Cx. In water, µ-RayStation calculations, compared to GATE calculations and EBT3 measurements, agreed within a maximal error of 3.2% (mean absolute error of 0.6% and 0.8% respectively) and maximal distance-to-agreement (DTA) was 0.2 mm at 50% of the central dose. For a 5 mm static beam in heterogeneous media, the maximal absolute error between µ-RayStation and GATE calculations was below 1.3% in each medium and DTA was 0.1 mm at interfaces. For calculations on a mouse CT, µ-RayStation and GATE calculations agreed well for both static and arc beams. The 2D local gamma passing rate was >98.9% for 1%/0.3 mm criteria and >92.9% for 1%/0.2 mm criteria. Moreover, µ-RayStation reduces calculation time significantly comparing with GATE (speed-up factor between 120 and 680). These findings show that the analytical irradiator model presented in this work combined with the µ-RayStation MC dose engine accurately computes dose for the XRAD225Cx irradiator. The improvements in calculation time and availability of functionality and tools for managing, planning and evaluating the irradiation makes this platform very useful for pre-clinical irradiation research.
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Affiliation(s)
- S Chiavassa
- Institut de Cancérologie de l'Ouest, Nantes, France. Author to whom any correspondence should be addressed
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Tseng Y, Maes S, Kicska G, Traneus E, Wong T, Stewart R, Saini J. Comparative Photon and Proton Dosimetry for Patients with Mediastinal Lymphoma in the Era of Monte Carlo Treatment Planning and Variable RBE. Int J Radiat Oncol Biol Phys 2018. [DOI: 10.1016/j.ijrobp.2018.06.227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Carlino A, Gouldstone C, Kragl G, Traneus E, Marrale M, Vatnitsky S, Stock M, Palmans H. End-to-end tests using alanine dosimetry in scanned proton beams. ACTA ACUST UNITED AC 2018; 63:055001. [DOI: 10.1088/1361-6560/aaac23] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Ödén J, Traneus E. Introducing Proton Track-End Objectives as a Tool to Mitigate the Elevated Relative Biological Effectiveness in Critical Structures. Int J Radiat Oncol Biol Phys 2017. [DOI: 10.1016/j.ijrobp.2017.06.2299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Carlino A, Palmans H, Kragl G, Traneus E, Gouldstone C, Vatnitsky S, Stock M. PO-0806: Dosimetric end-to-end test procedures using alanine dosimetry in scanned proton beam therapy. Radiother Oncol 2017. [DOI: 10.1016/s0167-8140(17)31243-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Saini J, St. James S, Traneus E, Wong T, Stewart R, Bloch C. SU-F-T-155: Validation of a Commercial Monte Carlo Dose Calculation Algorithm for Proton Therapy. Med Phys 2016. [DOI: 10.1118/1.4956291] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Stewart R, Streitmatter S, Traneus E, Moskvin V, Schuemann J. MO-FG-CAMPUS-TeP3-02: Benchmarks of a Proton Relative Biological Effectiveness (RBE) Model for DNA Double Strand Break (DSB) Induction in the FLUKA, MCNP, TOPAS, and RayStation™ Treatment Planning System. Med Phys 2016. [DOI: 10.1118/1.4957382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Kroniger K, Herzog M, Landry G, Traneus E, Dedes G, Parodi K. SU-C-204-01: A Fast Analytical Approach for Prompt Gamma and PET Predictions in a TPS for Proton Range Verification. Med Phys 2015. [DOI: 10.1118/1.4923825] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Ding X, Traneus E, Zhang J, Lin H, Zhai H, Rosen L, Wu H. SU-E-T-780: Use Robustness Optimization (RO) Method to Improve the Planning Efficiency for Pencil Beam Scanning Cranial Spinal Irradiation. Med Phys 2015. [DOI: 10.1118/1.4925144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Traneus E, Engwall E. PD-0276: On fast simulation of electron and proton grazing incidence outscatter from collimators. Radiother Oncol 2013. [DOI: 10.1016/s0167-8140(15)32582-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Vatanen T, Traneus E, Väänänen A, Lahtinen T. The effect of electron collimator leaf shape on the build-up dose in narrow electron MLC fields. Phys Med Biol 2009; 54:7211-26. [DOI: 10.1088/0031-9155/54/23/012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Tilly D, Sjöberg C, Tilly N, Traneus E, Ahnesjö A. ACCUMULATING DOSE FROM A 4D GEOMETRY BY AN ENERGY CONSERVING INTERPOLATION SCHEME. Radiother Oncol 2009. [DOI: 10.1016/s0167-8140(12)72679-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Vatanen T, Traneus E, Lahtinen T. Enhancement of electron-beam surface dose with an electron multi-leaf collimator (eMLC): a feasibility study. Phys Med Biol 2009; 54:2407-19. [PMID: 19336845 DOI: 10.1088/0031-9155/54/8/010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Use of a water-equivalent bolus in electron-beam radiotherapy is sometimes impractical and non-hygienic. Therefore, the feasibility of applying adjacent narrow beams for producing high surface dose electron beams without a bolus was investigated. Depth dose curves and profiles in water were calculated and measured for 6 and 9 MeV electron-beam segments (width 0.3-1.5 cm, length 10 cm) for source-to-surface distances (SSD) 102 and 105 cm. Segment shaping was performed with an add-on electron multi-leaf collimator prototype attached to the Varian 2100 C/D linac. Dose calculations were performed with the Voxel Monte Carlo++ algorithm. Resulting dose distributions in typical clinical cases were compared with the bolus technique. With a composite segmental field with 1.0 cm wide segments the surface dose was over 90% of the depth dose maximum for both energies. The build-up area practically disappeared with a 0.5 cm wide single beam. This led to decrease in the therapeutic range for composite fields with segment widths smaller than 1.0 cm. The new technique yielded similar surface doses as the bolus technique. The photon contamination was 4% with a 9 x 10 cm(2) field (1.0 cm wide segments) compared to 1% for the respective open field with 9 MeV with a bolus. The calculated dose agreed within 2 mm and 3% of the measured dose in 93.7% and 85.2% of the voxels. Adjacent narrow eMLC beams with a 1.0 cm width are suitable to produce electron fields with high surface dose. Despite a slight nonuniformity in the surface profiles in the lateral part of the field at SSD 102 cm, surface dose and target coverage are comparable with the bolus technique.
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Affiliation(s)
- T Vatanen
- Department of Oncology, Kuopio University Hospital, Box 1777, FIN-70211, Kuopio, Finland.
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Chen J, Traneus E, Lehmann J, Schreiber E, Faddegon BA. TU-FF-A1-02: Development of a Fluence Benchmark for Clinical Electron Beams. Med Phys 2007. [DOI: 10.1118/1.2761450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Faddegon B, Traneus E, Perl J, Tinslay J, Asai M. SU-FF-T-123: Comparison of Monte Carlo Simulation Results to An Experimental Thick-Target Bremsstrahlung Benchmark. Med Phys 2007. [DOI: 10.1118/1.2760781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Faddegon B, Traneus E, Chen J. SU-FF-T-36: A Preliminary Comparison of a New Fluence Benchmark for Clinical Electron Beams with Fluence Calculated with a Commercial Planning System. Med Phys 2007. [DOI: 10.1118/1.2760681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Kallne J, Ballabio L, Frenje J, Conroy S, Ericsson G, Tardocchi M, Traneus E, Gorini G. Observation of the alpha particle "Knock-On" neutron emission from magnetically confined DT fusion plasmas. Phys Rev Lett 2000; 85:1246-1249. [PMID: 10991523 DOI: 10.1103/physrevlett.85.1246] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2000] [Indexed: 05/23/2023]
Abstract
Suprathermal fuel ions from alpha-particle knock-on collisions in fusion DT plasmas are predicted to cause a weak feature in the neutron spectrum of d+t-->alpha+n. The knock-on feature has been searched for in the neutron emission of high ( >1 MW) fusion-power plasmas produced at JET and was found using a magnetic proton recoil type neutron spectrometer of high performance. Measurement and predictions agree both in absolute amplitude and in plasma-parameter dependence, supporting the interpretation and model. Moreover, the results provide input to projecting alpha-particle diagnostics for future self-heated fusion plasmas.
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Affiliation(s)
- J Kallne
- Department of Neutron Research, Uppsala University, EURATOM-NFR Association, Uppsala, Sweden
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