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Poulsen PR, Eley J, Langner U, Simone CB, Langen K. Efficient Interplay Effect Mitigation for Proton Pencil Beam Scanning by Spot-Adapted Layered Repainting Evenly Spread out Over the Full Breathing Cycle. Int J Radiat Oncol Biol Phys 2017; 100:226-234. [PMID: 29254775 DOI: 10.1016/j.ijrobp.2017.09.043] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 09/06/2017] [Accepted: 09/22/2017] [Indexed: 11/20/2022]
Abstract
PURPOSE To develop and implement a practical repainting method for efficient interplay effect mitigation in proton pencil beam scanning (PBS). METHODS AND MATERIALS A new flexible repainting scheme with spot-adapted numbers of repainting evenly spread out over the whole breathing cycle (assumed to be 4 seconds) was developed. Twelve fields from 5 thoracic and upper abdominal PBS plans were delivered 3 times using the new repainting scheme to an ion chamber array on a motion stage. One time was static and 2 used 4-second, 3-cm peak-to-peak sinusoidal motion with delivery started at maximum inhalation and maximum exhalation. For comparison, all dose measurements were repeated with no repainting and with 8 repaintings. For each motion experiment, the 3%/3-mm gamma pass rate was calculated using the motion-convolved static dose as the reference. Simulations were first validated with the experiments and then used to extend the study to 0- to 5-cm motion magnitude, 2- to 6-second motion periods, patient-measured liver tumor motion, and 1- to 6-fraction treatments. The effect of the proposed method was evaluated for the 5 clinical cases using 4-dimensional (4D) dose reconstruction in the planning 4D computed tomography scan. The target homogeneity index, HI = (D2 - D98)/Dmean, of a single-fraction delivery is reported, where D2 and D98 is the dose delivered to 2% and 98% of the target, respectively, and Dmean is the mean dose. RESULTS The gamma pass rates were 59.6% ± 9.7% with no repainting, 76.5% ± 10.8% with 8 repaintings, and 92.4% ± 3.8% with the new repainting scheme. Simulations reproduced the experimental gamma pass rates with a 1.3% root-mean-square error and demonstrated largely improved gamma pass rates with the new repainting scheme for all investigated motion scenarios. One- and two-fraction deliveries with the new repainting scheme had gamma pass rates similar to those of 3-4 and 6-fraction deliveries with 8 repaintings. The mean HI for the 5 clinical cases was 14.2% with no repainting, 13.7% with 8 repaintings, 12.0% with the new repainting scheme, and 11.6% for the 4D dose without interplay effects. CONCLUSIONS A novel repainting strategy for efficient interplay effect mitigation was proposed, implemented, and shown to outperform conventional repainting in experiments, simulations, and dose reconstructions. This strategy could allow for safe and more optimal clinical delivery of thoracic and abdominal proton PBS and better facilitate hypofractionated and stereotactic treatments.
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Langner UW, Eley JG, Dong L, Langen K. Comparison of multi-institutional Varian ProBeam pencil beam scanning proton beam commissioning data. J Appl Clin Med Phys 2017; 18:96-107. [PMID: 28422381 PMCID: PMC5689862 DOI: 10.1002/acm2.12078] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 02/24/2017] [Accepted: 03/06/2017] [Indexed: 11/09/2022] Open
Abstract
Purpose Commissioning beam data for proton spot scanning beams are compared for the first two Varian ProBeam sites in the United States, at the Maryland Proton Treatment Center (MPTC) and Scripps Proton Therapy Center (SPTC). In addition, the extent to which beams can be matched between gantry rooms at MPTC is investigated. Method Beam data for the two sites were acquired with independent dosimetry systems and compared. Integrated depth dose curves (IDDs) were acquired with Bragg peak ion chambers in a 3D water tank for pencil beams at both sites. Spot profiles were acquired at different distances from the isocenter at a gantry angle of 0° as well as a function of gantry angles. Absolute dose calibration was compared between SPTC and the gantries at MPTC. Dosimetric verification of test plans, output as a function of gantry angle, monitor unit (MU) linearity, end effects, dose rate dependence, and plan reproducibility were compared for different gantries at MPTC. Results The IDDs for the two sites were similar, except in the plateau region, where the SPTC data were on average 4.5% higher for lower energies. This increase in the plateau region decreased as energy increased, with no marked difference for energies higher than 180 MeV. Range in water coincided for all energies within 0.5 mm. The sigmas of the spot profiles in air were within 10% agreement at isocenter. This difference increased as detector distance from the isocenter increased. Absolute doses for the gantries measured at both sites were within 1% agreement. Test plans, output as function of gantry angle, MU linearity, end effects, dose rate dependence, and plan reproducibility were all within tolerances given by TG142. Conclusion Beam data for the two sites and between different gantry rooms were well matched.
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Lohmann P, Lerche C, Bauer E, Steger J, Stoffels G, Filss CP, Stegmayr C, Neumaier B, Shah NJ, Langen K, Galldiks N. P10.17 Predicting isocitrate dehydrogenase genotype in malignant glioma using FET PET radiomics. Neuro Oncol 2017. [DOI: 10.1093/neuonc/nox036.335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Lohmann P, Lerche C, Stoffels G, Filss CP, Stegmayr C, Neumaier B, Shah NJ, Langen K, Galldiks N. P09.26 FET PET radiomics - diagnosis of pseudoprogression in glioblastoma patients based on textural features. Neuro Oncol 2017. [DOI: 10.1093/neuonc/nox036.282] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Yu J, Park SS, Herman MG, Langen K, Mehta M, Feigenberg SJ. Free Breathing versus Breath-Hold Scanning Beam Proton Therapy and Cardiac Sparing in Breast Cancer. Int J Part Ther 2017; 3:407-413. [PMID: 31772990 DOI: 10.14338/ijpt-16-00021.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Accepted: 11/16/2016] [Indexed: 12/25/2022] Open
Abstract
Purpose To assess dose errors caused by the interplay effects of free-breathing (FB) motion and to assess the value of breath-hold (BH) in terms of cardiac dose reduction for scanning beam proton therapy (SBPT). Materials and Methods Three patients with left-sided breast cancer previously treated with photon therapy were included in this dosimetric study: 2 following breast-conserving surgery with 2 hypothetical target volumes (whole breast alone and whole breast plus regional nodes, including supraclavicular, axillary, and internal mammary lymph nodes); and 1 postmastectomy, with the target volume including the chest wall plus regional nodes. SBPT plans were generated with various beam angles that ranged between 2 tangential directions. For treatment with FB, nominal dose and dose with interplay effects considered were calculated based on FB 4-dimensional computed tomography scans. SBPT plans on the BH computed tomography were also calculated for one of the patients, who was selected to be treated with photon therapy with BH. Results Dosimetric differences between nominal and interplay dose were small (average target mean dose, -0.06 Gy; range, -0.23 to 0.06 Gy; average heart mean dose, 0.001 Gy; range, -0.12 to 0.05 Gy). The largest dose deviations occurred in plans calculated with tangential beam arrangements; the smallest was noted with the en face beam. The average value of the mean heart dose with FB was <1 Gy. For the selected patient, the mean heart doses were 0.5 and 0.2 Gy for FB and BH, respectively. Conclusion Dose deviations caused by the interplay effects of respiratory motion during FB do not have a significant impact in SBPT with en face beam arrangement. BH does not significantly reduce cardiac dose. SBPT delivery is feasible with FB and can provide optimal target coverage and maximal sparing of the cardiopulmonary system, which can translate into improved clinical outcomes and a decrease in treatment-related morbidity in left-sided breast cancer patients or those who require internal mammary node coverage.
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Chhabra A, Langen K, Mehta MP. An overview of modern proton therapy. Chin Clin Oncol 2016; 5:48. [PMID: 27334460 DOI: 10.21037/cco.2016.05.06] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Accepted: 05/01/2016] [Indexed: 11/06/2022]
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Langner U, Langen K, Eley J, Zhu M, Yu J, Chung H, Polf J, Dong L. SU-F-T-162: Comparison of Beam Data for Two Varian ProBeam Pencil Beam Scanning Proton Systems. Med Phys 2016. [DOI: 10.1118/1.4956298] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Mossahebi S, Langen K, Guerrero M, Yi B, Lu W, Kalavagunta C, Prado K, Chen S. SU-F-T-286: Calculation-Based Patient Specific IMRT QA Detects Potential Errors That Measurement-Based QA Does Not. Med Phys 2016. [DOI: 10.1118/1.4956426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Yu J, Nichols E, Strauss D, Chung H, Langner U, Langen K. SU-F-T-151: Measurement Evaluation of Skin Dose in Scanning Proton Beam Therapy for Breast Cancer. Med Phys 2016. [DOI: 10.1118/1.4956287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Langner U, Langen K. SU-F-T-161: The Effect of Pencil Beam Scanning Gantry Angle Dependent Spot Size Variations On Plan Quality. Med Phys 2016. [DOI: 10.1118/1.4956297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Polf J, Chung H, Langen K. SU-F-T-220: Validation of Hounsfield Unit-To-Stopping Power Ratio Calibration Used for Dose Calculation in Proton Radiotherapy. Med Phys 2016. [DOI: 10.1118/1.4956359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Zhu M, Yam M, Mehta M, Badiyan S, Young K, Malyapa R, Regine W, Langen K. SU-F-T-188: A Robust Treatment Planning Technique for Proton Pencil Beam Scanning Cranial Spinal Irradiation. Med Phys 2016. [DOI: 10.1118/1.4956325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Yu J, Strauss D, Langner U, Langen K. SU-F-T-170: Patient Surface Dose Measurements Using Optically Stimulated Luminescence Dosimeters in Scanning Proton Beam Therapy for Breast Cancer. Med Phys 2016. [DOI: 10.1118/1.4956307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Chen S, Guerrero M, Zhang B, Yi B, Mossahebi S, Prado K, D'Souza W, Langen K. SU-G-TeP4-11: Implementation of a Non-Measurement-Based Patient-Specific IMRT QA Program. Med Phys 2016. [DOI: 10.1118/1.4957136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Klein EE, El Naqa I, Langen K, Dogan N. Physics: The Use of Magnetic Resonance Imaging for Radiation Therapy is Accelerating in Utility and Novelty. Int J Radiat Oncol Biol Phys 2015; 93:953-6. [PMID: 26581131 DOI: 10.1016/j.ijrobp.2015.07.2276] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 07/20/2015] [Indexed: 11/24/2022]
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Langen K, Mehta M. Proton Beam Therapy Basics. J Am Coll Radiol 2015; 12:1204-6. [PMID: 26419311 DOI: 10.1016/j.jacr.2015.08.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 08/01/2015] [Indexed: 10/23/2022]
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Eley J, Mehta M, Molitoris J, Langner U, Langen K. SU-E-T-626: Practical Method to Implement Arc Therapy Using Scanned Particle Beams. Med Phys 2015. [DOI: 10.1118/1.4924989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Xu H, Guerrero M, Yang X, Chen S, Langen K, Prado K, Schinkel C. SU-E-T-182: Clinical Implementation of TG71-Based Electron MU Calculation and Comparison with a Commercial Secondary Calculation. Med Phys 2015. [DOI: 10.1118/1.4924543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Langen K, Guerrero M, Killefer M, Xu H, Zhou J, Zhang B, Chen S. SU-E-T-192: Commissioning of a Commercial 3D Dose Calculation Program. Med Phys 2015. [DOI: 10.1118/1.4924553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Zhou J, Lasio G, Yi B, Huang J, Chen S, Zhang B, Langen K, Prado K, D'souza W. SU-E-J-122: The CBCT Dose Calculation Using a Patient Specific CBCT Number to Mass Density Conversion Curve Based On a Novel Image Registration and Organ Mapping Method in Head-And-Neck Radiation Therapy. Med Phys 2015. [DOI: 10.1118/1.4924208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Chuong MD, Mehta MP, Langen K, Regine WF. Is proton beam therapy better than standard radiation therapy? The available evidence points to benefits of proton beam therapy. CLINICAL ADVANCES IN HEMATOLOGY & ONCOLOGY : H&O 2014; 12:861-864. [PMID: 25674846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
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Kebir S, Schafer N, Mack F, Schaub C, Niessen M, Stoffels G, Galldiks N, Langen K, Glas M, Herrlinger U. P16.17 * F-18-FET PET IMAGING FOR DIAGNOSIS OF LATE PSEUDOPROGRESSION IN PATIENTS WITH HIGH-GRADE GLIOMAS. Neuro Oncol 2014. [DOI: 10.1093/neuonc/nou174.313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Galldiks N, Ruge MI, Hamisch C, Stoffels G, Ceccon G, Rapp M, Sabel M, Langen K. O7.05 * DIFFERENTIATION OF LOCAL RECURRENT BRAIN METASTASIS FROM RADIATION-INDUCED CHANGES USING O-(2-[18F]FLUOROETHYL)-L-TYROSINE PET. Neuro Oncol 2014. [DOI: 10.1093/neuonc/nou174.56] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Galldiks N, Dunkl V, Stoffels G, Hutterer M, Rapp M, Kebir S, Goldbrunner R, Ruge MI, Schmidt M, Langen K. P16.10 * DIAGNOSIS OF PSEUDOPROGRESSION IN PATIENTS WITH GLIOBLASTOMA USING AMINO ACID PET. Neuro Oncol 2014. [DOI: 10.1093/neuonc/nou174.306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Cornelius J, Stoffels G, Filss C, Galldiks N, Slotty P, Kamp M, Hänggi D, Sabel M, Steiger H, Langen K. Diagnostic Potential of O-(2-18F-fluoroethyl)-L-tyrosine PET in Patients with Meningioma. Skull Base Surg 2014. [DOI: 10.1055/s-0034-1384135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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