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Langen K, Chen S. SU-E-T-388: Estimating the Radioactivity Inventory of a Cyclotron Based Pencil Beam Proton Therapy Facility. Med Phys 2014. [DOI: 10.1118/1.4888721] [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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Pukala J, Langen K, Bova F, Staton R, Manon R, Kelly P, Meeks S. MO-C-17A-01: BEST IN PHYSICS (JOINT IMAGING-THERAPY) - A Method to Estimate Deformable Dose Accumulation Errors in Patients with Cancers of the Head and Neck. Med Phys 2014. [DOI: 10.1118/1.4889124] [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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Zhang H, Prado K, Langen K, Yi B, Mehta M, Regine W, D' Souza W. SU-E-T-387: Achieving Optimal Patient Setup Imaging and Treatment Workflow Configurations in Multi-Room Proton Centers. Med Phys 2014. [DOI: 10.1118/1.4888720] [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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De Los Santos J, Popple R, Agazaryan N, Bayouth JE, Bissonnette JP, Bucci MK, Dieterich S, Dong L, Forster KM, Indelicato D, Langen K, Lehmann J, Mayr N, Parsai I, Salter W, Tomblyn M, Yuh WTC, Chetty IJ. Image guided radiation therapy (IGRT) technologies for radiation therapy localization and delivery. Int J Radiat Oncol Biol Phys 2013; 87:33-45. [PMID: 23664076 DOI: 10.1016/j.ijrobp.2013.02.021] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Revised: 02/14/2013] [Accepted: 02/16/2013] [Indexed: 12/27/2022]
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Waghorn BJ, Staton RJ, Rineer JM, Meeks SL, Langen K. A comparison of the dosimetric effects of intrafraction motion on step-and-shoot, compensator, and helical tomotherapy-based IMRT. J Appl Clin Med Phys 2013; 14:4210. [PMID: 23652252 PMCID: PMC5714423 DOI: 10.1120/jacmp.v14i3.4210] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Revised: 11/13/2012] [Accepted: 01/02/2013] [Indexed: 11/23/2022] Open
Abstract
Intrafraction motion during intensity‐modulated radiation therapy can cause differences between the planned and delivered patient dose. The magnitude of these differences is dependent on a number of variables, including the treatment modality. This study was designed to compare the relative susceptibility of plans generated with three different treatment modalities to intrafraction motion. The dosimetric effects of motion were calculated using computational algorithms for seven lung tumor patients. Three delivery techniques — MLC‐based step‐and‐shoot (SNS), beam attenuating compensators, and helical tomotherapy (HT) — were investigated. In total 840 motion‐encoded dose‐volume histograms (DVHs) were calculated for various combinations of CTV margins and sinusoidal CTV motion including CTV offsets. DVH‐based metrics (e.g., D95% and D05%) were used to score plan degradations. For all three modalities, dosimetric degradations were typically smaller than 3% if the CTV displacement was smaller than the CTV margin. For larger displacements, technique and direction‐specific sensitivities existed. While the HT plans show similar D95% degradations for motion in the SI and AP directions, SNS and compensator plans showed larger D95% degradations for motion in the SI direction than for motion in the AP direction. When averaged over all motion/margin combinations, compensator plans resulted in 0.9% and 0.6% smaller D95% reductions compared to SNS and HT plans, respectively. These differences were statistically significant. No statistically significant differences in D95% degradations were found between SNS and HT for data averaged over all margin and motion track combinations. For CTV motion that is larger than the CTV margin, the dosimetric impact on the CTV varies with treatment technique and the motion direction. For the cases presented here, the effect of motion on CTV dosimetry was statistically smaller for compensator deliveries than SNS and HT, likely due to the absence of the interplay effect which is present for the more dynamic treatment deliveries. The differences between modalities were, however, small and might not be clinically significant. As expected, margins that envelop the CTV motion provide dosimetric protection against motion for all three modalities. PACS numbers: 87.53.Jw, 87.55.dk, 87.55.de
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Ruan D, Shao W, DeMarco J, Tenn S, Langen K, Dieterich S, King C, Closkey SM, Low D, Kupelian P. Collection of Treatment Plan Parameters and Related Quality Indices Into Radiation Therapy Registries. Int J Radiat Oncol Biol Phys 2012. [DOI: 10.1016/j.ijrobp.2012.07.405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Pukala J, Staton R, Langen K. SU-E-J-201: What is the Importance of Dose Recalculation for Adaptive Radiotherapy Dose Assessment? Med Phys 2012; 39:3699. [PMID: 28519011 DOI: 10.1118/1.4735041] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To quantify the effect of using the planned dose distributions in lieu of performing dose recalculations on daily in-room images for adaptive radiotherapy (ART) dose assessment of head and neck cancer patients. METHODS 16 patients with cancers of the head and neck were treated using the TomoTherapy Hi-Art II (Accuray Inc., Sunnyvale, CA). Images of all patients were acquired prior to each treatment using the megavoltage CT (MVCT) capability of the TomoTherapy unit. Overall, images from 528 fractions were evaluated. For every image set, the delivered dose was estimated by both recalculating the dose distribution using the acquired MVCT and also by simply overlaying the planned distribution on the new images. ART dose assessment was performed using deformable image registration (DIR) to deform contours from the treatment plan to the images acquired during each fraction and to accumulate the estimated dose delivered during each fraction back to the reference treatment plan. The same DIR maps were applied to both dose estimation methods. Dosimetric endpoints were then compared between the DVHs computed using the recalculated or planned dose distributions. RESULTS The mean PTV D95% and D05% endpoints were 0.6±0.5% and 1.4±0.8% lower using the planned dose distributions compared to the recalculated distributions, respectively, across all patients. The mean parotid D50% was 2.4±1.5% greater using the planned distributions compared to the recalculated distributions. The parotid D50% from the planned distributions was also highly correlated with the parotid D50% from the recalculated distributions for each patient (mean r2=0.97±0.09). CONCLUSIONS For this treatment modality and site, dosimetric differences observed between overlaying the planned dose distributions and recalculating distributions on daily images were typically well within ±5%. This indicates that the dose distribution itself is robust against anatomic variations. This study was funded, in part, by a grant from Accuray Inc.
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Staton R, Biddle J, Langen K, Meeks S. SU-E-T-369: Evaluation of Dose Control System Performance on a TomoTherapy Hi-Art System. Med Phys 2012. [DOI: 10.1118/1.4735456] [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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Langen K, Papanikolaou N, Balog J, Crilly R, Followill D, Goddu S, Grant W, Olivera G, Ramsey C, Shi C. WE-B-BRA-02: QA of Helical Tomotherapy TG-148. Med Phys 2011. [DOI: 10.1118/1.3613301] [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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Waghorn B, Meeks S, Langen K. WE-C-BRB-06: Analyzing the Impact of Intra-Fraction Motion: Correlation of IMRT QA Metrics with D95%. Med Phys 2011. [DOI: 10.1118/1.3613325] [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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Pukala J, Meeks S, Langen K. SU-E-T-529: The Dosimetric Uncertainty of Helical MVCT Images for Use in Adaptive Radiotherapy. Med Phys 2011. [DOI: 10.1118/1.3612482] [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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Kupelian P, Langen K. Helical tomotherapy: image-guided and adaptive radiotherapy. ACTA ACUST UNITED AC 2011; 43:165-180. [PMID: 21625153 DOI: 10.1159/000322420] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Helical tomotherapy is a treatment device that is designed to deliver intensity-modulated radiation therapy treatments. Helical tomotherapy systems have been used to treat a wide spectrum of anatomical sites. In addition to its unique delivery technique, the capability to obtain megavoltage-based CT (MVCT) images is highly integrated into the system's image guidance. The introduction of MVCT imaging into clinical practice has prompted a range of technical and clinical investigations. The image quality, image dose and use of MVCT images for dose calculation have been investigated. At the same time, routine clinical use of MVCT imaging has provided a wealth of clinical experience. Both technical and clinical experiences with the MVCT system will be reviewed in this chapter.
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Waghorn B, Shah A, Meeks S, Langen K. MO-D-BRB-05: A Computational Method for Estimating the Dosimetric Effect of Intra-Fraction Motion on Step-And-Shoot IMRT and Compensator Plans. Med Phys 2010. [DOI: 10.1118/1.3469057] [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, Papanikolaou N, Balog J, Crilly R, Followill D, Goddu S, Grant W, Olivera G, Ramsey C, Shi C. TU-B-203-02: QA of Radiation Delivery Systems. Med Phys 2010. [DOI: 10.1118/1.3469183] [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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Mehlis M, Bakker TCM, Langen K, Frommen JG. Cain and Abel reloaded? Kin recognition and male-male aggression in three-spined sticklebacks Gasterosteus aculeatus L. JOURNAL OF FISH BIOLOGY 2009; 75:2154-2162. [PMID: 20738679 DOI: 10.1111/j.1095-8649.2009.02407.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The influence of relatedness on male-male aggression was tested in three-spined sticklebacks Gasterosteus aculeatus. The intensity of aggression against brothers and non-kin males did not differ significantly, indicating that kin recognition plays at most a minor role in aggressive interactions between male G. aculeatus.
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Langen K, Moore J, Kupelian P, Siebers J. SU-FF-T-131: Assessing the Dosimetric Impact of Intra-Fraction Prostate Motion On Step-And-Shoot IMRT Plans. Med Phys 2009. [DOI: 10.1118/1.3181605] [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. TU-E-BRB-05: Performance-Based QA for Radiotherapy: TG-148 - Tomotherapy Quality Assurance. Med Phys 2009. [DOI: 10.1118/1.3182414] [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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Ngwa W, Shah A, Meeks S, Kupelian P, Langen K. WE-E-BRB-01: Impact Or No Impact of Respiratory Motion On Helical Tomotherapy Dose Delivery. Med Phys 2009. [DOI: 10.1118/1.3182561] [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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Poulsen PR, Cho B, Langen K, Kupelian P, Keall PJ. Three-dimensional prostate position estimation with a single x-ray imager utilizing the spatial probability density. Phys Med Biol 2008; 53:4331-53. [DOI: 10.1088/0031-9155/53/16/008] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Lopatiuk-Tirpak O, Langen K, Meeks S, Kupelian P, Maryanski M, Hsi W, Palta J, Zeidan O. SU-GG-T-270: Evaluation of a Novel 3-D Polymer Gel Dosimetry System for Proton Radiotherapy. Med Phys 2008. [DOI: 10.1118/1.2962022] [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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Lopatiuk-Tirpak O, Langen K, Meeks S, Kupelian P, Maryanski M, Zeidan O. SU-GG-T-286: Performance of An Improved Optical Computed Tomography Polymer Gel Dosimeter System for 3-D Dose Verification of Static and Dynamic Phantom Deliveries. Med Phys 2008. [DOI: 10.1118/1.2962038] [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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Staton R, Langen K, Meeks S. TU-FF-A1-03: Dosimetric Effect of Target Degradation On Helical TomoTherapy Treatment Plans. Med Phys 2008. [DOI: 10.1118/1.2962640] [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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Ramsey C, Seibert R, Hines W, Meeks S, Langen K, Kupelian P, Li X. Predictive Adaptive Radiation Therapy for Lung Cancer. Int J Radiat Oncol Biol Phys 2007. [DOI: 10.1016/j.ijrobp.2007.07.042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Mañon R, Lee C, Langen K, Meeks S, Kupelian P, Haimerl J, Shellenberger T, Olivera G. Do Anatomic Changes During Radiation Impact Normal Tissue and Target Dosimetry? An Analysis of Calculated Cumulative Dose in Head and Neck Patients. Int J Radiat Oncol Biol Phys 2007. [DOI: 10.1016/j.ijrobp.2007.07.1583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Zeidan O, Lee C, Langen K, Kupelian P, Manon R, Meeks S. A Dosimetric Evaluation of Markers vs. Bony Anatomy Alignments for a Head and Neck Case. Int J Radiat Oncol Biol Phys 2007. [DOI: 10.1016/j.ijrobp.2007.07.1642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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