151
|
Park P, Cheung J, Zhu X, Liu W, Sahoo N, Court L, Mohan R, Li H, Dong L. TH-A-116-01: A Statistical Approach to Quantification and Visualization of Setup and Range Uncertainties for Proton Plan Verification. Med Phys 2013. [DOI: 10.1118/1.4815730] [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
|
152
|
Perles LA, Titt U, Mirkovic D, Mohan R. SU-E-T-297: Modeling the Cell Inactivation Process for High LET Particles by Using the Law of Mass Action. Med Phys 2013. [DOI: 10.1118/1.4814731] [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
|
153
|
Ge S, Quan M, Zhang L, Liu W, Mohan R. SU-E-T-701: Equivalence and Differences Between Robust Optimization Methods and PTV Based Optimization Method for IMRT and IMPT. Med Phys 2013. [DOI: 10.1118/1.4815128] [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
|
154
|
Safaa A, Markham R, Mohan R, Shanahan L, Coatsworth J, Batra R. A Regional Centre Experience on Cardiac Resynchronisation Therapy—A Five-year Audit at The Gold Coast Hospital (GCH). Heart Lung Circ 2013. [DOI: 10.1016/j.hlc.2013.05.164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
155
|
Sriramkumar D, Malmathanraj R, Mohan R, Umamaheswari S. Mammogram tumour classification using modified segmentation techniques. INTERNATIONAL JOURNAL OF BIOMEDICAL ENGINEERING AND TECHNOLOGY 2013. [DOI: 10.1504/ijbet.2013.058444] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
156
|
Sivakumar B, Raj SG, Kumar GR, Mohan R. Growth and Characterization of Lithium Potassium Phthalate (LiKP) Single Crystals for Third Order Nonlinear Optical Applications. B KOREAN CHEM SOC 2012. [DOI: 10.5012/bkcs.2012.33.11.3755] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
157
|
Yoshikazu T, Sahoo N, Poenisch F, Umezawa M, Briere T, Zhu R, Mohan R, Dong L. Experimental Evaluation of the Interplay Effect and Motion Management by Respiratory Gating in Synchrotron-based Spot Scanning Proton Beam Delivery. Int J Radiat Oncol Biol Phys 2012. [DOI: 10.1016/j.ijrobp.2012.07.350] [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]
|
158
|
Frank S, Cox J, Gillin M, Rosenthal D, Garden A, Ang K, Mohan R, Palmer M, Amin M, Zhu X. Intensity Modulated Proton Therapy for Head-and-Neck Cancer: The First Clinical Experience. Int J Radiat Oncol Biol Phys 2012. [DOI: 10.1016/j.ijrobp.2012.07.1260] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
159
|
Mohan R, Matney J, Bluett J, Palmer M, Choi N, Chang J, Komaki R, Cox J, Liao Z. IMRT Versus Passively Scattered Proton Therapy (PSPT) for Locally Advanced NSCLC -- Impact of Changing Techniques and Technologies Over the Course of a Randomized Trial. Int J Radiat Oncol Biol Phys 2012. [DOI: 10.1016/j.ijrobp.2012.07.1506] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
160
|
Mohan R, Oelfke U, Paganetti H, Soukup M. TH-C-213CD-01: Accuracy of Proton Dose Computation Algorithms and Need for Improvements. Med Phys 2012. [DOI: 10.1118/1.4736329] [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
|
161
|
Tsunashima Y, Sahoo N, Sakae T, Poenisch F, Umezawa M, Briere T, Zhu X, Mohan R, Dong L. SU-E-T-395: Achievability and Optimization of Synchrotron-Based Respiratory Gated Spot Scanning Proton Beam Delivery. Med Phys 2012; 39:3795. [DOI: 10.1118/1.4735484] [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
|
162
|
Sell M, Titt U, Perles L, Mirkovic D, Mohan R, Bangert M, Oelfke U. WE-E-BRB-02: Evaluation of Analytical Proton Dose Predictions with a Lung-Like Plastic Phantom. Med Phys 2012; 39:3956. [DOI: 10.1118/1.4736144] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
163
|
Park P, Cheung J, Chen Y, Zhu X, Sahoo N, Court L, Mohan R, Dong L. TH-A-BRA-09: Statistical Assessment of Plan Robustness Under Uncertainties: IMRT Vs. Proton Therapy. Med Phys 2012. [DOI: 10.1118/1.4736258] [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
|
164
|
Liu W, Frank S, Li X, Li Y, Zhang X, Zhu X, Mohan R. SU-E-T-565: Effectiveness of Robust Optimization in Head and Neck IMPT Dose Distributions. Med Phys 2012; 39:3835. [DOI: 10.1118/1.4735654] [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
|
165
|
Perles L, Mirkovic D, Anand A, Titt U, Mohan R. TH-E-BRB-04: Dose Response of EBT2 Film Modeled as a Bimolecular Reaction. Med Phys 2012. [DOI: 10.1118/1.4736354] [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
|
166
|
Peeler C, Mirkovic D, Grosshans D, Titt U, Mohan R. TH-C-213AB-05: Correlating Areas of Radiation Toxicity with Relative Biological Effectiveness-Weighted Dose Distributions in Proton Radiotherapy. Med Phys 2012. [DOI: 10.1118/1.4736294] [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
|
167
|
Titt U, Mirkovic D, Perles L, Sell M, Peeler C, Liu A, Mohan R. SU-E-T-474: Monte Carlo Phase Space Production to Model Magnetically Scanned Proton Beams for IMPT. Med Phys 2012; 39:3814. [PMID: 28517438 DOI: 10.1118/1.4735563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Accurate dose predictions in proton beam therapy using magnetically scanned beams are highly dependent on the accurate modeling of the lateral dose profiles. This study was performed to provide proton phase spaces for Monte Carlo simulations, used to accurately simulate doses at distances up to 12 cm from the central axis of the beam. METHODS Measured lateral dose profiles at various depths in water were compared to Monte Carlo simulations of doses for 90 discreet initial proton energies. Phase spaces were produced using a one dimensional energy distribution, and a combination of several two dimensional spatial and directional distributions. Simulations were performed iteratively using variations in the initial phase space distributions to achieve acceptable agreement between measured and simulated lateral dose profiles, i.e. differences in FWHM < 0.5 mm and dose differences less that 0.1% at distances up to 12.5 cm. RESULTS 90 phase spaces of proton sources for different initial beam energies were created for use in Monte Carlo simulations of scanned proton beam therapy patient plans. At a depth of 2 cm in water, the simulated and measured FWHM of the lateral dose profiles differed in in-plane direction by an average of 0.05 mm, in cross-plane direction by 0.13 mm. All simulated profiles were within 0.1% of the measured doses at distances between 2cm and 12.5 cm from the central beam axis. CONCLUSIONS A library of 90 phase space files has been created to accurately simulate magnetically scanned proton beams for IMPT, providing accurate dose distributions up to 12 cm distance from the central beam axis. This project is supported in part by P01CA021239 from the National Cancer Institute. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Cancer Institute or the National Institutes of Health.
Collapse
|
168
|
Liu W, Zhu X, Li X, Li Y, Zhang X, Frank S, Mohan R. SU-E-T-624: Comparison of PTV+PRV-Based Optimization and Robust Optimization in Intensity-Modulated Proton Therapy. Med Phys 2012; 39:3849-3850. [PMID: 28517515 DOI: 10.1118/1.4735714] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Robust optimization leads to IMPT plans that are more robust than and superior in optimality compared to PTV-based optimized plans. Robust optimization incorporates setup and range uncertainties, which implicitly adds margins to targets and organs-at-risk (OARs); whereas PTV-based optimization only considers setup uncertainties and adds margins only to targets in practice. The purpose of this work is to determine if the superiority of robustly optimized plans is due to not assigning margins to OARs during PTV-based optimization. METHODS Plan robustness and optimality of the PTV plus Planning organs-at-Risk Volume (PRVs)-based plans and robustly optimized plans were compared for 5 head and neck cancer cases and one rhabdomyosarcoma case. The PRVs were generated by expansion from OARs by 3 mm. 9 different dose distributions were computed - one each for ± setup uncertainties along three spatial directions, for ± range uncertainty, and the nominal dose distribution. The worst-case dose distribution was obtained by assigning the lowest dose among the 9 doses to each voxel in the target and the highest dose to each voxel outside the target. The DVHs from the worst-case dose were used to assess the plan optimality and robustness. D1cc doses for spinal cord and brainstem, mean doses Dmean for oral cavity and parotids, and D1% doses for other organs were also used to assess plan optimality. D5% and D95% doses are used to assess target dose coverage and homogeneity. RESULTS For H&N cases, PTV+PRV-based optimization was inferior to robust optimization. However, PTV+PRV-based optimization yielded plans that spared OARs better than PTV-based optimization, although the target dose robustness and homogeneity were comparable to the PTV-based optimization. The same conclusions are also valid in the rhabdomyosarcoma case. CONCLUSIONS We find that the PTV+PRV method can partly improve plan optimality, but it is still inferior to robust optimization method. This research is supported by National Cancer Institute (NCI) grant P01CA021239, the University Cancer Foundation via the Institutional Research Grant program at the University of Texas MD Anderson Cancer Center, and MD Anderson’s cancer center support grant CA016672.
Collapse
|
169
|
Liu W, Mohan R. SU-E-T-625: Robustness Evaluation and Robust Optimization of IMPT Plans Based on Per-Voxel Standard Deviation of Dose Distributions. Med Phys 2012; 39:3850. [PMID: 28517501 DOI: 10.1118/1.4735715] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Proton dose distributions, IMPT in particular, are highly sensitive to setup and range uncertainties. We report a novel method, based on per-voxel standard deviation (SD) of dose distributions, to evaluate the robustness of proton plans and to robustly optimize IMPT plans to render them less sensitive to uncertainties. METHODS For each optimization iteration, nine dose distributions are computed - the nominal one, and one each for ± setup uncertainties along x, y and z axes and for ± range uncertainty. SD of dose in each voxel is used to create SD-volume histogram (SVH) for each structure. SVH may be considered a quantitative representation of the robustness of the dose distribution. For optimization, the desired robustness may be specified in terms of an SD-volume (SV) constraint on the CTV and incorporated as a term in the objective function. Results of optimization with and without this constraint were compared in terms of plan optimality and robustness using the so called'worst case' dose distributions; which are obtained by assigning the lowest among the nine doses to each voxel in the clinical target volume (CTV) and the highest to normal tissue voxels outside the CTV. The SVH curve and the area under it for each structure were used as quantitative measures of robustness. Penalty parameter of SV constraint may be varied to control the tradeoff between robustness and plan optimality. We applied these methods to one case each of H&N and lung. RESULTS In both cases, we found that imposing SV constraint improved plan robustness but at the cost of normal tissue sparing. CONCLUSIONS SVH-based optimization and evaluation is an effective tool for robustness evaluation and robust optimization of IMPT plans. Studies need to be conducted to test the methods for larger cohorts of patients and for other sites. This research is supported by National Cancer Institute (NCI) grant P01CA021239, the University Cancer Foundation via the Institutional Research Grant program at the University of Texas MD Anderson Cancer Center, and MD Anderson’s cancer center support grant CA016672.
Collapse
|
170
|
Matney J, Bluett J, Vedam S, Dong L, Mohan R. TH-E-218-06: Dosimetric Effects of Respiratory Motion in Proton Vs. Photon Therapy for Stage II-III NSCLC. Med Phys 2012. [DOI: 10.1118/1.4736392] [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
|
171
|
Ge S, Liu W, Quan E, Mohan R. WE-G-BRCD-02: Speed Up Standard Optimization of IMPT Treatment Planning Through the Application of GPUs. Med Phys 2012; 39:3964-3965. [PMID: 28519616 DOI: 10.1118/1.4736179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE While intensity-modulated proton therapy (IMPT) has great potential to deliver highly conformal tumoricidal dose to targets whilst minimizing dose to nearby organs-at-risk, IMPT optimization is very time consuming and memory extensive due to finer dose grids and a large number of energy layers used compared to intensity-modulated radiation therapy (IMRT). In this presentation, for the first time, a new approach is introduced to speed up the IMPT treatment planning through application of parallel computing with Graphic Processor Units (GPUs). METHODS Parallel computation with GPUs, which are affordable and can be plugged in a workstation easily, is potentially a good way to improve the computation efficiency. In our approach, we used the standard quadratic objective function to optimize the intensity map of beamlets. The objective function and gradient equations, which are the most time consuming parts of the optimization, were calculated with GPUs. We compared the computation time of optimization done by an Intel ® Core™ i7 CPU and that by the same CPU accelerated by GPUs (TESLA C1060). The influence matrix was pre- calculated before optimization with an in-house proton pencil beam dose calculation engine. Two clinical cases were studied: one base-of-skull (BOS) case (clivus chordoma) and one prostate case (adenocarcinoma). The dose volume histogram (DVH) data for the tumor and critical organs were derived for comparison of optimization results generated by CPU and GPUs. RESULTS For the BOS case, application of GPUs for the optimization and overall gained 54 and 36.5 times speedup. For the prostate case, application of GPUs for the optimization and overall gained 69 and 28.5 times speedup. CONCLUSIONS The application of GPUs for the parallel computing of IMPT treatment plan optimization can dramatically improve the computation efficiency. The optimization time can be reduced from typically half to one hour to only several minutes.
Collapse
|
172
|
Chen Y, Zhang L, Court L, Liao Z, Zhu X, Mohan R, Dong L. SU-E-T-394: Comparison of Planned Dose Distribution Vs. Delivered Dose Distribution for Both IMRT and Proton Therapy Using Weekly Repeat 4DCT Data Sets. Med Phys 2012; 39:3795. [PMID: 28517186 DOI: 10.1118/1.4735483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To evaluate treatment deviations and the impact of treatment modality in the presence of breathing motion and anatomical changes during the course of lung cancer radiotherapy. METHODS Two non-small cell lung cancer patients were enrolled in a randomized clinical trial to compare IMRT and proton therapy. To rigorously evaluate the impact of motion and anatomical changes, we used a '5D' dose accumulation approach to sum dose distributions from phase-to-phase and week-to-week to the reference (end-expiration) phase of the original planning 4DCT data set. Six to eight weekly 4DCT data sets that consisted of 10 breathing phases were acquired during the treatment course. The original plan was re-calculated for each phase and deformably mapped to the reference phase to compare the 'delivered' dose distribution with the planned dose distribution of both the IMRT plan and the proton plan for each patient. DVHs derived from delivered dose distribution were compared to that from the planned dose distribution. RESULTS The delivered dose showed 3% and 2% increase in the dose to the CTV for IMRT and proton plan respectively. Target coverage remained acceptable despite tumor shrinkage from 29% to 49%. The doses to normal structures, such as lung and heart, increased more in the proton plan than in the IMRT plan. The V20 of the total lung volume increased by 4% and 6% from the delivered dose compared to the planned dose for IMRT and proton plan, respectively. CONCLUSIONS The results showed sufficient target coverage was maintained for both modalities. Increases in lung dose were observed in both modalities, but more in the proton arm, perhaps due to weight loss and tumor shrinkage. Adaptive proton therapy strategy is recommended to minimize normal tissue doses. Supported in part by NCI P01 CA021239-29A1.
Collapse
|
173
|
Mirkovic D, Titt U, Mohan R. SU-E-T-484: Potential Clinical Impact of Dosimetric Uncertainties in Proton Therapy. Med Phys 2012; 39:3816. [DOI: 10.1118/1.4735573] [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
|
174
|
Quan E, Liu W, Li Y, Zhang X, Zhu X, Mohan R, Wu R. WE-G-BRCD-03: Improvement in Robustness and Delivery Efficiency of Intensity-Modulated Proton Therapy Using Single-Field Optimization with Energy Absorber. Med Phys 2012; 39:3965. [DOI: 10.1118/1.4736180] [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
|
175
|
Titt U, Mirkovic D, Liu A, Mohan R. SU-E-T-435: Automatic Monte Carlo Dose Calculations of Proton Treatment Plans. Med Phys 2012; 39:3805. [DOI: 10.1118/1.4735524] [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
|
176
|
Bangert M, Titt U, Ziegenhein P, Mohan R, Oelfke U. SU-E-T-396: Beam Angle Optimization for IMPT Comparing Gantries and Fixed Beam Lines. Med Phys 2012; 39:3795. [PMID: 28517218 DOI: 10.1118/1.4735485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To explore the potential of beam angle optimization (BAO) for IMPT and compare fixed beamlines with gantries. METHODS For three patients with challenging intracranial lesions, we generate reference IMPT treatment plans applying three manually selected beam orientations and treatment plans applying three optimized beam orientations considering five scenarios: (1) patients are in supine position and the treatment room features (1.a) a horizontal beamline, (1.b) a horizontal, 45°, and vertical beamline, (1.c) a gantry, (2) patients are in supine or seated position and the treatment room features (2.a) a horizontal beamline, or (2.b) a horizontal, 45°, and vertical beamline. We use a genetic algorithm that considers up to 1,400 non-coplanar candidate beams and evaluates 10,000 beam ensembles for one BAO. Beam orientations that may compromise the robustness of treatment plans are excluded before the optimization based on an objective measure of existing tissue heterogeneities. RESULTS The optimized beam ensembles exhibit certain similarities even though the sets of candidate beams differ significantly for the five scenarios. Compared to manually selected beam orientations, they provide improved OAR sparing and equivalent target coverage. Compared to one another, they yield comparable target conformity (deviations of the conformity number <1%), target homogeneity (standard deviations of the target dose <0.8 Gy), and sparing of OARs (deviations of average mean and maximum doses in OARs +/- 1 Gy). Using a gantry, however, the integral dose can be reduced by 5-15% compared to a horizontal beamline with patients in supine position. For the investigated cases comparable reductions can be achieved by also irradiating in seated position with a horizontal, 45°, and vertical beamline. CONCLUSIONS BAO has the potential to provide beneficial IMPT treatment plans. Compared to fixed beamlines, gantries yield only modest effects regarding OAR sparing but may enable a significant reduction of integral dose for individual patients.
Collapse
|
177
|
Pereyra E, Torres C, Mohan R, Gomez L, Kouba G, Shoham O. A methodology and database to quantify the confidence level of methods for gas–liquid two-phase flow pattern prediction. Chem Eng Res Des 2012. [DOI: 10.1016/j.cherd.2011.08.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
178
|
Ravikumar L, Pradeep I, Thangaiyan T, Mohan R, Balachandran J. Synthesis, Characterization, and Conducting Properties of Poly(thiourea azomethines). INT J POLYM MATER PO 2012. [DOI: 10.1080/00914037.2011.584224] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
|
179
|
Mohan R. 321 INNOVATIVE AND EFFICIENT DOSE CALCULATION STRATEGIES FOR INTENSITY MODULATED AND PASSIVELY SCATTERED PROTON THERAPY. Radiother Oncol 2012. [DOI: 10.1016/s0167-8140(12)70281-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
180
|
Barnsley N, McAuley J, Mohan R, Dey A, Thomas P, Moseley G. The rubber hand illusion increases histamine reactivity in the real arm. Curr Biol 2011; 21:R945-6. [DOI: 10.1016/j.cub.2011.10.039] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
|
181
|
Ciura K, Welsh J, Nguyen N, Palmer M, Paolini M, Bluett J, Mohan R, Gomez D, Cox J, Chang J. Evaluating Stereotactic Body Radiotherapy with Protons to Reduce Chest Wall Dose in the Treatment of Lung Cancer. Int J Radiat Oncol Biol Phys 2011. [DOI: 10.1016/j.ijrobp.2011.06.177] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
182
|
Pang Q, Wei Q, Yuan X, López Guerra J, Gomez D, Yan Z, Liu Z, Mohan R, Komaki R, Liao Z. Functional Promoter rs2868371 Variant of HSPB1 Associates with the Risk of Radiation Pneumonitis in Patients with Non-small Cell Lung Cancer Treated with Radiotherapy. Int J Radiat Oncol Biol Phys 2011. [DOI: 10.1016/j.ijrobp.2011.06.346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
|
183
|
Wang J, Lin S, Dong L, Balter P, Mohan R, Komaki R, Cox J, Starkschall G. Interfractional Reproducibility of Gastro-Esophageal Junction (GEJ) Location for Patients with Esophageal Cancer. Int J Radiat Oncol Biol Phys 2011. [DOI: 10.1016/j.ijrobp.2011.06.1213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
|
184
|
Lopez Guerra J, Wei Q, Yuan X, Gomez D, Liu Z, Mohan R, Wei X, Yin M, Wang L, Liao Z. Functional Promoter rs2868371 Variant of HSPB1 Associates with Radiation Esophagitis in Patients with Non-small Cell Lung Cancer Treated with Radiotherapy. Int J Radiat Oncol Biol Phys 2011. [DOI: 10.1016/j.ijrobp.2011.06.104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
185
|
Mohan R, Jayesh K, Joshi RC, Al-Idrisi M, Narayanamurthy P, Majumdar SKD. Dosimetric evaluation of 120-leaf multileaf collimator in a Varian linear accelerator with 6-MV and 18-MV photon beams. J Med Phys 2011; 33:114-8. [PMID: 19893701 PMCID: PMC2772037 DOI: 10.4103/0971-6203.42757] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2008] [Accepted: 05/29/2008] [Indexed: 11/04/2022] Open
Abstract
In this study the dosimetric characteristics of 120-leaf multileaf collimators (MLCs) were evaluated for 6-MV and 18-MV photon beams. The dose rate, percentage depth dose, surface dose, dose in the build-up region, beam profile, flatness, symmetry, and penumbra width were measured using three field-defining methods: (i) 'Jaw only', (ii) 'MLC only', and (iii) 'MLC+Jaw'. Analysis of dose rate shows that the dose rate for 'MLC only' field was higher than that for 'Jaw only" and 'MLC+Jaw' fields in both the energies. The 'percentage of difference' of dose rates between 'MLC only' and 'MLC+Jaw' was (0.9% to 4.4%) and (1.14% to 7%) for 6 MV and 18 MV respectively. The surface dose and dose in the build-up region were more pronounced for 'MLC only' fields for both energies, and no significant difference was found in percentage depth dose beyond dmax for both energies. Beam profiles show that flatness and symmetry for both the energies were less than the 3%. The penumbra width for 'MLC only' field was more than that for the other two field-defining methods by (1 to 2 mm) and (0.8 to 1.3 mm) for 6-MV and 18-MV photon beams respectively. Analysis of 'width of 50% dose level' of the beam profiles at dmax to reflect the field size shows 1 to 2 mm more for 6-MV photons and 2.2 to 2.4 mm morefor 18-MV photons for 'MLC only' fields. The results of this study suggest that the characteristics of 120-leaf MLC system with 6 MV and 18 MV are same in all aspects except the surface dose, penumbra, dose in the build-up region, and width of 50% dose levels.
Collapse
|
186
|
Chen YP, Zhang L, Liao Z, Komaki R, Cox J, Balter P, Mohan R, Dong L. SU-D-BRC-04: Comparison of Tumor Shrinkage in Proton and Photon Therapy of Lung Cancer. Med Phys 2011. [DOI: 10.1118/1.3611528] [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
|
187
|
Majumdar D, Mohammed SS, Naseer MA, Jacob J, Mohan R, Ebenezer SB, Al Najar B, Al-Janahi S, Ramanathan V, Sabt SA, Patnaik RS, Hassan A. Respiratory gated simultaneous integrated boost-intensity modulated radiotherapy (SIB-IMRT) after breast conservative surgery for carcinoma of the breast: The Salmaniya Medical complex experience. Gulf J Oncolog 2011:53-59. [PMID: 21724530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/17/2011] [Indexed: 05/31/2023]
Abstract
PURPOSE To present our clinical experience using SIB-IMRT Technique for Intact Breast cancer. MATERIALS AND METHODS A retrospective review of 45 cases of Stage I-IV breast cancer patients treated with SIB-IMRT with respiratory gating after Conservative treatments from 25th November 2008 to 16th February 2010. The most common fractionation was 1.8 Gy to Ipsilateral Breast tissue and 2.2 Gy to the lumpectomy cavity giving whole breast dose as 50.4 Gy and Lumpectomy cavity dose as 61.6 Gy over 28 fractions concomitantly. Respiratory gating was done and CT-images were taken in inspiratory breath hold position. RESULTS A total of 45 patients with breast cancer - stage I (17.7%), II (71%), III (8.9%), IV (2.2%) were treated with SIB- IMRT with respiratory gated radiotherapy. Out of 45 patients, 24 are of left sided breast cancer and 21 are of right sided breast cancer patients. The median, Dose maximum (D-max) in SIB-IMRT is 106.2% of prescribed lumpectomy site dose. The median isodose line prescribed to PTV-2 is 100%. The Conformity index (CI) is 0.9688 (median value) and Homogeneity index (HI) 1.06 (median). The median ipsilateral lung, mean dose is 21.66 Gy and V-20 is 37.4%. For left sided cases the median value of mean heart dose, V-30 and V-40 are 22.98 Gy, 23.45% and 9.45 % respectively. Acute skin toxicity was of Grade-I in 2.2 %, Grade-II in 64.4 %, Grade-III in 31.1 %, and Grade-IV in 2.2 %. The global Breast cosmoses were seen excellent in majority (93%) of case at median follow up of 8 months duration. CONCLUSIONS Breast SIB-IMRT Technique is feasible and comparable with other treatment techniques with reduced treatment duration by six fractions. At median follow up of 8 months the skin toxicity and cosmoses are excellent in high percentage of cases.
Collapse
|
188
|
Yang M, Virshup G, Clayton J, Zhu XR, Mohan R, Dong L. Does kV-MV dual-energy computed tomography have an advantage in determining proton stopping power ratios in patients? Phys Med Biol 2011; 56:4499-515. [PMID: 21719949 DOI: 10.1088/0031-9155/56/14/017] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Conventional kilovoltage (kV) x-ray-based dual-energy CT (DECT) imaging using two different x-ray energy spectra is sensitive to image noise and beam hardening effects. The purpose of this study was to evaluate the theoretical advantage of the DECT method for determining proton stopping power ratios (SPRs) using a combination of kV and megavoltage (MV) x-ray energies. We investigated three representative x-ray energy pairs: 100 and 140 kVp comprised the kV-kV pair, 100 kVp and 1 MV comprised the kV-MV pair, and two 1 MV x-ray beams-one with and one without external filtration-comprised the MV-MV pair. The SPRs of 34 human tissues were determined using the DECT method with these three x-ray energy pairs. Small perturbations were introduced into the CT numbers and x-ray spectra used for the DECT calculation to simulate the effects of random noise and beam hardening. An error propagation analysis was performed on the DECT calculation algorithm to investigate the propagation of CT number uncertainty to final SPR estimation and to suggest the best x-ray energy combination. We found that the DECT method using each of the three beam pairs achieved similar accuracy in determining the SPRs of human tissues in ideal conditions. However, when CT number uncertainties and artifacts such as imaging noise and beam hardening effects were considered, the kV-MV DECT improved the accuracy of SPR estimation substantially over the kV-kV or MV-MV DECT methods. Furthermore, our error propagation analysis showed that the combination of 100 kVp and 1 MV beams was close to the optimal selection when using the DECT method to determine SPRs. Overall, the kV-MV combination makes the DECT method more robust in resolving the effective atomic numbers for biological tissues than the traditional kV-kV DECT method.
Collapse
|
189
|
Matney J, Bluett J, Wages C, Liu H, Chang J, Balter P, Dong L, Mohan R. SU-E-T-507: Respiratory Motion Management for Early Stage Lung Tumors: Is the Advantage Greater for Protons or Photons? Med Phys 2011. [DOI: 10.1118/1.3612460] [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
|
190
|
Ciangaru G, Sahoo N, Sawakuchi G, Zhu X, Mohan R, Gillin M. SU-E-T-646: Feasibility Study of Radiobiological Effectiveness-Based Treatment Plan Optimization for Spot-Scanned Proton Therapy Beams. Med Phys 2011. [DOI: 10.1118/1.3612609] [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
|
191
|
Titt U, Mirkovic D, Anand A, Perles L, Sawakuchi G, Mohan R. SU-D-BRB-01: On the Dependence of Scanned Proton Beam Dose Output Factors on the Field Size and the Accuracy of the Lateral Dose Profiles. Med Phys 2011. [DOI: 10.1118/1.3611519] [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
|
192
|
Robertson D, Mirkovic D, Mohan R, Beddar S. WE-E-BRB-01: Voxelized Quenching Correction for Proton Pencil Beams in a Liquid Scintillator Detector. Med Phys 2011. [DOI: 10.1118/1.3613368] [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
|
193
|
Perles LA, Ibbott GS, Blatnica A, Mirkovic D, Titt U, Gillin M, Mohan R. TU-G-BRB-08: 3D Proton Dose Distributions in an Anthropomorphic Lung Phantom, Comparing Monte Carlo, Film, and TLD Measurements. Med Phys 2011. [DOI: 10.1118/1.3613228] [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
|
194
|
Yang M, Zhu X, Clayton J, Virshup G, Mohan R, Dong L. SU-F-BRA-12: Comprehensive Uncertainty Analysis of Proton Stopping-Power-Ratio Estimation Using a KV-MV Dual Energy CT Scanner (DECT) for Margin Reduction. Med Phys 2011. [DOI: 10.1118/1.3612879] [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
|
195
|
Mohan R, Mirkovic D, Titt U, Song X, Li H, Zhu X, Gillin M. SU-E-T-687: Experimental Assessment of the Accuracy of a Semi-Empirical Model and a Monte Carlo System for Proton Dose Calculations for Highly Inhomogeneous Media. Med Phys 2011. [DOI: 10.1118/1.3612649] [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
|
196
|
Tsunashima Y, Poenisch F, Li H, Zhu X, Balter P, Umezawa M, Sahoo N, Mohan R, Dong L. TU-G-BRB-05: Dosimetric Characterization of Motion Effect in Delivering Uniform Target Dose Distribution Using Scanning Proton Beams. Med Phys 2011. [DOI: 10.1118/1.3613225] [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
|
197
|
Liu W, Zhang X, Li Y, Chen W, Mohan R. SU-E-T-845: Benefits from Achillesˈ Heel of Intensity-Modulated Proton Therapy via Worst-Case Robust Optimization. Med Phys 2011. [DOI: 10.1118/1.3612809] [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
|
198
|
Mirkovic D, Titt U, Mohan R. SU-E-T-664: Accuracy of Patient Dose Calculation in Proton Therapy of Lung Cancer: A Comparison of Monte Carlo and Pencil Beam Computations. Med Phys 2011. [DOI: 10.1118/1.3612627] [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
|
199
|
Anand A, Sahoo N, Zhu X, Titt U, Sawakuchi G, Li Y, Poenisch F, Amos R, Suzuki K, Ciangaru G, Mohan R, Gillin M. TH-C-BRB-10: Scanned Proton Pencil Beamˈs Lateral Profile Library to Describe the Spot Dose Characteristics. Med Phys 2011. [DOI: 10.1118/1.3613515] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
200
|
Chang JY, Komaki R, Lu C, When HY, Allen P, Tsao AS, Gillin M, Mohan R, Cox JD. Phase II study of high-dose proton therapy with concurrent chemotherapy for unresectable stage III non-small cell lung cancer. J Clin Oncol 2011. [DOI: 10.1200/jco.2011.29.15_suppl.7017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|