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McGuffey AS, Pitcher GM, Erhart KJ, Hogstrom KR. Dosimetric validation of intensity-modulated bolus electron conformal therapy planning and delivery using an anthropomorphic cylindrical head phantom. J Appl Clin Med Phys 2024; 25:e14347. [PMID: 38576174 PMCID: PMC11244665 DOI: 10.1002/acm2.14347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 02/23/2024] [Accepted: 03/06/2024] [Indexed: 04/06/2024] Open
Abstract
PURPOSE This work investigated the dosimetric accuracy of the intensity-modulated bolus electron conformal therapy (IM-BECT) planning and delivery process using the decimal ElectronRT (eRT) treatment planning system. METHODS An IM-BECT treatment plan was designed using eRT for a cylindrical, anthropomorphic retromolar trigone phantom. Treatment planning involved specification of beam parameters and design of a variable thickness wax bolus and Passive Radiotherapy Intensity Modulator for Electrons (PRIME) device, which was comprised of 33 tungsten island blocks of discrete diameters from 0.158 to 0.223 cm (Intensity Reduction Factors from 0.937 to 0.875, respectively) inside a 10.1 × 6.7 cm2 copper cutout. For comparison of calculation accuracy, a BECT plan was generated by copying the IM-BECT plan and removing the intensity modulation. For both plans, a 16 MeV electron beam was used with 104.7 cm source-to-surface distance to bolus. In-phantom TLD-100 measurements (N = 47) were compared with both eRT planned dose distributions, which used the pencil beam redefinition algorithm with modifications for passive electron intensity modulation (IM-PBRA). Dose difference and distance to agreement (DTA) metrics were computed for each measurement point. RESULTS Comparison of measured dose distributions with planned dose distributions yielded dose differences (calculated minus measured) characterized by a mean and standard deviation of -0.36% ± 1.64% for the IM-BECT plan, which was similar to -0.36% ± 1.90% for the BECT plan. All dose measurements were within 5% of the planned dose distribution, with both the BECT and IM-BECT measurement sets having 46/47 (97.8%) points within 3% or within 3 mm of the respective treatment plans. CONCLUSIONS It was found that the IM-BECT treatment plan generated using eRT was sufficiently accurate for clinical use when compared to TLD measurements in a cylindrical, anthropomorphic phantom, and was similarly accurate to the BECT treatment plan in the same phantom.
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Affiliation(s)
- Andrew S. McGuffey
- Department of Physics and AstronomyLouisiana State UniversityBaton RougeLouisianaUSA
| | - Garrett M. Pitcher
- Department of Physics and AstronomyLouisiana State UniversityBaton RougeLouisianaUSA
- Mary Bird Perkins Cancer CenterBaton RougeLouisianaUSA
| | | | - Kenneth R. Hogstrom
- Department of Physics and AstronomyLouisiana State UniversityBaton RougeLouisianaUSA
- Mary Bird Perkins Cancer CenterBaton RougeLouisianaUSA
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Zhang Y, Huang Y, Ding S, Liang J, Kuang J, Mao Q, Ying W, Shu Y, Li J, Jiang C. A clinical trial to compare a 3D-printed bolus with a conventional bolus with the aim of reducing cardiopulmonary exposure in postmastectomy patients with volumetric modulated arc therapy. Cancer Med 2021; 11:1037-1047. [PMID: 34939343 PMCID: PMC8855922 DOI: 10.1002/cam4.4496] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 11/13/2021] [Accepted: 12/03/2021] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND We compared the dosimetry, application, and acute toxicity of a 3D-printed and a conventional bolus for postmastectomy radiotherapy (PMRT) with volumetric modulated arc therapy (VMAT). Materials and Methods Eligible patients (n = 75) with PMRT breast cancer were randomly selected to receive VMAT with a conventional bolus or a 3D-printed bolus. The primary endpoint was a 10% decrease in the mean heart dose to left-sided breast cancer patients. The secondary endpoint was a 5% decrease in the mean ipsilateral lung dose to all patients. A comparative analysis was carried out of the dosimetry, normal tissue complication probability (NTCP), acute skin toxicity, and radiation pneumonitis. RESULTS Compared to a conventional bolus, the mean heart dose in left-sided breast cancer was reduced by an average of 0.8 Gy (5.5 ± 1.3 Gy vs. 4.7 ± 0.8 Gy, p = 0.035) and the mean dose to the ipsilateral lung was also reduced by an average of 0.8 Gy (12.4 ± 1.0 Gy vs. 11.6 ± 0.8 Gy, p < 0.001). The values for V50Gy of the PTV of the chest wall for the 3D-printed and conventional boluses were 95.4 ± 0.6% and 94.8 ± 0.8% (p = 0.026) and the values for the CI of the entire PTV were 0.83 ± 0.02 and 0.80 ± 0.03 (p < 0.001), respectively. The NTCP for the 3D-printed bolus was also reduced to an average of 0.14% (0.32 ± 0.19% vs. 0.18 ± 0.11%, p = 0.017) for the heart and 0.45% (3.70 ± 0.67% vs. 3.25 ± 0.18%, p < 0.001) for the ipsilateral lung. Grade 2 and Grade 1 radiation pneumonitis were 0.0% versus 7.5% and 14.3% versus 20.0%, respectively (p = 0.184). CONCLUSIONS The 3D-printed bolus may reduce cardiopulmonary exposure in postmastectomy patients with volumetric modulated arc therapy.
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Affiliation(s)
- Yun Zhang
- Department of Radiation Oncology, Jiangxi Cancer Hospital of Nanchang University, Nanchang, PR China
| | - Yuling Huang
- Department of Radiation Oncology, Jiangxi Cancer Hospital of Nanchang University, Nanchang, PR China
| | - Shenggou Ding
- Department of Radiation Oncology, Jiangxi Cancer Hospital of Nanchang University, Nanchang, PR China
| | - Jinghui Liang
- Department of Radiation Oncology, Jiangxi Cancer Hospital of Nanchang University, Nanchang, PR China
| | - Jie Kuang
- School of Public Health, Nanchang University, Nanchang, PR China
| | - Qingfeng Mao
- Department of Radiation Oncology, Jiangxi Cancer Hospital of Nanchang University, Nanchang, PR China
| | - Weiliang Ying
- Department of Radiation Oncology, Jiangxi Cancer Hospital of Nanchang University, Nanchang, PR China
| | - Yuxian Shu
- Department of Radiation Oncology, Jiangxi Cancer Hospital of Nanchang University, Nanchang, PR China
| | - Jingao Li
- Department of Radiation Oncology, Jiangxi Cancer Hospital of Nanchang University, Nanchang, PR China.,Key Laboratory of Personalized Diagnosis and Treatment of Nasopharyngeal Carcinoma Nanchang, Nanchang, PR China.,Medical College of Nanchang University, Nanchang, PR China
| | - Chunling Jiang
- Department of Radiation Oncology, Jiangxi Cancer Hospital of Nanchang University, Nanchang, PR China.,Key Laboratory of Personalized Diagnosis and Treatment of Nasopharyngeal Carcinoma Nanchang, Nanchang, PR China.,Medical College of Nanchang University, Nanchang, PR China
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Hilliard EN, Carver RL, Chambers EL, Kavanaugh JA, Erhart KJ, McGuffey AS, Hogstrom KR. Planning and delivery of intensity modulated bolus electron conformal therapy. J Appl Clin Med Phys 2021; 22:8-21. [PMID: 34558774 PMCID: PMC8504596 DOI: 10.1002/acm2.13386] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 11/30/2020] [Accepted: 06/23/2021] [Indexed: 12/05/2022] Open
Abstract
PURPOSE Bolus electron conformal therapy (BECT) is a clinically useful, well-documented, and available technology. The addition of intensity modulation (IM) to BECT reduces volumes of high dose and dose spread in the planning target volume (PTV). This paper demonstrates new techniques for a process that should be suitable for planning and delivering IM-BECT using passive radiotherapy intensity modulation for electrons (PRIME) devices. METHODS The IM-BECT planning and delivery process is an addition to the BECT process that includes intensity modulator design, fabrication, and quality assurance. The intensity modulator (PRIME device) is a hexagonal matrix of small island blocks (tungsten pins of varying diameter) placed inside the patient beam-defining collimator (cutout). Its design process determines a desirable intensity-modulated electron beam during the planning process, then determines the island block configuration to deliver that intensity distribution (segmentation). The intensity modulator is fabricated and quality assurance performed at the factory (.decimal, LLC, Sanford, FL). Clinical quality assurance consists of measuring a fluence distribution in a plane perpendicular to the beam in a water or water-equivalent phantom. This IM-BECT process is described and demonstrated for two sites, postmastectomy chest wall and temple. Dose plans, intensity distributions, fabricated intensity modulators, and quality assurance results are presented. RESULTS IM-BECT plans showed improved D90-10 over BECT plans, 6.4% versus 7.3% and 8.4% versus 11.0% for the postmastectomy chest wall and temple, respectively. Their intensity modulators utilized 61 (single diameter) and 246 (five diameters) tungsten pins, respectively. Dose comparisons for clinical quality assurance showed that for doses greater than 10%, measured agreed with calculated dose within 3% or 0.3 cm distance-to-agreement (DTA) for 99.9% and 100% of points, respectively. CONCLUSION These results demonstrated the feasibility of translating IM-BECT to the clinic using the techniques presented for treatment planning, intensity modulator design and fabrication, and quality assurance processes.
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Affiliation(s)
- Elizabeth N. Hilliard
- Department of Physics and AstronomyLouisiana State UniversityBaton RougeLouisianaUSA
| | - Robert L. Carver
- Department of Physics and AstronomyLouisiana State UniversityBaton RougeLouisianaUSA
- Mary Bird Perkins Cancer CenterBaton RougeLouisianaUSA
| | - Erin L. Chambers
- Department of Physics and AstronomyLouisiana State UniversityBaton RougeLouisianaUSA
| | - James A. Kavanaugh
- Department of Radiation OncologyWashington University School of MedicineSaint LouisMissouriUSA
| | | | - Andrew S. McGuffey
- Department of Physics and AstronomyLouisiana State UniversityBaton RougeLouisianaUSA
| | - Kenneth R. Hogstrom
- Department of Physics and AstronomyLouisiana State UniversityBaton RougeLouisianaUSA
- Mary Bird Perkins Cancer CenterBaton RougeLouisianaUSA
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McCallum S, Maresse S, Fearns P. Evaluating 3D-printed Bolus Compared to Conventional Bolus Types Used in External Beam Radiation Therapy. Curr Med Imaging 2021; 17:820-831. [PMID: 33530912 DOI: 10.2174/1573405617666210202114336] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 12/05/2020] [Accepted: 12/08/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND When treating superficial tumors with external beam radiation therapy, bolus is often used. Bolus increases surface dose, reduces dose to underlying tissue, and improves dose homogeneity. INTRODUCTION The conventional bolus types used clinically in practice have some disadvantages. The use of Three-Dimensional (3D) printing has the potential to create more effective boluses. CT data is used for dosimetric calculations for these treatments and often to manufacture the customized 3D-printed bolus. PURPOSE The aim of this review is to evaluate the published studies that have compared 3D-printed bolus against conventional bolus types. METHODS AND RESULTS A systematic search of several databases and a further appraisal for relevance and eligibility resulted in the 14 articles used in this review. The 14 articles were analyzed based on their comparison of 3D-printed bolus and at least one conventional bolus type. CONCLUSION The findings of this review indicated that 3D-printed bolus has a number of advantages. Compared to conventional bolus types, 3D-printed bolus was found to have equivalent or improved dosimetric measures, positional accuracy, fit, and uniformity. 3D-printed bolus was also found to benefit workflow efficiency through both time and cost effectiveness. However, factors such as patient comfort and staff perspectives need to be further explored to support the use of 3Dprinted bolus in routine practice.
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Affiliation(s)
- Stephanie McCallum
- Medical Radiation Science, Faculty of Science and Engineering, Curtin University, Perth, Australia
| | - Sharon Maresse
- Medical Radiation Science, Faculty of Science and Engineering, Curtin University, Perth, Australia
| | - Peter Fearns
- Medical Radiation Science, Faculty of Science and Engineering, Curtin University, Perth, Australia
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Chambers EL, Carver RL, Hogstrom KR. Useful island block geometries of a passive intensity modulator used for intensity-modulated bolus electron conformal therapy. J Appl Clin Med Phys 2020; 21:131-145. [PMID: 33207033 PMCID: PMC7769403 DOI: 10.1002/acm2.13079] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 07/01/2020] [Accepted: 08/13/2020] [Indexed: 12/04/2022] Open
Abstract
PURPOSE This project determined the range of island block geometric configurations useful for the clinical utilization of intensity-modulated bolus electron conformal therapy (IM-BECT). METHODS Multiple half-beam island block geometries were studied for seven electron energies 7-20 MeV at 100 and 103 cm source-to-surface distance (SSD). We studied relative fluence distributions at 0.5 cm and 2.0 cm depths in water, resulting in 28 unique beam conditions. For each beam condition, we studied intensity reduction factor (IRF) values of 0.70, 0.75, 0.80, 0.85, 0.90, and 0.95, and hexagonal packing separations for the island blocks of 0.50, 0.75, 1.00, 1.25, and 1.50 cm, that is, 30 unique IM configurations and 840 unique beam-IM combinations. A combination was deemed acceptable if the average intensity downstream of the intensity modulator agreed within 2% of that intended and the variation in fluence was less than ±2%. RESULTS For 100 cm SSD, and for 0.5 cm depth, results showed that beam energies above 13 MeV did not exhibit sufficient scatter to produce clinically acceptable fluence (intensity) distributions for all IRF values (0.70-0.95). In particular, 20 MeV fluence distributions were unacceptable for any values, and acceptable 16 MeV fluence distributions were limited to a minimum IRF of 0.85. For the 2.0 cm depth, beam energies up to and including 20 MeV had acceptable fluence distributions. For 103 cm SSD and for 0.5 cm and 2.0 cm depths, results showed that all beam energies (7-20 MeV) had clinically acceptable fluence distributions for all IRF values (0.70-0.95). In general, the more clinically likely 103 cm SSD had acceptable fluence distributions with larger separations (r), which allow larger block diameters. CONCLUSION The geometric operating range of island block separations and IRF values (block diameters) producing clinically appropriate IM electron beams has been determined.
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Affiliation(s)
- Erin L. Chambers
- Department of Physics and AstronomyLouisiana State UniversityBaton RougeLAUSA
| | - Robert L. Carver
- Department of Physics and AstronomyLouisiana State UniversityBaton RougeLAUSA
- Mary Bird Perkins Cancer CenterBaton RougeLAUSA
| | - Kenneth R. Hogstrom
- Department of Physics and AstronomyLouisiana State UniversityBaton RougeLAUSA
- Mary Bird Perkins Cancer CenterBaton RougeLAUSA
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Characterization of 3D-printed bolus produced at different printing parameters. Med Dosim 2020; 46:157-163. [PMID: 33172711 DOI: 10.1016/j.meddos.2020.10.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 09/17/2020] [Accepted: 10/20/2020] [Indexed: 11/20/2022]
Abstract
We aimed to analyze the effects of printing parameters on characterization of three-dimensional (3D) printed bolus used in external beam radiotherapy. Two sets of measurements were performed to investigate the dosimetric and physical characterization of 3D-printed bolus at different printing parameters. In the first step, boluses were produced at different infill-percentages, infill-patterns and printing directions. Two-dimensional (2D) dose measurements were performed in Elekta Versa HD linear accelerator using 6 MV photon energy. Measured 2D dose maps for both printed and reference bolus materials were compared using the 2D gamma analysis method. Additionally, patient-specific bolus was produced with defined optimum printing parameters for anthropomorphic head and neck phantom. Then, point dose measurements were performed to evaluate the feasibility of printed bolus in clinical use. In the second step, physical measurements were carried out to evaluate the printing accuracy, the mean hounsfield unit (HU) value and the weight of 3D-printed boluses. According to our measurement, infill-percentage, infill-pattern and printing direction significantly changed the dosimetric and physical properties of the 3D-printed bolus independently. Maximum gamma passing rate at 1.5 and 5 cm depths were found as 93.8% and 98.8%, respectively, for 60% infill-percentage, sunglass fill infill-pattern and horizontal printing direction. The printing accuracy of the products was within 0.4 mm. Dosimetric and physical properties of the printed bolus material changed significantly with the selected printing parameters. Therefore, it is important to note that each combination of these printing parameters that will be used in the production of patient-specific bolus should be investigated separately.
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Wang X, Swann B, Reyhan M, Yue NJ, Singh R, McKenna MG. A novel approach to embed eye shields in customized bolus on nasal dorsum treatment for electron radiotherapy. Med Dosim 2020; 46:132-135. [PMID: 33097371 DOI: 10.1016/j.meddos.2020.09.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 09/30/2020] [Indexed: 11/20/2022]
Abstract
We aim to demonstrate the unique use of embedded lead eye shields in an electron wax bolus when treating the nasal dorsum. A patient presented to the clinic with squamous cell carcinoma of the nasal dorsum requiring treatment with en face electrons. A 3D customized wax bolus was designed and imported into the treatment planning system (TPS) to calculate the dose distribution. Due to high lens dose, the bolus was customized further to create 2 milled open slots in the wax, over the lens of eye, to allow lead sheets totaling 4 mm to be slid into the wax. The patient was brought back to the clinic to be scanned with the wax bolus fitting snugly over the nose, eyes, and cheek regions. The 3D milled insert holes were contoured on the CT in the TPS, assigned HU of 2758, to mimic the lead insertion. The lens dose with lead inserts was compared to the plan without lead insert. To further confirm the lens dose, EBT3 films were placed on the right and left eye under the bolus, and nose dorsum on the first day of treatment. The maximum dose of right lens, as calculated in the TPS with the simulated lead shields in place, decreased from 989.5cGy to 457cGy. The maximum dose of left lens decreased from 1085.4cGy to 501cGy. The dose readings from EBT3 films were in good agreement with the TPS, with deviation of 3.32%, 0.26%, and 3.44% for right lens, left lens, and nose, respectively. Daily positioning deviations compared to the plan were 0.65 ± 0.16cm and 0.63 ± 0.29cm for right eye and left eye, respectively. This novel device demonstrated the feasibility, in terms of dose calculation accuracy in the TPS and fabrication, of using customized bolus with lead inserts to conveniently shield the lens of the eyes in an electron treatment for the nose, enabling a streamlined daily setup.
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Affiliation(s)
- Xiao Wang
- Department of Radiation Oncology, Rutgers-Cancer Institute of New Jersey, Rutgers-Robert Wood Johnson Medical School, New Brunswick, NJ, USA.
| | - Beth Swann
- Department of Radiation Oncology, Rutgers-Robert Wood Johnson University Hospital, Hamilton, NJ, USA
| | - Meral Reyhan
- Department of Radiation Oncology, Rutgers-Cancer Institute of New Jersey, Rutgers-Robert Wood Johnson Medical School, New Brunswick, NJ, USA
| | - Ning J Yue
- Department of Radiation Oncology, Rutgers-Cancer Institute of New Jersey, Rutgers-Robert Wood Johnson Medical School, New Brunswick, NJ, USA
| | - Rachana Singh
- Department of Radiation Oncology, Rutgers-Cancer Institute of New Jersey, Rutgers-Robert Wood Johnson Medical School, New Brunswick, NJ, USA
| | - Michael G McKenna
- Department of Radiation Oncology, Rutgers-Cancer Institute of New Jersey, Rutgers-Robert Wood Johnson Medical School, New Brunswick, NJ, USA
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Dyer BA, Campos DD, Hernandez DD, Wright CL, Perks JR, Lucero SA, Bewley AF, Yamamoto T, Zhu X, Rao SS. Characterization and clinical validation of patient-specific three-dimensional printed tissue-equivalent bolus for radiotherapy of head and neck malignancies involving skin. Phys Med 2020; 77:138-145. [PMID: 32829102 DOI: 10.1016/j.ejmp.2020.08.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 08/06/2020] [Accepted: 08/09/2020] [Indexed: 11/15/2022] Open
Abstract
PURPOSE Megavoltage radiotherapy to irregular superficial targets is challenging due to the skin sparing effect. We developed a three-dimensional bolus (3DB) program to assess the clinical impact on dosimetric and patient outcomes. MATERIALS AND METHODS Planar commercial bolus (PCB) and 3DB density, clarity, and net bolus effect were rigorously evaluated prior to clinical implementation. After IRB approval, patients with cutaneous or locally advanced malignancies deemed to require bolus for radiotherapy treatment were treated with custom 3DB. RESULTS The mean density of 3DB and PCB was of 1.07 g/cm 3 and 1.12 g/cm3, respectively. 3DB optic clarity was superior versus PCB at any material thickness. Phantom measurements of superficial dose with 3DB and PCB showed excellent bolus effect for both materials. 3DB reduced air gaps compared with PCB - particularly in irregular areas such as the ear, nose, and orbit. A dosimetric comparison of 3DB and PCB plans showed equivalent superficial homogeneity for 3DB and PCB (3DB median HI 1.249, range 1.111-1.300 and PCB median HI 1.165, range 1.094-1.279), but better conformity with 3DB (3DB median CI 0.993, range 0.962-0.993) versus PCB (PCB median CI 0.977, range 0.601-0.991). Patient dose measurements using 3DB confirm the delivered superficial dose was within 1% of the intended prescription (95% CI 97-102%; P = 0.11). CONCLUSIONS 3DB improves radiotherapy plan conformity, reduces air gap volume in irregular superficial areas which could affect superficial dose delivery, and provides excellent dose coverage to irregular superficial targets.
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Affiliation(s)
- Brandon A Dyer
- University of Washington, Department of Radiation Oncology, Seattle, WA, United States.
| | - David D Campos
- University of California Davis Comprehensive Cancer Center, Department of Radiation Oncology, Sacramento, CA, United States
| | - Daniel D Hernandez
- University of California Davis Comprehensive Cancer Center, Department of Radiation Oncology, Sacramento, CA, United States; University of California Davis, Department of Physics, Davis, CA, United States
| | - Cari L Wright
- University of California Davis Comprehensive Cancer Center, Department of Radiation Oncology, Sacramento, CA, United States
| | - Julian R Perks
- University of California Davis Comprehensive Cancer Center, Department of Radiation Oncology, Sacramento, CA, United States
| | - Steven A Lucero
- University of California Davis, Department of Biomedical Engineering, Electrical & Mechanical Prototyping, Davis, CA, United States
| | - Arnaud F Bewley
- University of California Davis, Department of Otolaryngology Head & Neck Surgery, Sacramento, CA, United States
| | - Tokihiro Yamamoto
- University of California Davis Comprehensive Cancer Center, Department of Radiation Oncology, Sacramento, CA, United States
| | - Xiandong Zhu
- University of California Davis, Department of Physics, Davis, CA, United States
| | - Shyam S Rao
- University of California Davis Comprehensive Cancer Center, Department of Radiation Oncology, Sacramento, CA, United States.
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Gunter AE, Burgoyne J, Park M, Kim N, Cao D, Mehta V. Novel application of vinylpolysiloxane hearing aid impression mold as patient-specific bolus for head and neck cancer radiotherapy. Clin Case Rep 2020; 8:944-949. [PMID: 32577239 PMCID: PMC7303862 DOI: 10.1002/ccr3.2731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Revised: 11/10/2019] [Accepted: 11/18/2019] [Indexed: 11/18/2022] Open
Abstract
Hearing aid impression material composed of vinylpolysiloxane is an ideal bolus material which may be used to aid in delivery of adjuvant radiation to complex surgical defects of the head and neck. It is affordable, easily accessed, and efficient.
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Affiliation(s)
- Anne Elizabeth Gunter
- Department of Radiation OncologySwedish Cancer InstituteSeattleWashington
- Present address:
Department of OtolaryngologyMadigan Army Medical CenterTacomaWashington
| | - John Burgoyne
- Department of Radiation OncologySwedish Cancer InstituteSeattleWashington
| | - Min Park
- Department of Radiation OncologySwedish Cancer InstituteSeattleWashington
| | - Namou Kim
- Department of Radiation OncologySwedish Cancer InstituteSeattleWashington
| | - Daliang Cao
- Department of Radiation OncologySwedish Cancer InstituteSeattleWashington
| | - Vivek Mehta
- Department of Radiation OncologySwedish Cancer InstituteSeattleWashington
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Munoz L, Rijken J, Hunter M, Nyathi T. Investigation of elastomeric materials for bolus using stereolithography printing technology in radiotherapy. Biomed Phys Eng Express 2020; 6:045014. [PMID: 33444275 DOI: 10.1088/2057-1976/ab9425] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE An investigation was conducted of an elastomeric material, VisiJet M2 (3D systems, USA) for use as 3D bolus within high energy photon beams for radiotherapy. Personalized conformal bolus material on complex structures like the nose can be challenging. This material was evaluated for its clinical feasibility due to its pliability and comfort compared to alternatives. METHOD Regular slabs of bolus were created of various thicknesses for dosimetric and non-dosimetric characterization. Verification culminated with the creation of a custom nose bolus for an end to end verification using an anthropomorphic head phantom. In vivo dosimetry using Gafchromic EBT3 (Ashland, USA) film validated delivered doses from a 6 MV conformal field and a pair of 6 MV volumetric modulated arc therapy (VMAT) beams. RESULTS & CONCLUSION Non-dosimetric and dosimetric tests were conducted to assess clinical suitability. The bolus was precisely created using stereolithographic (SLA) methods and presented a compliant and uniform water equivalent material with elastic memory. Measurement yielded a physical density of 1.10 g cm-3 and 1.06 relative to water electron density, and the bolus to skin distance was measured to be a maximum of 3 mm. A maximum measured dose difference of <2% was observed for dynamic treatment. Based on the investigation conducted, and the benefits presented for patient comfort while being uniform and water equivalent, and correctly represented within the treatment planning system (TPS), this material has the potential for clinical use for patient specific custom bolus.
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Affiliation(s)
- Luis Munoz
- GenesisCare, Flinders Private Hospital, Bedford Park, SA, Australia
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He C, Zhang S, Shi L. Three-Dimensionally-Precise Breast Conformal Device for IMRT in Breast Cancer Patients Treated With Breast-Conserving Surgery-A Pilot Randomized Controlled Trial. Technol Cancer Res Treat 2020; 19:1533033820971563. [PMID: 33174525 PMCID: PMC7672753 DOI: 10.1177/1533033820971563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 08/05/2020] [Accepted: 09/30/2020] [Indexed: 12/24/2022] Open
Abstract
OBJECTIVE To examine the accuracy and efficiency of breast radiotherapy after breast-conserving surgery of a novel 3-dimensional (3D) printing tissue compensator technology, the 3D-precise breast conformer, compared with a usual compensator and an unstructured compensator. METHODS This novel device is patented in China (patent No.: ZL2015 2 0259472.9). Thirty patients with breast cancer after breast-conserving surgery were randomly divided into 2 control groups (no compensator, NST group, and usual compensator, ST group) and 1 study group (3D-precise breast conformer, 3D-BCT group) (n = 10/group). Before radiotherapy, all patients were scanned in the same CT positioning conditions to prepare the treatment plans. RESULTS The 3D-BCT showed the best homogeneity index (HI) (0.08 ± 0.03) and conformity index (CI) (0.95 ± 0.03), while the NST group showed the worst HI (0.34 ± 0.07) and CI (0.78 ± 0.06), with the ST group between the 2 (HI: 0.15 ± 0.05; CI: 0.87 ± 0.04) (all P < 0.01). The common tissue compensation membrane could lead to 95-100% of the prescription dose covering 85-95% of the target volume, and the uniformity and conformability of the target dose were improved overall compared with the NST group. In the 3D-BCT group, 100% of the prescription dose covered the target volume of 95-100%. CONCLUSION The 3D-precision breast conformal device had the highest individualization, uniformity, and conformity. The V95, V98, CI, and HI of PTV were optimal in the 3D-BCT group, and an ideal isodose curve distribution of the breast and clavicle upper and lower target areas was achieved. This device could improve the surface dose and the efficacy of radiotherapy after breast-conserving surgery.
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Affiliation(s)
- Chunbo He
- Department of Radiation Oncology, The Fourth Hospital, Harbin Medical University, Harbin, China
| | - Shilin Zhang
- Department of Radiation Oncology, The Fourth Hospital, Harbin Medical University, Harbin, China
| | - Lei Shi
- Department of Radiation Oncology, The Fourth Hospital, Harbin Medical University, Harbin, China
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Craft DF, Balter P, Woodward W, Kry SF, Salehpour M, Ger R, Peters M, Baltz G, Traneus E, Howell RM. Design, fabrication, and validation of patient-specific electron tissue compensators for postmastectomy radiation therapy. Phys Imaging Radiat Oncol 2018; 8:38-43. [PMID: 33458415 PMCID: PMC7807570 DOI: 10.1016/j.phro.2018.11.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 11/09/2018] [Accepted: 11/13/2018] [Indexed: 11/17/2022] Open
Abstract
Background and purpose Postmastectomy radiotherapy (PMRT) is complex to plan and deliver, but could be improved with 3D-printed, patient-specific electron tissue compensators. The purposes of this study were to develop an algorithm to design patient-specific compensators that achieve clinical goals, to 3D-print the planned compensators, and validate calculated dose distributions with film and thermoluminescent dosimeter (TLD) measurements in 3D-printed phantoms of PMRT patients. Materials and methods An iterative algorithm was developed to design compensators corresponding to single-field, single-energy electron plans for PMRT patients. The 3D-printable compensators were designed to fit into the electron aperture, with cerrobend poured around it. For a sample of eight patients, calculated dose distributions for compensator plans were compared with patients’ (multi-field, multi-energy) clinical treatment plans. For all patients, dosimetric parameters were compared including clinical target volume (CTV), lung, and heart metrics. For validation, compensators were fabricated and irradiated for a set of six 3D-printed patient-specific phantoms. Dose distributions in the phantoms were measured with TLD and film. These measurements were compared with the treatment planning system calculated dose distributions. Results The compensator treatment plans achieved superior CTV coverage (97% vs 89% of the CTV receiving the prescription dose, p < 0.0025), and similar heart and lung doses (p > 0.35) to the conventional treatment plans. Average differences between calculated and measured TLD values were 2%, and average film profile differences were <2 mm. Conclusions We developed a new compensator based treatment methodology for PMRT and demonstrated its validity and superiority to conventional multi-field plans through end-to-end testing.
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Affiliation(s)
- Daniel F. Craft
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX 77030, USA
- Corresponding author at: Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Unit 94, Houston, TX 77030, USA.
| | - Peter Balter
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX 77030, USA
| | - Wendy Woodward
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX 77030, USA
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Stephen F. Kry
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX 77030, USA
| | - Mohammad Salehpour
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX 77030, USA
| | - Rachel Ger
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX 77030, USA
| | - Mary Peters
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX 77030, USA
| | - Garrett Baltz
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX 77030, USA
| | - Erik Traneus
- RaySearch Laboratories AB, Stockholm 111 34, Sweden
| | - Rebecca M. Howell
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX 77030, USA
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Zou W, Burgdorf B, Yue NJ, Yin L, Zhang M, Khan A, Jabbour SK, McDonough J, Dong L, Teo BKK. Efficient double-scattering proton therapy with a patient-specific bolus. Phys Med 2018; 50:1-6. [PMID: 29891088 PMCID: PMC10865432 DOI: 10.1016/j.ejmp.2018.05.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 05/01/2018] [Accepted: 05/03/2018] [Indexed: 11/29/2022] Open
Abstract
PURPOSE Passive scattering proton radiotherapy utilizes beam-specific compensators to shape the dose to the distal end of the tumor target. These compensators typically require therapists to enter the treatment room to mount between beams. This study investigates a novel approach that utilizes a single patient-specific bolus to accomplish the role of multi-field compensators to improve the efficiency of the treatment delivery. METHODS Ray-tracing from the proton virtual source was used to convert the beam-specific compensators (mounted on the gantry nozzle) into an equivalent bolus thickness on the patient surface. The field bolus contours were combined to create a single bolus. A 3D acrylic bolus was milled for a head phantom. The dose distribution of the compensator plan was compared to the bolus plan using 3D Gamma analysis and film measurements. Boluses for two clinical patients were also designed. RESULTS The calculated phantom dose distribution of the original proton compensator plan was shown to be equivalent to the plan with the surface bolus. Film irradiations with the proton bolus also confirmed the dosimetric equivalence of the two techniques. The dose distribution equivalency of the bolus plans for the clinical patients were demonstrated. CONCLUSIONS We presented a novel approach that uses a single patient-specific bolus to replace patient compensators during passive scattering proton delivery. This approach has the potential to reduce the treatment time, the compensator manufacturing costs, the risk of potential collision between the compensator and the patient/couch, and the waste of compensator material.
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Affiliation(s)
- Wei Zou
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA 19104, United States.
| | - Brendan Burgdorf
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Ning J Yue
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, Rutgers University, New Brunswick, NJ 08903, United States
| | - Lingshu Yin
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Miao Zhang
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, United States
| | - Atif Khan
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, United States
| | - Salma K Jabbour
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, Rutgers University, New Brunswick, NJ 08903, United States
| | - James McDonough
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Lei Dong
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Boon-Keng Kevin Teo
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA 19104, United States
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Zhang R, Heins D, Sanders M, Guo B, Hogstrom K. Evaluation of a mixed beam therapy for postmastectomy breast cancer patients: Bolus electron conformal therapy combined with intensity modulated photon radiotherapy and volumetric modulated photon arc therapy. Med Phys 2018; 45:2912-2924. [PMID: 29749075 DOI: 10.1002/mp.12958] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 04/30/2018] [Accepted: 04/30/2018] [Indexed: 12/25/2022] Open
Abstract
PURPOSE The purpose of this study was to assess the potential benefits and limitations of a mixed beam therapy, which combined bolus electron conformal therapy (BECT) with intensity modulated photon radiotherapy (IMRT) and volumetric modulated photon arc therapy (VMAT), for left-sided postmastectomy breast cancer patients. METHODS Mixed beam treatment plans were produced for nine postmastectomy radiotherapy (PMRT) patients previously treated at our clinic with VMAT alone. The mixed beam plans consisted of 40 Gy to the chest wall area using BECT, 40 Gy to the supraclavicular area using parallel opposed IMRT, and 10 Gy to the total planning target volume (PTV) by optimizing VMAT on top of the BECT + IMRT dose distribution. The treatment plans were created in a commercial treatment planning system (TPS), and all plans were evaluated based on PTV coverage, dose homogeneity index (DHI), conformity index (CI), dose to organs at risk (OARs), normal tissue complication probability (NTCP), and secondary cancer complication probability (SCCP). The standard VMAT alone planning technique was used as the reference for comparison. RESULTS Both techniques produced clinically acceptable PMRT plans but with a few significant differences: VMAT showed significantly better CI (0.70 vs 0.53, P < 0.001) and DHI (0.12 vs 0.20, P < 0.001) over mixed beam therapy. For normal tissues, mixed beam therapy showed better OAR sparing and significantly reduced NTCP for cardiac mortality (0.23% vs 0.80%, P = 0.01) and SCCP for contralateral breast (1.7% vs 3.1% based on linear model, and 1.2% vs 1.9% based on linear-exponential model, P < 0.001 in both cases), but showed significantly higher mean (50.8 Gy vs 49.3 Gy, P < 0.001) and maximum skin doses (59.7 Gy vs 53.3 Gy, P < 0.001) compared with VMAT. Patients with more tissue (minimum distance between the distal PTV surface and lung approximately > 0.5 cm and volume of tissue between the distal PTV surface and heart or lung approximately > 250 cm3 ) between distal PTV surface and lung may benefit the most from mixed beam therapy. CONCLUSION This work has demonstrated that mixed beam therapy (BECT + IMRT:VMAT = 4:1) produces clinically acceptable plans having reduced OAR doses and risks of side effects compared with VMAT. Even though VMAT alone produces more homogenous and conformal dose distributions, mixed beam therapy remains as a viable option for treating postmastectomy patients, possibly leading to reduced normal tissue complications.
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Affiliation(s)
- Rui Zhang
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA, 70803, USA.,Department of Radiation Oncology, Mary Bird Perkins Cancer Center, Baton Rouge, LA, 70809, USA
| | - David Heins
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA, 70803, USA
| | - Mary Sanders
- Department of Radiation Oncology, Mary Bird Perkins Cancer Center, Baton Rouge, LA, 70809, USA
| | - Beibei Guo
- Department of Experimental Statistics, Louisiana State University, Baton Rouge, LA, 70803, USA
| | - Kenneth Hogstrom
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA, 70803, USA.,Department of Radiation Oncology, Mary Bird Perkins Cancer Center, Baton Rouge, LA, 70809, USA
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Clinical application of 3D-printed-step-bolus in post-total-mastectomy electron conformal therapy. Oncotarget 2018; 8:25660-25668. [PMID: 27784001 PMCID: PMC5421959 DOI: 10.18632/oncotarget.12829] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 10/19/2016] [Indexed: 11/25/2022] Open
Abstract
The 3D-printed boluses were used during the radiation therapy of the chest wall in six patients with breast cancer after modified radical mastectomy (MRM). We measured the in-vivo skin doses while both conventional and 3D-printed boluses were placed on the chest wall and compared the mean doses delivered to the ipsilateral lung and the heart. The homogeneity and conformity of the dose distribution in the chest wall for both types of boluses were also evaluated. The uniformity index on the chest skin was improved when the 3D-printed boluses were used, with the overall average skin dose being closer to the prescribed one in the former case (-0.47% versus -4.43%). On comparing the dose-volume histogram (DVH), it was found that the 3D-printed boluses resulted in a reduction in the mean dose to the ipsilateral lung by up to 20%. The precision of dose delivery was improved by 3% with the 3D-printed boluses; in contrast, the conventional step bolus resulted in a precision level of 5%. In conclusion, the use of the 3D-printed boluses resulted in better dose homogeneity and conformity to the chest wall as well as the sparing of the normal organs, especially the lung. This suggested that their routine use on the chest wall as a therapeutic approach during post-mastectomy radiation therapy offers numerous advantages over conventional step boluses.
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16
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Yoon J, Heins D, Zhao X, Sanders M, Zhang R. Measurement and modeling of out-of-field doses from various advanced post-mastectomy radiotherapy techniques. Phys Med Biol 2017; 62:9039-9053. [PMID: 29048329 DOI: 10.1088/1361-6560/aa94b5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
More and more advanced radiotherapy techniques have been adopted for post-mastectomy radiotherapies (PMRT). Patient dose reconstruction is challenging for these advanced techniques because they increase the low out-of-field dose area while the accuracy of out-of-field dose calculations by current commercial treatment planning systems (TPSs) is poor. We aim to measure and model the out-of-field radiation doses from various advanced PMRT techniques. PMRT treatment plans for an anthropomorphic phantom were generated, including volumetric modulated arc therapy with standard and flattening-filter-free photon beams, mixed beam therapy, 4-field intensity modulated radiation therapy (IMRT), and tomotherapy. We measured doses in the phantom where the TPS calculated doses were lower than 5% of the prescription dose using thermoluminescent dosimeters (TLD). The TLD measurements were corrected by two additional energy correction factors, namely out-of-beam out-of-field (OBOF) correction factor K OBOF and in-beam out-of-field (IBOF) correction factor K IBOF, which were determined by separate measurements using an ion chamber and TLD. A simple analytical model was developed to predict out-of-field dose as a function of distance from the field edge for each PMRT technique. The root mean square discrepancies between measured and calculated out-of-field doses were within 0.66 cGy Gy-1 for all techniques. The IBOF doses were highly scattered and should be evaluated case by case. One can easily combine the measured out-of-field dose here with the in-field dose calculated by the local TPS to reconstruct organ doses for a specific PMRT patient if the same treatment apparatus and technique were used.
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Affiliation(s)
- Jihyung Yoon
- Medical Physics Program, Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA, United States of America
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17
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Chiu T, Tan J, Brenner M, Gu X, Yang M, Westover K, Strom T, Sher D, Jiang S, Zhao B. Three-dimensional printer-aided casting of soft, custom silicone boluses (SCSBs) for head and neck radiation therapy. Pract Radiat Oncol 2017; 8:e167-e174. [PMID: 29452869 DOI: 10.1016/j.prro.2017.11.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 11/03/2017] [Accepted: 11/06/2017] [Indexed: 10/18/2022]
Abstract
PURPOSE Custom tissue compensators provide dosimetric advantages for treating superficial or complex anatomy, but currently available fabrication technology is expensive or impractical for most clinical operations and yields compensators that are difficult for patients to tolerate. We aimed to develop an inexpensive, clinically feasible workflow for generating patient-specific, soft, custom silicone boluses (SCSBs) for head-and-neck (HN) radiation therapy. METHODS AND MATERIALS We developed a method using 3-dimensional printed parts for generating SCSBs for the treatment of HN cancers. The clinical workflow for generation of SCSBs was characterized inclusive of patient simulation to treatment in terms of resource time and cost. Dosimetric properties such as percentage depth dose and dose profiles were measured for SCSBs using GaF films. Comprehensive measurements were also conducted on an HN phantom. SCSBs were generated and used for electron or photon based radiation treatments of 7 HN patients with lesions at nose, cheek, eye, or ears. In vivo dose measurements with optically simulated luminescence dosimeters were performed. RESULTS Total design and fabrication time from patient simulation to radiation treatment start required approximately 1 week, with fabrication constituting 1 to 2 working days depending on bolus surface area, volume, and complexity. Computed tomography and dosimetric properties of the soft bolus were similar to water. In vivo dose measurements on 7 treated patients confirmed that the dose deposition conformed to planned doses. Material costs were lower than currently available hard plastic boluses generated with 3-dimensional printing technology. All treated patients tolerated SCSBs for the duration of therapy. CONCLUSIONS Generation and use of SCSBs for clinical use is feasible and effective for the treatment of HN cancers.
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Affiliation(s)
- Tsuicheng Chiu
- Department of Radiation Oncology, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas
| | - Jun Tan
- Department of Radiation Oncology, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas
| | - Mathew Brenner
- Department of Radiation Oncology, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas
| | - Xuejun Gu
- Department of Radiation Oncology, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas
| | - Ming Yang
- Department of Radiation Oncology, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas
| | - Kenneth Westover
- Department of Radiation Oncology, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas
| | - Tobin Strom
- Department of Radiation Oncology, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas
| | - David Sher
- Department of Radiation Oncology, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas
| | - Steve Jiang
- Department of Radiation Oncology, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas
| | - Bo Zhao
- Department of Radiation Oncology, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas.
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Hogstrom KR, Carver RL, Chambers EL, Erhart K. Introduction to passive electron intensity modulation. J Appl Clin Med Phys 2017; 18:10-19. [PMID: 28875590 PMCID: PMC5689915 DOI: 10.1002/acm2.12163] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 06/19/2017] [Accepted: 06/28/2017] [Indexed: 11/23/2022] Open
Abstract
This work introduces a new technology for electron intensity modulation, which uses small area island blocks within the collimating aperture and small area island apertures in the collimating insert. Due to multiple Coulomb scattering, electrons contribute dose under island blocks and lateral to island apertures. By selecting appropriate lateral positions and diameters of a set of island blocks and island apertures, for example, a hexagonal grid with variable diameter circular island blocks, intensity modulated beams can be produced for appropriate air gaps between the intensity modulator (position of collimating insert) and the patient. Such a passive radiotherapy intensity modulator for electrons (PRIME) is analogous to using physical attenuators (metal compensators) for intensity modulated x‐ray therapy (IMXT). For hexagonal spacing, the relationship between block (aperture) separation (r) and diameter (d) and the local intensity reduction factor (IRF) is discussed. The PRIME principle is illustrated using pencil beam calculations for select beam geometries in water with half beams modulated by 70%–95% and for one head and neck field of a patient treated with bolus electron conformal therapy. Proof of principle is further illustrated by showing agreement between measurement and calculation for a prototype PRIME. Potential utilization of PRIME for bolus electron conformal therapy, segmented‐field electron conformal therapy, modulated electron radiation therapy, and variable surface geometries is discussed. Further research and development of technology for the various applications is discussed. In summary, this paper introduces a practical, new technology for electron intensity modulation in the clinic, demonstrates proof of principle, discusses potential clinical applications, and suggests areas of further research and development.
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Affiliation(s)
- Kenneth R Hogstrom
- Mary Bird Perkins Cancer Center, Baton Rouge, LA, USA.,Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA, USA
| | - Robert L Carver
- Mary Bird Perkins Cancer Center, Baton Rouge, LA, USA.,Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA, USA
| | - Erin L Chambers
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA, USA
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Eldib A, Jin L, Martin J, Fan J, Li J, Chibani O, Veltchev I, Price R, Galloway T, Ma CMC. Investigating the dosimetric benefits of modulated electron radiation therapy (MERT) for partial scalp patients. Biomed Phys Eng Express 2017. [DOI: 10.1088/2057-1976/aa70ab] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Fujimoto K, Shiinoki T, Yuasa Y, Hanazawa H, Shibuya K. Efficacy of patient-specific bolus created using three-dimensional printing technique in photon radiotherapy. Phys Med 2017; 38:1-9. [PMID: 28610688 DOI: 10.1016/j.ejmp.2017.04.023] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 04/17/2017] [Accepted: 04/17/2017] [Indexed: 11/18/2022] Open
Abstract
PURPOSE A commercially available bolus ("commercial-bolus") does not make complete contact with the irregularly shaped patient skin. This study aims to customise a patient-specific three-dimensional (3D) bolus using a 3D printing technique ("3D-bolus") and to evaluate its clinical feasibility for photon radiotherapy. METHODS The 3D-bolus was designed using a treatment planning system (TPS) in Digital Imaging and Communications in Medicine-Radiotherapy (DICOM-RT) format, and converted to stereolithographic format for printing. To evaluate its physical characteristics, treatment plans were created for water-equivalent phantoms that were bolus-free, or had a flat-form printed 3D-bolus, a TPS-designed bolus ("virtual-bolus"), or a commercial-bolus. These plans were compared based on the percentage depth dose (PDD) and target-volume dose volume histogram (DVH) measurements. To evaluate the clinical feasibility, treatment plans were created for head phantoms that were bolus-free or had a 3D-bolus, a virtual-bolus, or a commercial-bolus. These plans were compared based on the target volume DVH. RESULTS In the physical evaluation, the 3D-bolus provided effective dose coverage in the build-up region, which was equivalent to the commercial-bolus. With regard to the clinical feasibility, the air gaps were lesser with the 3D-bolus when compared to the commercial-bolus. Furthermore, the prescription dose could be delivered appropriately to the target volume. The 3D-bolus has potential use for air-gap reduction compared to the commercial-bolus and facilitates target-volume dose coverage and homogeneity improvement. CONCLUSIONS A 3D-bolus produced using a 3D printing technique is comparable to a commercial-bolus applied to an irregular-shaped skin surface.
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Affiliation(s)
- Koya Fujimoto
- Department of Radiation Oncology, Graduate School of Medicine, Yamaguchi University, 1-1-1 Minamikogushi, Yamaguchi 755-8535, Japan; Department of Radiological Technology, Yamaguchi University Hospital, 1-1-1 Minamikogushi, Yamaguchi 755-8535, Japan
| | - Takehiro Shiinoki
- Department of Radiation Oncology, Graduate School of Medicine, Yamaguchi University, 1-1-1 Minamikogushi, Yamaguchi 755-8535, Japan.
| | - Yuki Yuasa
- Department of Radiation Oncology, Graduate School of Medicine, Yamaguchi University, 1-1-1 Minamikogushi, Yamaguchi 755-8535, Japan; Department of Radiological Technology, Yamaguchi University Hospital, 1-1-1 Minamikogushi, Yamaguchi 755-8535, Japan
| | - Hideki Hanazawa
- Department of Radiation Oncology, Graduate School of Medicine, Yamaguchi University, 1-1-1 Minamikogushi, Yamaguchi 755-8535, Japan
| | - Keiko Shibuya
- Department of Radiation Oncology, Graduate School of Medicine, Yamaguchi University, 1-1-1 Minamikogushi, Yamaguchi 755-8535, Japan
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An alternative option to reduce lung dose for electron scar boost irradiation in post-mastectomy breast cancer patients with a thin chest wall. JOURNAL OF RADIOTHERAPY IN PRACTICE 2017. [DOI: 10.1017/s1460396916000467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
AbstractAimWe evaluated water-equivalent slabs as an alternative to a bolus to reduce radiation dose to the underlying lungs during electron scar boost irradiation in breast cancer patients with a thin chest wall undergoing post-mastectomy radiation therapy.Materials and methodsPercent depth doses (PDDs) and attenuation factors were obtained for 6 MeV (the lowest electron energy in most clinics) with solid water slabs (1–10 mm by 1 mm increments) placed on top of electron cones. Scatter dose to contralateral breast caused by the solid water slabs was measured on a human-like phantom using two selective scar boost patient setups.ResultsThe PDD plots showed that the solid water slabs had similar dosimetric effects to the bolus with lower skin dose to ipsilateral breast for the same thickness. Slab attenuation and scatter dose to the contralateral breast were increased by ~220% and by a factor of 3 with a 5 mm slab, respectively.FindingsOur results demonstrate the feasibility of using water-equivalent slabs to reduce lung dose for electron scar boost treatment in mastectomy patients with a thin chest wall. However, the increases in treatment time and scatter dose to the contralateral breast are the disadvantages of this approach.
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Łukowiak M, Jezierska K, Boehlke M, Więcko M, Łukowiak A, Podraza W, Lewocki M, Masojć B, Falco M. Utilization of a 3D printer to fabricate boluses used for electron therapy of skin lesions of the eye canthi. J Appl Clin Med Phys 2017; 18:76-81. [PMID: 28291910 PMCID: PMC5689892 DOI: 10.1002/acm2.12013] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 10/02/2016] [Indexed: 11/20/2022] Open
Abstract
This work describes the use of 3D printing technology to create individualized boluses for patients treated with electron beam therapy for skin lesions of the eye canthi. It aimed to demonstrate the effectiveness of 3D-printed over manually fabricated paraffin boluses. The study involved 11 patients for whom the construction of individual boluses were required. CT scans of the fabricated 3D-printed boluses and paraffin boluses were acquired and superimposed onto patient CT scans to compare their fitting, bolus homogeneity, and underlying dose distribution. To quantify the level of matching, multiple metrics were utilized. Matching Level Index (ML) values ranged from 0 to 100%, where 100% indicated a perfect fit between the reference bolus (planned in treatment planning system) and 3D-printed and paraffin bolus. The average ML (± 1 SD) of the 3D-printed boluses was 95.1 ± 2.1%, compared to 46.0 ± 10.1% for the manually fabricated paraffin bolus. Correspondingly, mean doses were closer to the prescribed doses, and dose spreads were less for the dose distributions from the 3D-printed boluses, as compared to those for the manually fabricated paraffin boluses. It was concluded that 3D-printing technology is a viable method for fabricating boluses for small eye lesions and provides boluses superior to our boluses manually fabricated from paraffin sheets.
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Affiliation(s)
- Magdalena Łukowiak
- Department of Medical PhysicsWest Pomeranian Oncology CenterSzczecinPoland
| | - Karolina Jezierska
- Department of Medical PhysicsPomeranian Medical UniversitySzczecinPoland
| | - Marek Boehlke
- Department of Medical PhysicsWest Pomeranian Oncology CenterSzczecinPoland
| | - Marzena Więcko
- Department of Medical PhysicsWest Pomeranian Oncology CenterSzczecinPoland
| | - Adam Łukowiak
- Department of Medical DevicesSamodzielny Publiczny Wojewódzki Szpital Zespolony im. Marii Skłodowskiej–CurieSzczecinPoland
| | - Wojciech Podraza
- Department of Medical PhysicsPomeranian Medical UniversitySzczecinPoland
| | - Mirosław Lewocki
- Department of Medical PhysicsWest Pomeranian Oncology CenterSzczecinPoland
| | - Bartłomiej Masojć
- Department of RadiotherapyWest Pomeranian Oncology CenterSzczecinPoland
| | - Michał Falco
- Department of RadiotherapyWest Pomeranian Oncology CenterSzczecinPoland
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Maruyama D, Yamazaki S, Honda E, Suzuki E, Hommatsu K, Oshiba R, Sato N. [Basic Study on Visibility and Water Equivalency of a New Colorless Transparent Bolus for Electron Radiotherapy]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2017; 73:194-201. [PMID: 28331147 DOI: 10.6009/jjrt.2017_jsrt_73.3.194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Boluses used in electron radiotherapy need to have radiation field visibility and water equivalence. In this report, we have examined field visibility and water equivalence of a new colorless transparent bolus. We examined field visibility, water equivalence, and dose profile. Field visibility was evaluated by comparison to conventional bolus. Water equivalence was investigated by a measured fluence scaling factor. The dose profile was measured by using radiochromic film with the bolus and an ionization chamber in water. We confirmed that the irradiation field could clearly be seen through the transparent colorless bolus. The bolus did not cast a field edge as compared with the conventional bolus. The fluence scaling factor was less than 0.8% as compared to water. We confirmed that the colorless transparent bolus was treated as a water equivalent material. The percentage depth dose (PDD) measured by using radiochromic film with the bolus matched the PDD measured with an ionization chamber in water. R50 was less than 1 mm as compared to PDD measured with an ionization chamber. It was confirmed that the colorless transparent bolus can use to set up patient without losing visibility on flat ground planes. The fluence scaling factor and dose profile measured by using the bolus matched the results measured in water. Therefore, the new colorless transparent bolus has feasibility to improve patient setup efficiency and can improve calculation accuracy by using the fluence scaling factor.
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Affiliation(s)
- Daiki Maruyama
- Department of Medical Technology, Japanese Red Cross Medical Center
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Park SY, Choi CH, Park JM, Chun M, Han JH, Kim JI. A Patient-Specific Polylactic Acid Bolus Made by a 3D Printer for Breast Cancer Radiation Therapy. PLoS One 2016; 11:e0168063. [PMID: 27930717 PMCID: PMC5145239 DOI: 10.1371/journal.pone.0168063] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 11/23/2016] [Indexed: 11/19/2022] Open
Abstract
Purpose The aim of this study was to assess the feasibility and advantages of a patient-specific breast bolus made using a 3D printer technique. Methods We used the anthropomorphic female phantom with breast attachments, which volumes are 200, 300, 400, 500 and 650 cc. We simulated the treatment for a right breast patient using parallel opposed tangential fields. Treatment plans were used to investigate the effect of unwanted air gaps under bolus on the dose distribution of the whole breast. The commercial Super-Flex bolus and 3D-printed polylactic acid (PLA) bolus were applied to investigate the skin dose of the breast with the MOSFET measurement. Two boluses of 3 and 5 mm thicknesses were selected. Results There was a good agreement between the dose distribution for a virtual bolus generated by the TPS and PLA bolus. The difference in dose distribution between the virtual bolus and Super-Flex bolus was significant within the bolus and breast due to unwanted air gaps. The average differences between calculated and measured doses in a 200 and 300 cc with PLA bolus were not significant, which were -0.7% and -0.6% for 3mm, and -1.1% and -1.1% for 5 mm, respectively. With the Super-Flex bolus, however, significant dose differences were observed (-5.1% and -3.2% for 3mm, and -6.3% and -4.2% for 5 mm). Conclusion The 3D-printed solid bolus can reduce the uncertainty of the daily setup and help to overcome the dose discrepancy by unwanted air gaps in the breast cancer radiation therapy.
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Affiliation(s)
- So-Yeon Park
- Department of Radiation Oncology, Seoul National University Hospital, Seoul, Republic of Korea
- Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea
- Biomedical Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Chang Heon Choi
- Department of Radiation Oncology, Seoul National University Hospital, Seoul, Republic of Korea
- Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea
- Biomedical Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Jong Min Park
- Department of Radiation Oncology, Seoul National University Hospital, Seoul, Republic of Korea
- Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea
- Biomedical Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea
- Center for Convergence Research on Robotics, Advance Institutes of Convergence Technology, Suwon, Republic of Korea
| | - MinSoo Chun
- Department of Radiation Oncology, Seoul National University Hospital, Seoul, Republic of Korea
- Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea
- Biomedical Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Ji Hye Han
- Department of Radiation Oncology, Seoul National University Hospital, Seoul, Republic of Korea
- Biomedical Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Jung-in Kim
- Department of Radiation Oncology, Seoul National University Hospital, Seoul, Republic of Korea
- Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea
- Biomedical Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea
- * E-mail:
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Zeinali-Rafsanjani B, Faghihi R, Mosleh-Shirazi MA, Mosalaei A, Hadad K. Revision of orthovoltage chest wall treatment using Monte Carlo simulations. Technol Health Care 2016; 25:413-424. [PMID: 27886021 DOI: 10.3233/thc-161276] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
PURPOSE Given the high local control rates observed in breast cancer patients undergoing chest wall irradiation by kilovoltage x-rays, we aimed to revisit this treatment modality by accurate calculation of dose distributions using Monte Carlo simulation. METHODS AND MATERIAL The machine components were simulated using the MCNPX code. This model was used to assess the dose distribution of chest wall kilovoltage treatment in different chest wall thicknesses and larger contour or fat patients in standard and mid sternum treatment plans. Assessments were performed at 50 and 100 cm focus surface distance (FSD) and different irradiation angles. In order to evaluate different plans, indices like homogeneity index, conformity index, the average dose of heart, lung, left anterior descending artery (LAD) and percentage target coverage (PTC) were used. Finally, the results were compared with the indices provided by electron therapy which is a more routine treatment of chest wall. RESULT These indices in a medium chest wall thickness in standard treatment plan at 50 cm FSD and 15 degrees tube angle was as follows: homogeneity index 2.57, conformity index 7.31, average target dose 27.43 Gy, average dose of heart, lung and LAD, 1.03, 2.08 and 1.60 Gy respectively and PTC 11.19%. Assessments revealed that dose homogeneity in planning target volume (PTV) and conformity between the high dose region and PTV was poor. To improve the treatment indices, the reference point was transferred from the chest wall skin surface to the center of PTV. The indices changed as follows: conformity index 7.31, average target dose 60.19 Gy, the average dose of heart, lung and LAD, 3.57, 6.38 and 5.05 Gy respectively and PTC 55.24%. Coverage index of electron therapy was 89% while it was 22.74% in the old orthovoltage method and also the average dose of the target was about 50 Gy but in the given method it was almost 30 Gy. CONCLUSION The results of the treatment study show that the optimized standard and mid sternum treatment for different chest wall thicknesses is with 50 cm FSD and zero (vertical) tube angle, while in large contour patients, it is with 100 cm FSD and zero tube angle. Finally, chest wall kilovoltage and electron therapies were compared, which revealed that electron therapy produces a better dose distribution than kilovoltage therapy.
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Affiliation(s)
- B Zeinali-Rafsanjani
- Medical Radiation Department, School of Mechanical Engineering, Shiraz University, Shiraz, Iran.,Medical Imaging Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - R Faghihi
- Medical Radiation Department, School of Mechanical Engineering, Shiraz University, Shiraz, Iran.,Radiation Research Center, School of Mechanical Engineering, Shiraz University, Shiraz, Iran
| | - M A Mosleh-Shirazi
- Medical Imaging Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.,Radiotherapy and Oncology Department, Shiraz University of Medical Sciences, Shiraz, Iran
| | - A Mosalaei
- Radiotherapy and Oncology Department, Shiraz University of Medical Sciences, Shiraz, Iran
| | - K Hadad
- Medical Radiation Department, School of Mechanical Engineering, Shiraz University, Shiraz, Iran
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Carver RL, Sprunger CP, Hogstrom KR, Popple RA, Antolak JA. Evaluation of the Eclipse eMC algorithm for bolus electron conformal therapy using a standard verification dataset. J Appl Clin Med Phys 2016; 17:52-60. [PMID: 27167259 PMCID: PMC5690899 DOI: 10.1120/jacmp.v17i3.5885] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 02/03/2016] [Accepted: 01/23/2016] [Indexed: 11/23/2022] Open
Abstract
The purpose of this study was to evaluate the accuracy and calculation speed of electron dose distributions calculated by the Eclipse electron Monte Carlo (eMC) algorithm for use with bolus electron conformal therapy (ECT). The recent commercial availability of bolus ECT technology requires further validation of the eMC dose calculation algorithm. eMC‐calculated electron dose distributions for bolus ECT have been compared to previously measured TLD‐dose points throughout patient‐based cylindrical phantoms (retromolar trigone and nose), whose axial cross sections were based on the mid‐PTV (planning treatment volume) CT anatomy. The phantoms consisted of SR4 muscle substitute, SR4 bone substitute, and air. The treatment plans were imported into the Eclipse treatment planning system, and electron dose distributions calculated using 1% and <0.2% statistical uncertainties. The accuracy of the dose calculations using moderate smoothing and no smoothing were evaluated. Dose differences (eMC‐calculated less measured dose) were evaluated in terms of absolute dose difference, where 100% equals the given dose, as well as distance to agreement (DTA). Dose calculations were also evaluated for calculation speed. Results from the eMC for the retromolar trigone phantom using 1% statistical uncertainty without smoothing showed calculated dose at 89% (41/46) of the measured TLD‐dose points was within 3% dose difference or 3 mm DTA of the measured value. The average dose difference was −0.21%, and the net standard deviation was 2.32%. Differences as large as 3.7% occurred immediately distal to the mandible bone. Results for the nose phantom, using 1% statistical uncertainty without smoothing, showed calculated dose at 93% (53/57) of the measured TLD‐dose points within 3% dose difference or 3 mm DTA. The average dose difference was 1.08%, and the net standard deviation was 3.17%. Differences as large as 10% occurred lateral to the nasal air cavities. Including smoothing had insignificant effects on the accuracy of the retromolar trigone phantom calculations, but reduced the accuracy of the nose phantom calculations in the high‐gradient dose areas. Dose calculation times with 1% statistical uncertainty for the retromolar trigone and nose treatment plans were 30 s and 24 s, respectively, using 16 processors (Intel Xeon E5‐2690, 2.9 GHz) on a framework agent server (FAS). In comparison, the eMC was significantly more accurate than the pencil beam algorithm (PBA). The eMC has comparable accuracy to the pencil beam redefinition algorithm (PBRA) used for bolus ECT planning and has acceptably low dose calculation times. The eMC accuracy decreased when smoothing was used in high‐gradient dose regions. The eMC accuracy was consistent with that previously reported for accuracy of the eMC electron dose algorithm and shows that the algorithm is suitable for clinical implementation of bolus ECT. PACS number(s): 87.55.kd
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Affiliation(s)
- Robert L Carver
- Mary Bird Perkins Cancer Center; Louisiana State University.
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Three-dimensional customized bolus for intensity-modulated radiotherapy in a patient with Kimura's disease involving the auricle. Cancer Radiother 2016; 20:205-9. [PMID: 27020714 DOI: 10.1016/j.canrad.2015.11.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 11/03/2015] [Accepted: 11/10/2015] [Indexed: 11/21/2022]
Abstract
In radiotherapy, a commercial bolus often does not provide a suitable fit over irregular surfaces. To address this issue, we fabricated a customized bolus using 3D printing technology. The aim of our study was to evaluate the application of this 3D-printed bolus in a clinical setting. The patient was a 45-year-old man with recurrent Kimura's disease involving the auricle, receiving radiotherapy in our oncology department. A customized bolus, 5mm in thickness, was fabricated based on reconstruction of computed tomography (CT) images. The bolus was printed on a Dimension 1200 series SST 3D printer. Repeat CT-based simulation indicated an acceptable fit of the 3D-printed bolus to the target region, with a maximum air gap of less than 5mm at the tragus. Most of the surface area of the target region was covered by the 95% isodose line. The plan with the 3D-printed bolus improved target coverage compared to that without a bolus. And the plan with the 3D-printed bolus yielded comparable results to those with the paraffin wax bolus. In conclusion, a customized bolus using a 3D printer was successfully applied to an irregular surface.
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Mahdavi H, Jabbari K, Roayaei M. Evaluation of various boluses in dose distribution for electron therapy of the chest wall with an inward defect. J Med Phys 2016; 41:38-44. [PMID: 27051169 PMCID: PMC4795416 DOI: 10.4103/0971-6203.177288] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 12/19/2015] [Accepted: 12/19/2015] [Indexed: 11/26/2022] Open
Abstract
Delivering radiotherapy to the postmastectomy chest wall can be achieved using matched electron fields. Surgical defects of the chest wall change the dose distribution of electrons. In this study, the improvement of dose homogeneity using simple, nonconformal techniques of thermoplastic bolus application on a defect is evaluated. The proposed phantom design improves the capability of film dosimetry for obtaining dose profiles of a patient's anatomical condition. A modeled electron field of a patient with a postmastectomy inward surgical defect was planned. High energy electrons were delivered to the phantom in various settings, including no bolus, a bolus that filled the inward defect (PB0), a uniform thickness bolus of 5 mm (PB1), and two 5 mm boluses (PB2). A reduction of mean doses at the base of the defect was observed by any bolus application. PB0 increased the dose at central parts of the defect, reduced hot areas at the base of steep edges, and reduced dose to the lung and heart. Thermoplastic boluses that compensate a defect (PB0) increased the homogeneity of dose in a fixed depth from the surface; adversely, PB2 increased the dose heterogeneity. This study shows that it is practical to investigate dose homogeneity profiles inside a target volume for various techniques of electron therapy.
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Affiliation(s)
- Hoda Mahdavi
- Department of Radiotherapy, Seyed al-Shohada Hospital, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Keyvan Jabbari
- Department of Medical Physics and Engineering, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mahnaz Roayaei
- Department of Radiotherapy, Seyed al-Shohada Hospital, Isfahan University of Medical Sciences, Isfahan, Iran
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Choi WK, Chun JC, Ju SG, Min BJ, Park SY, Nam HR, Hong CS, Kim M, Koo BY, Lim DH. Efficacy and Accuracy of Patient Specific Customize Bolus Using a 3-Dimensional Printer for Electron Beam Therapy. ACTA ACUST UNITED AC 2016. [DOI: 10.14316/pmp.2016.27.2.64] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Woo Keun Choi
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
- Department of Medical Physics, Kyonggi University, Suwon, Korea
| | - Jun Chul Chun
- Department of Medical Physics, Kyonggi University, Suwon, Korea
| | - Sang Gyu Ju
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Byung Jun Min
- Department of Radiation Oncology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Su Yeon Park
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Hee Rim Nam
- Department of Radiation Oncology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Chae-Seon Hong
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - MinKyu Kim
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Bum Yong Koo
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Do Hoon Lim
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
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Burleson S, Baker J, Hsia AT, Xu Z. Use of 3D printers to create a patient-specific 3D bolus for external beam therapy. J Appl Clin Med Phys 2015; 16:5247. [PMID: 26103485 PMCID: PMC5690114 DOI: 10.1120/jacmp.v16i3.5247] [Citation(s) in RCA: 98] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 12/22/2014] [Accepted: 12/17/2014] [Indexed: 11/23/2022] Open
Abstract
The purpose of this paper is to demonstrate that an inexpensive 3D printer can be used to manufacture patient‐specific bolus for external beam therapy, and to show we can accurately model this printed bolus in our treatment planning system for accurate treatment delivery. Percent depth‐dose measurements and tissue maximum ratios were used to determine the characteristics of the printing materials, acrylonitrile butadiene styrene and polylactic acid, as bolus material with physical density of 1.04 and 1.2 g/cm3, and electron density of 3.38×1023electrons/cm3 and 3.80×1023 electrons/cm3, respectively. Dose plane comparisons using Gafchromic EBT2 film and the RANDO phantom were used to verify accurate treatment planning. We accurately modeled a printing material in Eclipse treatment planning system, assigning it a Hounsfield unit of 260. We were also able to verify accurate treatment planning using gamma analysis for dose plane comparisons. With gamma criteria of 5% dose difference and 2 mm DTA, we were able to have 86.5% points passing, and with gamma criteria of 5% dose difference and 3 mm DTA, we were able to have 95% points passing. We were able to create a patient‐specific bolus using an inexpensive 3D printer and model it in our treatment planning system for accurate treatment delivery. PACS numbers: 87.53.Jw, 87.53.Kn, 87.56.ng
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Zou W, Fisher T, Zhang M, Kim L, Chen T, Narra V, Swann B, Singh R, Siderit R, Yin L, Teo BKK, McKenna M, McDonough J, Ning YJ. Potential of 3D printing technologies for fabrication of electron bolus and proton compensators. J Appl Clin Med Phys 2015; 16:4959. [PMID: 26103473 PMCID: PMC5690113 DOI: 10.1120/jacmp.v16i3.4959] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Revised: 01/12/2015] [Accepted: 12/17/2014] [Indexed: 11/29/2022] Open
Abstract
In electron and proton radiotherapy, applications of patient-specific electron bolus or proton compensators during radiation treatments are often necessary to accommodate patient body surface irregularities, tissue inhomogeneity, and variations in PTV depths to achieve desired dose distributions. Emerging 3D printing technologies provide alternative fabrication methods for these bolus and compensators. This study investigated the potential of utilizing 3D printing technologies for the fabrication of the electron bolus and proton compensators. Two printing technologies, fused deposition modeling (FDM) and selective laser sintering (SLS), and two printing materials, PLA and polyamide, were investigated. Samples were printed and characterized with CT scan and under electron and proton beams. In addition, a software package was developed to convert electron bolus and proton compensator designs to printable Standard Tessellation Language file format. A phantom scalp electron bolus was printed with FDM technology with PLA material. The HU of the printed electron bolus was 106.5 ± 15.2. A prostate patient proton compensator was printed with SLS technology and polyamide material with -70.1 ± 8.1 HU. The profiles of the electron bolus and proton compensator were compared with the original designs. The average over all the CT slices of the largest Euclidean distance between the design and the fabricated bolus on each CT slice was found to be 0.84 ± 0.45 mm and for the compensator to be 0.40 ± 0.42 mm. It is recommended that the properties of specific 3D printed objects are understood before being applied to radiotherapy treatments.
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Affiliation(s)
- Wei Zou
- Rutgers Cancer Institute of New Jersey.
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Su S, Moran K, Robar JL. Design and production of 3D printed bolus for electron radiation therapy. J Appl Clin Med Phys 2014; 15:4831. [PMID: 25207410 PMCID: PMC5875499 DOI: 10.1120/jacmp.v15i4.4831] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 04/16/2014] [Accepted: 04/13/2014] [Indexed: 12/22/2022] Open
Abstract
This is a proof‐of‐concept study demonstrating the capacity for modulated electron radiation therapy (MERT) dose distributions using 3D printed bolus. Previous reports have involved bolus design using an electron pencil beam model and fabrication using a milling machine. In this study, an in‐house algorithm is presented that optimizes the dose distribution with regard to dose coverage, conformity, and homogeneity within the planning target volume (PTV). The algorithm takes advantage of a commercial electron Monte Carlo dose calculation and uses the calculated result as input. Distances along ray lines from the distal side of 90% isodose line to distal surface of the PTV are used to estimate the bolus thickness. Inhomogeneities within the calculation volume are accounted for using the coefficient of equivalent thickness method. Several regional modulation operators are applied to improve the dose coverage and uniformity. The process is iterated (usually twice) until an acceptable MERT plan is realized, and the final bolus is printed using solid polylactic acid. The method is evaluated with regular geometric phantoms, anthropomorphic phantoms, and a clinical rhabdomyosarcoma pediatric case. In all cases the dose conformity are improved compared to that with uniform bolus. For geometric phantoms with air or bone inhomogeneities, the dose homogeneity is markedly improved. The actual printed boluses conform well to the surface of complex anthropomorphic phantoms. The correspondence of the dose distribution between the calculated synthetic bolus and the actual manufactured bolus is shown. For the rhabdomyosarcoma patient, the MERT plan yields a reduction of mean dose by 38.2% in left kidney relative to uniform bolus. MERT using 3D printed bolus appears to be a practical, low‐cost approach to generating optimized bolus for electron therapy. The method is effective in improving conformity of the prescription isodose surface and in sparing immediately adjacent normal tissues. PACS number: 81.40.Wx
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Carver RL, Hogstrom KR, Chu C, Fields RS, Sprunger CP. Accuracy of pencil-beam redefinition algorithm dose calculations in patient-like cylindrical phantoms for bolus electron conformal therapy. Med Phys 2014; 40:071720. [PMID: 23822424 DOI: 10.1118/1.4811104] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE The purpose of this study was to document the improved accuracy of the pencil beam redefinition algorithm (PBRA) compared to the pencil beam algorithm (PBA) for bolus electron conformal therapy using cylindrical patient phantoms based on patient computed tomography (CT) scans of retromolar trigone and nose cancer. METHODS PBRA and PBA electron dose calculations were compared with measured dose in retromolar trigone and nose phantoms both with and without bolus. For the bolus treatment plans, a radiation oncologist outlined a planning target volume (PTV) on the central axis slice of the CT scan for each phantom. A bolus was designed using the planning.decimal(®) (p.d) software (.decimal, Inc., Sanford, FL) to conform the 90% dose line to the distal surface of the PTV. Dose measurements were taken with thermoluminescent dosimeters placed into predrilled holes. The Pinnacle(3) (Philips Healthcare, Andover, MD) treatment planning system was used to calculate PBA dose distributions. The PBRA dose distributions were calculated with an in-house C++ program. In order to accurately account for the phantom materials a table correlating CT number to relative electron stopping and scattering powers was compiled and used for both PBA and PBRA dose calculations. Accuracy was determined by comparing differences in measured and calculated dose, as well as distance to agreement for each measurement point. RESULTS The measured doses had an average precision of 0.9%. For the retromolar trigone phantom, the PBRA dose calculations had an average ± 1σ dose difference (calculated - measured) of -0.65% ± 1.62% without the bolus and -0.20% ± 1.54% with the bolus. The PBA dose calculation had an average dose difference of 0.19% ± 3.27% without the bolus and -0.05% ± 3.14% with the bolus. For the nose phantom, the PBRA dose calculations had an average dose difference of 0.50% ± 3.06% without bolus and -0.18% ± 1.22% with the bolus. The PBA dose calculations had an average dose difference of 0.65% ± 6.21% without bolus and 1.75% ± 5.94% with the bolus. From a clinical perspective an agreement of 5% or better between planned (calculated) and delivered (measured) dose is desired. Statistically, this was true for 99% (± 2σ) of the dose points for three of the four cases for the PBRA dose calculations, the exception being the nose without bolus for which this was true for 89% (± 1.6σ) of the dose points. For the retromolar trigone, with and without bolus, the PBA showed agreement of 5% or better for approximately 86% (± 1.5σ) of the dose points. For the nose, with and without bolus, the PBA showed agreement of 5% or better for only approximately 58% (± 0.8σ) of the dose points. CONCLUSIONS The measured data, whose high precision makes them useful for evaluation of the accuracy of electron dose algorithms, will be made publicly available. Based on the spread in dose differences, the PBRA has at least twice the accuracy of the PBA. From a clinical perspective the PBRA accuracy is acceptable in the retromolar trigone and nose for electron therapy with and without bolus.
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Affiliation(s)
- Robert L Carver
- Mary Bird Perkins Cancer Center, 4950 Essen Lane, Baton Rouge, Louisiana 70809, USA.
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Matsuura T, Miyamoto N, Shimizu S, Fujii Y, Umezawa M, Takao S, Nihongi H, Toramatsu C, Sutherland K, Suzuki R, Ishikawa M, Kinoshita R, Maeda K, Umegaki K, Shirato H. Integration of a real-time tumor monitoring system into gated proton spot-scanning beam therapy: an initial phantom study using patient tumor trajectory data. Med Phys 2014; 40:071729. [PMID: 23822433 DOI: 10.1118/1.4810966] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE In spot-scanning proton therapy, the interplay effect between tumor motion and beam delivery leads to deterioration of the dose distribution. To mitigate the impact of tumor motion, gating in combination with repainting is one of the most promising methods that have been proposed. This study focused on a synchrotron-based spot-scanning proton therapy system integrated with real-time tumor monitoring. The authors investigated the effectiveness of gating in terms of both the delivered dose distribution and irradiation time by conducting simulations with patients' motion data. The clinically acceptable range of adjustable irradiation control parameters was explored. Also, the relation between the dose error and the characteristics of tumor motion was investigated. METHODS A simulation study was performed using a water phantom. A gated proton beam was irradiated to a clinical target volume (CTV) of 5 × 5 × 5 cm(3), in synchronization with lung cancer patients' tumor trajectory data. With varying parameters of gate width, spot spacing, and delivered dose per spot at one time, both dose uniformity and irradiation time were calculated for 397 tumor trajectory data from 78 patients. In addition, the authors placed an energy absorber upstream of the phantom and varied the thickness to examine the effect of changing the size of the Bragg peak and the number of required energy layers. The parameters with which 95% of the tumor trajectory data fulfill our defined criteria were accepted. Next, correlation coefficients were calculated between the maximum dose error and the tumor motion characteristics that were extracted from the tumor trajectory data. RESULTS With the assumed CTV, the largest percentage of the data fulfilled the criteria when the gate width was ± 2 mm. Larger spot spacing was preferred because it increased the number of paintings. With a prescribed dose of 2 Gy, it was difficult to fulfill the criteria for the target with a very small effective depth (the sum of an assumed energy absorber's thickness and the target depth in the phantom) because of the sharpness of the Bragg peak. However, even shallow targets could be successfully irradiated by employing an adequate number of paintings and by placing an energy absorber of sufficient thickness to make the effective target depth more than 12 cm. The authors also observed that motion in the beam direction was the main cause of dose distortion, followed by motion in the lateral plane perpendicular to the scan direction. CONCLUSIONS The results suggested that by properly adjusting irradiation control parameters, gated proton spot-scanning beam therapy can be robust to target motion. This is an important first step toward establishing treatment plans in real patient geometry.
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Affiliation(s)
- Taeko Matsuura
- Department of Medical Physics, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, 060-8638, Japan
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Opp D, Forster K, Li W, Zhang G, Harris EE. Evaluation of bolus electron conformal therapy compared with conventional techniques for the treatment of left chest wall postmastectomy in patients with breast cancer. Med Dosim 2013; 38:448-53. [DOI: 10.1016/j.meddos.2013.08.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Revised: 06/26/2013] [Accepted: 08/14/2013] [Indexed: 12/25/2022]
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Kavanaugh JA, Hogstrom KR, Chu C, Carver RA, Fontenot JP, Henkelmann G. Delivery confirmation of bolus electron conformal therapy combined with intensity modulated x-ray therapy. Med Phys 2013; 40:021724. [PMID: 23387747 DOI: 10.1118/1.4788657] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE The purpose of this study was to demonstrate that a bolus electron conformal therapy (ECT) dose plan and a mixed beam plan, composed of an intensity modulated x-ray therapy (IMXT) dose plan optimized on top of the bolus ECT plan, can be accurately delivered. METHODS Calculated dose distributions were compared with measured dose distributions for parotid and chest wall (CW) bolus ECT and mixed beam plans, each simulated in a cylindrical polystyrene phantom that allowed film dose measurements. Bolus ECT plans were created for both parotid and CW PTVs (planning target volumes) using 20 and 16 MeV beams, respectively, whose 90% dose surface conformed to the PTV. Mixed beam plans consisted of an IMXT dose plan optimized on top of the bolus ECT dose plan. The bolus ECT, IMXT, and mixed beam dose distributions were measured using radiographic films in five transverse and one sagittal planes for a total of 36 measurement conditions. Corrections for film dose response, effects of edge-on photon irradiation, and effects of irregular phantom optical properties on the Cerenkov component of the film signal resulted in high precision measurements. Data set consistency was verified by agreement of depth dose at the intersections of the sagittal plane with the five measured transverse planes. For these same depth doses, results for the mixed beam plan agreed with the sum of the individual depth doses for the bolus ECT and IMXT plans. The six mean measured planar dose distributions were compared with those calculated by the treatment planning system for all modalities. Dose agreement was assessed using the 4% dose difference and 0.2 cm distance to agreement. RESULTS For the combined high-dose region and low-dose region, pass rates for the parotid and CW plans were 98.7% and 96.2%, respectively, for the bolus ECT plans and 97.9% and 97.4%, respectively, for the mixed beam plans. For the high-dose gradient region, pass rates for the parotid and CW plans were 93.1% and 94.62%, respectively, for the bolus ECT plans and 89.2% and 95.1%, respectively, for the mixed beam plans. For all regions, pass rates for the parotid and CW plans were 98.8% and 97.3%, respectively, for the bolus ECT plans and 97.5% and 95.9%, respectively, for the mixed beam plans. For the IMXT component of the mixed beam plans, pass rates for the parotid and CW plans were 93.7% and 95.8%. CONCLUSIONS Bolus ECT and mixed beam therapy dose delivery to the phantom were more accurate than IMXT delivery, adding confidence to the use of planning, fabrication, and delivery for bolus ECT tools either alone or as part of mixed beam therapy. The methodology reported in this work could serve as a basis for future standardization of the commissioning of bolus ECT or mixed beam therapy. When applying this technology to patients, it is recommended that an electron dose algorithm more accurate than the pencil beam algorithm, e.g., a Monte Carlo algorithm or analytical transport such as the pencil beam redefinition algorithm, be used for planning to ensure the desired accuracy.
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Affiliation(s)
- James A Kavanaugh
- Department of Physics and Astronomy, Louisiana State University and Agricultural and Mechanical College, Baton Rouge, LA 70803, USA.
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Single Institutional Experience of Electron Conformal Therapy (ECT) and Modulated Electron Therapy (MET) for Post-mastectomy Chest Wall Irradiation. JOURNAL OF RADIOTHERAPY IN PRACTICE 2013. [DOI: 10.1017/s146039691200012x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
AbstractObjective: Two opposed tangential photon beams followed by scar boost with electrons is a common technique for post-mastectomy radiotherapy to the chest wall. However with current advances in x-rays (conformal and intensity modulated radiotherapy), the electrons have gained less attention; and most of the centres are using the conventional electron therapy techniques. Here we share our experience of electron conformal therapy (ECT) and modulated electron therapy (MET) for post-mastectomy scar boost.Materials and methods: For post-mastectomy chest wall irradiation, 25 patients were treated with ECT and MET in five steps (a) virtual simulation and image acquisition using CT scanner Siemens® followed by (b) data transfer to Coherence Siemens® for contouring of skin, clinical target volume (CTV), planning target volume (PTV) and organs at risk (OARs), followed by (c) forward and reverse planning applying segmented fields using Prowess Panther treatment planning system (TPS) Siemens® and shaping of fields on beam’s eye view (BEV), (d) data transfer to computer assisted fabrication device (Autimo 2D) for lead cut outs and wax blocks and finally (e) quality assurance (QA) and modified treatment delivery.Results: Apart from energy selection and tumor delineation, the ECT and MET showed maximal sparing of OARs (< 70% of prescribed dose), and improved dose conformity compared to single energy single field plans. Phantom and in vivo dosimetric measurements showed excellent agreement with calculated doses with difference ±2%. Conformity improved little beyond allowing three energies due to energy overlap and field-size constraints and conformity improvement was found at the expanse of dose heterogeneity within the PTV.Conclusions: ECT and MET is time saving and can be utilised for treating superficial targets to improve the treatment outcome and with better QA; however, efforts are required to design commercially available eMLC (electron multileaf collimators) in modern linear accelerators.
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Zhang RR, Feygelman V, Harris ER, Rao N, Moros EG, Zhang GG. Is wax equivalent to tissue in electron conformal therapy planning? A Monte Carlo study of material approximation introduced dose difference. J Appl Clin Med Phys 2013; 14:3991. [PMID: 23318384 PMCID: PMC5713917 DOI: 10.1120/jacmp.v14i1.3991] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Revised: 07/13/2012] [Accepted: 09/27/2012] [Indexed: 11/23/2022] Open
Abstract
With CT-based Monte Carlo (MC) dose calculations, material composition is often assigned based on the standard Hounsfield unit ranges. This is known as the density threshold method. In bolus electron conformal therapy (BolusECT), the bolus material, machineable wax, would be assigned as soft tissue and the electron density is assumed equivalent to soft tissue based on its Hounsfield unit. This study investigates the dose errors introduced by this material assignment. BEAMnrc was used to simulate electron beams from a Trilogy accelerator. SPRRZnrc was used to calculate stopping power ratios (SPR) of tissue to wax, SPR (tissue) (wax), and tissue to water, SPR(tissue) (water), for 6, 9, 12, 15, and 18 MeV electron beams, of which 12 and 15MeV beams are the most commonly used energies in BolusECT. DOSXYZnrc was applied in dose distribution calculations in a tissue phantom with either flat wax slabs of various thicknesses or a wedge-shaped bolus on top. Dose distribution for two clinical cases, a chest wall and a head and neck, were compared with the bolus material treated as wax or tissue. The SPR(tissue) (wax) values for 12 and 15MeV beams are between 0.935 and 0.945, while the SPR(tissue) (water) values are between 0.990 and 0.991. For a 12 MeV beam, the dose in tissue immediately under the bolus is overestimated by 2.5% for a 3 cm bolus thickness if the wax bolus is treated as tissue. For 15 MeV beams, the error is 1.4%. However, in both clinical cases the differences in the PTV DVH is negligible. Due to stopping power differences, dose differences of up to 2.5% are observed in MC simulations if the bolus material is misassigned as tissue in BolusECT dose calculations. However, for boluses thinner than 2 cm that are more likely encountered in practice, the error is within clinical tolerance.
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Affiliation(s)
- Ray R Zhang
- School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA
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Rosca F. A hybrid electron and photon IMRT planning technique that lowers normal tissue integral patient dose using standard hardware. Med Phys 2012; 39:2964-71. [PMID: 22755681 DOI: 10.1118/1.4709606] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Affiliation(s)
- Florin Rosca
- Department of Radiation Oncology, Massachusetts General Hospital, Danvers, MA 01923, USA.
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Eley JG, Hogstrom KR, Matthews KL, Parker BC, Price MJ. Potential of discrete Gaussian edge feathering method for improving abutment dosimetry in eMLC-delivered segmented-field electron conformal therapy. Med Phys 2011; 38:6610-22. [PMID: 22149843 DOI: 10.1118/1.3660289] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE The purpose of this work was to investigate the potential of discrete Gaussian edge feathering of the higher energy electron fields for improving abutment dosimetry in the planning volume when using an electron multileaf collimator (eMLC) to deliver segmented-field electron conformal therapy (ECT). METHODS A discrete (five-step) Gaussian edge spread function was used to match dose penumbras of differing beam energies (6-20 MeV) at a specified depth in a water phantom. Software was developed to define the leaf eMLC positions of an eMLC that most closely fit each electron field shape. The effect of 1D edge feathering of the higher energy field on dose homogeneity was computed and measured for segmented-field ECT treatment plans for three 2D PTVs in a water phantom, i.e., depth from the water surface to the distal PTV surface varied as a function of the x-axis (parallel to leaf motion) and remained constant along the y-axis (perpendicular to leaf motion). Additionally, the effect of 2D edge feathering was computed and measured for one radially symmetric, 3D PTV in a water phantom, i.e., depth from the water surface to the distal PTV surface varied as a function of both axes. For the 3D PTV, the feathering scheme was evaluated for 0.1-1.0-cm leaf widths. Dose calculations were performed using the pencil beam dose algorithm in the Pinnacle(3) treatment planning system. Dose verification measurements were made using a prototype eMLC (1-cm leaf width). RESULTS 1D discrete Gaussian edge feathering reduced the standard deviation of dose in the 2D PTVs by 34, 34, and 39%. In the 3D PTV, the broad leaf width (1 cm) of the eMLC hindered the 2D application of the feathering solution to the 3D PTV, and the standard deviation of dose increased by 10%. However, 2D discrete Gaussian edge feathering with simulated eMLC leaf widths of 0.1-0.5 cm reduced the standard deviation of dose in the 3D PTV by 33-28%, respectively. CONCLUSIONS A five-step discrete Gaussian edge spread function applied in 2D improves the abutment dosimetry but requires an eMLC leaf resolution better than 1 cm.
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Affiliation(s)
- John G Eley
- Department of Physics and Astronomy, Louisiana State University and Agricultural and Mechanical College, 202 Nicholson Hall, Tower Drive, Baton Rouge, Louisiana 70803-4001, USA.
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Kim MM, Kudchadker RJ, Kanke JE, Zhang S, Perkins GH. Bolus electron conformal therapy for the treatment of recurrent inflammatory breast cancer: a case report. Med Dosim 2011; 37:208-13. [PMID: 21978532 DOI: 10.1016/j.meddos.2011.07.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2011] [Revised: 07/04/2011] [Accepted: 07/21/2011] [Indexed: 10/16/2022]
Abstract
The treatment of locoregionally recurrent breast cancer in patients who have previously undergone radiation therapy is challenging. Special techniques are often required that both eradicate the disease and minimize the risks of retreatment. We report the case of a patient with an early-stage left breast cancer who developed inflammatory-type recurrence requiring re-irradiation of the chest wall using bolus electron conformal therapy with image-guided treatment delivery. The patient was a 51-year-old woman who had undergone lumpectomy, axillary lymph node dissection, and adjuvant whole-breast radiation therapy for a stage I left breast cancer in June 1998. In March 2009, she presented at our institution with biopsy-proven recurrent inflammatory carcinoma and was aggressively treated with multi-agent chemotherapy followed by mastectomy that left a positive surgical margin. Given the patient's prior irradiation and irregular chest wall anatomy, bolus electron conformal therapy was used to treat her chest wall and draining lymphatics while sparing the underlying soft tissue. The patient still had no evidence of disease 21 months after treatment. Our results indicate that bolus electron conformal therapy is an accessible, effective radiation treatment approach for recurrent breast cancer in patients with irregular chest wall anatomy as a result of surgery. This approach may complement standard techniques used to reduce locoregional recurrence in the postmastectomy setting.
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Affiliation(s)
- Michelle M Kim
- Department of Radiation Oncology, The University of Texas M.D. Anderson Cancer Center, Houston, TX, USA.
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Zeidan OA, Chauhan BD, Estabrook WW, Willoughby TR, Manon RR, Meeks SL. Image-guided bolus electron conformal therapy - a case study. J Appl Clin Med Phys 2010; 12:3311. [PMID: 21330977 PMCID: PMC5718591 DOI: 10.1120/jacmp.v12i1.3311] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2010] [Revised: 07/02/2010] [Accepted: 08/27/2010] [Indexed: 11/23/2022] Open
Abstract
We report on our initial experience with daily image guidance for the treatment of a patient with a basal cell carcinoma of the nasal dorsum using bolus electron conformal therapy. We describe our approach to daily alignment using treatment machine‐integrated megavoltage (MV) planar imaging in conjunction with cone beam CT (CBCT) volumetric imaging to ensure the best possible setup reproducibility. Based on MV imaging, beam aperture misalignment with the intended treatment region was as large as 0.5 cm in the coronal plane. Four of the five fractions analyzed show induced shifts when compared to digitally reconstructed radiographs (DRR), in the range of 0.2−0.5 cm. Daily inspection of CBCT images show that the bolus device can have significant tilt in any given direction by as much as 13° with respect to beam axis. In addition, we show that CBCT images reveal air gaps between bolus and skin that vary from day to day, and can potentially degrade surface dose coverage. Retrospective dose calculation on CBCT image sets shows that when daily shifts based on MV imaging are not corrected, geometrical miss of the planning target volume (PTV) can cause an underdosing as large as 14% based on DVH analysis of the dose to the 90% of the PTV volume. PACS number: 87.55.kh
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Affiliation(s)
- Omar A Zeidan
- Department of Radiation Oncology, M.D. Anderson Cancer Center Orlando, Orlando, FL 32806, USA.
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Catalano G, Canino P, Cassinotti M, Pagella S, Piazzi V, Re S, Wizemann G, Bucci E. Ultrasound transmission gel as a bolus device for skin irradiation of irregular surfaces: technical note. Radiol Med 2010; 115:975-82. [PMID: 20352358 DOI: 10.1007/s11547-010-0546-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2009] [Accepted: 10/27/2009] [Indexed: 11/29/2022]
Abstract
PURPOSE This paper describes an uncommon radiation treatment of the external ear, with ultrasound (US) transmission gel used as bolus device to compensate for the irregularity of the target surface. MATERIALS AND METHODS Postoperative radiotherapy for cutaneous carcinoma was performed with a single high-energy electron beam directed over the ear auricle. Due to the irregular surface of the target, a "missing tissue" compensator was employed. Daily, after patient positioning, the concha was filled and flattened with US gel, and a dose of 54 Gy in 27 fractions was delivered. RESULTS Water equivalence of the gel was verified by comparing the gel's computed tomography (CT) number [Hounsfield units (HU)] and density with the corresponding values for water and another commercial bolus device. Whereas ultrasound gel and water had comparable values (HU: 0; density 1 g/cm(3) for both), the corresponding values for the commercial device were slightly higher (HU: 80; density 1.02 g/cm(3)). CONCLUSIONS Ultrasound gel proved to be an easy, fast and cheap compensating tool. Its water equivalence allows it to be used as an alternative to water, though easier to position and with lower risk of displacement. Thus, it is recommendable as a practical tool for most irregular sites. Further investigations are warranted to validate this solution in more complex irradiation techniques.
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Affiliation(s)
- G Catalano
- Unit of Radiotherapy, MultiMedica Clinical Institute, Viale Piemonte 70, 21053 Castellanza, Italy.
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Greenbaum MP, Strom EA, Allen PK, Perkins GH, Oh JL, Tereffe W, Yu TK, Buchholz TA, Woodward WA. Low locoregional recurrence rates in patients treated after 2000 with doxorubicin based chemotherapy, modified radical mastectomy, and post-mastectomy radiation. Radiother Oncol 2010; 95:312-6. [PMID: 20227126 DOI: 10.1016/j.radonc.2010.02.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2009] [Revised: 02/15/2010] [Accepted: 02/17/2010] [Indexed: 10/19/2022]
Abstract
PURPOSE To determine the rate of locoregional recurrence (LRR) associated with modern tri-modality therapy. METHODS We retrospectively reviewed data from 291 consecutive PMRT patients treated from 1999 to 2001. These patients were compared to an historical group of 313 patients treated from 1979 to 1988 who had fluoroscopic simulation and contour-generated 2D planning. 1999-2001 spans the adoption of CT simulators for breast radiation therapy and a comparison was made between patients simulated before and after the implementation of CT simulation. Five-year actuarial rates for LRR, distal metastasis (DM), and overall survival (OS) between the pre and post CT simulation cohorts were compared as well. RESULTS Compared to a 2D planned historic control, the combined contemporary patients had improved outcomes at 5years for all endpoints studied; LRR 3.0% vs. 11.5%, DM 29.2% vs. 39.2%, and OS 79.2% vs. 70.6% (p=0.0004, 0.0052, 0.0012, respectively). Significant factors in a multivariate analysis for LRR were: advanced T-stage (RR=2.14, CI=1.11-4.11, p=0.023), and percent positive nodes (RR=1.01, CI=1.00-1.02, p=0.012). The comparison of the pre and post CT-simulated PMRT patients (1999-2001) found no significant difference in any endpoint. CONCLUSIONS The rate of locoregional control for PMRT patients treated with modern radiotherapy is outstanding and has improved significantly compared to historical controls.
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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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Gerbi BJ, Antolak JA, Deibel FC, Followill DS, Herman MG, Higgins PD, Huq MS, Mihailidis DN, Yorke ED, Hogstrom KR, Khan FM. Recommendations for clinical electron beam dosimetry: supplement to the recommendations of Task Group 25. Med Phys 2009; 36:3239-79. [PMID: 19673223 DOI: 10.1118/1.3125820] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The goal of Task Group 25 (TG-25) of the Radiation Therapy Committee of the American Association of.Physicists in Medicine (AAPM) was to provide a methodology and set of procedures for a medical physicist performing clinical electron beam dosimetry in the nominal energy range of 5-25 MeV. Specifically, the task group recommended procedures for acquiring basic information required for acceptance testing and treatment planning of new accelerators with therapeutic electron beams. Since the publication of the TG-25 report, significant advances have taken place in the field of electron beam dosimetry, the most significant being that primary standards laboratories around the world have shifted from calibration standards based on exposure or air kerma to standards based on absorbed dose to water. The AAPM has published a new calibration protocol, TG-51, for the calibration of high-energy photon and electron beams. The formalism and dosimetry procedures recommended in this protocol are based on the absorbed dose to water calibration coefficient of an ionization chamber at 60Co energy, N60Co(D,w), together with the theoretical beam quality conversion coefficient k(Q) for the determination of absorbed dose to water in high-energy photon and electron beams. Task Group 70 was charged to reassess and update the recommendations in TG-25 to bring them into alignment with report TG-51 and to recommend new methodologies and procedures that would allow the practicing medical physicist to initiate and continue a high quality program in clinical electron beam dosimetry. This TG-70 report is a supplement to the TG-25 report and enhances the TG-25 report by including new topics and topics that were not covered in depth in the TG-25 report. These topics include procedures for obtaining data to commission a treatment planning computer, determining dose in irregularly shaped electron fields, and commissioning of sophisticated special procedures using high-energy electron beams. The use of radiochromic film for electrons is addressed, and radiographic film that is no longer available has been replaced by film that is available. Realistic stopping-power data are incorporated when appropriate along with enhanced tables of electron fluence data. A larger list of clinical applications of electron beams is included in the full TG-70 report available at http://www.aapm.org/pubs/reports. Descriptions of the techniques in the clinical sections are not exhaustive but do describe key elements of the procedures and how to initiate these programs in the clinic. There have been no major changes since the TG-25 report relating to flatness and symmetry, surface dose, use of thermoluminescent dosimeters or diodes, virtual source position designation, air gap corrections, oblique incidence, or corrections for inhomogeneities. Thus these topics are not addressed in the TG-70 report.
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Affiliation(s)
- Bruce J Gerbi
- University of Minnesota, Minneapolis, Minnesota 55455, USA.
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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] [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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Jin L, Ma CM, Fan J, Eldib A, Price RA, Chen L, Wang L, Chi Z, Xu Q, Sherif M, Li JS. Dosimetric verification of modulated electron radiotherapy delivered using a photon multileaf collimator for intact breasts. Phys Med Biol 2008; 53:6009-25. [DOI: 10.1088/0031-9155/53/21/008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Al-Yahya K, Verhaegen F, Seuntjens J. Design and dosimetry of a few leaf electron collimator for energy modulated electron therapy. Med Phys 2008; 34:4782-91. [PMID: 18196806 DOI: 10.1118/1.2795827] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Despite the capability of energy modulated electron therapy (EMET) to achieve highly conformal dose distributions in superficial targets it has not been widely implemented due to problems inherent in electron beam radiotherapy such as planning dosimetry accuracy, and verification as well as a lack of systems for automated delivery. In previous work we proposed a novel technique to deliver EMET using an automated "few leaf electron collimator" (FLEC) that consists of four motor-driven leaves fit in a standard clinical electron beam applicator. Integrated with a Monte Carlo based optimization algorithm that utilizes patient-specific dose kernels, a treatment delivery was incorporated within the linear accelerator operation. The FLEC was envisioned to work as an accessory tool added to the clinical accelerator. In this article the design and construction of the FLEC prototype that match our compact design goals are presented. It is controlled using an in-house developed EMET controller. The structure of the software and the hardware characteristics of the EMET controller are demonstrated. Using a parallel plate ionization chamber, output measurements were obtained to validate the Monte Carlo calculations for a range of fields with different energies and sizes. Further verifications were also performed for comparing 1-D and 2-D dose distributions using energy independent radiochromic films. Comparisons between Monte Carlo calculations and measurements of complex intensity map deliveries show an overall agreement to within +/- 3%. This work confirms our design objectives of the FLEC that allow for automated delivery of EMET. Furthermore, the Monte Carlo dose calculation engine required for EMET planning was validated. The result supports the potential of the prototype FLEC for the planning and delivery of EMET.
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Affiliation(s)
- Khalid Al-Yahya
- Health Sciences Center Saad Specialist Hospital, Al-Khobar, Saudi Arabia 31952
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Kirova YM, Campana F, Fournier-Bidoz N, Stilhart A, Dendale R, Bollet MA, Fourquet A. Postmastectomy Electron Beam Chest Wall Irradiation in Women With Breast Cancer: A Clinical Step Toward Conformal Electron Therapy. Int J Radiat Oncol Biol Phys 2007; 69:1139-44. [PMID: 17689024 DOI: 10.1016/j.ijrobp.2007.05.007] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2007] [Revised: 04/26/2007] [Accepted: 04/30/2007] [Indexed: 11/18/2022]
Abstract
PURPOSE Electron beam radiotherapy of the chest wall with or without lymph node irradiation has been used at the Institut Curie for >20 years. The purpose of this report was to show the latest improvements of our technique developed to avoid hot spots and improve the homogeneity. METHODS AND MATERIALS The study was split into two parts. A new electron irradiation technique was designed and compared with the standard one (dosimetric study). The dose distributions were calculated using our treatment planning software ISIS (Technologie Diffusion). The dose calculation was performed using the same calculation parameters for the new and standard techniques. Next, the early skin toxicity of our new technique was evaluated prospectively in the first 25 patients using Radiation Therapy Oncology Group criteria (clinical study). RESULTS The maximal dose found on the five slices was 53.4 +/- 1.1 Gy for the new technique and 59.1 +/- 2.3 Gy for the standard technique. The hot spots of the standard technique plans were situated at the overlap between the internal mammary chain and chest wall fields. The use of one unique field that included both chest wall and internal mammary chain volumes solved the problem of junction. To date, 25 patients have been treated with the new technique. Of these patients, 12% developed Grade 0, 48% Grade 1, 32% Grade 2, and 8% Grade 3 toxicity. CONCLUSIONS This report describes an improvement in the standard postmastectomy electron beam technique of the chest wall. This new technique provides improved target homogeneity and conformality compared with the standard technique. This treatment was well tolerated, with a low rate of early toxicity events.
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Affiliation(s)
- Youlia M Kirova
- Department of Radiation Oncology, Institut Curie, Paris, France.
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