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Sakai Y, Monzen H, Tamura M, Nakamura K, Nishimura Y. Double enhancement effect of a surface dose with tungsten rubber bolus in photon radiotherapy for keloids and superficial tumors. Phys Eng Sci Med 2023; 46:179-184. [PMID: 36484890 DOI: 10.1007/s13246-022-01208-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 12/05/2022] [Indexed: 12/13/2022]
Abstract
To clarify the dosimetric characteristics of a real-time variable shape rubber-containing tungsten (STR) bolus in a clinical plan and investigate the efficacy of the STR bolus in photon radiotherapy for keloids and other superficial tumors. A 5 mm gel bolus or 1 mm STR bolus was placed on a solid water phantom. Tangential irradiation was performed using a TomoTherapy Radixact-X9 and 6 MV X-ray flattening-filter-free beam, and the surface dose was measured with radiochromic film. Clinical-like plans (TomoDirect; TD and TomoHelical; TH) were applied with the same geometry and the dose distributions were measured. The increase in surface dose by the build-up effect and backscatter was 37.7% and 8.0% for the gel bolus, and 40.5% and 26.4% for the STR bolus, respectively. In the TD and TH plans, the increase in surface dose was 27.4% and 48.3% for the gel bolus, and 39.0% and 63.2% for the STR bolus. Similary, changes in the sagittal plane dose were - 3.9% and 6.1% for the gel bolus, and - 6.3% and 6.9% for the STR bolus. The STR bolus effectively increased the surface dose by the build-up effect and backscatter in photon radiotherapy for keloids and other superficial tumors.
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Affiliation(s)
- Yusuke Sakai
- Department of Medical Physics, Graduate School of Medical Sciences, Kindai University, 377-2 Onohigashi, Osakasayama, Osaka, 589-8511, Japan
- Department of Radiotherapy, Takarazuka City Hospital, 4-5-1 Kohama, Takarazuka, Hyogo, 665-0827, Japan
| | - Hajime Monzen
- Department of Medical Physics, Graduate School of Medical Sciences, Kindai University, 377-2 Onohigashi, Osakasayama, Osaka, 589-8511, Japan.
| | - Mikoto Tamura
- Department of Medical Physics, Graduate School of Medical Sciences, Kindai University, 377-2 Onohigashi, Osakasayama, Osaka, 589-8511, Japan
| | - Kenji Nakamura
- Department of Medical Physics, Graduate School of Medical Sciences, Kindai University, 377-2 Onohigashi, Osakasayama, Osaka, 589-8511, Japan
- Department of Radiotherapy, Takarazuka City Hospital, 4-5-1 Kohama, Takarazuka, Hyogo, 665-0827, Japan
| | - Yasumasa Nishimura
- Department of Radiation Oncology, Faculty of Medicine, Kindai University, 377-2 Onohigashi, Osakasayama, Osaka, 589-8511, Japan
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Buang S, Ab Razak NNAN, Aziz MZA, Raof N. Evaluation of brass alloy density as tissue equivalence bolus using electron density phantom and optical density method. Appl Radiat Isot 2022; 187:110310. [PMID: 35714516 DOI: 10.1016/j.apradiso.2022.110310] [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: 07/07/2021] [Revised: 05/09/2022] [Accepted: 05/30/2022] [Indexed: 11/19/2022]
Abstract
The brass mesh bolus alloy has been shown to be a promising substitute for tissue-equivalent bolus to increase the surface dose during breast cancer radiotherapy treatment. This study is aimed to evaluate the brass alloy density in order to better understand the brass qualities as a bolus in radiotherapy. The mass density of brass alloy determined in this work are using solid approaches, i) traditional density method, ii) Computed Tomography (CT) number using electron density phantom and CT scan and iii) mean pixel value via ImageJ software. According to ANOVA F (2,6) 2.982, p0.126, there was no statistically significant difference between the groups. As a result, all methods for calculating the density of brass alloy are valid. The X2 test of CT number of brass plug to breast substitute in electron density phantom indicates no association. Density analysis using computed tomography and an electron density phantom, as well as the traditional density method and Image J analysis, were all shown to be acceptable methods for estimating the density of the brass alloy. Considering this, brass alloy can be considered as a potential substitute for tissue-equivalent bolus with further extensive of research in conjunction to CT number.
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Affiliation(s)
- Sakinah Buang
- School of Physics, Universiti Sains Malaysia, Malaysia.
| | | | | | - NurSyatina Raof
- Advanced Medical Dental Institute, Universiti Sains Malaysia, Malaysia
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Lobo D, Banerjee S, Srinivas C, Athiyamaan MS, Reddy S, Sunny J, Ravichandran R, Kotian H, Prakash Saxena PU. Surface Dose Measurements in Chest Wall Postmastectomy Radiotherapy to Achieve Optimal Dose Delivery with 6 MV Photon Beam. J Med Phys 2021; 46:324-333. [PMID: 35261503 PMCID: PMC8853458 DOI: 10.4103/jmp.jmp_59_21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 06/23/2021] [Accepted: 07/08/2021] [Indexed: 11/04/2022] Open
Abstract
Aim A tissue-equivalent bolus of sufficient thickness is used to overcome build up effect to the chest wall region of postmastectomy radiotherapy (PMRT) patients with tangential technique till Radiation Therapy Oncology Group (RTOG) Grade 2 (dry desquamation) skin reaction is observed. The aim of this study is to optimize surface dose delivered to chest wall in three-dimensional radiotherapy using EBT3 film. Materials and Methods Measurements were conducted with calibrated EBT3 films with thorax phantom under "open beam, Superflab gel (0.5 cm) and brass bolus conditions to check correlation against TPS planned doses. Eighty-two patients who received 50 Gy in 25# were randomly assigned to Group A (Superflab 0.5 cm gel bolus for first 15 fractions followed by no bolus in remaining 10 fractions), Group B or Group C (Superflab 0.5 cm gel or single layer brass bolus, respectively, till reaching RTOG Grade 2 skin toxicity). Results Phantom measured and TPS calculated surface doses were within - 5.5%, 4.7%, and 8.6% under open beam, 0.5 cm gel, and single layer of brass bolus applications, respectively. The overall surface doses (OSD) were 80.1% ±2.9% (n = 28), 92.6% ±4.6% (n = 28), and 87.4% ±4.7% (n = 26) in Group A, B, and C, respectively. At the end of treatment, 7 out of 28; 13 out of 28; and 9 out of 26 patients developed Grade 2 skin toxicity having the OSD value of 83.0% ±1.6% (n = 7); 93.7% ±3.2% (n = 13); and 89.9% ±5.6% (n = 9) in Groups A, B, and C, respectively. At the 20th-23rd fraction, 2 out of 7; 6 out of 13; and 4 out of 9 patients in Groups A, B, and C developed a Grade 2 skin toxicity, while the remaining patients in each group developed at the end of treatment. Conclusions Our objective to estimate the occurrence of optimal dose limit for bolus applications in PMRT could be achieved using clinical EBT3 film dosimetry. This study ensured correct dose to scar area to protect cosmetic effects. This may also serve as quality assurance on optimal dose delivery for expected local control in these patients.
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Affiliation(s)
- Dilson Lobo
- Department of Radiation Oncology, Kasturba Medical College (A Constituent Institution of Manipal Academy of Higher Education), Mangalore, Karnataka, India
| | - Sourjya Banerjee
- Department of Radiation Oncology, Kasturba Medical College (A Constituent Institution of Manipal Academy of Higher Education), Mangalore, Karnataka, India
| | - Challapalli Srinivas
- Department of Radiation Oncology, Kasturba Medical College (A Constituent Institution of Manipal Academy of Higher Education), Mangalore, Karnataka, India
| | - M S Athiyamaan
- Department of Radiation Oncology, Kasturba Medical College (A Constituent Institution of Manipal Academy of Higher Education), Mangalore, Karnataka, India
| | - Shreyas Reddy
- Department of Radiation Oncology, Kasturba Medical College (A Constituent Institution of Manipal Academy of Higher Education), Mangalore, Karnataka, India
| | - Johan Sunny
- Department of Radiation Oncology, Kasturba Medical College (A Constituent Institution of Manipal Academy of Higher Education), Mangalore, Karnataka, India
| | - Ramamoorthy Ravichandran
- Department of Radiation Oncology, Kasturba Medical College (A Constituent Institution of Manipal Academy of Higher Education), Mangalore, Karnataka, India
| | - Himani Kotian
- Department of Community Medicine, Kasturba Medical College (A Constituent Institution of Manipal Academy of Higher Education), Mangalore, Karnataka, India
| | - P U Prakash Saxena
- Department of Radiation Oncology, Kasturba Medical College (A Constituent Institution of Manipal Academy of Higher Education), Mangalore, Karnataka, India
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Okuhata K, Tamura M, Monzen H, Nishimura Y. Dosimetric characteristics of a thin bolus made of variable shape tungsten rubber for photon radiotherapy. Phys Eng Sci Med 2021; 44:1249-1255. [PMID: 34542835 DOI: 10.1007/s13246-021-01059-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 09/09/2021] [Indexed: 10/20/2022]
Abstract
In this study, we aim to clarify the dosimetric characteristics of a real time variable shape rubber containing tungsten (STR) as a thin bolus in 6-MV photon radiotherapy. The percentage depth doses (PDDs) and lateral dose profiles (irradiation field = 10 × 10 cm2) in the water-equivalent phantom were measured and compared between no bolus, a commercial 5-mm gel bolus, and 0.5-, 1-, 2-, and 3-mm STR boluses. The characteristics of the PDDs were evaluated according to relative doses at 1 mm depth (D1mm) and depth of maximum dose (dmax). To determine the distance of the shift caused by the STR bolus, the PDD value at a depth of 100 mm without a bolus was obtained. For each STR thickness, the difference between the depth corresponding to this PDD value and 100 mm was calculated. The penumbra size and width of the 50% dose were evaluated using lateral dose profiles. The D1mm with no bolus, 5-mm gel bolus, and 0.5-, 1-, 2-, and 3-mm STR boluses were 47.6%, 91.5%, 78.2%, 86.6%, 89.3%, and 89.4%, respectively, and the respective dmax values were 15, 10, 13, 12, 11, and 10 mm. The shifting distance of the 0.5-, 1-, 2-, and 3-mm STR boluses were 2.7, 4.4, 4.8, and 4.9 mm, respectively. There were no differences for those in lateral dose profiles. The 1-mm-thick STR thin bolus shifted the depth dose profile by 4.4 mm and could be used as a customized bolus for photon radiotherapy.
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Affiliation(s)
- Katsuya Okuhata
- Department of Medical Physics, Graduate School of Medical Sciences, Kindai University, 377-2 Onohigashi, Osakasayama, Osaka, 5898511, Japan.,Department of Radiology, Kansai Electric Power Hospital, 2-1-7 Fukushima, Fukushima-ku, Osaka-shi, Osaka, 5530003, Japan
| | - Mikoto Tamura
- Department of Medical Physics, Graduate School of Medical Sciences, Kindai University, 377-2 Onohigashi, Osakasayama, Osaka, 5898511, Japan
| | - Hajime Monzen
- Department of Medical Physics, Graduate School of Medical Sciences, Kindai University, 377-2 Onohigashi, Osakasayama, Osaka, 5898511, Japan.
| | - Yasumasa Nishimura
- Department of Radiation Oncology, Faculty of Medicine, Kindai University, 377-2 Onohigashi, Osakasayama, Osaka, 5898511, Japan
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Fiedler DA, Hoffman S, Roeske JC, Hentz CL, Small W, Kang H. Dosimetric assessment of brass mesh bolus and transparent polymer-gel type bolus for commonly used breast treatment delivery techniques. Med Dosim 2021; 46:e10-e14. [PMID: 33536152 DOI: 10.1016/j.meddos.2021.01.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 12/08/2020] [Accepted: 01/05/2021] [Indexed: 11/29/2022]
Abstract
We investigated skin dose enhancements of brass mesh bolus (BMB) and a recently developed transparent polymer-gel bolus (PGB) for clinically relevant breast treatment delivery techniques. The dose enhancement of the breast surface with BMB and PGB were compared to that of tissue-equivalent bolus. Three breast treatment plans were generated on CT scans of an anthropomorphic chest phantom: tangential step-and-shoot 3D conformal (3DCRT) planned using Field-in-Field (FiF), tangential sliding-window 3DCRT using Electronic Compensator (EC), and volumetric modulated arc therapy (VMAT). All plans were created using 6 MV photons and a prescription dose (Rx) of 180 cGy per fraction. Skin doses of all 3 plans were measured with radiochromic films, separately delivered in triplicate. Each plan was delivered to the phantom without bolus, and then with BMB (1 or 2 layers; 3 or 10 mm tissue-equivalent), PGB, and Superflab (3, 5, and 10 mm tissue-equivalent). Doses were determined by reading the radiochromic films with a flatbed scanner, and analyzing the images using a calibration curve for each specific batch. For all bolus types and plans, surface doses averaged over the 3 measurements were between 88.4% and 107.4% of Rx. Without bolus, average measured skin doses were between 51.2% and 64.2% of Rx. Skin doses with BMB and PGB were comparable to that with tissue-equivalent bolus. Over all 3 treatment delivery techniques, using BMB resulted in average skin doses of 92.8% and 102.1% for 1- and 2 layers, respectively, and using PGB results in average skin doses of 94.8%, 98.2%, and 99.7% for 3, 5, and 10-mm tissue-equivalent, respectively. The average measured skin doses with BMB and PGB agreed within ± 3% compared to the tissue-equivalent thickness bolus. We concluded that BMB and PGB are clinically equivalent in skin dose enhancement for breast treatment as the 3, 5, and 10 mm tissue-equivalent bolus.
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Affiliation(s)
- Derek A Fiedler
- Department of Radiation Oncology, Loyola University Medical Center, Maywood, IL, 60637 USA
| | - Sabrina Hoffman
- Department of Radiation Oncology, Loyola University Medical Center, Maywood, IL, 60637 USA
| | - John C Roeske
- Department of Radiation Oncology, Stritch School of Medicine, Cardinal Bernardine Cancer Center, Loyola University Chicago, Maywood, IL, 60637 USA
| | - Courtney L Hentz
- Department of Radiation Oncology, Stritch School of Medicine, Cardinal Bernardine Cancer Center, Loyola University Chicago, Maywood, IL, 60637 USA
| | - William Small
- Department of Radiation Oncology, Stritch School of Medicine, Cardinal Bernardine Cancer Center, Loyola University Chicago, Maywood, IL, 60637 USA
| | - Hyejoo Kang
- Department of Radiation Oncology, Stritch School of Medicine, Cardinal Bernardine Cancer Center, Loyola University Chicago, Maywood, IL, 60637 USA.
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Study on the radiation attenuation properties of locally available bees-wax as a tissue equivalent bolus material in radiotherapy. Radiat Phys Chem Oxf Engl 1993 2020. [DOI: 10.1016/j.radphyschem.2019.108559] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Fagerstrom JM. Dosimetric characterization of a rigid, surface-contour-specific thermoplastic bolus material. Med Dosim 2019; 44:401-404. [PMID: 30952385 DOI: 10.1016/j.meddos.2019.02.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 01/22/2019] [Accepted: 02/19/2019] [Indexed: 10/27/2022]
Abstract
A dosimetric analysis of a commercially available thermoplastic sheet bolus, Klarity EZ BolusTM, was completed. Attenuation characteristics were evaluated using different configurations of a rectilinear water-mimicking plastic phantom irradiated by a high-energy linear accelerator using three photon energies, five electron energies. These results were compared with data obtained during the linear accelerator commissioning process to determine depths of water that attenuated beams similarly. CT scans of the flat, unmolded sheet bolus, as well as of the bolus molded to a cylindrical phantom, were analyzed. The product was found to form a durable and rigid, contour-specific bolus with a water-equivalent thickness of approximately 6 mm for a single sheet, and 11 mm for two sheets in tandem.
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Affiliation(s)
- Jessica M Fagerstrom
- Northwest Medical Physics Center, Lynnwood, WA 98036, USA; Kaiser Permanente, Seattle, WA 98112, USA.
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Al-Rahbi ZS, Cutajar DL, Metcalfe P, Rosenfeld AB. Dosimetric effects of brass mesh bolus on skin dose and dose at depth for postmastectomy chest wall irradiation. Phys Med 2018; 54:84-93. [DOI: 10.1016/j.ejmp.2018.09.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 09/21/2018] [Indexed: 11/28/2022] Open
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Richmond N. The accuracy of treatment planning system dose modelling in the presence of brass mesh bolus. Rep Pract Oncol Radiother 2017; 22:354-359. [PMID: 28761391 DOI: 10.1016/j.rpor.2017.06.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 02/17/2017] [Accepted: 06/30/2017] [Indexed: 10/19/2022] Open
Abstract
AIM This work assesses the dosimetric accuracy of three commercial treatment planning system (TPS) photon dose calculation algorithms in the presence of brass mesh used as a bolus. BACKGROUND Bolus material is used in radiotherapy to provide dose build-up where superficial tissues require irradiation. They are generally water equivalent but high density materials can also be used. MATERIALS AND METHODS Dose calculations were performed on Monaco and Masterplan TPS (Elekta AB, Sweden) using phantoms defined by the three DICOM CT image sets of water equivalent blocks (no bolus, 1 layer and 2 layers of brass mesh) exported from the CT scanner. The effect of the mesh on monitor units, build-up dose, phantom exit dose and beam penumbra were compared to measured data. RESULTS Dose calculations for 6 and 15 MV photon beams on plain water equivalent phantoms were seen to agree well with measurement validating the basic planning system algorithms and models. Dose in the build-up region, phantom exit dose and beam penumbra were poorly modelled in the presence of the brass mesh. The beam attenuation created by the bolus material was overestimated by all three calculation algorithms, at both photon energies, e.g. 1.6% for one layer and up to 3.1% for two layers at 6 MV. The poor modelling of the physical situation in the build-up region is in part a consequence of the high HU artefact caused by the mesh in the CT image. CONCLUSIONS CT imaging is not recommended with the brass mesh bolus in situ due to the poor accuracy of the subsequent TPS modelling.
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Affiliation(s)
- Neil Richmond
- Department of Medical Physics, The James Cook University Hospital, Marton Road, Middlesbrough TS4 3BW, UK
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