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Arjmand M, Ghassemi F, Rafiepour P, Zeinali R, Riazi-Esfahani H, Beiki-Ardakani A. Dosimetric Investigation of Six Ru-106 Eye Plaques by EBT3 Radiochromic Films and Monte Carlo Simulation. J Biomed Phys Eng 2023; 13:309-316. [PMID: 37609514 PMCID: PMC10440413 DOI: 10.31661/jbpe.v0i0.2010-1206] [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: 10/11/2020] [Accepted: 02/10/2021] [Indexed: 08/24/2023]
Abstract
Background Ophthalmic brachytherapy using radioactive plaques is an effective technique for the treatment of uveal melanoma. Ru-106 eye plaques are considered as interesting issue due to their steep gradient dose. The pre-planning evaluation of dosimetric parameters is essential for the treatment planning system. Objective The current study aims at providing dose distributions of six Ru-106 eye plaques (CCA, CCB, CGD, CIB, COB and COD) using radiochromic EBT3 film, Geant4 Monte Carlo toolkit and the treatment planning software (Plaque Simulator). Material and Methods In this experimental study, an in-house phantom was employed for depth dose measurements with EBT3 films. Also, Geant4.10.5 scoring mesh was implemented to obtain the 2D dose distribution of the plaques. The results were compared with Plaque Simulator software and the manufacturer's (BEBIG) data. The gamma index criterion (3%/3 mm) was used to evaluate dose distributions obtained by the film measurements and Geant4 simulation. Results A good agreement was achieved between simulation and experimental results. Gamma index passing rate was 94.2%, 89.3%, 88.2%, 82.2%, 92.2% and 90.1% for CCA, CCB, CGD, CIB, COB and COD plaques, respectively. Absolute dose rate (mGy/min) obtained by EBT3 film at the depth of 2 mm was 79.4 mGy/min, 81.0 mGy/min, 78.6 mGy/min, 62.2 mGy/min, 75.2 mGy/min and 81.2 mGy/min for CCA, CCB, CGD, CIB, COB and COD plaques, respectively. Conclusion The measured dose distributions and lateral dose profiles may be utilized in the treatment planning system to cover clinical volumes such as the clinical target volume and the gross tumor volume.
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Affiliation(s)
- Mojtaba Arjmand
- Ocular Oncology service, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Fariba Ghassemi
- Retina & Vitreous Service- Ocular Oncology Service, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Payman Rafiepour
- Department of Nuclear Engineering, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Reyhaneh Zeinali
- Department of Medical Physics, Tabriz University of Medical Science, Tabriz, Iran
| | - Hamid Riazi-Esfahani
- Ocular Oncology service, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
- Retina Service, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Akbar Beiki-Ardakani
- Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
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Modified Geometry of 106Ru Asymmetric Eye Plaques to Improve Dosimetric Calculations in Ophthalmic Brachytherapy. J Pers Med 2022; 12:jpm12050723. [PMID: 35629144 PMCID: PMC9144752 DOI: 10.3390/jpm12050723] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 04/22/2022] [Accepted: 04/27/2022] [Indexed: 11/29/2022] Open
Abstract
Ru/Rh asymmetric plaques for ophthalmic brachytherapy have special geometric designs with a cutout intended to prevent irradiation of critical ocular structures proximal to the tumor. In this work, we present new geometric models for PENELOPE+PenEasy Monte Carlo simulations of these applicators, differing from the vendor-reported geometry, that better match their real geometry to assess their dosimetric impact. Simulation results were benchmarked to experimental dosimetric data from radiochromic film measurements, data provided by the manufacturer in the calibration certificates, and other experimental results published in the literature, obtaining, in all cases, better agreement with the modified geometries. The clinical impact of the new geometric models was evaluated by simulating real clinical cases using patient-specific eye models. The cases calculated using the modified geometries presented higher doses to the critical structures proximal to the cutout region. The modified geometric models presented in this work provide a more accurate representation of the asymmetric plaques, greatly improving the agreement between Monte Carlo calculations and experimental measurements. Lack of consideration of accurate geometric models has been shown to be translated into notable increases in dose to organs at risk in clinical cases.
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Nakamura S, Murakami N, Suzuki S, Ito K, Takemori M, Nakayama H, Kaga K, Chiba T, Iijima K, Takahashi K, Goka T, Itami J, Okamoto H, Igaki H. Monte Carlo simulation of tilted contact plaque brachytherapy placement for juxtapapillary retinoblastoma. Radiat Oncol 2022; 17:16. [PMID: 35073956 PMCID: PMC8785594 DOI: 10.1186/s13014-022-01986-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Accepted: 01/10/2022] [Indexed: 11/24/2022] Open
Abstract
Background The 106-Ruthenium contact plaque applicator is utilized for the treatment of intraocular tumor within a thickness of less than 6 mm. If anything obstructs the placement of the plaque applicator, the treatment is generally difficult because the applicator has to be temporarily located just on the opposite side of the retinal tumor. Furthermore, the plaque applicator edge of approximately 1 mm does not contain 106Ru, estimating the delivered radiation dose for eccentric tumor is challenging because the lateral dose profile is inadequately provided by the manufacture’s certification. This study aims to simulate tumor coverage of the tilted applicator placement for treating an infant with juxtapapillary retinoblastoma and to achieve the effective treatment. Case presentation We present an infant with retinoblastoma whose tumor involved macular and was invading just temporal side of the optic disc. Additionally, posterior staphyloma was induced by a series of previous treatments, making it more difficult to treat the standard plaque placement. Thus, the applicator type of CCA was intentionally tilted to the eyeball and the distance between the posterior edge of the applicator and the eyeball had to be then equal to or more than 2 mm based on the dose distribution of the applicator calculated using Monte Carlo simulation to minimize damage to surrounding tissues while covering the tumor. It was then comparable to the certification and previous reports. Based on the acquired dose distribution, the optimal placement of the applicator was derived from varying the distance between the applicator’s edge and the eyeball, and the distance was then determined to be 2 mm. In this case, the minimum dose rate in the tumor was 25.5 mGy/min, and the time required to deliver the prescribed dose was 26.2 h. Therefore, the tilted 106Ru plaque applicator placement could deliver the required dose for the treatment. The physical examination revealed no active tumor as a result of the treatment. Conclusions Optimizing the placement of the 106Ru plaque applicator, it was possible to guarantee that the prescribed dose will be delivered to the tumor even if the standard placement is not possible for the juxtapapillary tumor.
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On measuring the 3D dose distribution for notched and circular Ru-106 plaque shapes through Gafchromic film dosimetry approach. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2021.109792] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Niroomand‐Rad A, Chiu‐Tsao S, Grams MP, Lewis DF, Soares CG, Van Battum LJ, Das IJ, Trichter S, Kissick MW, Massillon‐JL G, Alvarez PE, Chan MF. Report of AAPM Task Group 235 Radiochromic Film Dosimetry: An Update to TG‐55. Med Phys 2020; 47:5986-6025. [DOI: 10.1002/mp.14497] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 09/15/2020] [Accepted: 09/17/2020] [Indexed: 12/12/2022] Open
Affiliation(s)
| | | | | | | | | | | | - Indra J. Das
- Radiation Oncology Northwestern University Memorial Hospital Chicago IL USA
| | - Samuel Trichter
- New York‐Presbyterian HospitalWeill Cornell Medical Center New York NY USA
| | | | - Guerda Massillon‐JL
- Instituto de Fisica Universidad Nacional Autonoma de Mexico Mexico City Mexico
| | - Paola E. Alvarez
- Imaging and Radiation Oncology Core MD Anderson Cancer Center Houston TX USA
| | - Maria F. Chan
- Memorial Sloan Kettering Cancer Center Basking Ridge NJ USA
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Dual-energy CT imaging of orbits during episcleral brachytherapy with Ru-106 plaques: A phantom study on its potential for plaque position verification. Phys Med 2020; 73:1-7. [DOI: 10.1016/j.ejmp.2020.03.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 03/18/2020] [Accepted: 03/20/2020] [Indexed: 11/22/2022] Open
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Krause F, Möller M, Risske F, Siebert FA. Dosimetry of ruthenium-106 ophthalmic applicators with thin layer thermoluminescence dosimeters - Clinical quality control. Z Med Phys 2020; 30:142-147. [DOI: 10.1016/j.zemedi.2019.11.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 10/23/2019] [Accepted: 11/08/2019] [Indexed: 10/25/2022]
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Thomson RM, Furutani KM, Kaulich TW, Mourtada F, Rivard MJ, Soares CG, Vanneste FM, Melhus CS. AAPM recommendations on medical physics practices for ocular plaque brachytherapy: Report of task group 221. Med Phys 2020; 47:e92-e124. [PMID: 31883269 DOI: 10.1002/mp.13996] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 11/12/2019] [Accepted: 12/23/2019] [Indexed: 12/14/2022] Open
Abstract
The American Association of Physicists in Medicine (AAPM) formed Task Group 221 (TG-221) to discuss a generalized commissioning process, quality management considerations, and clinical physics practice standards for ocular plaque brachytherapy. The purpose of this report is also, in part, to aid the clinician to implement recommendations of the AAPM TG-129 report, which placed emphasis on dosimetric considerations for ocular brachytherapy applicators used in the Collaborative Ocular Melanoma Study (COMS). This report is intended to assist medical physicists in establishing a new ocular brachytherapy program and, for existing programs, in reviewing and updating clinical practices. The report scope includes photon- and beta-emitting sources and source:applicator combinations. Dosimetric studies for photon and beta sources are reviewed to summarize the salient issues and provide references for additional study. The components of an ocular plaque brachytherapy quality management program are discussed, including radiation safety considerations, source calibration methodology, applicator commissioning, imaging quality assurance tests for treatment planning, treatment planning strategies, and treatment planning system commissioning. Finally, specific guidelines for commissioning an ocular plaque brachytherapy program, clinical physics practice standards in ocular plaque brachytherapy, and other areas reflecting the need for specialized treatment planning systems, measurement phantoms, and detectors (among other topics) to support the clinical practice of ocular brachytherapy are presented. Expected future advances and developments for ocular brachytherapy are discussed.
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Affiliation(s)
- Rowan M Thomson
- Carleton Laboratory for Radiotherapy Physics, Physics Department, Carleton University, Ottawa, ON, K1S 5B6, Canada
| | - Keith M Furutani
- Department of Radiation Oncology, Mayo Clinic, Rochester, MN, 55905, USA
| | - Theodor W Kaulich
- Department of Medical Physics, University of Tübingen, 72074, Tübingen, Germany
| | - Firas Mourtada
- Department of Radiation Oncology, Christiana Care Hospital, Newark, DE, 19713, USA
| | - Mark J Rivard
- Department of Radiation Oncology, Warren Alpert Medical School of Brown University, Providence, RI, 02903, USA
| | | | | | - Christopher S Melhus
- Department of Radiation Oncology, Tufts University School of Medicine, Boston, MA, 02111, USA
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Mathis T, Espensen CA, Caujolle J, Herault J, Fog LS, Maschi C, Kodjikian L, Baillif S, Kiilgaard JF, Thariat J. Ultra-widefield fundus photography for radiation therapy planning of ocular tumours. Acta Ophthalmol 2020; 98:e191-e196. [PMID: 31518055 DOI: 10.1111/aos.14250] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Accepted: 08/26/2019] [Indexed: 01/05/2023]
Abstract
PURPOSE The use of planar ultra-widefield fundus photography (UWF) may result in distortions and inaccurate measurement. The aim of the study was to evaluate the accuracy of UWF instead of the standard narrow field (SF) for the treatment planning phase of ocular tumours. METHODS Distortions between conformal SF and UWF were assessed in 43 patients with choroidal melanoma treated with either proton therapy or brachytherapy. imagej software was used to measure distortion. RESULTS The median interquartile range ([IQR]) distortion for all cases was 3.7% [1.7-10.8]. For cases with tumours within 6 mm of the optic disc, distortions appeared clinically nonsignificant. For peripheral and/or large tumours, significantly larger distortions were observed on UWF (median 4.4% [2.7-22.6] for tumours ≥6 mm from the optic disc versus 3.3% [1.6-9.9] for those <6 mm, p = 0.04). Images can be subdivided into three groups: minimal distortion (79.1% of eyes), similar level of major distortion for both measured distances (11.6%) and distortion with unequal level of distortion between the measured distances (9.3%). CONCLUSION Distortions with UWF appeared minimal in posterior regions of the fundus and increased with the distance from the posterior pole. UWF could therefore be used for treatment planning of ocular tumours as the planned radiation dose to the macula and optic disc are not impacted.
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Affiliation(s)
- Thibaud Mathis
- Department of Ophthalmology Croix‐Rousse University Hospital Hospices Civils de Lyon Lyon France
- UMR‐CNRS 5510 Matéis Villeurbane France
| | - Charlotte A. Espensen
- Department of Ophthalmology Rigshospitalet Copenhagen Denmark
- Department of Oncology Section of Radiotherapy Rigshospitalet Copenhagen Denmark
| | | | - Joel Herault
- Department of Radiation Oncology Centre Antoine‐Lacassagne Nice France
| | - Lotte S. Fog
- Department of Ophthalmology Rigshospitalet Copenhagen Denmark
| | - Celia Maschi
- Department of Ophthalmology Pasteur II University Hospital Nice France
| | - Laurent Kodjikian
- Department of Ophthalmology Croix‐Rousse University Hospital Hospices Civils de Lyon Lyon France
- UMR‐CNRS 5510 Matéis Villeurbane France
| | - Stephanie Baillif
- Department of Ophthalmology Pasteur II University Hospital Nice France
| | | | - Juliette Thariat
- Department of Radiation Oncology Centre Francois Baclesse/ARCHADE‐ Normandie Univeristy Caen France
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Filì M, Trocme E, Bergman L, See TRO, André H, Bartuma K, Girnita L, All-Eriksson C, Seregard S, Stålhammar G. Ruthenium-106 versus iodine-125 plaque brachytherapy of 571 choroidal melanomas with a thickness of ≥5.5 mm. Br J Ophthalmol 2019; 104:26-32. [DOI: 10.1136/bjophthalmol-2018-313419] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 02/08/2019] [Accepted: 03/05/2019] [Indexed: 02/03/2023]
Abstract
BackgroundEpiscleral brachytherapy is the most common eye-preserving treatment for medium-sized choroidal melanomas. γ-emitting iodine-125 (125I) and β-emitting ruthenium-106 (106Ru) are widely used. The latter is however generally reserved for thinner tumours (<6 mm). In this study, we compare ocular and patient survival in thicker tumours treated with the respective radioisotope.MethodsAll patients with ≥5.5 mm thick choroidal melanomas who were treated with plaque brachytherapy at a single institution between 1 November 1979 and 31 December 2015 were included (n=571). Size-controlled Cox regression HRs for postbrachytherapy enucleation, repeated brachytherapy and melanoma-related mortality were calculated, as well as Kaplan-Meier disease-specific survival and relative 10-year survival in matched subgroups.Results317 patients were treated with 106Ru and 254 with 125I. The rate of repeated brachytherapy was significantly higher among patients treated with 106Ru (8%) than with 125I (1%, p<0.001). Size-controlled Cox regression HRs for postbrachytherapy enucleation (125I vs 106Ru 0.7, p=0.083) and melanoma-related mortality were not significant (125I vs 106Ru 1.1, p=0.63). Similarly, Kaplan-Meier disease-specific and relative 10-year survival was comparable in matched groups of 5.5–7.4 mm (relative survival 106Ru 59%, 125I 56%) and ≥7.5 mm thick tumours (relative survival 106Ru 46%, 125I 44%).ConclusionsRates of repeated brachytherapy were significantly higher among patients treated with 106Ru versus 125I for thick choroidal melanomas. There were, however, no significant differences in rates of enucleation or patient survival.
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Hansen JB, Culberson WS, DeWerd LA. A convex windowless extrapolation chamber to measure surface dose rate from 106 Ru/ 106 Rh episcleral plaques. Med Phys 2019; 46:2430-2443. [PMID: 30873611 DOI: 10.1002/mp.13488] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 02/19/2019] [Accepted: 02/28/2019] [Indexed: 11/08/2022] Open
Abstract
PURPOSE A convex windowless extrapolation chamber was developed as a primary measurement device to determine surface dose rate from curved 106 Ru/106 Rh episcleral plaques. METHODS A convex extrapolation chamber without an entrance window was constructed for this work, and surface dose rate measurements were performed with two curved CCB-type 106 Ru/106 Rh plaques (S/N 2545 and 2596) manufactured by Eckert & Ziegler BEBIG. FARO ® Gage measurements were performed to verify the radius of curvature for the convex electrode and the concave plaque surface. Furthermore, the collecting electrode area was verified through capacitance measurements. Chamber correction factors for divergence and backscatter were generated using the EGSnrc cavity user code. For each source, surface dose rate was measured with the convex extrapolation chamber and compared with on-contact measurements made with curved un-laminated EBT3 film strips. A Monte Carlo correction was generated for radiochromic film measurements to account for volume averaging within the active layer and effects of phantom scatter. Additionally, extrapolation chamber results for each plaque were compared with scintillation detector measurements performed by the manufacturer. For the second source (S/N 2596), a comparison was also made with the Monte Carlo-corrected surface dose rate measured at the National Physical Laboratory (NPL) using cylindrical alanine pellets. Finally, source measurements were performed using conventional ionization chambers (Exradin A26, A1SL, and A20) within a custom fixture to investigate the transfer of extrapolation chamber surface dose rate to clinics. RESULTS For the first 106 Ru/106 Rh plaque (S/N 2545), average surface dose rate from the convex windowless extrapolation chamber was found to be 1.5% higher than the corresponding value from curved un-laminated EBT3 film measurements and 5.6% lower than the manufacturer value. For the second source (S/N 2596), the extrapolation chamber surface dose rate was 2.5% higher than the un-laminated EBT3 film result, 4.5% lower than the manufacturer value, and 3.9% higher compared to corrected alanine measurements made at NPL. Total uncertainty in the extrapolation chamber measurement was estimated to be approximately ± 7.0% (k = 2). For the plaque measurements made using conventional ionization chambers with a custom fixture, surface dose rate from the transfer technique was found to agree within 3.8% with the expected convex extrapolation chamber result for S/N 2596. CONCLUSIONS A convex windowless extrapolation chamber was developed as a primary measurement device for 106 Ru/106 Rh plaques. Through comparison with the extrapolation chamber, the accuracy of surface dose rate measurements from current dosimetry techniques was assessed and agreement was seen within 5.6%. Finally, it was found that conventional ionization chambers could be calibrated with a reference 106 Ru/106 Rh plaque in order to transfer the extrapolation chamber result for surface dose rate to clinics.
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Affiliation(s)
- Jon B Hansen
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Wesley S Culberson
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Larry A DeWerd
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53705, USA
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Retina dose as a predictor for visual acuity loss in 106 Ru eye plaque brachytherapy of uveal melanomas. Radiother Oncol 2018; 127:379-384. [DOI: 10.1016/j.radonc.2017.11.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 09/22/2017] [Accepted: 11/20/2017] [Indexed: 12/20/2022]
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Trichter S, Soares CG, Zaider M, DeWyngaert JK, DeWerd LA, Kleiman NJ. 15 years of
106
Ru eye plaque dosimetry at Memorial Sloan-Kettering Cancer Center and Weill Cornell Medical Center using radiochromic film in a Solid Water phantom. Biomed Phys Eng Express 2018. [DOI: 10.1088/2057-1976/aab674] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Hermida-López M, Brualla L. Absorbed dose distributions from ophthalmic 106 Ru/ 106 Rh plaques measured in water with radiochromic film. Med Phys 2018; 45:1699-1707. [PMID: 29399810 DOI: 10.1002/mp.12777] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 12/19/2017] [Accepted: 01/06/2018] [Indexed: 11/08/2022] Open
Abstract
PURPOSE Brachytherapy with 106 Ru/106 Rh plaques offers good outcomes for small-to-medium choroidal melanomas and retinoblastomas. The dose measurement of the plaques is challenging, due to the small range of the emitted beta particles and steep dose gradients involved. The scarce publications on film dosimetry of 106 Ru/106 Rh plaques used solid phantoms. This work aims to develop a practical method for measuring the absorbed dose distribution in water produced by 106 Ru/106 Rh plaques using EBT3 radiochromic film. METHODS Experimental setups were developed to determine the dose distribution at a plane perpendicular to the symmetry axis of the plaque and at a plane containing the symmetry axis. One CCA and two CCX plaques were studied. The dose maps were obtained with the FilmQA Pro 2015 software, using the triple-channel dosimetry method. The measured dose distributions were compared to published Monte Carlo simulation and experimental data. RESULTS A good agreement was found between measurements and simulations, improving upon published data. Measured reference dose rates agreed within the experimental uncertainty with data obtained by the manufacturer using a scintillation detector, with typical differences below 5%. The attained experimental uncertainty was 4.1% (k = 1) for the perpendicular setup, and 7.9% (k = 1) for the parallel setup. These values are similar or smaller than those obtained by the manufacturer and other authors, without the need of solid phantoms that are not available to most users. CONCLUSIONS The proposed method may be useful to the users to perform quality assurance preclinical tests of 106 Ru/106 Rh plaques.
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Affiliation(s)
- Marcelino Hermida-López
- NCTeam, Strahlenklinik, Universitätsklinikum Essen, Essen, Germany.,Servei de Física i Protecció Radiològica, Hospital Universitari Vall d'Hebron, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Lorenzo Brualla
- NCTeam, Strahlenklinik, Universitätsklinikum Essen, Essen, Germany
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Hansen JB, Culberson WS, DeWerd LA. Windowless extrapolation chamber measurement of surface dose rate from a 90 Sr/ 90 Y ophthalmic applicator. RADIAT MEAS 2018. [DOI: 10.1016/j.radmeas.2017.11.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Hermida-López M, Brualla L. Technical Note: Monte Carlo study of106Ru/106Rh ophthalmic plaques including the106Rh gamma spectrum. Med Phys 2017; 44:2581-2585. [DOI: 10.1002/mp.12248] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Revised: 02/27/2017] [Accepted: 03/21/2017] [Indexed: 11/07/2022] Open
Affiliation(s)
- Marcelino Hermida-López
- NCTeam, Strahlenklinik; Universitätsklinikum Essen; Hufelandstraße 55 D-45122 Essen Germany
- Servei de Física i Protecció Radiològica; Hospital Universitari Vall d'Hebron, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona Pg. Vall d’Hebron; 119-129 08035 Barcelona Spain
| | - Lorenzo Brualla
- NCTeam, Strahlenklinik; Universitätsklinikum Essen; Hufelandstraße 55 D-45122 Essen Germany
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Heilemann G, Fetty L, Dulovits M, Blaickner M, Nesvacil N, Georg D, Dunavoelgyi R. Treatment plan optimization and robustness of 106 Ru eye plaque brachytherapy using a novel software tool. Radiother Oncol 2017; 123:119-124. [DOI: 10.1016/j.radonc.2017.01.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 12/13/2016] [Accepted: 01/11/2017] [Indexed: 02/03/2023]
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Ruthenium-106 brachytherapy for thick uveal melanoma: reappraisal of apex and base dose radiation and dose rate. J Contemp Brachytherapy 2016; 8:66-73. [PMID: 26985199 PMCID: PMC4793070 DOI: 10.5114/jcb.2016.57818] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 01/20/2016] [Indexed: 11/17/2022] Open
Abstract
Purpose To evaluate the outcomes of ruthenium-106 (106Ru) brachytherapy in terms of radiation parameters in patients with thick uveal melanomas. Material and methods Medical records of 51 patients with thick (thickness ≥ 7 mm and < 11 mm) uveal melanoma treated with 106Ru brachytherapy during a ten-year period were reviewed. Radiation parameters, tumor regression, best corrected visual acuity (BCVA), and treatment-related complications were assessed. Results Fifty one eyes of 51 consecutive patients including 25 men and 26 women with a mean age of 50.5 ± 15.2 years were enrolled. Patients were followed for 36.1 ± 26.5 months (mean ± SD). Mean radiation dose to tumor apex and to sclera were 71 (± 19.2) Gy and 1269 (± 168.2) Gy. Radiation dose rates to tumor apex and to sclera were 0.37 (± 0.14) Gy/h and 6.44 (± 1.50) Gy/h. Globe preservation was achieved in 82.4%. Preoperative mean tumor thickness of 8.1 (± 0.9) mm decreased to 4.5 (± 1.6) mm, 3.4 (± 1.4) mm, and 3.0 (± 1.46) mm at 12, 24, and 48 months after brachytherapy (p = 0.03). Four eyes that did not show regression after 6 months of brachytherapy were enucleated. Secondary enucleation was performed in 5 eyes because of tumor recurrence or neovascular glaucoma. Tumor recurrence was evident in 6 (11.8%) patients. Mean Log MAR (magnification requirement) visual acuity declined from 0.75 (± 0.63) to 0.94 (± 0.5) (p = 0.04). Best corrected visual acuity of 20/200 or worse was recorded in 37% of the patients at the time of diagnosis and 61.7% of the patients at last exam (p = 0.04). Non-proliferative and proliferative radiation-induced retinopathy was observed in 20 and 7 eyes. Conclusions Thick uveal melanomas are amenable to 106Ru brachytherapy with less than recommended apex radiation dose and dose rates.
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