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Semeniuk O, Yu E, Rivard MJ. Current and Emerging Radiotherapy Options for Uveal Melanoma. Cancers (Basel) 2024; 16:1074. [PMID: 38473430 DOI: 10.3390/cancers16051074] [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: 01/21/2024] [Revised: 03/01/2024] [Accepted: 03/04/2024] [Indexed: 03/14/2024] Open
Abstract
What treatment options are there for patients having uveal melanoma? A randomized, prospective, multi-institutional clinical trial (COMS) showed no difference in survival between brachytherapy and enucleation for medium-sized lesions. With the obvious benefit of retaining the eye, brachytherapy has flourished and many different approaches have been developed such as low-dose-rate sources using alternate low-energy photon-emitting radionuclides, different plaque designs and seed-loading techniques, high-dose-rate brachytherapy sources and applicators, and low- and high-dose-rate beta-emitting sources and applicators. There also have been developments of other radiation modalities like external-beam radiotherapy using linear accelerators with high-energy photons, particle accelerators for protons, and gamma stereotactic radiosurgery. This article examines the dosimetric properties, targeting capabilities, and outcomes of these approaches. The several modalities examined herein have differing attributes and it may be that no single approach would be considered optimal for all patients and all lesion characteristics.
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Affiliation(s)
- Oleksii Semeniuk
- Department of Radiation Oncology, Warren Alpert Medical School, Brown University and Rhode Island Hospital, Providence, RI 02903, USA
| | - Esther Yu
- Department of Radiation Oncology, Warren Alpert Medical School, Brown University and Rhode Island Hospital, Providence, RI 02903, USA
| | - Mark J Rivard
- Department of Radiation Oncology, Warren Alpert Medical School, Brown University and Rhode Island Hospital, Providence, RI 02903, USA
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Semeniuk O, Malkov V, Chamberland MJP, Weersink RA. Monte Carlo investigation of dose distribution of uniformly and non-uniformly loaded standard and notched eye plaques. J Appl Clin Med Phys 2023; 24:e14149. [PMID: 37738654 PMCID: PMC10691642 DOI: 10.1002/acm2.14149] [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: 06/08/2023] [Revised: 08/06/2023] [Accepted: 08/16/2023] [Indexed: 09/24/2023] Open
Abstract
To investigate the effect of using non-uniform loading and notched plaques on dose distribution for eye plaques. Using EGSnrc Monte Carlo (MC) simulations, we investigate eye plaque dose distributions in water and in an anatomically representative eye phantom. Simulations were performed in accordance with TG43 formalism and compared against full MC simulations which account for inter-seed and inhomogeneity effects. For standard plaque configurations, uniformly and non-uniformly loaded plaque dose distributions in water showed virtually no difference between each other. For standard plaque, the MC calculated dose distribution in planes parallel to the plaque is narrower than the TG43 calculation due to attenuation at the periphery of the plaque by the modulay. MC calculated the dose behind the plaque is fully attenuated. Similar results were found for the notched plaque, with asymmetric attenuation along the plane of the notch. Cumulative dose volume histograms showed significant reductions in the calculated MC doses for both tumor and eye structures, compared to TG43 calculations. The effect was most pronounced for the notch plaque where the MC dose to the optic nerve was greatly attenuated by the modulay surrounding the optic nerve compared to the TG43. Thus, a reduction of optic nerve D95% from 14 to 0.2 Gy was observed, when comparing the TG43 calculation to the MC result. The tumor D95% reduced from 89.2 to 79.95 Gy for TG43 and MC calculations, respectively. TG43 calculations overestimate the absolute dose and the lateral dose distribution of both standard and notched eye plaques, leading to the dose overestimation for the target and organs at risk. The dose matching along the central axis for the non-uniformly loaded plaques to that of uniformly loaded ones was found to be sufficient for providing comparable coverage and can be clinically used in eye-cancer-busy centers.
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Affiliation(s)
- Oleksii Semeniuk
- Radiation Medicine ProgramPrincess Margaret Cancer CenterTorontoCanada
- Present address:
Department of Radiation OncologyRhode Island HospitalUSA
| | - Victor Malkov
- Department of Radiation OncologyUniversity of TorontoTorontoCanada
| | | | - Robert A. Weersink
- Department of Radiation OncologyUniversity of TorontoTorontoCanada
- Department of Medical BiophysicsUniversity of TorontoTorontoCanada
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Finger PT, Stewart R, Rivard MJ, Beers RJ, Kamen J, Lama S, Chin KJ, Mohney K, Welles TS, Sauerwein WAG, Rosenzweig K. First clinical implementation of Yttrium-90 Disc Brachytherapy after FDA clearance. Brachytherapy 2023; 22:416-427. [PMID: 36948988 DOI: 10.1016/j.brachy.2023.02.004] [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: 11/23/2022] [Revised: 01/04/2023] [Accepted: 02/15/2023] [Indexed: 03/24/2023]
Abstract
PURPOSE Herein, we study if high-dose-rate (HDR) yttrium-90 (90Y) brachytherapy could be utilized by medical physicists, radiation oncologists, and ophthalmic surgeons. METHODS AND MATERIALS Yttrium-90 (90Y) beta-emitting brachytherapy sources received United States Food and Drug Administration clearance for episcleral treatment of ocular tumors and benign growths. Dose calibration traceable to the National Institute of Standards and Technology as well as treatment planning and target delineation methods were established. Single-use systems included a 90Y-disc affixed within specialized, multifunction, handheld applicator. Low-dose-rate to high-dose-rate prescription conversions and depth-dose determinations were performed. Radiation safety was evaluated based on live exposure rates during assembly and surgeries. Clinical data for radiation safety, treatment tolerability, and local control was collected. RESULTS Practice parameters for the medical physicist, radiation oncologist, and ophthalmic surgeon were defined. Device sterilizations, calibrations, assemblies, surgical methods, and disposals were reproducible and effective. Treated tumors included iris melanoma, iridociliary melanoma, choroidal melanoma, and a locally invasive squamous carcinoma. Mean calculated 90Y disc activity was 14.33 mCi (range 8.8-16.6), prescription dose 27.8 Gy (range 22-30), delivered to depth of 2.3 mm (range 1.6-2.6), at treatment durations of 420 s (7.0 min, range 219 s-773 s). Both insertion and removal were performed during one surgical session. After surgery, each disc-applicator- system was contained for decay in storage. Treatments were well-tolerated. CONCLUSIONS HDR 90Y episcleral brachytherapy devices were created, implementation methods developed, and treatments performed on 6 patients. Treatments were single-surgery, rapid, and well-tolerated with short-term follow up.
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Affiliation(s)
- Paul T Finger
- The Department of Ocular Tumor, Orbital Disease, and Ophthalmic Radiation Therapy, The New York Eye Cancer Center, New York, NY; The Departments of Ophthalmology, Radiation Oncology, and Radiation Safety, New York Eye and Ear Infirmary of Mount Sinai and Icahn School of Medicine at Mount Sinai, New York, NY; Scientific Advisory Board and Employees of Liberty Vision Corporation, Portsmouth, NH.
| | - Robert Stewart
- The Departments of Ophthalmology, Radiation Oncology, and Radiation Safety, New York Eye and Ear Infirmary of Mount Sinai and Icahn School of Medicine at Mount Sinai, New York, NY
| | - Mark J Rivard
- Scientific Advisory Board and Employees of Liberty Vision Corporation, Portsmouth, NH
| | - Raymond J Beers
- The Departments of Ophthalmology, Radiation Oncology, and Radiation Safety, New York Eye and Ear Infirmary of Mount Sinai and Icahn School of Medicine at Mount Sinai, New York, NY
| | - Jacob Kamen
- The Departments of Ophthalmology, Radiation Oncology, and Radiation Safety, New York Eye and Ear Infirmary of Mount Sinai and Icahn School of Medicine at Mount Sinai, New York, NY
| | - Shyam Lama
- The Departments of Ophthalmology, Radiation Oncology, and Radiation Safety, New York Eye and Ear Infirmary of Mount Sinai and Icahn School of Medicine at Mount Sinai, New York, NY
| | - Kimberly J Chin
- The Department of Ocular Tumor, Orbital Disease, and Ophthalmic Radiation Therapy, The New York Eye Cancer Center, New York, NY; Scientific Advisory Board and Employees of Liberty Vision Corporation, Portsmouth, NH
| | - Kyle Mohney
- Scientific Advisory Board and Employees of Liberty Vision Corporation, Portsmouth, NH
| | - Toby S Welles
- Scientific Advisory Board and Employees of Liberty Vision Corporation, Portsmouth, NH
| | | | - Kenneth Rosenzweig
- The Departments of Ophthalmology, Radiation Oncology, and Radiation Safety, New York Eye and Ear Infirmary of Mount Sinai and Icahn School of Medicine at Mount Sinai, New York, NY
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Taherparvar P, Fardi Z. Comparison between dose distribution from 103Pd, 131Cs, and 125I plaques in a real human eye model with different tumor size. Appl Radiat Isot 2022; 182:110146. [DOI: 10.1016/j.apradiso.2022.110146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 02/05/2022] [Accepted: 02/07/2022] [Indexed: 11/17/2022]
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Zhang YS, Hu TC, Ye YC, Han JH, Li XJ, Zhang YH, Chen WZ, Chai HY, Pan X, Wang X, Yang YL. Carbon ion radiotherapy for synchronous choroidal melanoma and lung cancer: A case report. World J Clin Cases 2021; 9:10374-10381. [PMID: 34904113 PMCID: PMC8638059 DOI: 10.12998/wjcc.v9.i33.10374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 09/08/2021] [Accepted: 09/30/2021] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Despite being the most common intraocular malignancy among adults, choroidal melanoma is a rare cancer type, even more so when accompanied by lung cancer. We report a patient with synchronous choroid melanoma and lung cancer treated with carbon ion radiotherapy (CIRT). CASE SUMMARY A 41-year-old woman was transferred to our center with a diagnosis of choroidal melanoma in her right eye. During the examination, we found a right lung tumor that was histologically diagnosed as lung cancer. The patient was treated with CIRT for both malignant neoplasms. The CIRT dose was 70 photon equivalent doses (GyE) in five fractions for the right eye choroidal melanoma and 72 GyE in 16 fractions for the right lung cancer. At 3 mo after CIRT, the choroidal melanoma completely disappeared, as did the right lung cancer 7 mo after; the patient was in complete remission. CONCLUSION CIRT may be an effective treatment for double primary lung cancer and choroid melanoma.
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Affiliation(s)
- Yan-Shan Zhang
- Heavy Ion Center, Wuwei Cancer Hospital, Wuwei 733000, Gansu Province, China
| | - Ting-Chao Hu
- Heavy Ion Center, Wuwei Cancer Hospital, Wuwei 733000, Gansu Province, China
| | - Yan-Cheng Ye
- Heavy Ion Center, Wuwei Cancer Hospital, Wuwei 733000, Gansu Province, China
| | - Jin-Hua Han
- Department of Ophthalmology, Wuwei Cancer Hospital, Wuwei 733000, Gansu Province, China
| | - Xiao-Jun Li
- Heavy Ion Center, Wuwei Cancer Hospital, Wuwei 733000, Gansu Province, China
| | - Yi-He Zhang
- Heavy Ion Center, Wuwei Cancer Hospital, Wuwei 733000, Gansu Province, China
| | - Wei-Zuo Chen
- Heavy Ion Center, Wuwei Cancer Hospital, Wuwei 733000, Gansu Province, China
| | - Hong-Yu Chai
- Heavy Ion Center, Wuwei Cancer Hospital, Wuwei 733000, Gansu Province, China
| | - Xin Pan
- Heavy Ion Center, Wuwei Cancer Hospital, Wuwei 733000, Gansu Province, China
| | - Xin Wang
- Heavy Ion Center, Wuwei Cancer Hospital, Wuwei 733000, Gansu Province, China
| | - Yu-Ling Yang
- Heavy Ion Center, Wuwei Cancer Hospital, Wuwei 733000, Gansu Province, China
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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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Thornton S, Coupland SE, Heimann H, Hussain R, Groenewald C, Kacperek A, Damato B, Taktak A, Eleuteri A, Kalirai H. Effects of plaque brachytherapy and proton beam radiotherapy on prognostic testing: a comparison of uveal melanoma genotyped by microsatellite analysis. Br J Ophthalmol 2020; 104:1462-1466. [DOI: 10.1136/bjophthalmol-2019-315363] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 01/13/2020] [Accepted: 01/17/2020] [Indexed: 01/17/2023]
Abstract
Background/aimsProton beam radiotherapy and plaque brachytherapy are commonly applied in primary uveal melanoma (UM); however, their effect on chromosome 3 classification of UM by microsatellite analysis (MSA) for prognostication purposes is unknown, where the tumour is sampled post-irradiation. This study examined the prognostic accuracy of genotyping UM biopsied before or after administration of radiotherapy, by MSA.Methods407 UM patients treated at the Liverpool Ocular Oncology Centre between January 2011 to December 2017, were genotyped for chromosome 3 by MSA; 172 and 176 primary UM were sampled prior to and post irradiation, respectively.ResultsGenotyping by MSA was successful in 396/407 (97%) of UM samples (196 males, 211 females; median age of 61 years (range 12 to 93) at primary treatment). There was no demonstrable association between a failure of MSA to produce a chromosome 3 classification and whether radiation was performed pre-biopsy or post-biopsy with an OR of 0.96 (95% CI 0.30 to 3.00, p=0.94). There was no evidence of association (measured as HRs) between risk of metastatic death and sampling of a primary UM before administration of radiotherapy (HR 1.1 (0.49 to 2.50), p=0.81). Monosomy 3 (HR 12.0 (4.1 to 35.0), p<0.001) was significantly associated with increased risk of metastatic death.Conclusions and relevanceThis study revealed that successful genotyping of UM using MSA is possible, irrespective of irradiation status. Moreover, we found no evidence that biopsy prior to radiotherapy increases metastatic mortality.
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Binder C, Mruthyunjaya P, Schefler AC, Seider MI, Crilly R, Hung A, Meltsner S, Mowery Y, Kirsch DG, Teh BS, Jennelle RLS, Studenski MT, Liu W, Lee C, Hayman JA, Kastner B, Hadsell M, Skalet AH. Practice Patterns for the Treatment of Uveal Melanoma with Iodine-125 Plaque Brachytherapy: Ocular Oncology Study Consortium Report 5. Ocul Oncol Pathol 2019; 6:210-218. [PMID: 32509767 DOI: 10.1159/000504312] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 08/06/2019] [Indexed: 11/19/2022] Open
Abstract
Background Treatment planning for I-125 plaque therapy for uveal melanoma has advanced significantly since the Collaborative Ocular Melanoma Study trial, with more widely available image-guided planning and improved dosimetry. Objective We evaluated real-world practice patterns for I-125 plaque brachytherapy in the United States by studying practice patterns at centers that comprise the Ocular Oncology Study Consortium (OOSC). Methods The OOSC database and responses to a treatment practice survey were evaluated. The database contains treatment information from 9 institutions. Patients included in the database were treated between 2010 and 2014. The survey was conducted in 2018 and current treatment planning methods and prescriptions were queried. Results Examination of the OOSC database revealed that average doses to critical structures were highly consistent, with the exception of one institution. Survey responses indicated that most centers followed published guidelines regarding dose and prescription point. Dose rate ranged from 51 to 118 cGy/h. As of 2018, most institutions use pre-loaded plaques and fundus photographs and/or computed tomography or magnetic resonance imaging in planning. Conclusions While there were differences in dosimetric practices, overall agreement in plaque brachytherapy practices was high among OOSC institutions. Clinical margins and planning systems were similar among institutions, while prescription dose, dose rates, and dosimetry varied.
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Affiliation(s)
- Christina Binder
- Department of Radiation Medicine, Oregon Health and Science University, Portland, Oregon, USA
| | - Prithvi Mruthyunjaya
- Department of Ophthalmology, Byers Eye Institute, Stanford University, Palo Alto, California, USA.,Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, USA
| | | | - Michael I Seider
- The Permanente Medical Group, San Francisco, California, USA.,Department of Ophthalmology, University of California, San Francisco, California, USA
| | - Richard Crilly
- Department of Radiation Medicine, Oregon Health and Science University, Portland, Oregon, USA
| | - Arthur Hung
- Department of Radiation Medicine, Oregon Health and Science University, Portland, Oregon, USA
| | - Sheridan Meltsner
- Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina, USA
| | - Yvonne Mowery
- Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina, USA
| | - David G Kirsch
- Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina, USA
| | - Bin S Teh
- Department of Radiation Oncology, Houston Methodist Cancer Center, Houston, Texas, USA
| | - Richard L S Jennelle
- Department of Radiation Oncology, University of Southern California Medical Center, Los Angeles, California, USA
| | - Matthew T Studenski
- Department of Radiation Oncology/Sylvester Comprehensive Cancer Center, University of Miami, Miami, Florida, USA
| | - Wu Liu
- Department of Radiation Oncology, Stanford University, Palo Alto, California, USA.,Department of Therapeutic Radiology, Yale University and Yale-New haven Hospital, New Haven, Connecticut, USA
| | - Choonik Lee
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan, USA
| | - James A Hayman
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan, USA
| | - Brian Kastner
- Radiation Oncology Centers, PC, Spectrum Health, Grand Rapids, Michigan, USA
| | - Michael Hadsell
- Department of Radiation Oncology, Porter Adventist, Centura Health, Denver, Colorado, USA
| | - Alison H Skalet
- Department of Radiation Medicine, Oregon Health and Science University, Portland, Oregon, USA.,Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, USA
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Treatment planning considerations for 125I eye plaque brachytherapy. J Contemp Brachytherapy 2019; 11:280-284. [PMID: 31435435 PMCID: PMC6701382 DOI: 10.5114/jcb.2019.86370] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Accepted: 04/10/2019] [Indexed: 12/21/2022] Open
Abstract
Effective cancer brachytherapy requires a treatment plan that delivers high-dose to tumor, while minimizing the dose to critical normal tissues. Therefore, an accurate knowledge of the sources and magnitude of the techniques is essential for producing robust and well optimized-plans. The purpose of this technical note is to establish general procedures and strategies for optimization and customization of the plaques loaded with radioactive seeds, particularly focusing on the definition of useful tactics to limit high doses to organs at risk and adapt the treatment time to the necessity of institution.
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WITHDRAWN: Improvement of dose distribution in ocular brachytherapy with 125I seeds-20mm COMS plaque followed to loading of choroidal tumor by gold nanoparticles. Radiat Phys Chem Oxf Engl 1993 2018. [DOI: 10.1016/j.radphyschem.2018.09.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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De Caluwé A, Termote K, Van Gestel D, Van Limbergen E. Dose-response in choroidal melanoma. Radiother Oncol 2018; 127:374-378. [PMID: 29680322 DOI: 10.1016/j.radonc.2018.03.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 03/13/2018] [Accepted: 03/15/2018] [Indexed: 01/21/2023]
Abstract
PURPOSE In choroidal melanoma the radiation threshold dose for local control remains largely unknown. The present study examined a group of patients that received a wide range of minimum tumor dose in order to investigate a dose-response relationship. A literature review is performed to compare our results with available evidence in brachytherapy and charged particle external beam radiotherapy. MATERIALS AND METHODS A retrospective study was conducted on all choroidal melanomas treated with Strontium-90 (Sr-90) at the University Hospital of Leuven between 1983 and 2012. Local failure was defined as primary endpoint and was estimated according to the competing risk method. RESULTS In 135 patients, the minimum tumor dose (Dmin) ranged from 0 Gy to 287 Gy (median: 27.6 Gy). Multivariable analysis revealed Dmin ≥ 65 Gy (p = 0.04; HR = 0.09) and tumor distant from the optic disc (p < 0.001, HR = 0.09) to be independent variables favoring local control. The scleral dose, the tumor diameter and tumor height did not significantly affect local failure in multivariate analysis. CONCLUSION This is the first study to examine a group of patients treated with a Dmin ranging from 0 Gy to >250 Gy. Treatment with a Dmin of 65 Gy is necessary to achieve durable tumor response. The dose-response data provided by our study could be used for the design of future trials examining the ideal dose for the treatment of choroidal melanoma with brachytherapy or charged particle external beam radiotherapy.
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Affiliation(s)
- Alex De Caluwé
- Department of Radiation Oncology, Institut Jules Bordet - Université Libre de Bruxelles (ULB), Brussels, Belgium.
| | - Karolien Termote
- Department of Ophthalmology, University Hospital of Brussels (UZ Brussel), Brussels, Belgium
| | - Dirk Van Gestel
- Department of Radiation Oncology, Institut Jules Bordet - Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Erik Van Limbergen
- Department of Radiation Oncology, University Hospital of Leuven (UZ Leuven), Leuven, Belgium
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Plaque brachytherapy for posterior uveal melanoma in 2018: improved techniques and expanded indications. Curr Opin Ophthalmol 2018. [PMID: 29538180 DOI: 10.1097/icu.0000000000000468] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PURPOSE OF REVIEW Plaque brachytherapy remains the dominant globe-sparing therapy of uveal melanoma. This report highlights recent advances, which have expanded plaque brachytherapy's uses as well as improved the surgical technique. RECENT FINDINGS Plaque brachytherapy is effective for tumors that may previously have demanded enucleation. Plaque brachytherapy can be used to control large melanomas as well as melanomas touching the optic nerve. Improvements in planning and design have made plaque therapy simpler for the surgical operator and may reduce collateral radiation damage to normal ocular structures. The COMS implies a required dose of 85 Gy to the tumor apex for treatment of uveal melanoma. However, multiple reports indicate that lower doses may be equally effective for tumor control while reducing radiation dose to uninvolved structures. Vitreoretinal surgeons can be called upon safely to treat long-term side effects of radiation or tumor death such as intractable vitreous hemorrhage or inflammation. Further, vitreoretinal surgeons have employed tumor endoresection as primary local tumor control or in combination with plaque brachytherapy. SUMMARY Plaque brachytherapy for uveal melanoma remains highly effective for local tumor control and prevention of metastasis. Indications for plaque brachytherapy have expanded, and the technique has improved.
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Johnson JE, Deufel CL, Furutani KM. Investigating the dosimetric impact of seed location uncertainties in Collaborative Ocular Melanoma Study-based eye plaques. Brachytherapy 2016; 15:661-8. [PMID: 27475484 DOI: 10.1016/j.brachy.2016.06.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 06/01/2016] [Accepted: 06/05/2016] [Indexed: 02/08/2023]
Abstract
PURPOSE To quantify the dosimetric effects of random and systematic seed position uncertainties in Collaborative Ocular Melanoma Study-based eye plaques. METHODS AND MATERIALS An eye plaque dose calculation routine was created using Task Group 43 formalism. A variety of clinical configurations were simulated, including two seed models: (125)I and (103)Pd, three eye plaque sizes, and eight plaque/eye orientations. Dose was calculated at four ocular anatomic sites and three central axis plaque depths. Random seed positional uncertainty was modeled by adding Gaussian random displacements, in one of three seed-motion degrees of freedom, to each seed's nominal coordinate. Distributions of dosimetric outcomes were obtained and fitted after 10(6) randomizations. Similar analysis was performed for deterministic, systematic shifts of the plaque along the eye surface and radially from the globe center. RESULTS Random seed placement uncertainties of 0.2-mm root mean square (RMS) (amplitude) produce dose changes that are typically <4% for each degree of freedom (95% confidence interval). Systematic seed placement uncertainties are generally greater than random uncertainty 95% confidence intervals (factor of 0.72-2.15), with the relative magnitudes depending on plaque size and location of interest. Eye plaque dosimetry is most sensitive to seed movement toward the center of the eye. Dosimetric uncertainty also increases with increasing dose gradients, which are typically greatest near the inner sclera, with smaller plaques, and with lower energy radionuclides (e.g., (103)Pd). CONCLUSIONS Dosimetric uncertainties due to the random seed positional displacements anticipated in the clinic are expected to be <4% for each degree of freedom in most circumstances.
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Ocular Brachytherapy. Brachytherapy 2016. [DOI: 10.1007/978-3-319-26791-3_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Li H, Rychahou PG, Cui Z, Pi F, Evers BM, Shu D, Guo P, Luo W. RNA Nanoparticles Derived from Three-Way Junction of Phi29 Motor pRNA Are Resistant to I-125 and Cs-131 Radiation. Nucleic Acid Ther 2015; 25:188-97. [PMID: 26017686 DOI: 10.1089/nat.2014.0525] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Radiation reagents that specifically target tumors are in high demand for the treatment of cancer. The emerging field of RNA nanotechnology might provide new opportunities for targeted radiation therapy. This study investigates whether chemically modified RNA nanoparticles derived from the packaging RNA (pRNA) three-way junction (3WJ) of phi29 DNA-packaging motor are resistant to potent I-125 and Cs-131 radiation, which is a prerequisite for utilizing these RNA nanoparticles as carriers for targeted radiation therapy. pRNA 3WJ nanoparticles were constructed and characterized, and the stability of these nanoparticles under I-125 and Cs-131 irradiation with clinically relevant doses was examined. RNA nanoparticles derived from the pRNA 3WJ targeted tumors specifically and they were stable under irradiation of I-125 and Cs-131 with clinically relevant doses ranging from 1 to 90 Gy over a significantly long time up to 20 days, while control plasmid DNA was damaged at 20 Gy or higher.
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Affiliation(s)
- Hui Li
- 1 Nanobiotechnology Center, University of Kentucky , Lexington, Kentucky.,2 Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky , Lexington, Kentucky
| | - Piotr G Rychahou
- 3 Department of Surgery, Markey Cancer Center, University of Kentucky , Lexington, Kentucky
| | - Zheng Cui
- 2 Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky , Lexington, Kentucky
| | - Fengmei Pi
- 1 Nanobiotechnology Center, University of Kentucky , Lexington, Kentucky.,2 Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky , Lexington, Kentucky
| | - B Mark Evers
- 4 Markey Cancer Center, University of Kentucky , Lexington, Kentucky
| | - Dan Shu
- 1 Nanobiotechnology Center, University of Kentucky , Lexington, Kentucky.,2 Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky , Lexington, Kentucky.,4 Markey Cancer Center, University of Kentucky , Lexington, Kentucky
| | - Peixuan Guo
- 1 Nanobiotechnology Center, University of Kentucky , Lexington, Kentucky.,2 Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky , Lexington, Kentucky.,4 Markey Cancer Center, University of Kentucky , Lexington, Kentucky
| | - Wei Luo
- 5 Department of Radiation Medicine, Markey Cancer Center, University of Kentucky , Lexington, Kentucky
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Luo W, Molloy J, Aryal P, Feddock J, Randall M. Determination of prescription dose for Cs-131 permanent implants using the BED formalism including resensitization correction. Med Phys 2014; 41:024101. [PMID: 24506655 DOI: 10.1118/1.4860255] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE The current widely used biological equivalent dose (BED) formalism for permanent implants is based on the linear-quadratic model that includes cell repair and repopulation but not resensitization (redistribution and reoxygenation). The authors propose a BED formalism that includes all the four biological effects (4Rs), and the authors propose how it can be used to calculate appropriate prescription doses for permanent implants with Cs-131. METHODS A resensitization correction was added to the BED calculation for permanent implants to account for 4Rs. Using the same BED, the prescription doses with Au-198, I-125, and Pd-103 were converted to the isoeffective Cs-131 prescription doses. The conversion factor F, ratio of the Cs-131 dose to the equivalent dose with the other reference isotope (Fr: with resensitization, Fn: without resensitization), was thus derived and used for actual prescription. Different values of biological parameters such as α, β, and relative biological effectiveness for different types of tumors were used for the calculation. RESULTS Prescription doses with I-125, Pd-103, and Au-198 ranging from 10 to 160 Gy were converted into prescription doses with Cs-131. The difference in dose conversion factors with (Fr) and without (Fn) resensitization was significant but varied with different isotopes and different types of tumors. The conversion factors also varied with different doses. For I-125, the average values of Fr/Fn were 0.51/0.46, for fast growing tumors, and 0.88/0.77 for slow growing tumors. For Pd-103, the average values of Fr/Fn were 1.25/1.15 for fast growing tumors, and 1.28/1.22 for slow growing tumors. For Au-198, the average values of Fr/Fn were 1.08/1.25 for fast growing tumors, and 1.00/1.06 for slow growing tumors. Using the biological parameters for the HeLa/C4-I cells, the averaged value of Fr was 1.07/1.11 (rounded to 1.1), and the averaged value of Fn was 1.75/1.18. Fr of 1.1 has been applied to gynecological cancer implants with expected acute reactions and outcomes as expected based on extensive experience with permanent implants. The calculation also gave the average Cs-131 dose of 126 Gy converted from the I-125 dose of 144 Gy for prostate implants. CONCLUSIONS Inclusion of an allowance for resensitization led to significant dose corrections for Cs-131 permanent implants, and should be applied to prescription dose calculation. The adjustment of the Cs-131 prescription doses with resensitization correction for gynecological permanent implants was consistent with clinical experience and observations. However, the Cs-131 prescription doses converted from other implant doses can be further adjusted based on new experimental results, clinical observations, and clinical outcomes.
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Affiliation(s)
- Wei Luo
- Department of Radiation Medicine, University of Kentucky, Lexington, Kentucky 40536
| | - Janelle Molloy
- Department of Radiation Medicine, University of Kentucky, Lexington, Kentucky 40536
| | - Prakash Aryal
- Department of Radiation Medicine, University of Kentucky, Lexington, Kentucky 40536
| | - Jonathan Feddock
- Department of Radiation Medicine, University of Kentucky, Lexington, Kentucky 40536
| | - Marcus Randall
- Department of Radiation Medicine, University of Kentucky, Lexington, Kentucky 40536
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Chiu-Tsao ST, Napoli JJ, Davis SD, Hanley J, Rivard MJ. Dosimetry for 131Cs and 125I seeds in solid water phantom using radiochromic EBT film. Appl Radiat Isot 2014; 92:102-14. [PMID: 25038559 DOI: 10.1016/j.apradiso.2014.06.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 06/23/2014] [Indexed: 12/31/2022]
Abstract
PURPOSE To measure the 2D dose distributions with submillimeter resolution for (131)Cs (model CS-1 Rev2) and (125)I (model 6711) seeds in a Solid Water phantom using radiochromic EBT film for radial distances from 0.06cm to 5cm. To determine the TG-43 dosimetry parameters in water by applying Solid Water to liquid water correction factors generated from Monte Carlo simulations. METHODS Each film piece was positioned horizontally above and in close contact with a (131)Cs or (125)I seed oriented horizontally in a machined groove at the center of a Solid Water phantom, one film at a time. A total of 74 and 50 films were exposed to the (131)Cs and (125)I seeds, respectively. Different film sizes were utilized to gather data in different distance ranges. The exposure time varied according to the seed air-kerma strength and film size in order to deliver doses in the range covered by the film calibration curve. Small films were exposed for shorter times to assess the near field, while larger films were exposed for longer times in order to assess the far field. For calibration, films were exposed to either 40kV (M40) or 50kV (M50) x-rays in air at 100.0cm SSD with doses ranging from 0.2Gy to 40Gy. All experimental, calibration and background films were scanned at a 0.02cmpixel resolution using a CCD camera-based microdensitometer with a green light source. Data acquisition and scanner uniformity correction were achieved with Microd3 software. Data analysis was performed using ImageJ, FV, IDL and Excel software packages. 2D dose distributions were based on the calibration curve established for 50kV x-rays. The Solid Water to liquid water medium correction was calculated using the MCNP5 Monte Carlo code. Subsequently, the TG-43 dosimetry parameters in liquid water medium were determined. RESULTS Values for the dose-rate constants using EBT film were 1.069±0.036 and 0.923±0.031cGyU(-1)h(-1) for (131)Cs and (125)I seed, respectively. The corresponding values determined using the Monte Carlo method were 1.053±0.014 and 0.924±0.016cGyU(-1)h(-1) for (131)Cs and (125)I seed, respectively. The radial dose functions obtained with EBT film measurements and Monte Carlo simulations were plotted for radial distances up to 5cm, and agreed within the uncertainty of the two methods. The 2D anisotropy functions obtained with both methods also agreed within their uncertainties. CONCLUSION EBT film dosimetry in a Solid Water phantom is a viable method for measuring (131)Cs (model CS-1 Rev2) and (125)I (model 6711) brachytherapy seed dose distributions with submillimeter resolution. With the Solid Water to liquid water correction factors generated from Monte Carlo simulations, the measured TG-43 dosimetry parameters in liquid water for these two seed models were found to be in good agreement with those in the literature.
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Affiliation(s)
| | - John J Napoli
- John Theurer Cancer Center at Hackensack University Medical Center, Hackensack, NJ 07601, USA
| | - Stephen D Davis
- Medical Physics, McGill University Health Centre, Montreal, QC, Canada H3G 1A4
| | - Joseph Hanley
- Princeton Radiation Oncology Center, Monroe, NJ 08831, USA
| | - Mark J Rivard
- Department of Radiation Oncology, Tufts University School of Medicine, Boston, MA 02111, USA
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Barbosa N, da Rosa L, Menezes A, Reis J, Facure A, Braz D. Assessment of ocular beta radiation dose distribution due to 106Ru/106Rh brachytherapy applicators using MCNPX Monte Carlo code. INTERNATIONAL JOURNAL OF CANCER THERAPY AND ONCOLOGY 2014. [DOI: 10.14319/ijcto.0203.8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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Barbosa N, da Rosa L, Facure A, Braz D. Brachytherapy treatment simulation of strontium-90 and ruthenium-106 plaques on small size posterior uveal melanoma using MCNPX code. Radiat Phys Chem Oxf Engl 1993 2014. [DOI: 10.1016/j.radphyschem.2012.12.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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The American Brachytherapy Society consensus guidelines for plaque brachytherapy of uveal melanoma and retinoblastoma. Brachytherapy 2013; 13:1-14. [PMID: 24373763 DOI: 10.1016/j.brachy.2013.11.008] [Citation(s) in RCA: 222] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Revised: 11/05/2013] [Accepted: 11/21/2013] [Indexed: 02/07/2023]
Abstract
PURPOSE To present the American Brachytherapy Society (ABS) guidelines for plaque brachytherapy of choroidal melanoma and retinoblastoma. METHODS AND MATERIALS An international multicenter Ophthalmic Oncology Task Force (OOTF) was assembled to include 47 radiation oncologists, medical physicists, and ophthalmic oncologists from 10 countries. The ABS-OOTF produced collaborative guidelines, based on their eye cancer-specific clinical experience and knowledge of the literature. This work was reviewed and approved by the ABS Board of Directors as well as within the journal's peer-reivew process. RESULTS The ABS-OOTF reached consensus that ophthalmic plaque radiation therapy is best performed in subspecialty brachytherapy centers. Quality assurance, methods of plaque construction, and dosimetry should be consistent with the 2012 joint guidelines of the American Association of Physicists in Medicine and ABS. Implantation of plaque sources should be performed by subspecialty-trained surgeons. Although there exist select restrictions related to tumor size and location, the ABS-OOTF agreed that most melanomas of the iris, ciliary body, and choroid could be treated with plaque brachytherapy. The ABS-OOTF reached consensus that tumors with gross orbital extension and blind painful eyes and those with no light perception vision are unsuitable for brachytherapy. In contrast, only select retinoblastomas are eligible for plaque brachytherapy. Prescription doses, dose rates, treatment durations, and clinical methods are described. CONCLUSIONS Plaque brachytherapy is an effective eye and vision-sparing method to treat patients with intraocular tumors. Practitioners are encouraged to use ABS-OOTF guidelines to enhance their practice.
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Quantifying the dosimetric influences of radiation coverage and brachytherapy implant placement uncertainty on eye plaque size selection. Brachytherapy 2013; 12:508-20. [DOI: 10.1016/j.brachy.2012.09.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Revised: 09/11/2012] [Accepted: 09/11/2012] [Indexed: 12/13/2022]
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Keeping an eye on the ring: COMS plaque loading optimization for improved dose conformity and homogeneity. J Contemp Brachytherapy 2013; 4:165-75. [PMID: 23346146 PMCID: PMC3551379 DOI: 10.5114/jcb.2012.30683] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Revised: 06/29/2012] [Accepted: 07/19/2012] [Indexed: 12/15/2022] Open
Abstract
PURPOSE To improve tumor dose conformity and homogeneity for COMS plaque brachytherapy by investigating the dosimetric effects of varying component source ring radionuclides and source strengths. MATERIAL AND METHODS The MCNP5 Monte Carlo (MC) radiation transport code was used to simulate plaque heterogeneity-corrected dose distributions for individually-activated source rings of 14, 16 and 18 mm diameter COMS plaques, populated with (103)Pd, (125)I and (131)Cs sources. Ellipsoidal tumors were contoured for each plaque size and MATLAB programming was developed to generate tumor dose distributions for all possible ring weighting and radionuclide permutations for a given plaque size and source strength resolution, assuming a 75 Gy apical prescription dose. These dose distributions were analyzed for conformity and homogeneity and compared to reference dose distributions from uniformly-loaded (125)I plaques. The most conformal and homogeneous dose distributions were reproduced within a reference eye environment to assess organ-at-risk (OAR) doses in the Pinnacle(3) treatment planning system (TPS). The gamma-index analysis method was used to quantitatively compare MC and TPS-generated dose distributions. RESULTS Concentrating > 97% of the total source strength in a single or pair of central (103)Pd seeds produced the most conformal dose distributions, with tumor basal doses a factor of 2-3 higher and OAR doses a factor of 2-3 lower than those of corresponding uniformly-loaded (125)I plaques. Concentrating 82-86% of the total source strength in peripherally-loaded (131)Cs seeds produced the most homogeneous dose distributions, with tumor basal doses 17-25% lower and OAR doses typically 20% higher than those of corresponding uniformly-loaded (125)I plaques. Gamma-index analysis found > 99% agreement between MC and TPS dose distributions. CONCLUSIONS A method was developed to select intra-plaque ring radionuclide compositions and source strengths to deliver more conformal and homogeneous tumor dose distributions than uniformly-loaded (125)I plaques. This method may support coordinated investigations of an appropriate clinical target for eye plaque brachytherapy.
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Abstract
PURPOSE To evaluate the radiation dose to a surgeon's hands during I eye plaque procedures. METHODS Sixteen consecutive patients with uveal melanomas were scheduled for eye plaque brachytherapy. The same surgeon wore thermoluminescent dosimeters on the dominant index finger and thumb while placing and removing the eye plaque to measure radiation dose. Additional laboratory experiments were performed to measure unobstructed (by surgical gloves or other parts of the hand) radiation exposure from a plaque. RESULTS Hand radiation doses during eye plaque brachytherapy are very low, but measurable, with plaques containing an average of 1.3 GBq of 125I. CONCLUSION Using these data, a surgeon would need to perform more than 1,000 cases each year to approach or exceed the annual regulatory radiation dose limits for the extremities.
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Chiu-Tsao ST, Astrahan MA, Finger PT, Followill DS, Meigooni AS, Melhus CS, Mourtada F, Napolitano ME, Nath R, Rivard MJ, Rogers DWO, Thomson RM. Dosimetry of (125)I and (103)Pd COMS eye plaques for intraocular tumors: report of Task Group 129 by the AAPM and ABS. Med Phys 2012; 39:6161-84. [PMID: 23039655 DOI: 10.1118/1.4749933] [Citation(s) in RCA: 146] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Dosimetry of eye plaques for ocular tumors presents unique challenges in brachytherapy. The challenges in accurate dosimetry are in part related to the steep dose gradient in the tumor and critical structures that are within millimeters of radioactive sources. In most clinical applications, calculations of dose distributions around eye plaques assume a homogenous water medium and full scatter conditions. Recent Monte Carlo (MC)-based eye-plaque dosimetry simulations have demonstrated that the perturbation effects of heterogeneous materials in eye plaques, including the gold-alloy backing and Silastic insert, can be calculated with reasonable accuracy. Even additional levels of complexity introduced through the use of gold foil "seed-guides" and custom-designed plaques can be calculated accurately using modern MC techniques. Simulations accounting for the aforementioned complexities indicate dose discrepancies exceeding a factor of ten to selected critical structures compared to conventional dose calculations. Task Group 129 was formed to review the literature; re-examine the current dosimetry calculation formalism; and make recommendations for eye-plaque dosimetry, including evaluation of brachytherapy source dosimetry parameters and heterogeneity correction factors. A literature review identified modern assessments of dose calculations for Collaborative Ocular Melanoma Study (COMS) design plaques, including MC analyses and an intercomparison of treatment planning systems (TPS) detailing differences between homogeneous and heterogeneous plaque calculations using the American Association of Physicists in Medicine (AAPM) TG-43U1 brachytherapy dosimetry formalism and MC techniques. This review identified that a commonly used prescription dose of 85 Gy at 5 mm depth in homogeneous medium delivers about 75 Gy and 69 Gy at the same 5 mm depth for specific (125)I and (103)Pd sources, respectively, when accounting for COMS plaque heterogeneities. Thus, the adoption of heterogeneous dose calculation methods in clinical practice would result in dose differences >10% and warrant a careful evaluation of the corresponding changes in prescription doses. Doses to normal ocular structures vary with choice of radionuclide, plaque location, and prescription depth, such that further dosimetric evaluations of the adoption of MC-based dosimetry methods are needed. The AAPM and American Brachytherapy Society (ABS) recommend that clinical medical physicists should make concurrent estimates of heterogeneity-corrected delivered dose using the information in this report's tables to prepare for brachytherapy TPS that can account for material heterogeneities and for a transition to heterogeneity-corrected prescriptive goals. It is recommended that brachytherapy TPS vendors include material heterogeneity corrections in their systems and take steps to integrate planned plaque localization and image guidance. In the interim, before the availability of commercial MC-based brachytherapy TPS, it is recommended that clinical medical physicists use the line-source approximation in homogeneous water medium and the 2D AAPM TG-43U1 dosimetry formalism and brachytherapy source dosimetry parameter datasets for treatment planning calculations. Furthermore, this report includes quality management program recommendations for eye-plaque brachytherapy.
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Gagne NL, Leonard KL, Rivard MJ. Radiobiology for eye plaque brachytherapy and evaluation of implant duration and radionuclide choice using an objective function. Med Phys 2012; 39:3332-42. [DOI: 10.1118/1.4718683] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
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Saidi P, Sadeghi M, Tenreiro C. Experimental measurements and Monte Carlo calculations for (103)Pd dosimetry of the 12 mm COMS eye plaque. Phys Med 2012; 29:286-94. [PMID: 22592132 DOI: 10.1016/j.ejmp.2012.04.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2011] [Revised: 03/10/2012] [Accepted: 04/09/2012] [Indexed: 10/28/2022] Open
Abstract
Monte Carlo simulations and TLD dosimetry have been performed to determine the dose distributions along the central axis of the 12 mm COMS eye plaques loaded with IRA1-(103)Pd seeds. Several simulations and measurements have been employed to investigate the effect of Silastic insert and air in front of the eye on dosimetry results along the central axis of the plaque and at some critical ocular structures. Measurements were performed using TLD-GR200A circular chip dosimeters in a PMMA eye phantom. The central axis TLD chips locations were arranged in one central column of eye phantom, in 3 mm intervals. The off-axis TLD chips locations were arranged in three off-axis columns around the central axis column. Version 5 of the MCNP code was also used to evaluate the dose distribution around the plaque. The presence of the Silastic insert results in dose reduction of 14% at 5 mm; also about 7% dose reduction appears at the interface point, due to the air presence and lack of the scattering condition. The overall dosimetric parameters for the COMS eye plaque loaded with new palladium seeds are similar to a commercial widely used seed such as Theragenics200. As the dose calculations under TG-43 assumptions do not consider the effect of the plaque backing and Silastic insert for accurate dosimetry, it's suggested to apply the effect of the eye plaque materials and air on dosimetry results along the central axis of the plaque and at some critical ocular structures.
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Affiliation(s)
- Pooneh Saidi
- Department of Medical Radiation Engineering, Science and Research Branch, Islamic Azad University, 1477893855 Tehran, Iran.
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Leonard KL, Gagne NL, Mignano JE, Duker JS, Bannon EA, Rivard MJ. A 17-year retrospective study of institutional results for eye plaque brachytherapy of uveal melanoma using 125I, 103Pd, and 131Cs and historical perspective. Brachytherapy 2011; 10:331-9. [DOI: 10.1016/j.brachy.2011.01.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2010] [Revised: 01/14/2011] [Accepted: 01/17/2011] [Indexed: 10/18/2022]
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Rivard MJ, Chiu-Tsao ST, Finger PT, Meigooni AS, Melhus CS, Mourtada F, Napolitano ME, Rogers DWO, Thomson RM, Nath R. Comparison of dose calculation methods for brachytherapy of intraocular tumors. Med Phys 2011; 38:306-16. [PMID: 21361199 DOI: 10.1118/1.3523614] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To investigate dosimetric differences among several clinical treatment planning systems (TPS) and Monte Carlo (MC) codes for brachytherapy of intraocular tumors using 125I or 103Pd plaques, and to evaluate the impact on the prescription dose of the adoption of MC codes and certain versions of a TPS (Plaque Simulator with optional modules). METHODS Three clinical brachytherapy TPS capable of intraocular brachytherapy treatment planning and two MC codes were compared. The TPS investigated were Pinnacle v8.0dp1, BrachyVision v8.1, and Plaque Simulator v5.3.9, all of which use the AAPM TG-43 formalism in water. The Plaque Simulator software can also handle some correction factors from MC simulations. The MC codes used are MCNP5 v1.40 and BrachyDose/EGSnrc. Using these TPS and MC codes, three types of calculations were performed: homogeneous medium with point sources (for the TPS only, using the 1D TG-43 dose calculation formalism); homogeneous medium with line sources (TPS with 2D TG-43 dose calculation formalism and MC codes); and plaque heterogeneity-corrected line sources (Plaque Simulator with modified 2D TG-43 dose calculation formalism and MC codes). Comparisons were made of doses calculated at points-of-interest on the plaque central-axis and at off-axis points of clinical interest within a standardized model of the right eye. RESULTS For the homogeneous water medium case, agreement was within approximately 2% for the point- and line-source models when comparing between TPS and between TPS and MC codes, respectively. For the heterogeneous medium case, dose differences (as calculated using the MC codes and Plaque Simulator) differ by up to 37% on the central-axis in comparison to the homogeneous water calculations. A prescription dose of 85 Gy at 5 mm depth based on calculations in a homogeneous medium delivers 76 Gy and 67 Gy for specific 125I and 103Pd sources, respectively, when accounting for COMS-plaque heterogeneities. For off-axis points-of-interest, dose differences approached factors of 7 and 12 at some positions for 125I and 103Pd, respectively. There was good agreement (approximately 3%) among MC codes and Plaque Simulator results when appropriate parameters calculated using MC codes were input into Plaque Simulator. Plaque Simulator and MC users are perhaps at risk of overdosing patients up to 20% if heterogeneity corrections are used and the prescribed dose is not modified appropriately. CONCLUSIONS Agreement within 2% was observed among conventional brachytherapy TPS and MC codes for intraocular brachytherapy dose calculations in a homogeneous water environment. In general, the magnitude of dose errors incurred by ignoring the effect of the plaque backing and Silastic insert (i.e., by using the TG-43 approach) increased with distance from the plaque's central-axis. Considering the presence of material heterogeneities in a typical eye plaque, the best method in this study for dose calculations is a verified MC simulation.
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Affiliation(s)
- Mark J Rivard
- Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA.
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Zhang H, Martin D, Chiu-Tsao ST, Meigooni A, Thomadsen BR. A comprehensive dosimetric comparison between (131)Cs and (125)I brachytherapy sources for COMS eye plaque implant. Brachytherapy 2010; 9:362-72. [PMID: 20116342 DOI: 10.1016/j.brachy.2009.07.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2009] [Revised: 06/23/2009] [Accepted: 07/28/2009] [Indexed: 10/19/2022]
Abstract
PURPOSE To verify the dosimetric characteristics of (131)Cs source in the Collaborative Ocular Melanoma Study (COMS) eye plaque brachytherapy, to compare (131)Cs with (125)I in a sample implant, and to examine the accuracy of treatment planning system in dose calculation. METHODS AND MATERIALS Monte Carlo (MC) technique was used to generate three-dimensional dose distributions of a 16-mm COMS eye plaque loaded with (131)Cs and (125)I brachytherapy sources separately. A spherical eyeball, 24.6mm in diameter, and an ellipsoidal tumor, 6mm in height and 12mm in diameter, were used to evaluate the doses delivered. The simulations were carried out both with and without the gold and gold alloy plaque. A water-equivalent seed carrier was used instead of the silastic insert designed for the traditional COMS eye plaque. The 13 sources involved were also individually simulated to evaluate the intersource effect. In addition, a treatment planning system was used to calculate the doses at the central axis for comparison with MC data. RESULTS The gold plaque had significantly reduced the dose in the tumor volume; at the prescription point of this study, that is, 6mm from the edge of inner sclera, the gold plaque reduced the dose by about 7% for both types of (131)Cs and (125)I sources, but the gold alloy plaque reduced the dose only by 4% for both types of sources. The intersource effect reduced the dose by 2% for both types of sources. At the same prescription dose, the treatment with the gold plaque applicator tended to create more hot regions for either type of sources than were seen with the homogeneous water phantom. The doses of TPS agree with the MC. CONCLUSION The (131)Cs source is comparable to the (125)I source in the eye plaque brachytherapy. The TPS can provide accurate dose calculations for eye plaque implants with either type of sources.
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Affiliation(s)
- Hualin Zhang
- Department of Radiation Oncology, The Ohio State University, Columbus, OH 43210-1228, USA.
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Rivard MJ, Melhus CS, Granero D, Perez-Calatayud J, Ballester F. An approach to using conventional brachytherapy software for clinical treatment planning of complex, Monte Carlo-based brachytherapy dose distributionsa). Med Phys 2009; 36:1968-75. [DOI: 10.1118/1.3121510] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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