Evolution of dose distribution for a ¹²⁵I eye plaque using MCNPX and Plaque Simulator software

Abstract

Objective: Eye plaque radiation therapy is the treatment of choice for small- and medium-sized choroidal melanomas. This study investigated the dose distribution around eye plaques containing ¹²⁵I seeds to treat ocular melanoma using Monte Carlo N-Particle eXtended (MCNPX) and Plaque Simulator (PS) software.

Methods: Dosimetry evaluation and comparison of the resulting isodose curves for ¹²⁵I COMS plaques were performed using the MCNPX code. The isodose curves and dose distributions were calculated using PS treatment planning for a ¹²⁵I COMS plaque.

Results: In the validation, the maximum relative difference between the results of this study and those reported in other literature was approximately 9%–10% for the COMS plaques. The dose distributions of MCNPX were lower than those of PS with a relative difference of approximately 27.7%–35.4%. The dose distribution may differ depending on the ¹²⁵I source spectra and seed design used in the two methods. In addition, the dose algorithm used in PS made a major contribution to the relative differences between the results.

Conclusion: The PS did not provide accurate details of dose distribution near the surface of the plaque insert. The source parameters used in each program should be studied more carefully to determine the source of the differences in the estimated dose values.

Keywords

¹²⁵I seed / dosimetry calculation / Eye plaque / Monte Carlo N-Particle eXtended (MCNPX) / treatment planning system

References

[1] PeddadaK V., Sangani R, MenonH, et al. Complications and adverse events of plaque brachytherapy for ocular melanoma. J Contemp Brachytherapy. 2019;11:392-397.

[2] MeliaM, MoyCS, ReynoldsSM, et al. Collaborative Ocular Melanoma Study-Quality of Life Study Group. Quality of life after iodine 125 brachytherapy vs enucleation for choroidal melanoma: 5-year results from the Collaborative Ocular Melanoma Study: COMS QOLS report No. 3. Arch Ophthalmol. 2006;124:226-238.

[3] JovanovicP, Mihajlovic M, Djordjevic-JocicJ, et al. Ocular melanoma: An overview of the current status. Int J Clin Exp Pathol. 2013;6:1230-1244.

[4] Collaborative Ocular Melanoma Study Group. The COMS randomized trial of iodine 125 brachytherapy for choroidal melanoma: V. Twelve-year mortality rates and prognostic factors: COMS report No. 28. Arch Ophthalmol. 2006;124:1684-1693.

[5] MiguelD, Saornil MA, De FrutosJM, et al. Regression of posterior uveal melanoma following iodine-125 plaque radiotherapy based on pre-treatment tumor apical height. J Contemp Brachytherapy. 2021;13:117-125.

[6] MesserJA, ZuhourRJ, HaqueW, et al. Eye plaque brachytherapy versus enucleation for ocular melanoma: an analysis from the National Cancer Database. J Contemp Brachytherapy. 2020;12:303-310.

[7] SimpsonER, GallieB, LaperrierreN. The American Brachytherapy Society consensus guidelines for plaque brachytherapy of uveal melanoma and retinoblastoma. Brachytherapy. 2014;13:1-14

[8] GhassemiF, Sheibani S, ArjmandM, et al. Comparison of iodide-125 and ruthenium-106 brachytherapy in the treatment of choroidal melanomas. Clin Ophthalm. 2020;14:339-346.

[9] RivardMJ, Coursey BM, DeWerdLA, et al. Update of AAPM Task Group No. 43 Report: A revised AAPM protocol for brachytherapy dose calculations. Med Phys. 2004;31(3):633-674.

[10] HendricksJS, Mckinney GW, WatersLS, et al. MCNPX extensions version 2.5.0, Los Alamos National Laboratory report LA-UR-05-2675 (April 2005).

[11] PelowitzDB. MCNPXTM user's manual version 2.6.0. Los Alamos, NM: Los Alamos National Laboratory; 2008. ???LA-CP-07–1473.

[12] Chiu-TsaoST, Astrahan MA, FingerPT, et al. Dosimetry of ¹²⁵I and ¹⁰³Pd COMS eye plaques for intraocular tumors: Report of Task Group 129 by the AAPM and ABS. Med Phys. 2012;39:6161-6184.

[13] Chiu-TsaoST, Astrahan MA, FingerPT, et al. Dosimetry of ¹²⁵I and ¹⁰³Pd COMS eye plaques for intraocular tumors: Report of Task Group 129 by the AAPM and ABS. Med Phys. 2012;39:6161-6184.

[14] Chiu-TsaoST, Anderson LL, O'BrienK, et al. Dosimetry for ¹²⁵I seed (model 6711) in eye plaques. Med Phys. 1993:20:383-389.

[15] MelhusCS, RivardMJ. COMS eye plaque brachytherapy dosimetry simulations for ¹⁰³Pd, ¹²⁵I, and ¹³¹Cs. Med Phys. 2008;35(7):3364-3371.

[16] ThomsonRM, TaylorRE, RogersDW. Monte Carlo dosimetry for 125I and 103Pd eye plaque brachytherapy. Med Phys. 2008;35(12):5530-5543.

[17] LohrabianV, Sheibani S, AghamiriMR, et al. Determination of dosimetric characteristics of irseed ¹²⁵I brachytherapy source. Iran J Med Phys. 2013:10:109-117.

[18] KnutsenS, Hafslund R, MongeOR, et al. Dosimetric verification of a dedicated 3D treatment planning system for episcleral plaque therapy. Int J Radiat Oncol Biol Phys. 2001;51(4):1159-1166.

[19] AstrahanMA, LuxtonG, JozsefG, et al. An interactive treatment planning system for ophthalmic plaque radiotherapy. Int J Radiat Oncol Biol Phys. 1990;18(3):679-687.

[20] BristolJR. Comparison of Eye Plaque Dosimetry Using Deterministic and Monte Carlo Methods. Master of Science, Oregon State University, 2010.

[21] RivardMJ, MelhusCS, GraneroD, Perez-Calatayud J, BallesterF. An approach to using conventional brachytherapy software for clinical treatment planning of complex, Monte Carlo-based brachytherapy dose distribution. Med Phys. 2009;36:1968-1975.

[22] ZimmermannLW, AmoushA, WilkinsonDA. Episcleral eye plaque dosimetry comparison for the Eye Physics EP917 using Plaque Simulator and Monte Carlo simulation. J Appl Clin Med Phys. 2015;16(6):226-239.

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2024 The Author(s). Precision Radiation Oncology published by John Wiley & Sons Australia, Ltd on behalf of Shandong Cancer Hospital & Institute.