Dosimetric characterization of radioactive sources employed in prostate cancer therapy

Zilio, Valéry Olivier; Joneja, Om Parkash; Popowski, Youri; Chawla, R.

doi:10.1016/j.brachy.2004.09.006

Cited by 11 publications

(8 citation statements)

References 24 publications

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“…The code is the latest version of MCNP. MCNP and its sister code MCNPX ͑the extension for particle type and energy ranges of MCNP͒ have been used by many authors for brachytherapy seed studies, 4,6,7,[11][12][13][14][15][16][17][18][19] so their feasibility and appropriateness have been well verified. There are several tally types available in MCNP5 for scoring the dose rate.…”

Section: Iib Monte Carlo Simulationmentioning

confidence: 99%

Dosimetric characterization of model Cs‐1 Rev2 cesium‐131 brachytherapy source in water phantoms and human tissues with MCNP5 Monte Carlo simulation

Wang

Zhang

2008

Medical Physics

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A recently developed alternative brachytherapy seed, Cs-1 Rev2 cesium-131, has begun to be used in clinical practice. The dosimetric characteristics of this source in various media, particularly in human tissues, have not been fully evaluated. The aim of this study was to calculate the dosimetric parameters for the Cs-1 Rev2 cesium-131 seed following the recommendations of the AAPM TG-43U1 report [Rivard et al., Med. Phys. 31, 633-674 (2004)] for new sources in brachytherapy applications. Dose rate constants, radial dose functions, and anisotropy functions of the source in water, Virtual Water, and relevant human soft tissues were calculated using MCNP5 Monte Carlo simulations following the TG-43U1 formalism. The results yielded dose rate constants of 1.048, 1.024, 1.041, and 1.044 cGy h(-1) U(-1) in water, Virtual Water, muscle, and prostate tissue, respectively. The conversion factor for this new source between water and Virtual Water was 1.02, between muscle and water was 1.006, and between prostate and water was 1.004. The authors' calculation of anisotropy functions in a Virtual Water phantom agreed closely with Murphy's measurements [Murphy et al., Med. Phys. 31, 1529-1538 (2004)]. Our calculations of the radial dose function in water and Virtual Water have good agreement with those in previous experimental and Monte Carlo studies. The TG-43U1 parameters for clinical applications in water, muscle, and prostate tissue are presented in this work.

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Section: Iib Monte Carlo Simulationmentioning

confidence: 99%

Dosimetric characterization of model Cs‐1 Rev2 cesium‐131 brachytherapy source in water phantoms and human tissues with MCNP5 Monte Carlo simulation

Wang

Zhang

2008

Medical Physics

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“…Other more detailed compositions, up to 33 elements, have already been studied by other authors. 24 However, insignificant differences have been reported and, from a dosimetry standpoint, the ten-element composition is equivalent to the 33element composition. 24 The prostate tissue is considered to be homogeneous and the tissue density is set constant to 1.045 g / cm 3 .…”

Section: Monte Carlo In Prostate Tissue "Mcp…mentioning

confidence: 99%

“…The TG-43u1 calculations overestimate the D 90 values calculated with MCP by 5.8%-12.8%, depending on the seed density and prostate size. This difference corresponds to [13][14][15][16][17][18][19][20][21][22][23][24][25][26] Gy. This is illustrating the systematic effect when taking into account the interseed attenuation and prostate composition corrections in the dosimetry.…”

Section: Overall Comparisonmentioning

confidence: 99%

Impact of interseed attenuation and tissue composition for permanent prostate implants

et al. 2006

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The purpose is to evaluate the impact of interseed attenuation and prostate composition for prostate treatment plans with 125I permanent seed implants using the Monte Carlo (MC) method. The effect of seed density (number of seeds per prostate unit volume) is specifically investigated. The study focuses on treatment plans that were generated for clinical cases. For each plan, four different dose calculation techniques are compared: TG-43 based calculation, superposition MC, full MC with water prostate, and full MC with realistic prostate tissue. The prostate tissue description is from the ICRP report 23 (W. S. Snyer, M. J. Cook, E. S. Nasset, L. R. Karkhausen, G. P. Howells, and I. H. Tipton, "Report of the task group on reference man," Technical Report 23, International Commission on Radiological Protection, 1974). According to the comparisons, the seed density has an influence on interseed attenuation. A plan with a typical low seed density (42 0.6 mCi seeds in a 26 cm3 prostate) suffers a 1.2% drop in the CTV D90 value due to interseed attenuation. A drop of 3.0% is calculated for a higher seed density (75 0.3 mCi seeds, same prostate). The influence of the prostate composition is similar for all seed densities and prostate sizes. The difference between MC simulations in water and MC simulations in prostate tissue is between 4.4% and 4.8% for the D90 parameter. Overall, the effect on D90 is ranging from 5.8% to 12.8% when comparing clinically approved TG-43 and MC simulations in prostate tissue. The impact varies from one patient to the other and depends on the prostate size and the number of seeds. This effect can reach a significant level when reporting correlations between clinical effect and deposited dose.

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“…A fonte de 192 Ir é um emissor gama e possui aproximadamente 17 linhas de emissão, onde o valor médio é de 397 keV [23]. O espectro de radiação primário usado nas simulações, foi composto pelas 17 linhas mais prováveis de 65 keV à 1378 keV [24]. A geometria da fonte clínica de 192 Ir, Varian modelo GammaMed Plus, foi modelada consistido em um cilindro de parte ativa de 192 Ir com 0,35 cm de comprimento e 0,03 cm de raio.…”

Section: Modelagem Da Fonte Com O Pacote Penelopeunclassified

Avaliação de parâmetros dosimétricos de uma fonte de Braquiterapia em regiões próximas à fonte

2018

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Neste trabalho foram determinadas as funções dosimétricas de uma fonte clínica de braquiterapia de alta taxa de dose de Irídio-192 em distâncias próximas à fonte. O fator geométrico foi determinado analiticamente, enquanto que a função de dose radial e a função de anisotropia foram determinadas para distâncias de até 5 cm do centro da fonte utilizando simulação Monte Carlo com o pacote PENLEOPE. Uma fonte de 192Ir de alta taxa de dose (Varian, modelo GammaMed Plus) foi modelada e posicionada no centro de um objeto simulador cúbico de 30 cm de lado e preenchido com água. Foi realizada a paralelização do pacote PENELOPE para a realização das simulações, utilizando 8 processadores, onde o número de partículas primárias em cada processador permaneceu constante em 109, a energia de corte para fótons e elétrons foi de 100 keV e os parâmetros de condensação de histórias (C1 e C2) foram de 0,3, otimizando o tempo de simulação e não adicionando incertezas sistemáticas aos resultados. Perfis de dose relativa obtidos utilizando simulação Monte Carlo foram comparados com o sistema de planejamento BrachyVision em três diferentes planos axiais em relação à fonte: plano central; 0,4 cm acima da fonte, na direção do topo do encapsulamento; e 0,4 cm abaixo da fonte, na direção do cabo. Quando comparados entre si, ambos os conjuntos de dados possuem o mesmo comportamento, com diferenças máximas de 2%, indicando que o pacote PENELOPE apresenta-se como ferramenta promissora em cálculos dosimétricos de fontes de braquiterapia de alta taxa de dose.

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Dosimetric characterization of radioactive sources employed in prostate cancer therapy

Cited by 11 publications

References 24 publications

Dosimetric characterization of model Cs‐1 Rev2 cesium‐131 brachytherapy source in water phantoms and human tissues with MCNP5 Monte Carlo simulation

Dosimetric characterization of model Cs‐1 Rev2 cesium‐131 brachytherapy source in water phantoms and human tissues with MCNP5 Monte Carlo simulation

Impact of interseed attenuation and tissue composition for permanent prostate implants

Avaliação de parâmetros dosimétricos de uma fonte de Braquiterapia em regiões próximas à fonte

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