Advantages of multiple algorithm support in treatment planning system for external beam dose calculations

Animesh,

doi:10.4103/0973-1482.16085

Cited by 14 publications

(4 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…An algorithm is defined as sequence of instructions that operate on a set of input data, transforming that information into a set of output results that are of interest to the user. [3]…”

Section: Introductionmentioning

confidence: 99%

Comparative study of convolution, superposition, and fast superposition algorithms in conventional radiotherapy, three-dimensional conformal radiotherapy, and intensity modulated radiotherapy techniques for various sites, done on CMS XIO planning system

Muralidhar¹,

Murthy²,

Raju³

2009

J Med Phys

View full text Add to dashboard Cite

The aim of this study is to compare the dosimetry results that are obtained by using Convolution, Superposition and Fast Superposition algorithms in Conventional Radiotherapy, Three-Dimensional Conformal Radiotherapy (3D-CRT), and Intensity Modulated Radiotherapy (IMRT) for different sites, and to study the suitability of algorithms with respect to site and technique. For each of the Conventional, 3D-CRT, and IMRT techniques, four different sites, namely, Lung, Esophagus, Prostate, and Hypopharynx were analyzed. Treatment plans were created using 6MV Photon beam quality using the CMS XiO (Computerized Medical System, St.Louis, MO) treatment planning system. The maximum percentage of variation recorded between algorithms was 3.7% in case of Ca.Lung, for the IMRT Technique. Statistical analysis was performed by comparing the mean relative difference, Conformity Index, and Homogeneity Index for target structures. The fast superposition algorithm showed excellent results for lung and esophagus cases for all techniques. For the prostate, the superposition algorithm showed better results in all techniques. In the conventional case of the hypopharynx, the convolution algorithm was good. In case of Ca. Lung, Ca Prostate, Ca Esophagus, and Ca Hypopharynx, OARs got more doses with the superposition algorithm; this progressively decreased for fast superposition and convolution algorithms, respectively. According to this study the dosimetric results using different algorithms led to significant variation and therefore care had to be taken while evaluating treatment plans. The choice of a dose calculation algorithm may in certain cases even influence clinical results.

show abstract

“…An algorithm is defined as sequence of instructions that operate on a set of input data, transforming that information into a set of output results that are of interest to the user. [3]…”

Section: Introductionmentioning

confidence: 99%

Comparative study of convolution, superposition, and fast superposition algorithms in conventional radiotherapy, three-dimensional conformal radiotherapy, and intensity modulated radiotherapy techniques for various sites, done on CMS XIO planning system

Muralidhar¹,

Murthy²,

Raju³

2009

J Med Phys

View full text Add to dashboard Cite

show abstract

“…Todos os testes foram realizados para a validação do OS em dois aceleradores lineares. O sistema para planejamento utilizado foi o XiO versão 4.70 e algoritmo presente no sistema de planejamento que melhor calcula heterogeneidades é o Superposition [8,22] Os resultados do percentual de variação da dose medida com a dose calculada pelo sistema de planejamento para todos os tomógrafos disponível na UNICAMP são mostrados nos gráficos das Figuras 8 e 9 para feixes de 6 e 10 MV, respectivamente. É possível observar que os pontos medidos no OS criado não são todos os pontos recomendados pelo TRS-430, tabela 1.…”

Section: Resultsunclassified

Comissionamento do sistema de planejamento para uso de correção de heterogeneidades: Construção de um fantoma de baixo custo para validação e controle de qualidade em radioterapia.

et al. 2018

View full text Add to dashboard Cite

A implementação de correções por heterogeneidades no sistema de planejamento de tratamentos radioterápicos melhora a exatidão do cálculo de dose em pacientes submetidos a teleterapia. Estudos mostram que planejamentos sem levar em conta a correção de heterogeneidade podem produzir um subdosagem de até 20% para tumores de pulmão na entrega de dose. Para a validação é necessário adquirir um dos fantomas disponíveis comercialmente. Esses Fantomas permitem a realização dos testes recomendados pelo TRS-430 (Commissioning and Quality Assurance of Computerized Planning Systems for Radiation Treatment of Cancer) e implementação das correções de heterogeneidades. Esse trabalho visa comparar os fantomas disponíveis comercialmente e fazer a análise para construção de um próprio fantoma para validação de forma a cobrir os requisitos necessários

show abstract

“…For the 3DCRT and the regular-field plan, the Multigrid Superposition algorithm with a 2 mm dose grid was used with heterogeneity corrections applied. This is the most accurate algorithm available on XiO [33,35,36].…”

Section: Treatment Planningmentioning

confidence: 99%

External beam patient dose verification based on the integral quality monitor (IQM^®) output signals

Mahuvava

Plessis²

2020

Biomed. Phys. Eng. Express

View full text Add to dashboard Cite

Background: The Integral Quality Monitor (IQM ® ) can essentially measure the integral fluence through a segment and provide real-time information about the accuracy of radiation delivery based on comparisons of measured segment signals and pre-calculated reference values. However, the present IQM chamber cannot calculate the dose in the patient. Aim: This study aims to make use of IQM field output signals to calculate the number of monitor units (MUs) delivered through an arbitrary treatment field in order to convert Monte Carlo (MC)-generated dose distributions in a patient model into absolute dose. Methods: XiO and Monaco treatment planning systems (TPSs) were used to define treatment beam portals for cervix and esophagus conformal radiotherapy as well as prostate intensity-modulated radiotherapy for the translation of patient and beam setup information from DICOM to DOSXYZnrc. The planned beams were simulated in a patient model built from actual patient CT images and each simulated integral field/segment was weighted with its MUs before summation to get the total dose in the plan. The segment beam weights (MUs) were calculated as the ratio of the open-field IQM measured signal and the calculated signal per MU extracted from chamber sensitivity maps. These are the actual MUs delivered not just MUs set. The beam weighting method was evaluated by comparing weighted MC doses with original planned doses using profile and isodose comparisons, dose difference maps, γ analysis and dose-volume histogram (DVH) data. Results: γ pass rates of up to 98% were found, except for the esophagus plan where the γ pass rate was below 45%. DVH comparisons showed good agreement for most organs, with the largest differences observed in low-density lung. However, these discrepancies can result from differences in dose calculation algorithms or differences in MUs used for dose weighting planned by the TPS and MUs calculated using IQM field output signals. To test this, a 4-field box DOSXYZnrc MC simulation weighted with planned (XiO) MUs was compared with the same simulation weighted with IQM-based MUs. Dose differences of up to 5% were found on the isocentre slice. For XiO versus MC, up to 7% dose differences were found, indicating additional error due to limitations of XiO's superposition algorithm. Dose differences between MC Monaco and MC EGSnrc were less than 3%. Conclusions: The most valuable comparison was MC versus MC as it eliminated algorithm discrepancies and evaluated dose differences precisely according to beam weighting. For XiO TPS, care must be taken as dose differences may also arise due to limitations in XiO's planning software, not merely due to differences in MUs. Overall, the IQM was successfully used to compute beam dose weights to accurately reconstruct the patient dose using unweighted MC beams. Our technique can be used for pre-treatment QA provided each segment output is known and an accurate linac source model is available.

show abstract

Advantages of multiple algorithm support in treatment planning system for external beam dose calculations

Cited by 14 publications

References 0 publications

Comparative study of convolution, superposition, and fast superposition algorithms in conventional radiotherapy, three-dimensional conformal radiotherapy, and intensity modulated radiotherapy techniques for various sites, done on CMS XIO planning system

Comparative study of convolution, superposition, and fast superposition algorithms in conventional radiotherapy, three-dimensional conformal radiotherapy, and intensity modulated radiotherapy techniques for various sites, done on CMS XIO planning system

Comissionamento do sistema de planejamento para uso de correção de heterogeneidades: Construção de um fantoma de baixo custo para validação e controle de qualidade em radioterapia.

External beam patient dose verification based on the integral quality monitor (IQM^®) output signals

Contact Info

Product

Resources

About

Advantages of multiple algorithm support in treatment planning system for external beam dose calculations

Cited by 14 publications

References 0 publications

Comparative study of convolution, superposition, and fast superposition algorithms in conventional radiotherapy, three-dimensional conformal radiotherapy, and intensity modulated radiotherapy techniques for various sites, done on CMS XIO planning system

Comparative study of convolution, superposition, and fast superposition algorithms in conventional radiotherapy, three-dimensional conformal radiotherapy, and intensity modulated radiotherapy techniques for various sites, done on CMS XIO planning system

Comissionamento do sistema de planejamento para uso de correção de heterogeneidades: Construção de um fantoma de baixo custo para validação e controle de qualidade em radioterapia.

External beam patient dose verification based on the integral quality monitor (IQM®) output signals

Contact Info

Product

Resources

About

External beam patient dose verification based on the integral quality monitor (IQM^®) output signals