Correlation of dose computed using different algorithms with local control following stereotactic ablative radiotherapy (SABR)-based treatment of non-small-cell lung cancer

Chetty, Indrin J.; Devpura, Suneetha; Liu, Dezhi; Chen, Daiquan; Li, Haisen; Wen, Ning; Kumar, Sanath; Fraser, C; Siddiqui, M. Salim; Munther, Ajlouni; Movsas, Benjamin

doi:10.1016/j.radonc.2013.10.012

Cited by 34 publications

(44 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The smaller the PTV volumes, the greater the dose overestimation found. This result agreed with the previous study (10) . However, the observed tumor volume dependence in dose overestimation was not found in centrally located tumors.…”

Section: Discussionsupporting

confidence: 93%

Dose differences in intensity‐modulated radiotherapy plans calculated with pencil beam and Monte Carlo for lung SBRT

Liu

Zhuang

Stephans

et al. 2015

J Applied Clin Med Phys

View full text Add to dashboard Cite

For patients with medically inoperable early‐stage non‐small cell lung cancer (NSCLC) treated with stereotactic body radiation therapy, early treatment plans were based on a simpler dose calculation algorithm, the pencil beam (PB) calculation. Because these patients had the longest treatment follow‐up, identifying dose differences between the PB calculated dose and Monte Carlo calculated dose is clinically important for understanding of treatment outcomes. Previous studies found significant dose differences between the PB dose calculation and more accurate dose calculation algorithms, such as convolution‐based or Monte Carlo (MC), mostly for three‐dimensional conformal radiotherapy (3D CRT) plans. The aim of this study is to investigate whether these observed dose differences also exist for intensity‐modulated radiotherapy (IMRT) plans for both centrally and peripherally located tumors. Seventy patients (35 central and 35 peripheral) were retrospectively selected for this study. The clinical IMRT plans that were initially calculated with the PB algorithm were recalculated with the MC algorithm. Among these paired plans, dosimetric parameters were compared for the targets and critical organs. When compared to MC calculation, PB calculation overestimated doses to the planning target volumes (PTVs) of central and peripheral tumors with different magnitudes. The doses to 95% of the central and peripheral PTVs were overestimated by 9.7%±5.6% and 12.0%±7.3%, respectively. This dose overestimation did not affect doses to the critical organs, such as the spinal cord and lung. In conclusion, for NSCLC treated with IMRT, dose differences between the PB and MC calculations were different from that of 3D CRT. No significant dose differences in critical organs were observed between the two calculations.PACS number: 87.53.Ly

show abstract

Section: Discussionsupporting

confidence: 93%

Dose differences in intensity‐modulated radiotherapy plans calculated with pencil beam and Monte Carlo for lung SBRT

Liu

Zhuang

Stephans

et al. 2015

J Applied Clin Med Phys

View full text Add to dashboard Cite

show abstract

“…In our study firstly, we observed an overestimation of TCP by MB-PBC than AAA. On the other hand, a remarkable and significant discrepancy in estimating NTCP was observed confirming the results of several other studies (32)(33)(34). Secondly, γ-maps confirmed the observed results from CT imaging showing dose distribution.…”

Section: Discussionsupporting

confidence: 87%

Assessing the shift of radiobiological metrics in lung radiotherapy plans using 2D gamma index

Chaikh

Balosso

2016

Transl. Lung Cancer Res.

View full text Add to dashboard Cite

Background: The purpose of this work is to investigate the 2D gamma (γ) maps to illustrate the change of radiobiological outcomes for lung radiotherapy plans and evaluate the correlation between tumor control probability (TCP), normal tissue complication probability (NTCP) with γ passing rates (γ-rates).Methods: Nine patients with lung cancer were used. The doses were calculated using Modified Batho method integrated with pencil beam convolution (MB-PBC) and anisotropic analytical algorithm (AAA) using the same beam arrangements and prescription dose. The TCP and NTCP were estimated, respectively, using equivalent uniform dose (EUD) model and Lyman-Kutcher-Burman (LKB) model. The correlation between ΔTCP or ΔNTCP with γ-rates, from 2%/2 and 3%/3 mm, were tested to explore the best correlation predicting the relevant γ criteria using Spearman's rank test (ρ). Wilcoxon paired test was used to calculate P value.Results: TCP value was significantly lower in the recalculated AAA plans as compared to MB plans.However, AAA predicted more NTCP on lung pneumonitis according to the LKB model and using relevant radiobiological parameters (n, m and TD50) for MB-PBC and AAA, with P=0.03. The data showed a weak correlation between radiobiological metrics with γ-rates or γ-mean, ρ<0.3.Conclusions: AAA and MB yield different TCP values as well as NTCP for lung pneumonitis based on the LKB model parameters. Therefore, 2D γ-maps, generated with 2%/2 or 3%/3 mm, could illustrate visual information about the radiobiological changes. The information is useful to evaluate the clinical outcome of a radiotherapy treatment and to approve the treatment plan of the patient if the dose constraints are respected. On the other hand, the γ-maps tool can be used as quality assurance (QA) process to check the predicted TCP and NTCP from radiobiological models.

show abstract

“…The discrepancies between the AXB10 and the XVMC algorithm were within 3%. Chetty et al 48 did not benchmark various dose calculation algorithms as such in their work, but studied the correlation of dose distributions with local control in stereotactic ablative radiotherapy (SABR). The included algorithms were the AXB11, the AAA, XVMC fast MC algorithm in iPlan TPS, two types of pencil beam algorithms and the CCC algorithm in Pinnacle TPS.…”

Section: The Axb Algorithm and Patient Plansmentioning

confidence: 99%

The accuracy of the Acuros XB algorithm in external beam radiotherapy – a comprehensive review

Ojala

2014

Int J Cancer Ther Oncol

View full text Add to dashboard Cite

Review Article AbstractThe accuracy of dose calculation algorithms has been a topic of interest among the radiotherapy community throughout last decades. On one hand the advancements in computers and algorithms has improved the accuracy, but on the other hand the developments in other parts of treatment process, in treatment delivery techniques and in treatment devices have always pushed the requirements to the next level. In this review article a comprehensive overview on the accuracy of a new type 'c' dose calculation algorithm, the Acuros XB (AXB) algorithm (Varian Medical Systems, Inc., Palo Alto, CA, USA), is provided. All the articles that have applied the AXB algorithm in terms of external beam radiotherapy are included and the research frames with reported deviations to reference methods are described. For the homogeneous water phantoms the reported accuracy was from 1% to 2%, being of similar level for heterogeneous phantoms, in rare occasions lower. In anthropometric and anthropomorphic phantoms the mean deviations were about 2% and slightly larger for single points and/or small regions. With patient plans the reported average discrepancies were less than from 3% to 5%. Almost without exceptions, the algorithm has proven to perform better than other existing commercial dose calculation algorithms. The number of such papers, in which the AXB algorithm is the only dose determination method, is already notable, which indicates that the accuracy of the algorithm is trusted for reference use and it also, with reported dosimetric results, implies that the AXB algorithm has reached its maturity.

show abstract

Correlation of dose computed using different algorithms with local control following stereotactic ablative radiotherapy (SABR)-based treatment of non-small-cell lung cancer

Cited by 34 publications

References 47 publications

Dose differences in intensity‐modulated radiotherapy plans calculated with pencil beam and Monte Carlo for lung SBRT

Dose differences in intensity‐modulated radiotherapy plans calculated with pencil beam and Monte Carlo for lung SBRT

Assessing the shift of radiobiological metrics in lung radiotherapy plans using 2D gamma index

The accuracy of the Acuros XB algorithm in external beam radiotherapy – a comprehensive review

Contact Info

Product

Resources

About