Dosimetric Impact of Acuros XB Dose-to-Water and Dose-to-Medium Reporting Modes on Lung Stereotactic Body Radiation Therapy and Its Dependency on Structure Composition

Muñoz-Montplet, C.; Fuentes-Raspall, Rafael; Jurado-Bruggeman, D.; Agramunt-Chaler, S.; Onsès-Segarra, Albert; Buxó, María

doi:10.1016/j.adro.2021.100722

Cited by 4 publications

(11 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It implied that the dose reported for PTV 6996 _Air Cavity under AXB_Lung might be overestimated for an air‐filled nasal cavity, leading to the possibility of underdosage or insufficient coverage to PTV 6996 . According to AAPM Task Group Report 105, 5% change in dose can result in 10%–20% change in tumor control probability or up to 20%–30% change in normal tissue complication probability if the prescribed dose is within the steepest region of dose–effect curves 9,13 . Therefore, attention should be put to ensure the accuracy of material assignment for dose calculation in AXB such that optimal dosage was given for tumor control.…”

Section: Discussionmentioning

confidence: 99%

“…According to AAPM Task Group Report 105, 5% change in dose can result in 10%–20% change in tumor control probability or up to 20%–30% change in normal tissue complication probability if the prescribed dose is within the steepest region of dose–effect curves. 9 , 13 Therefore, attention should be put to ensure the accuracy of material assignment for dose calculation in AXB such that optimal dosage was given for tumor control.…”

Section: Discussionmentioning

confidence: 99%

“…6,7 Several publications have reported that AXB provides an accurate dose calculation in heterogeneous environment. 5,[7][8][9] However, no study has been conducted to evaluate the effect of material assignment on dose calculation in the presence of air cavity in nasopharyngeal region using real clinical cases. There-fore, the aim of this study was to assess the dosimetric impact of material assignment to nasal cavity under AXB using real clinical NPC cases.…”

Section: Introductionmentioning

confidence: 99%

“…Several publications have reported that AXB provides an accurate dose calculation in heterogeneous environment 5,7–9 . However, no study has been conducted to evaluate the effect of material assignment on dose calculation in the presence of air cavity in nasopharyngeal region using real clinical cases.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

The effect of material assignment in nasal cavity on dose calculation for nasopharyngeal carcinoma (NPC) using Acuros XB

Cheung

Chow

Kan

et al. 2022

J Applied Clin Med Phys

View full text Add to dashboard Cite

To evaluate the effect of material assignment in nasal cavity on dose calculation for the volumetric modulated arc therapy (VMAT) of nasopharyngeal carcinoma (NPC) using Acuros XB (AXB) algorithm. Methods:The VMAT plans of 30 patients with NPC were calculated using AXB with material auto-assignment of nasal cavity to lung and reassignment to air respectively. The doses to the planning target volumes (PTVs) overlapping with nasal cavity with material auto-assignment of lung (AXB_Lung) were compared to the values obtained when nasal cavity was reassigned to air (AXB_Air) under the dose-to-medium (D m ) reporting mode of AXB. Results: For dose calculated under AXB_Lung, the D 98% , D 2% , and D mean of the PTV 69.96 _Air Cavity (PTV of prescription dose 69.96 Gy overlapping with nasal cavity) were on average 16.1%,1.6%,and 8.6% larger than that calculated under AXB_Air, respectively. Up to 19.5% difference in D 98% , 3% difference in D 2% , and 11.2% difference in D mean were observed in the worst cases for PTV 69.96 . Similar trend was observed for the PTV 5940 _Air Cavity, in which the D 98% , D 2% , and D mean calculated under AXB_Lung were on average 14.7%, 2.5%, and 10.2% larger than that calculated under AXB_Air, respectively. In the worst cases, the difference observed in D 98% , D 2% , and D mean could be up to 17.7%, 4.5%, and 12.7%, respectively. Conclusions: Significant dose difference calculated by AXB between the material assignment of lung and air in nasal cavity for NPC cases might imply the possibility of underdosage to the PTVs that overlap with inhomogeneity. Therefore, attention should be put to ensure that accurate material assignment for dose calculation under AXB such that optimal dosage was given for tumor control.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The effect of material assignment in nasal cavity on dose calculation for nasopharyngeal carcinoma (NPC) using Acuros XB

Cheung

Chow

Kan

et al. 2022

J Applied Clin Med Phys

View full text Add to dashboard Cite

show abstract

“…This CF depended on the medium atomic composition, beam spectrum, and the dose reporting mode of the original dose distribution, which were illustrated in 30 for converting a volume medium into waterwhere D w,vol and D m,vol represented the dose-to-water and dose-to-medium volume, respectively; f i was the fraction corresponding to material i in the volume composition; CFmAXB,Dm 6MV was the value of CF for the tissues of AXB (mAXB), 6-MV photon beam, and dose-to-medium. Previously published literature 31 listed the values of CF for AXB human tissues.…”

Section: Methodsmentioning

confidence: 99%

Radiobiological Comparison of Acuros External Beam and Anisotropic Analytical Algorithm on Esophageal Carcinoma Radiotherapy Treatment Plans

et al. 2022

View full text Add to dashboard Cite

Objective The present study aimed to investigate the dose differences and radiobiological assessment between Anisotropic Analytical Algorithm (AAA) and Acuros External Beam (AXB) with its 2 calculation models, namely, dose-to-water (AXB-Dw) and dose-to-medium (AXB-Dm), on esophageal carcinoma radiotherapy treatment plans. Materials and methods The AXB-Dw and AXB-Dm plans were generated by recalculating the initial 66 AAA plans using the AXB algorithm with the same monitor units and beam parameters as those in the original plan. The dosimetric and radiobiological assessment parameters were calculated for the planning target volume (PTV) and organs at risk (OARs). The gamma agreement for the PTV and the correlation between it and the volume of the air cavity and bone among the different algorithms were compared simultaneously. The dose discrepancy between the theoretical calculation and treatment planning system (TPS) when switching from AXB-Dm to AXB-Dw was analyzed according to the composition of the structures. Results The PTV dose of AXB-Dm plans was significantly smaller than that of the AAA and AXB-Dw plans (P < .05), except for D2. The difference values for AAA vs AXB-Dm (∆ Dx,(AAA-AXB,Dm)) and AXB-Dw vs AXB-Dm (∆ Dx,(AXB,Dw-AXB,Dm)) were 1.94% [1.27%, 2.64%] and 1.95% [1.56%, 2.27%], respectively. For the spinal cord and heart, there were obvious differences between the AAA vs AXB-Dm (spinal cord: 1.15%, heart: 2.89%) and AXB-Dw vs AXB-Dm (spinal cord: 1.88%, heart: 3.25%) plans. For the lung, the differences between AAA vs AXB-Dm and AAA vs AXB-Dw were significantly larger than those of AXB-Dm vs AXB-Dw. Compared to the case of AAA and AXB-Dw, the decrease in biologically effective dose (BED10, [Formula: see text]) of AXB-Dm due to dose non-uniformity exceeded 6.5%, even for a small [Formula: see text]. The average values of equivalent uniform dose in the AAA, AXB-Dw, and AXB-Dm plans were 52.03±.39 Gy, 52.24 ± .81 Gy, and 51.13 ± .47 Gy, respectively. The tumor control probability (TCP) results for PTV in the AAA, AXB-Dw, and AXB-Dm plans were 62.29 ± 1.57%, 62.82 ± 1.69%, and 58.68±1.88%, respectively. With the 2%/2 mm and 3%/3 mm acceptance criteria, the mean values of [Formula: see text], [Formula: see text], and [Formula: see text] were 87.24, 63.3, and 64.81% vs 97.86, 91.77, and 89.25%, respectively. The dose discrepancy between the theoretical calculation and TPS when switching from AXB-Dm to AXB-Dw was approximately 1.63%. Conclusions The AAA and AXB-Dw algorithms overestimated the radiobiological parameters when the tumor particularly consisted of nonuniform tissues. A relatively small dose difference could cause a significant reduction in the corresponding TCP. Dose distribution algorithms should be carefully chosen by physicists and oncologists to improve tumor control, as well as to optimize OARs protection.

show abstract

Dosimetric evaluation of VMAT treatment plans for patients with stage IIB or III non-small cell lung carcinomas

et al. 2023

View full text Add to dashboard Cite

Introduction: Volumetric-modulated arc therapy (VMAT) has emerged as a promising radiation treatment technique. One of the challenges in VMAT planning for lung carcinoma is the lack of consistency among different institutions with respect to what is considered an acceptable treatment plan in terms of target coverage and doses to the organs at risk (OAR). Additionally, the accuracy of dose calculations in the presence of heterogeneous medium (i.e. air) is another challenge in lung VMAT planning. Our objective is to develop an institutional criteria for non-stereotactic body radiotherapy (non-SBRT) lung treatment plans by evaluating the dosimetric impact of plan normalisation and dose calculation algorithms, including the Anisotropic Analytical Algorithm (AAA), AcurosXB (AXB) and Monte Carlo (MC) simulation, on VMAT plans for non-small cell lung cancer (NSCLC). Methods: The CT dataset of 20 patients with NSCLC was randomly selected to ensure a spectrum of target sizes and locations. All treatment planning was accomplished with 2–3 VMAT arcs and a prescription of 60 Gy in 30 fractions. Two plan normalisation methods were employed: (i) planning target volume (PTV) V100% = 95% and (ii) PTV V95% = 95%. Results: All three dose calculation algorithms revealed heterogeneous and conformal plans irrespective of plan normalisations. The PTV and OARs dose–volume constraints were met using both normalisation methods. However, we observed that AAA overestimated the minimum PTV doses by 2–5% regardless of plan normalisation. The mean PTV-V100% was lower for AAA in comparison with AXB and MC algorithms. Conclusions: VMAT is an effective radiotherapy technique for achieving greater target dose conformity, heterogeneity and dose fall-off from the PTV for the treatment of NSCLC. The results of this study can provide the basis for the development of local plan acceptability criteria for NSCLC VMAT plans, and the clinical implementation can be achieved with minimal or no imposition on resources and time constraints. Occasionally, plan normalisation of PTV-V95% = 95% may be required to ensure that the OAR dose tolerances are not exceeded.

show abstract

Dosimetric Impact of Acuros XB Dose-to-Water and Dose-to-Medium Reporting Modes on Lung Stereotactic Body Radiation Therapy and Its Dependency on Structure Composition

Cited by 4 publications

References 40 publications

The effect of material assignment in nasal cavity on dose calculation for nasopharyngeal carcinoma (NPC) using Acuros XB

The effect of material assignment in nasal cavity on dose calculation for nasopharyngeal carcinoma (NPC) using Acuros XB

Radiobiological Comparison of Acuros External Beam and Anisotropic Analytical Algorithm on Esophageal Carcinoma Radiotherapy Treatment Plans

Dosimetric evaluation of VMAT treatment plans for patients with stage IIB or III non-small cell lung carcinomas

Contact Info

Product

Resources

About