Development of a novel methodology for QA of respiratory-gated and VMAT beam delivery using Octavius 4D phantom

Yang, Bin; Geng, Hui; Ding, Ying; Kong, Cheol-Won; Cheung, C.W.; Chiu, Tin Lok; Lam, W.W.; Cheung, K.Y.; Yu, Siu Ki

doi:10.1016/j.meddos.2018.02.008

Cited by 5 publications

(4 citation statements)

References 19 publications

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“…This feature makes these ARRAYs less suitable for dose verification of VMAT with rotating beams. So, Delta 4, ArcCheck and Octavius 4D for dose verification of VMAT are more common in daily work [23][24][25].…”

Section: Gamma Standard and Passing Ratementioning

confidence: 99%

Study on the ability of 3D gamma analysis and bio-mathematical model in detecting dose changes caused by dose-calculation-grid-size (DCGS)

Bai

Zhu

et al. 2020

Radiat Oncol

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Objective: To explore the efficacy and sensitivity of 3D gamma analysis and bio-mathematical model for cervical cancer in detecting dose changes caused by dose-calculation-grid-size (DCGS). Methods: 17 patients' plans for cervical cancer were enrolled (Pinnacle TPS, VMAT), and the DCGS was changed from 2.0 mm to 5.0 mm to calculate the planned dose respectively. The dose distribution calculated by DCGS = 2.0 mm as the "reference" data set (RDS), the dose distribution calculated by the rest DCGS as the"measurement"data set (MDS), the 3D gamma passing rates and the (N) TCPs of the all structures under different DCGS were obtained, and then analyze the ability of 3D gamma analysis and (N) TCP model in detecting dose changes and what factors affect this ability. Results: The effect of DCGS on planned dose was obvious. When the gamma standard was 1.0 mm, 1.0 and 10.0%, the difference of the results of the DCGS on dose-effect could be detected by 3D gamma analysis (all p value < 0.05). With the decline of the standard, 3D gamma analysis' ability to detect this difference shows weaker. When the standard was 1.0 mm, 3.0 and 10.0%, the p value of > 0.05 accounted for the majority. With DCGS = 2.0 mm being RDS, Δgammapassing-rate presented the same trend with Δ(N) TCPs of all structures except for the femurs only when the 1.0 mm, 1.0 and 10.0% standards were adopted for the 3D gamma analysis. Conclusions: The 3D gamma analysis and bio-mathematical model can be used to analyze the effect of DCGS on the planned dose. For comparison, the former's detection ability has a lot to do with the designed standard, and the latter's capability is related to the parameters and calculated accuracy instrinsically.

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Section: Gamma Standard and Passing Ratementioning

confidence: 99%

Study on the ability of 3D gamma analysis and bio-mathematical model in detecting dose changes caused by dose-calculation-grid-size (DCGS)

Bai

Zhu

et al. 2020

Radiat Oncol

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show abstract

“…So, Delta 4, ArcCheck and Octavius 4D for dose veri cation of VMAT are more common in daily work [23][24][25].…”

Section: D Gamma Standard and Passing Ratementioning

confidence: 99%

Study on the ability of 3D gamma analysis and bio-mathematical model in detecting dose changes caused by dose-calculation-grid-size (DCGS)

Bai¹,

Zhu²,

Wu³

et al. 2020

Preprint

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Objective: To explore the efficacy and sensitivity of 3D gamma analysis and bio-mathematical model for cervical cancer in detecting dose changes caused by dose-calculation-grid-size (DCGS).Methods：17 patients’ plans for cervical cancer were enrolled (Pinnacle TPS，VMAT), and the DCGS was changed from 2.0mm to 5.0mm to calculate the planned dose respectively. The dose distribution calculated by DCGS = 2.0mm as the “reference” data set (RDS), the dose distribution calculated by the rest DCGS as the“measurement”data set (MDS), the 3D gamma passing rates and the (N)TCPs of the all structures under different DCGS were obtained, and then analyze the ability of 3D gamma analysis and (N)TCP model in detecting dose changes and what factors affect this ability.Results: The effect of DCGS on planned dose was obvious. When the gamma standard was 1.0mm, 1.0% and 10.0%, the difference of the results of the DCGS on dose-effect could be detected by 3D gamma analysis (all p value < 0.05). With the decline of the standard, 3D gamma analysis’ ability to detect this difference shows weaker. When the standard was 1.0mm, 3.0% and 10.0%, the p value of > 0.05 accounted for the majority. With DCGS=2.0mm being RDS, ∆gamma-passing-rate presented the same trend with ∆(N)TCPs of all structures except for the femurs only when the 1.0mm, 1.0% and 10.0% standards were adopted for the 3D gamma analysis.Conclusions: The 3D gamma analysis and bio-mathematical model can be used to analyze the effect of DCGS on the planned dose. For comparison, the former’s detection ability has a lot to do with the designed standard, and the latter’s capability is related to the parameters and calculated accuracy instrinsically.

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“…An extensively employed method for the patient QA is delivery of a verification plan to a 2-dimensional (2D) 1 , 2 or 3-dimensional (3D) detector arrays. 3 - 5 The agreement between the measured and planned dose distribution in the 2D detector arrays or 3D phantoms is quantified by combining dose difference (DD) and distance to agreement (DTA). This method is called conventional gamma analysis.…”

Section: Introductionmentioning

confidence: 99%

“…New developments in commercially available verification systems allow reconstructing dose on patient computed tomography (CT) data sets based on the measurements by the QA devices, such as Delta 4 phantom with Delta 4DVH Anatomy software (Scandidos), 15 , 16 ArcCheck phantom with 3DVH software (Sun Nuclear Corporation) 15 , 17 - 19 and Octavius 4D system (PTW). 5 With these platforms, comparisons between the reconstructed and planned dose–volume histogram (DVH) can be made with clinical considerations. Stambaugh et al 15 and Hauri et al 16 have previously investigated the dose calculation accuracy of the pencil beam (PB) algorithm in Delta 4DVH Anatomy software.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Delta^4DVH Anatomy in 3D Patient-Specific IMRT Quality Assurance

Tang

Yang

Dai

et al. 2020

Technol Cancer Res Treat

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Purpose: To evaluate the performance of Delta4DVH Anatomy in patient-specific intensity-modulated radiotherapy quality assurance. Materials and Methods: Dose comparisons were performed between Anatomy doses calculated with treatment plan dose measured modification and pencil beam algorithms, treatment planning system doses, film doses, and ion chamber measured doses in homogeneous and inhomogeneous geometries. The sensitivity of Anatomy doses to machine errors and output calibration errors was also investigated. Results: For a Volumetric Modulated Arc Therapy (VMAT) plan evaluated on the Delta4 geometry, the conventional gamma passing rate was 99.6%. For a water-equivalent slab geometry, good agreements were found between dose profiles in film, treatment planning system, and Anatomy treatment plan dose measured modification and pencil beam calculations. Gamma passing rate for Anatomy treatment plan dose measured modification and pencil beam doses versus treatment planning system doses was 100%. However, gamma passing rate dropped to 97.2% and 96% for treatment plan dose measured modification and pencil beam calculations in inhomogeneous head & neck phantom, respectively. For the 10 patients’ quality assurance plans, good agreements were found between ion chamber measured doses and the planned ones (deviation: 0.09% ± 1.17%). The averaged gamma passing rate for conventional and Anatomy treatment plan dose measured modification and pencil beam gamma analyses in Delta4 geometry was 99.6% ± 0.89%, 98.54% ± 1.60%, and 98.95% ± 1.27%, respectively, higher than averaged gamma passing rate of 97.75% ± 1.23% and 93.04% ± 2.69% for treatment plan dose measured modification and pencil beam in patients’ geometries, respectively. Anatomy treatment plan dose measured modification dose profiles agreed well with those in treatment planning system for both Delta4 and patients’ geometries, while pencil beam doses demonstrated substantial disagreement in patients’ geometries when compared to treatment planning system doses. Both treatment planning system doses are sensitive to multileaf collimator and monitor unit (MU) errors for high and medium dose metrics but not sensitive to the gantry and collimator rotation error smaller than 3°. Conclusions: The new Delta4DVH Anatomy with treatment plan dose measured modification algorithm is a useful tool for the anatomy-based patient-specific quality assurance. Cautions should be taken when using pencil beam algorithm due to its limitations in handling heterogeneity and in high-dose gradient regions.

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Development of a novel methodology for QA of respiratory-gated and VMAT beam delivery using Octavius 4D phantom

Cited by 5 publications

References 19 publications

Study on the ability of 3D gamma analysis and bio-mathematical model in detecting dose changes caused by dose-calculation-grid-size (DCGS)

Study on the ability of 3D gamma analysis and bio-mathematical model in detecting dose changes caused by dose-calculation-grid-size (DCGS)

Study on the ability of 3D gamma analysis and bio-mathematical model in detecting dose changes caused by dose-calculation-grid-size (DCGS)

Evaluation of Delta^4DVH Anatomy in 3D Patient-Specific IMRT Quality Assurance

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Development of a novel methodology for QA of respiratory-gated and VMAT beam delivery using Octavius 4D phantom

Cited by 5 publications

References 19 publications

Study on the ability of 3D gamma analysis and bio-mathematical model in detecting dose changes caused by dose-calculation-grid-size (DCGS)

Study on the ability of 3D gamma analysis and bio-mathematical model in detecting dose changes caused by dose-calculation-grid-size (DCGS)

Study on the ability of 3D gamma analysis and bio-mathematical model in detecting dose changes caused by dose-calculation-grid-size (DCGS)

Evaluation of Delta4DVH Anatomy in 3D Patient-Specific IMRT Quality Assurance

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Evaluation of Delta^4DVH Anatomy in 3D Patient-Specific IMRT Quality Assurance