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Bai H, Zhu S, Wu X, Liu X, Chen F, Yan J. Study on the ability of 3D gamma analysis and bio-mathematical model in detecting dose changes caused by dose-calculation-grid-size (DCGS). Radiat Oncol 2020; 15:161. [PMID: 32631380 PMCID: PMC7336463 DOI: 10.1186/s13014-020-01603-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 06/23/2020] [Indexed: 02/06/2023] Open
Abstract
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, ∆gamma-passing-rate presented the same trend with ∆(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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Affiliation(s)
- Han Bai
- Department of Radiation Oncology, Yunnan Tumor Hospital, The Third Affiliated Hospital of Kunming Medical University, No.519 Kunzhou, Road, Xishan District, Kunming, Yunnan, China
| | - Sijin Zhu
- Department of Radiation Oncology, Yunnan Tumor Hospital, The Third Affiliated Hospital of Kunming Medical University, No.519 Kunzhou, Road, Xishan District, Kunming, Yunnan, China
| | - Xingrao Wu
- Department of Radiation Oncology, Yunnan Tumor Hospital, The Third Affiliated Hospital of Kunming Medical University, No.519 Kunzhou, Road, Xishan District, Kunming, Yunnan, China.
| | - Xuhong Liu
- Department of Radiation Oncology, Yunnan Tumor Hospital, The Third Affiliated Hospital of Kunming Medical University, No.519 Kunzhou, Road, Xishan District, Kunming, Yunnan, China
| | - Feihu Chen
- Department of Radiation Oncology, Yunnan Tumor Hospital, The Third Affiliated Hospital of Kunming Medical University, No.519 Kunzhou, Road, Xishan District, Kunming, Yunnan, China
| | - Jiawen Yan
- Department of Radiation Oncology, Yunnan Tumor Hospital, The Third Affiliated Hospital of Kunming Medical University, No.519 Kunzhou, Road, Xishan District, Kunming, Yunnan, China
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Tang D, Yang Z, Dai X, Cao Y. Evaluation of Delta 4DVH Anatomy in 3D Patient-Specific IMRT Quality Assurance. Technol Cancer Res Treat 2020; 19:1533033820945816. [PMID: 32720589 PMCID: PMC7388137 DOI: 10.1177/1533033820945816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
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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Affiliation(s)
- Du Tang
- Department of Oncology, Xiangya Hospital, Central South University, Changsha, China
| | - Zhen Yang
- Department of Oncology, Xiangya Hospital, Central South University, Changsha, China
| | - Xunzhang Dai
- Department of Oncology, Xiangya Hospital, Central South University, Changsha, China
| | - Ying Cao
- Department of Oncology, Xiangya Hospital, Central South University, Changsha, China
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Yang B, Chiu TL, Law WK, Geng H, Lam WW, Leung TM, Yiu LH, Cheung KY, Yu SK. Performance evaluation of the CyberKnife system in real-time target tracking during beam delivery using a moving phantom coupled with two-dimensional detector array. Radiol Phys Technol 2019; 12:86-95. [PMID: 30604357 DOI: 10.1007/s12194-018-00495-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 12/16/2018] [Accepted: 12/19/2018] [Indexed: 10/27/2022]
Abstract
The aim of the current study was to evaluate the tracking error of the Synchrony Respiratory Tracking system by conducting beam-by-beam analyses to determine the variation in the tracking beams measured during target motion. A moving phantom of in-house design coupled with a two-dimensional (2D) detector array was used to simulate respiratory motion in the superoinferior (SI) and anteroposterior (AP) direction. A styrofoam block with four implanted fiducial markers was placed on top of the detector to enable the fiducial-based respiratory tracking. Measurements were performed with the phantom under either stationary mode or sinusoidal motion of 6-s cycle and 15/20-mm amplitude at SI and AP direction. The measurement data were saved as movie files that were used to calculate the center shift of the beam with 100-ms sampling time. The tracking accuracy of the system was defined as the targeting error, which could be tracked with probability of > 95% (Ep95). The mean ± standard deviation of Ep95 was 0.28 ± 0.08 mm under stationary condition; 0.66 ± 0.23 mm (range: 0.28-1.22 mm) under sinusoidal respiratory motion. The maximum drift of the beam center for all beam paths was 2.7 mm. The tracking accuracy of CyberKnife Synchrony system was successfully evaluated using a moving phantom and 2D detector array; the maximum tracking error was < 1.5 mm for sinusoidal motion of amplitude ≤ 20 mm.
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Affiliation(s)
- Bin Yang
- Medical Physics and Research Department, Hong Kong Sanatorium & Hospital, 2 Village Road, Happy Valley, Hong Kong, China.
| | - Tin Lok Chiu
- Medical Physics and Research Department, Hong Kong Sanatorium & Hospital, 2 Village Road, Happy Valley, Hong Kong, China
| | - Wai Kong Law
- Medical Physics and Research Department, Hong Kong Sanatorium & Hospital, 2 Village Road, Happy Valley, Hong Kong, China
| | - Hui Geng
- Medical Physics and Research Department, Hong Kong Sanatorium & Hospital, 2 Village Road, Happy Valley, Hong Kong, China
| | - Wai Wang Lam
- Medical Physics and Research Department, Hong Kong Sanatorium & Hospital, 2 Village Road, Happy Valley, Hong Kong, China
| | - Tat Ming Leung
- Biomedical Engineering Department, Hong Kong Sanatorium & Hospital, 2 Village Road, Happy Valley, Hong Kong, China
| | - Lok Hang Yiu
- Biomedical Engineering Department, Hong Kong Sanatorium & Hospital, 2 Village Road, Happy Valley, Hong Kong, China
| | - Kin Yin Cheung
- Medical Physics and Research Department, Hong Kong Sanatorium & Hospital, 2 Village Road, Happy Valley, Hong Kong, China
| | - Siu Ki Yu
- Medical Physics and Research Department, Hong Kong Sanatorium & Hospital, 2 Village Road, Happy Valley, Hong Kong, China
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Urso P, Lorusso R, Marzoli L, Corletto D, Imperiale P, Pepe A, Bianchi L. Practical application of Octavius ® -4D: Characteristics and criticalities for IMRT and VMAT verification. J Appl Clin Med Phys 2018; 19:517-524. [PMID: 30009564 PMCID: PMC6123102 DOI: 10.1002/acm2.12412] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 03/28/2018] [Accepted: 06/07/2018] [Indexed: 11/12/2022] Open
Abstract
Octavius®‐4D is a very effective device in radiotherapy treatment quality assurance (QA), due to its simple set‐up and analysis package. However, even if it is widely used, its main characteristics and criticalities were only partially investigated. Taking start from its commissioning, the aim of this work was to study the main dependencies of the device response. The outcome dependence was studied comparing results by different delivery techniques [Intensity Modulated Radiation Therapy, IMRT (n = 29) and RapidArc, RA (n = 15)], anatomical regions [15 head/neck, 19 pelvis and 10 pancreas] and linear accelerators [DHX (n = 14) and Trilogy (n = 30)]. Moreover, the agreement dependency on the section of the phantom was assessed. Plan evaluations obtained by 2D, 3D, and volumetric γ‐index (both local and global) were also compared. Generally, high dose gradient resulted critically managed by the assembly, with a smoother effect in RA technique. Worse agreements emerged in the 2D γ‐index vs those of 3D and volumetric (P < 0.001), that were instead statistically comparable in global metric (P > 0.300). Volumetric plan evaluation was coherent with the average of passing rates on the 3 phantom axes (r ≥ 0.9), but transversal section provided best agreements vs sagittal and coronal ones (P < 0.050). The three studied districts furnished comparable results (P > 0.050) while the two LINACs provided different agreements (P < 0.005). The study pointed out that the phantom transversal section better fits the planned dose distribution, so this should be accounted when a two‐dimensional evaluation is needed. Moreover, the major reliability of the 3D metric with respect to the 2D one, as it better agrees with the dosimetric evaluation on the whole volume, suggests that it should be preferred in a two‐dimensional evaluation. Better agreements, obtained with RA vs IMRT technique, confirm that Octavius®‐4D is specifically conceived for rotational delivery. Lastly, the assembly resulted sensitive to different technology.
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Affiliation(s)
- Patrizia Urso
- Department of Medical Physics, A.S.S.T. Valle Olona, Busto Arsizio, Italy
| | - Rita Lorusso
- Department of Medical Physics, A.S.S.T. Valle Olona, Busto Arsizio, Italy
| | - Luca Marzoli
- Department of Medical Physics, A.S.S.T. Valle Olona, Busto Arsizio, Italy
| | - Daniela Corletto
- Department of Medical Physics, A.S.S.T. Valle Olona, Busto Arsizio, Italy
| | - Paolo Imperiale
- Department of Medical Physics, A.S.S.T. Valle Olona, Busto Arsizio, Italy
| | - Annalisa Pepe
- Department of Medical Physics, A.S.S.T. Valle Olona, Busto Arsizio, Italy
| | - Lorenzo Bianchi
- Department of Medical Physics, A.S.S.T. Valle Olona, Busto Arsizio, Italy
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