Study on Motion Management of Pancreatic Cancer Treated by CyberKnife

Shenghua, Jing; Jiang, Changhui; Ji, Xiaoqin; Qiu, Xiangnan; Li, Jing; Sun, Xiangdong; Zhu, Xiaodong

doi:10.3389/fonc.2021.767832

Cited by 5 publications

(6 citation statements)

References 28 publications

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“…A variety of SBRT techniques can be used to reduce the irradiated volume in the case of respiratory target motion 26 . The Synchrony real‐time tumor tracking technology incorporated into the CK provides a high degree of precision in delivering the radiation dose 27 . In this context, evaluating the SRTS is crucial to assess the precision of dose delivery.…”

Section: Discussionmentioning

confidence: 99%

A retrospective multi‐center feasibility study of a new PTV margin estimation approach for moving targets using CyberKnife log files

Miandoab

Saramad

Setayeshi

et al. 2023

J Applied Clin Med Phys

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Purpose This study investigates a new approach for estimating the planning target volume (PTV) margin for moving tumors treated with robotic stereotactic body radiotherapy (SBRT). Methods In this new approach, the covariance of modeling and prediction errors was estimated using error propagation and implemented in the Van Herk formula to form a Modified Van Herk formula (MVHF). To perform a retrospective multi‐center analysis, the MVHF was studied using 163 patients treated with different system versions of robotic SBRT (G3 version 6.2.3, VSI version 8.5, and VSI version 9.5) and compared with two established PTV margins estimation methods: The original Van Herk Formula (VHF) and the Uncertainty Estimation Method (UEM). Results Overall, the PTV margins provided by the three formalisms are similar with 4–5 mm in the lung region and 4 mm in abdomen region to the PTV margins used in clinical. Furthermore, when analyzing individual patients, a difference of up to 1 mm was found between the PTV margin estimations using MVHF and VHF. The corresponding average discrepancies for the superior‐inferior (SI) direction ranged between −0.19 mm to 0.38 mm in CK G3 version 6.2.3, −0.36 mm to 0.33 mm in CK VSI version 8.5, and −0.34 mm to 0.40 mm in CK VSI version 9.5. Conclusions It was found that for the lower left lung, upper left lung, lower right lung, upper right lung, central liver, and upper liver, the effect of covariance between model and prediction errors in SI direction was around 20%, 30%, 25%, 25%, 25%, and 30%, respectively. Notable covariance effects between model and prediction errors can be considered in PTV margin estimation using a modified VHF, which allowed for more precise target localization in robotic SBRT for moving tumors. Overall, in each of the three directions, the difference between MVHF and utilized clinical margins is 0.65 mm in the lung and abdominal region. Therefore, to improve the clinical PTV margins with the new approach, it is suggested to use the adaptive PTV margins in the next fractions.

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Section: Discussionmentioning

confidence: 99%

A retrospective multi‐center feasibility study of a new PTV margin estimation approach for moving targets using CyberKnife log files

Miandoab

Saramad

Setayeshi

et al. 2023

J Applied Clin Med Phys

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“…A previous study on patients treated with protons showed the robustness of dose coverage for pancreas motion below 3.7 mm (Knäusl et al 2023). Nevertheless, patients' pancreas movement is not restricted to the margin of the so-called small movers but can increase individually up to several cm in the CC direction (Bhasin et al 2006, Knybel et al 2014, Dolde et al 2019a, Jing et al 2021. To cover this wide range of pancreatic movement observed in patients, breathinginduced motion from 3.98 to 18.19 mm was studied with PPIeT.…”

Section: Phantom Motionmentioning

confidence: 99%

“…The pancreatic motion is highly variable, where values from 1.0 mm up to 27.3 mm in the craniocaudal (CC) direction were found (Bhasin et al 2006, Knybel et al 2014, Dolde et al 2019a, Jing et al 2021. Although motion management strategies have improved pancreatic treatment outcomes, these often impose unease on the patient by the obligation of breath holding or wearing a corset (Dolde et al 2019a).…”

Section: Introductionmentioning

confidence: 99%

A phantom to simulate organ motion and its effect on dose distribution in carbon ion therapy for pancreatic cancer

Stengl,

Panow,

Arbes

et al. 2023

Phys. Med. Biol.

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Objective: Carbon ion radiotherapy is a promising radiation technique for malignancies like pancreatic cancer. However, organs’ motion imposes challenges for achieving homogeneous dose delivery. In this study, an anthropomorphic Pancreas Phantom for Ion-beam Therapy (PPIeT) was developed to simulate breathing and gastrointestinal motion during radiotherapy.Approach: The developed phantom contains a pancreas, two kidneys, a duodenum, a spine and a spinal cord. The shell of the organs was 3D printed and filled with agarose-based mixtures. Hounsfield Units (HU) of PPIeTs’ organs were measured by CT. The pancreas motion amplitude in cranial-caudal (CC) direction was evaluated from patients’ 4D CT data. Motions within the obtained range were simulated and analyzed in PPIeT using MRI. Additionally, GI motion was mimicked by changing the volume of the duodenum and quantified by MRI. A patient-like treatment plan was calculated for carbon ions, and the phantom was irradiated in a static and moving condition. Dose measurements in the organs were performed using an ionization chamber and dosimetric films.Main results: PPIeT presented tissue equivalent HU and reproducible breathing-induced CC displacements of the pancreas between (3.98±0.36) mm and a maximum of (18.19±0.44) mm. The observed maximum change in distance of (14.28±0.12) mm between pancreas and duodenum was consistent with findings in patients. Carbon ion irradiation revealed homogenous coverage of the virtual tumor at the pancreas in static condition with a 1 % deviation from the treatment plan. Instead, the dose delivery during motion with the maximum amplitude yielded an underdosage of 21 % at the target and an increased uncertainty by two orders of magnitude. Significance: A dedicated phantom was designed and developed for breathing motion assessment of dose deposition during carbon ion radiotherapy. PPIeT is a unique tool for dose verification in the pancreas and its organs at risk during end-to-end tests.

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“…8,9 However, it has been reported that the prone position induces larger respiratory motion than the supine position. 10 In cases in which such motion occurs (e.g., in the lungs), the Synchrony respiratory tracking system has been used for tumor tracking, [11][12][13][14][15][16][17] and the tracking data can be retrieved as log files after irradiation. Xsight spine prone tracking (XSPT) enables real-time tracking by combining the Synchrony system with XST to compensate for respiratory motion in the prone position.…”

Section: Introductionmentioning

confidence: 99%

“…Xsight spine prone tracking (XSPT) enables real-time tracking by combining the Synchrony system with XST to compensate for respiratory motion in the prone position. The tracking error resulting from using the Synchrony system in the supine position during treatments of the lung, liver, and pancreas has been studied, [13][14][15][16][17] whereas that in the prone position has not been investigated. In addition, Hoogeman et al demonstrated that the prone position results in more systematic and accidental errors than the supine position.…”

Section: Introductionmentioning

confidence: 99%

Respiratory motion tracking of spine stereotactic radiotherapy in prone position

Mizonobe

Akasaka

Uehara

et al. 2023

J Applied Clin Med Phys

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The CyberKnife system is a specialized device for non-coplanar irradiation; however, it possesses the geometric restriction that the beam cannot be irradiated from under the treatment couch. Prone positioning is expected to reduce the dose to normal lung tissue in spinal stereotactic body radiotherapy (SBRT) owing to the efficiency of beam arrangement; however, respiratory motion occurs.Therefore,the Xsight spine prone tracking (XSPT) system is used to reduce the effects of respiratory motion. The purpose of this study was to evaluate the motion-tracking error of the spine in the prone position. Materials and Methods: Data from all 25 patients who underwent spinal SBRT at our institution between April 2020 and February 2022 using CyberKnife (VSI, version 11.1.0) with the XSPT tracking system were retrospectively analyzed using log files. The tumor motion, correlation, and prediction errors for each patient were examined. Furthermore, to assess the potential relationships between the parameters, the relationships between the tumor-motion amplitudes and correlation or prediction errors were investigated using linear regression. Results:The tumor-motion amplitudes in each direction were as follows: superior-inferior (SI), 0.51 ± 0.39 mm; left-right (LR), 0.37 ± 0.29 mm; and anterior-posterior (AP), 3.43 ± 1.63 mm. The overall mean correlation and prediction errors were 0.66 ± 0.48 mm and 0.06 ± 0.07 mm, respectively. The prediction errors were strongly correlated with the tumor-motion amplitudes, whereas the correlation errors were not. Conclusions: This study demonstrated that the correlation error of spinal SBRT in the prone position is sufficiently small to be independent of the tumormotion amplitude. Furthermore, the prediction error is small, contributing only slightly to the tracking error. These findings will improve the understanding of how to compensate for respiratory-motion uncertainty in the prone position.

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Study on Motion Management of Pancreatic Cancer Treated by CyberKnife

Cited by 5 publications

References 28 publications

A retrospective multi‐center feasibility study of a new PTV margin estimation approach for moving targets using CyberKnife log files

A retrospective multi‐center feasibility study of a new PTV margin estimation approach for moving targets using CyberKnife log files

A phantom to simulate organ motion and its effect on dose distribution in carbon ion therapy for pancreatic cancer

Respiratory motion tracking of spine stereotactic radiotherapy in prone position

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