Estimating intrafraction tumor motion during fiducial-based liver stereotactic radiotherapy via an iterative closest point (ICP) algorithm

Li, Wu-zhou; Liang, Zhiwen; Cao, Yi; Cao, Tingting; Hong, Quan; Yang, Zhiyong; Li, Qin; Dai, Zhitao

doi:10.1186/s13014-019-1401-2

Cited by 15 publications

(10 citation statements)

References 34 publications

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“…Meanwhile, it establishes a correlation model with respiratory signals on the body surface to achieve realtime tracking. However, in a clinical setting, fiducial (Li et al, 2019). In the paper, we optimized the positioning methods for ineligible patients to reduce the errors caused by breathing and reduce the target area's leakage.…”

Section: Discussionmentioning

confidence: 99%

Radiation dosimetric influence by different target volume definition in Cyberknife lung cancer and abdomen stereotactic body radiotherapy

Zhou

Yi-kun

et al. 2021

Journal of Radiation Research and Applied Sciences

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Purpose:The dosimetric characteristics between four-dimensional with end-expiration and end-inspiration CT dose distributions of Cyberknifeare to be evaluated. Methods: A set of four dimensional (4D) CT images and two sets of CT scans,includingendinspiration and end-expiration breath-hold, were obtained from 15 CyberKnife treated patients. Three internal target volumes (ITVs) were created from the three sequence images. Allpatients were treated using ITV-based strategy with an additional ITV-to-PTV margin of 3 mm. Results: In all of the 15 patients, the PTVfuse consistently has the smallest volumes compared to other PTV's. The nCI and coveragesof the plans were based on PTVfuse, which provided statistically significant differences for PTV4DE and PTV4DI. Additionally, the dose of normal tissue showed no statistical differences in the three type of plans (plan PTV4DE VS PTV4DI, p = 0.76), (plan PTV4DE VSPTVfuse, p = 0.23) and (plan PTV4DI VSPTVfuse, p = 0.16). Conclusion:The fusion of breath-hold sequences is beneficial to provide excellent target coverage than the end-inspiration or end-expiration with 4D-CT approach for target definition. Furthermore, the fusion of the end-expiration and end-inspiration CT scans may be used as an alternative to 4D CT in the absence of multi-modality images.

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Section: Discussionmentioning

confidence: 99%

Radiation dosimetric influence by different target volume definition in Cyberknife lung cancer and abdomen stereotactic body radiotherapy

Zhou

Yi-kun

et al. 2021

Journal of Radiation Research and Applied Sciences

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“…The key component of the framework is the fiducial detection model, which is an fCN‐based deep learning model and needs prior training (Section 2.A). The other components, namely, the 3D position reconstruction and intrafraction motion estimation modules, are an extension of our previous work 27 and will be summarized in Sections 2.B and 2.C, respectively.…”

Section: Methodsmentioning

confidence: 99%

Artificial intelligence‐based framework in evaluating intrafraction motion for liver cancer robotic stereotactic body radiation therapy with fiducial tracking

Liang

Zhou²,

Yang

et al. 2020

Medical Physics

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Purpose This study aimed to design a fully automated framework to evaluate intrafraction motion using orthogonal x‐ray images from CyberKnife. Methods The proposed framework includes three modules: (a) automated fiducial marker detection, (b) three‐dimensional (3D) position reconstruction, and (c) intrafraction motion evaluation. A total of 5927 images from real patients treated with CyberKnife fiducial tracking were collected. The ground truth was established by labeling coarse bounding boxes manually, and binary mask images were then obtained by applying a binary threshold and filter. These images and labels were used to train a detection model using a fully convolutional network (fCN). The output of the detection model can be used to reconstruct the 3D positions of the fiducial markers and then evaluate the intrafraction motion via a rigid transformation. For a patient test, the motion amplitudes, rotations, and fiducial cohort deformations were calculated used the developed framework for 13 patients with a total of 52 fractions. Results The precision and recall of the fiducial marker detection model were 98.6% and 95.6%, respectively, showing high model performance. The mean (±SD) centroid error between the predicted fiducial markers and the ground truth was 0.25 ± 0.47 pixels on the test data. For intrafraction motion evaluation, the mean (±SD) translations in the superior–posterior (SI), left–right (LR), and anterior–posterior (AP) directions were 13.1 ± 2.2 mm, 2.0 ± 0.4 mm, and 5.2 ± 1.4 mm, respectively, and the mean (±SD) rotations in the roll, pitch and yaw directions were 2.9 ± 1.5°, 2.5 ± 1.5°, and 3.1 ± 2.2°. Seventy‐one percent of the fractions had rotations larger than the system limitations. With rotation correction during rigid registration, only 2 of the 52 fractions had residual errors larger than 2 mm in any direction, while without rotation correction, the probability of large residual errors increased to 46.2%. Conclusion We developed a framework with high performance and accuracy for automatic fiducial marker detection, which can be used to evaluate intrafraction motion using orthogonal x‐ray images from CyberKnife. For liver patients, most fractions have fiducial cohort rotations larger than the system limitations; however, the fiducial cohort deformation is small, especially for the scenario with rotation correction.

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“…After 2015, the number of publications is increased significantly. There are 9 publications in 2016 [118][119][120][121][122][123][124][125][126], 7 publications in 2017 [127][128][129][130][131][132][133], 10 publications in 2018 [134][135][136][137][138][139][140][141][142][143], 9 publications in 2019 [144][145][146][147][148][149][150][151][152] and 8 publications in 2020 [153][154][155][156][157][158][159][160]. Within the subspecialty of radiation therapy, the numbers of publications in the fields of clinical implementation, plan optimization, plan evaluation and quality assurance are 23 papers (37%), 16 papers (26%), 14 papers (23%) and 9 papers (14%), respectively.…”

Section: Scientific Researchmentioning

confidence: 99%

The status of medical physics in radiotherapy in China

Yan

Huang

et al. 2021

Physica Medica

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To present an overview of the status of medical physics in radiotherapy in China, including facilities and devices, occupation, education, research, etc. Materials and methods: The information about medical physics in clinics was obtained from the 9-th nationwide survey conducted by the China Society for Radiation Oncology in 2019. The data of medical physics in education and research was collected from the publications of the official and professional organizations. Results: By 2019, there were 1463 hospitals or institutes registered to practice radiotherapy and the number of accelerators per million population was 1.5. There were 4172 medical physicists working in clinics of radiation oncology. The ratio between the numbers of radiation oncologists and medical physicists is 3.51. Approximately, 95% of medical physicists have an undergraduate or graduate degrees in nuclear physics and biomedical engineering. 86% of medical physicists have certificates issued by the Chinese Society of Medical Physics. There has been a fast growth of publications by authors from mainland of China in the top international medical physics and radiotherapy journals since 2018. Conclusions: Demand for medical physicists in radiotherapy increased quickly in the past decade. The distribution of radiotherapy facilities in China became more balanced. High quality continuing education and training programs for medical physicists are deficient in most areas. The role of medical physicists in the clinic has not been clearly defined and their contributions have not been fully recognized by the community.Prof. Xu Haichao in 1940s at Peking Union Medical College (PUMC). He worked with Prof. Marvin Williomus, an American medical physicist, to treat cancer patients using a 400 kV X-ray unit [7]. The department of radiology in Caner Institute of Chinese Academy of Medical Sciences (CICAMS) started to treat patients with a Cobalt-60 unit in 1958. At the same year, the division of radiation physics in CICAMS was founded. They made the manual multi-leaf collimator and installed it on Cobalt-60 machine in 1965. Later, they made the remote control system for brachytherapy machine using Cobalt-60 source ball in 1965Cobalt-60 source ball in -1967.From 1970, China began to build linear accelerators and on-board imaging devices. As a result, 25 MeV Betatron, Simulator and Cobalt-60 brachytherapy machine were produced by Tianjing therapeutic instrument factory [9]. Meanwhile, Beijing Medical Apparatus and Instruments Institute built the first linear accelerator [10]. Since 1976, the major hospitals started to purchase high-end linear accelerators, CT, Brachytron and planning software from USA and Europe [11]. Following the clinical application of the linear accelerators, text books in Chinese

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Estimating intrafraction tumor motion during fiducial-based liver stereotactic radiotherapy via an iterative closest point (ICP) algorithm

Cited by 15 publications

References 34 publications

Radiation dosimetric influence by different target volume definition in Cyberknife lung cancer and abdomen stereotactic body radiotherapy

Radiation dosimetric influence by different target volume definition in Cyberknife lung cancer and abdomen stereotactic body radiotherapy

Artificial intelligence‐based framework in evaluating intrafraction motion for liver cancer robotic stereotactic body radiation therapy with fiducial tracking

The status of medical physics in radiotherapy in China

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