Evaluation of lung tumor motion in a large sample: Target‐related and clinical factors influencing tumor motion based on four‐dimensional CT

Li, Fengxiang; Qu, Yanlin; Zhang, Tingting; Cui, Zhen; Sun, Xin; Zhang, Tao; Li, Jianbin

doi:10.1002/cam4.4255

Cited by 3 publications

(3 citation statements)

References 36 publications

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“…The average of lung target motion amplitude in the screened subjects ranges 2 to 16 mm, 1.5 to 8 mm and 0 to 7 mm in SI, AP and LR direction, respectively. The respiratory characteristics of the subjects resembled that from previous lung motion studies [17][18][19]. The average respiratory cycle of the patients was 4.3±1.2 s. Motion control is always an important concern in lung cancer radiotherapy since patient-specific target motion is one of the attributions leading to inconsistency between planned and actual delivered dose to PTV.…”

Section: Discussionmentioning

confidence: 69%

Performance evaluation of online motion synchronizing systems for patient-specific respiratory movements with helical tomotherapy

Chan¹,

Fok²,

Chiu³

et al. 2022

Biomed. Phys. Eng. Express

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Background and Purpose:The introduction of online motion synchronizing system on helical tomotherapy paves way for robust motion tracking. A recent upgrade launches modifications on both hardware and software of the kV tracking system. An evaluation on the kV subsystems, prior(Version1) and post upgrade(Version2), was performed to compare tracking accuracy by means of fiducial tracking error and resulted root-mean-square (RMS). Impacts influenced by various patient-specific breathing pattern regularities and target movements were also investigated to refine motion tracking error estimations upon future selection of possible candidates. Materials and Methods:Respiratory patterns from twenty-five lung cases were imported individually into a commercial dynamic platform model. Situating a phantom implanted with gold fiducial markers on the platform, superior-inferior(SI) movements of corresponding targets were simulated. Each case was delivered via an identical treatment plan in Version1 and was repeated in Version2. Motion tracking accuracy, by means of discrepancies between subsystem predicted model and raw data motion recorded in patient CT simulation, was analyzed statistically. Wilcoxon signed ranked test was employed to evaluate the difference in tracking error range between the two versions. Statistical model was fitted to inspect the dependence of internal target movement towards fiducial tracking errors. Results:A small difference of ±1 mm was exhibited in 99% of fiducial tracking errors for all cases experimented under both versions. RMS errors were all below 0.5 mm. Version2 demonstrated a greater extremity in fiducial tracking error (p=0.04). A positive correlation was depicted between internal target amplitudes and 95% interval of fiducial tracking errors (p< 0.02). Overall, irregular respiratory patterns tended to have greater fiducial tracking errors. Conclusions:The excellent tracking performance in both kV subsystem versions offers motion compensations benefits, yet Version1 outperformed Version2 in fiducial tracking accuracy. It is noticeable that greater magnitude in internal target movement and irregular breathing patterns yield greater tracking error.

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Section: Discussionmentioning

confidence: 69%

Performance evaluation of online motion synchronizing systems for patient-specific respiratory movements with helical tomotherapy

Chan¹,

Fok²,

Chiu³

et al. 2022

Biomed. Phys. Eng. Express

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“…The displacement and deformation of lung tumors caused by respiratory movement vary considerably owing to factors such as tumor location, GTV size, and staging of NSCLC 4,5 . This individual variability makes it challenging for radiation oncologists to accurately expand the safety margin and delineate the PTV based on traditional experience and documentation if they aim to cover the full range of tumor movement during the respiratory cycle 6,7 . Several researchers, including David, 8 Li, 9 and Guckenberger, 10 have used different methods to measure tumor displacement caused by respiratory motion.…”

Section: Introductionmentioning

confidence: 99%

“…4,5 This individual variability makes it challenging for radiation oncologists to accurately expand the safety margin and delineate the PTV based on traditional experience and documentation if they aim to cover the full range of tumor movement during the respiratory cycle. 6,7 Several researchers, including David, 8 Li, 9 and Guckenberger, 10 have used different methods to measure tumor displacement caused by respiratory motion. The use of fourdimensional (4D) cone beam CT (CBCT) technology allows the real-time observation of tumor trajectory and displacement measurement in three dimensions.…”

Section: Introductionmentioning

confidence: 99%

Impact of different respiratory gating methods on target delineation and a radiotherapy plan for solitary pulmonary tumors

Shang,

Duan,

Yin

et al. 2024

Cancer Medicine

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Background and PurposeRespiratory movement has an important impact on the radiotherapy for lung tumor. Respiratory gating technology is helpful to improve the accuracy of target delineation. This study investigated the value of prospective and retrospective respiratory gating simulations in target delineation and radiotherapy plan design for solitary pulmonary tumors (SPTs) in radiotherapy.MethodsThe enrolled patients underwent CT simulation with three‐dimensional (3D) CT non gating, prospective respiratory gating, and retrospective respiratory gating simulation. The target volumes were delineated on three sets of CT images, and radiotherapy plans were prepared accordingly. Tumor displacements and movement information obtained using the two respiratory gating approaches, as well as the target volumes and dosimetry parameters in the radiotherapy plan were compared.ResultsNo significant difference was observed in tumor displacement measured using the two gating methods (p > 0.05). However, the internal gross tumor volumes (IGTVs), internal target volumes (ITVs), and planning target volumes (PTVs) based on the retrospective respiratory gating simulation were larger than those obtained using prospective gating (group A: pIGTV = 0.041, pITV = 0.003, pPTV = 0.008; group B: pIGTV = 0.025, pITV = 0.039, pPTV = 0.004). The two‐gating PTVs were both smaller than those delineated on 3D non gating images (p < 0.001). V5Gy, V10Gy, V20Gy, V30Gy, and mean lung dose in the two gated radiotherapy plans were lower than those in the 3D non gating plan (p < 0.001); however, no significant difference was observed between the two gating plans (p > 0.05).ConclusionsThe application of respiratory gating could reduce the target volume and the radiation dose that the normal lung tissue received. Compared to prospective respiratory gating, the retrospective gating provides more information about tumor movement in PTV.

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