Evaluation of reproducibility of tumor repositioning during multiple breathing cycles for liver stereotactic body radiotherapy treatment

Bedos, L.; Riou, O.; Aillères, N.; Braccini, A.; Molinier, J.; Moscardo, C. Llacer; Azria, D.; Fenoglietto, P.

doi:10.1016/j.rpor.2016.07.007

Cited by 16 publications

(22 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…al. [13]used a KV plain lm to acquire the end-expiratory image to analyse the patient's intra-fraction errors and found that the 99% intra-fraction error in the SI direction was within 5 mm, which was smaller than in our study. However, the images were collected before the treatment beam was on, and the acquisition time was limited, which cannot represent intrafraction errors.…”

Section: Discussioncontrasting

confidence: 65%

“…Markus Oechsner reported [16]that AIP is more suitable for 3D CBCT than MIP. Bedos L et al also believed that [13] CBCT was an average image and that registration with the planned AIP image can represent the patient's breathing pattern, so we used AIP as the reference image for registration with 3D CBCT images for liver SBRT. In the inter-and intra-fraction CBCT, the liver contour can be clearly displayed (Fig.…”

Section: Discussionmentioning

confidence: 99%

“…GTV was delineated in each phase (total ten phases) to obtain ITV, and a uniform 5 mm PTV margin [4,13] was expanded around the ITV. The average intensity projections (AIP) were adopted for treatment planning and image registration with CBCT images [13,16] (XVI Release 5.0.2, Elekta Versa HD, Stockholm, Sweden). Full arc or partial arc VMAT plans were designed using the 6 MeV (1400 MU/min) or 10 MeV (2400 MU/min) photon FFF mode.…”

Section: Positioning Treatment Planning Treatmentmentioning

confidence: 99%

“…CBCT corrects the inter-fraction errors pretreatment for each fraction, and the 5 mm PTV margin is considered adequate for intra-fraction errors, which include the amplitude variations and the baseline drift of respiratory motion during treatment. At present, to analyse intra-fractional errors, post-treatment CBCT [10][11][12], KV uoroscopy [5,13], and electromagnetics [14] are used. KV uoroscopy is a form of two-dimensional imaging, analogous to electromagnetic tracking, which usually requires implantation of mental markers for veri cation.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Analysis of the Amplitude Changes and Baseline Drift of Respiratory Motion during Liver Stereotactic Body Radiation Therapy Based on Intra-Fraction CBCT

Zeng

Wang

Zhou

et al. 2020

Preprint

View full text Add to dashboard Cite

Abstract Purpose: To evaluate the amplitude changes and baseline drift of respiratory motion in liver stereotactic body radiation therapy based on intra-fraction cone beam CT (CBCT).Materials and methods: Twenty-four liver SBRT patients underwent a four-dimensional computed tomography (4D CT) scan, inter-fraction cone-beam computed tomography (CBCT), and intra-fraction CBCT to evaluate the amplitude changes and baseline drift of respiratory motion. The amplitude changes were defined as the variations between the amplitude measured in the 4D CT and those measured with fluoroscopy in inter- and intra-fraction CBCT. The baseline drifts were defined as the difference between the liver position errors and the setup errors in inter- and intra-fraction CBCT. Manual registration of the liver contour was performed to obtain liver position errors, and bone registration was performed to obtain setup errors. Meanwhile, the correlation among the liver position errors, the relative diaphragm position, and the amplitude changes was evaluated. Results: The systematic and random errors of the baseline drifts for intra-fraction CBCT in the medial-lateral (ML), superior-inferior (SI), and anterior-posterior (AP) views were 0.99 and 1.6 mm, 2.03 and 2.46 mm, and 1.02 and 2.07 mm, respectively. The corresponding PTV margin was 3.61 mm, 6.8 mm, and 4.00 mm, respectively. The amplitude variation ranged from -169.33% to 65.47% in inter-fraction CBCT and from -171.04% to 60.00% in intra-fraction CBCT. Inter-fraction liver position errors were significantly related to the setup errors. The relative diaphragm position was not statistically related to the baseline drifts in the inter-fraction nor in the intra-fraction. Conclusions: Using intra-fraction CBCT, significant amplitude variations and baseline drifts of respiratory motion were found compared with those in 4D CT. The relative diaphragm position in a single breathing cycle cannot reflect the liver position during dose delivery. At least a 6.8 mm PTV margin in the SI direction is recommended to compensate for the baseline drift.

show abstract

Section: Discussioncontrasting

confidence: 65%

Section: Discussionmentioning

confidence: 99%

Section: Positioning Treatment Planning Treatmentmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Analysis of the Amplitude Changes and Baseline Drift of Respiratory Motion during Liver Stereotactic Body Radiation Therapy Based on Intra-Fraction CBCT

Zeng

Wang

Zhou

et al. 2020

Preprint

View full text Add to dashboard Cite

show abstract

“…The geometric miss occurs due to a wrong detection of targets' positions, and this decreases dose coverage for tumors. 17 Moreover, a wrong detection of tumor positions in ABH may significantly increase treatment time as the ABH system does not allow to deliver irradiation without the images, which indicate that markers' positions were correct. [14][15][16] The aim of this study is to investigate the detectability of fiducial markers' positions for real-time target tracking systems, which are equipping with a standard linac.…”

Section: Introductionmentioning

confidence: 99%

Detectability of fiducials’ positions for real‐time target tracking system equipping with a standard linac for multiple fiducial markers

Ueda

Ohira

et al. 2020

J Applied Clin Med Phys

View full text Add to dashboard Cite

Purpose To investigate the detectability of fiducial markers’ positions for real‐time target tracking system equipping with a standard linac. The hypothesis is that the detectability depends on the type of fiducial marker and the gantry angle of acquired triggered images. Methods Three types of ball fiducials and four slim fiducials with lengths of 3 and 5 mm were prepared for this study. Triggered images with three similar fiducials were acquired at every 10° during the conformal arc irradiation to detect the target position. Although only one type of arrangement was prepared for the ball fiducials, a three‐type arrangement was prepared for the slim fiducials, such as parallel, orthogonal, and oblique with 45° to the gantry‐couch direction. To measure the detectability of the real‐time target tracking system for each fiducial and arrangement, detected marker positions were compared with expected marker positions at every angle of acquired triggered images. Results For the ball‐type fiducial, the maximum difference between the detected marker positions and expected marker positions was 0.3 mm in all directions. For the slim fiducial arranged parallel and oblique with 45°, the maximum difference was 0.4 mm in all directions. When each slim fiducial was arranged orthogonal to the gantry‐couch direction, the maximum difference was 1.5 mm for the length of 3 mm, and 3.2 mm for the length of 5 mm. Conclusions The detectability of fiducial markers’ positions for the real‐time target tracking system equipping with a standard linac depends on the form and insertion angles of the fiducials.

show abstract

Fiducial marker position affects target volume in stereotactic lung irradiation

Akasaka

Mizonobe

Oki

et al. 2022

J Applied Clin Med Phys

View full text Add to dashboard Cite

Real-time tracking systems of moving respiratory targets such as CyberKnife,Radixact,or Vero4DRT are an advanced robotic radiotherapy device used to deliver stereotactic body radiotherapy (SBRT). The internal target volume (ITV) of lung tumors is assessed through a fiducial marker fusion using four-dimensional computed tomography (CT). It is important to minimize the ITV to protect normal lung tissue from exposure to radiation and the associated side effects post SBRT. However, the ITV may alter if there is a change in the position of the fiducial marker with respect to the tumor. This study investigated the relationship between fiducial marker position and the ITV in order to prevent radiation exposure of normal lung tissue, and correct target coverage. Materials and methods: This study retrospectively reviewed 230 lung cancer patients who received a fiducial marker for SBRT between April 2015 and September 2021. The distance of the fiducial marker to the gross tumor volume (GTV) in the expiratory (d ex ) and inspiratory (d in ) CT, and the ratio of the ITV/V(GTV ex ), were investigated. Results: Upon comparing each lobe, although there was no significant difference in the d diff and the ITV/V(GTV ex ) between all lobes for d ex < 10 mm, there was significant difference in the d diff and the ITV/V(GTV ex ) between the lower and upper lobes for d ex ≥ 10 mm (p < 0.05). Moreover, there was significant difference in the d diff and the ITV/V(GTV ex ) between d ex ≥10 mm and d ex < 10 mm in all lung regions (p < 0.05). Conclusion:The ITV that had no margin from GTVs increased when d ex was ≥10 mm for all lung regions (p < 0.05). Furthermore, the increase in ITV tended to be greater in the lower lung lobe. These findings can help decrease the possibility of adverse events post SBRT, and correct target coverage.

show abstract

Evaluation of reproducibility of tumor repositioning during multiple breathing cycles for liver stereotactic body radiotherapy treatment

Cited by 16 publications

References 24 publications

Analysis of the Amplitude Changes and Baseline Drift of Respiratory Motion during Liver Stereotactic Body Radiation Therapy Based on Intra-Fraction CBCT

Analysis of the Amplitude Changes and Baseline Drift of Respiratory Motion during Liver Stereotactic Body Radiation Therapy Based on Intra-Fraction CBCT

Detectability of fiducials’ positions for real‐time target tracking system equipping with a standard linac for multiple fiducial markers

Fiducial marker position affects target volume in stereotactic lung irradiation

Contact Info

Product

Resources

About