Quantifying intra‐ and inter‐fractional motion in breast radiotherapy

Jones, Scott; Fitzgerald, Rhys; Owen, Robert; Ramsay, Jonathan

doi:10.1002/jmrs.61

Cited by 16 publications

(21 citation statements)

References 20 publications

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“…(a) is without OSMS and (b) is with OSMS portal imaging was used for relative measurements to get a more realistic intrafraction motion and they report intrafraction motion to be less than 1 mm and comparable to our results 13. (a) is without OSMS and (b) is with OSMS portal imaging was used for relative measurements to get a more realistic intrafraction motion and they report intrafraction motion to be less than 1 mm and comparable to our results 13.…”

supporting

confidence: 81%

Evaluation of setup and intrafraction motion for surface guided whole‐breast cancer radiotherapy

Hattel

Andersen

Wahlstedt

et al. 2019

J Applied Clin Med Phys

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Surface Guided Radiotherapy (SGRT) is a relatively new technique for positioning patients and for monitoring patient movement during treatment. SGRT is completely non‐invasive since it uses visible light for determining the position of the patient surface. A reduction in daily imaging for patient setup is possible if the accuracy of SGRT is comparable to imaging. It allows for monitoring of intrafraction motion and the radiation beam can be held beyond a certain threshold resulting in a more accurate irradiation. The purpose of this study was to investigate setup uncertainty and the intrafraction motion in non‐gated whole breast cancer radiotherapy treatment using an integrated implementation of AlignRT (OSMS) system as SGRT. In initial setup, SGRT was compared to three‐point setup using tattoos on the patient and orthogonal kV imaging. For the investigation of intrafraction motion, OSMS monitored the patient with six degrees of freedom during treatment. Using three‐point setup resulted in a setup root‐mean‐square error from the isocenter of 5.4 mm. This was improved to 4.2 mm using OSMS. For the translational directions, OSMS showed improvements in the lateral direction (P = 0.0009, Wilcoxon rank‐sum), but for the longitudinal direction and rotation it was not possible to show improvements (P = 0.96 and P = 0.46, respectively). The vertical direction proved more accurate for three‐point setup than OSMS (P = 0.000004). Intrafraction motion was very limited with a translational median of 1.1 mm from the isocenter. While OSMS showed marked improvements over laser and tattoo setup, the system did not prove accurate enough to replace the daily orthogonal kV images aligned to bony anatomy.

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supporting

confidence: 81%

Evaluation of setup and intrafraction motion for surface guided whole‐breast cancer radiotherapy

Hattel

Andersen

Wahlstedt

et al. 2019

J Applied Clin Med Phys

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“…In this study, using a virtual bolus, we focused on taking into account interfraction movements. Indeed, a systematic review covering 3378 studies concluded that interfraction motion is larger than intrafraction32 which was confirmed in another recent study 33…”

Section: Discussionmentioning

confidence: 79%

Safety and benefit of using a virtual bolus during treatment planning for breast cancer treated with arc therapy

Tyran

Tallet

Resbeut

et al. 2018

J Applied Clin Med Phys

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PurposeThis study evaluates the benefit of a virtual bolus method for volumetric modulated arc therapy (VMAT) plan optimization to compensate breast modifications that may occur during breast treatment.MethodsTen files were replanned with VMAT giving 50 Gy to the breast and 47 Gy to the nodes within 25 fractions. The planning process used a virtual bolus for the first optimization, then the monitors units were reoptimized without bolus, after fixing the segments shapes. Structures and treatment planning were exported on a second scanner (CT) performed during treatment as a consequence to modifications in patient's anatomy. The comparative end‐point was clinical target volume's coverage. The first analysis compared the VMAT plans made using the virtual bolus method (VB‐VMAT) to the plans without using it (NoVB‐VMAT) on the first simulation CT. Then, the same analysis was performed on the second CT. Finally, the level of degradation of target volume coverage between the two CT using VB‐VMAT was compared to results using a standard technique of forward‐planned multisegment technique (Tan‐IMRT).ResultsUsing a virtual bolus for VMAT does not degrade dosimetric results on the first CT. No significant result in favor of the NoVB‐VMAT plans was noted. The VB‐VMAT method led to significant better dose distribution on a second CT with modified anatomies compared to NoVB‐VMAT. The clinical target volume's coverage by 95% (V95%) of the prescribed dose was 98.9% [96.1–99.6] on the second CT for VB‐VMAT compared to 92.6% [85.2–97.7] for NoVB‐VMAT (P = 0.0002). The degradation of the target volume coverage for VB‐VMAT is not worse than for Tan‐IMRT: the median differential of V95% between the two CT was 0.9% for VMAT and 0.7% for Tan‐IMRT (P = 1).ConclusionThis study confirms the safety and benefit of using a virtual bolus during the VMAT planning process to compensate potential breast shape modifications.

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“…The measured data were then verified by both the medical physicist and the radiation oncologist. According to the methods reported in previously published articles, the measurements were performed on portal images (Figure 1 ), so that the lateral shifts could not be quantified ( 6 , 7 , 11 , 12 ).…”

Section: Methodsmentioning

confidence: 99%

Dosimetric Effects of the Interfraction Variations during Whole Breast Radiotherapy: A Prospective Study

et al. 2015

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IntroductionThe aim of this work was to assess the dosimetric impact of the interfraction variations during breast radiotherapy.Materials and methodsDaily portal imaging measurements were prospectively performed in 10 patients treated with adjuvant whole breast irradiation (50 Gy/25 fractions). Margins between the clinical target volume and the planning target volume (PTV) were 5 mm in the three dimensions. Parameters of interest were the central lung distance (CLD) and the inferior central margin (ICM). Daily movements were applied to the baseline treatment planning (TP1) to design a further TP (TP2). The PTV coverage and organ at risk exposure were measured on both TP1 and TP2, before being compared.ResultsA total of 241 portal images were analyzed. The random and systematic errors were 2.6 and 3.7 mm for the CLD, 4.3 and 6.9 mm for the ICM, respectively. No significant consequence on the PTV treatments was observed (mean variations: +0.1%, p = 0.56 and −1.8%, p = 0.08 for the breast and the tumor bed, respectively). The ipsilateral lung and heart exposure was not significantly modified.ConclusionIn our series, the daily interfraction variations had no significant effect on the PTV coverage or healthy tissue exposure during breast radiotherapy.

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Quantifying intra‐ and inter‐fractional motion in breast radiotherapy

Cited by 16 publications

References 20 publications

Evaluation of setup and intrafraction motion for surface guided whole‐breast cancer radiotherapy

Evaluation of setup and intrafraction motion for surface guided whole‐breast cancer radiotherapy

Safety and benefit of using a virtual bolus during treatment planning for breast cancer treated with arc therapy

Dosimetric Effects of the Interfraction Variations during Whole Breast Radiotherapy: A Prospective Study

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