A simulation study of tolerance of breathing amplitude variations in radiotherapy of lung cancer using 4DCT and time-resolved 4DMRI Journal Article


Authors: Li, G.; Sehovic, A.; Xu, L.; Shukla, P.; Zhang, L.; Zhou, Y.; Wang, P.; Wu, A.; Rimner, A.; Zhang, P.
Article Title: A simulation study of tolerance of breathing amplitude variations in radiotherapy of lung cancer using 4DCT and time-resolved 4DMRI
Abstract: As patient breathing irregularities can introduce a large uncertainty in targeting the internal tumor volume (ITV) of lung cancer patients, and thereby affect treatment quality, this study evaluates dose tolerance of tumor motion amplitude variations in ITV-based volumetric modulated arc therapy (VMAT). A motion-incorporated planning technique was employed to simulate treatment delivery of 10 lung cancer patients’ clinical VMAT plans using original and three scaling-up (by 0.5, 1.0, and 2.0 cm) motion waveforms from single-breath four-dimensional computed tomography (4DCT) and multi-breath time-resolved 4D magnetic resonance imaging (TR-4DMRI). The planning tumor volume (PTV = ITV + 5 mm margin) dose coverage (PTV D95%) was evaluated. The repeated waveforms were used to move the isocenter in sync with the clinical leaf motion and gantry rotation. The continuous VMAT arcs were broken down into many static beam fields at the control points (2°-interval) and the composite plan represented the motion-incorporated VMAT plan. Eight motion-incorporated plans per patient were simulated and the plan with the native 4DCT waveform was used as a control. The first (D95% ≤ 95%) and second (D95% ≤ 90%) plan breaching points due to motion amplitude increase were identified and analyzed. The PTV D95% in the motion-incorporated plans was 99.4 ± 1.0% using 4DCT, closely agreeing with the corresponding ITV-based VMAT plan (PTV D95% = 100%). Tumor motion irregularities were observed in TR-4DMRI and triggered D95% ≤ 95% in one case. For small tumors, 4 mm extra motion triggered D95% ≤ 95%, and 6–8 mm triggered D95% ≤ 90%. For large tumors, 14 mm and 21 mm extra motions triggered the first and second breaching points, respectively. This study has demonstrated that PTV D95% breaching points may occur for small tumors during treatment delivery. Clinically, it is important to monitor and avoid systematic motion increase, including baseline drift, and large random motion spikes through threshold-based beam gating. © 2022 by the authors.
Keywords: liver; lung; pancreatic cancer; stereotactic body radiotherapy (sbrt); 4dct motion simulation; motion-incorporated radiotherapy planning; motion-tolerance of itv-based planning; respiratory motion irregularities; time-resolved 4dmri motion simulation; volumetric-modulated arc therapy (vmat)
Journal Title: Journal of Clinical Medicine
Volume: 11
Issue: 24
ISSN: 2077-0383
Publisher: MDPI  
Date Published: 2022-12-02
Start Page: 7390
Language: English
DOI: 10.3390/jcm11247390
PROVIDER: scopus
PMCID: PMC9784418
PUBMED: 36556006
DOI/URL:
Notes: Article -- Export Date: 1 February 2023 -- Source: Scopus
Altmetric
Citation Impact
BMJ Impact Analytics
MSK Authors
  1. Ying Zhou
    35 Zhou
  2. Andreas Rimner
    527 Rimner
  3. Abraham Jing-Ching Wu
    404 Wu
  4. Pengpeng Zhang
    179 Zhang
  5. Guang Li
    99 Li
  6. Ping   Wang
    11 Wang
  7. Lei Zhang
    32 Zhang
  8. Lee Xu
    3 Xu
  9. Pawas Shukla
    2 Shukla