Impact of post-correction validation scans on intrafraction tumour misalignment in lung stereotactic body radiotherapy.
1/5 보강
[BACKGROUND AND PURPOSE] Tumour position may change after the acquisition of an initial cone-beam computed-tomography for setup correction (CBCT).
- 표본수 (n) 167
APA
Rossi MMG, Stam B, et al. (2025). Impact of post-correction validation scans on intrafraction tumour misalignment in lung stereotactic body radiotherapy.. Physics and imaging in radiation oncology, 36, 100868. https://doi.org/10.1016/j.phro.2025.100868
MLA
Rossi MMG, et al.. "Impact of post-correction validation scans on intrafraction tumour misalignment in lung stereotactic body radiotherapy.." Physics and imaging in radiation oncology, vol. 36, 2025, pp. 100868.
PMID
41399701 ↗
Abstract 한글 요약
[BACKGROUND AND PURPOSE] Tumour position may change after the acquisition of an initial cone-beam computed-tomography for setup correction (CBCT). In this study, the impact of post-correction validation (CBCT) and intra-arc scans (CBCT) on intrafraction tumour misalignment during volumetric-modulated-arc-therapy (VMAT) lung stereotactic-body radiotherapy (SBRT) was evaluated.
[MATERIAL AND METHODS] Early stage lung cancer patients (n = 167) treated with VMAT SBRT had the following image guided (IG)RT protocol: (1) CBCT, (2) CBCT to verify tumour alignment, (3) an intra-arc scan (CBCT) during both VMAT arcs. Additional corrections were made for residual misalignments ≥0.3 cm. The actual and two simulated protocols were analysed: (1) clinical (CBCT), (2) simulations without validation scans (CBCT), (3) simulations without repeat CBCTs (CBCT). Grand-mean (GM), systematic (∑) and random (σ) tumour misalignment in CBCT and CBCT were calculated. Patient characteristics were evaluated for association with extra validation scans.
[RESULTS] CBCT triggered a second correction in 20.4 % of fractions in 47 % of patients and CBCT in 14.4 % of fractions in 40 % of patients. Omitting CBCT increased ∑ and σ ranging from 27-30 % and 20-45 % for the different directions. Omitting also CBCT further increased ∑ ranging from 55-90 %. Omitting CBCT and CBCT would require a 1-2 mm planning target volume margin increase. Respiratory amplitude and body mass index (BMI) were significantly associated with extra corrections (area under the curve: 0.75).
[CONCLUSION] This study demonstrates that CBCT and CBCT reduce geometric uncertainties in VMAT lung SBRT. Respiratory amplitude and BMI were significantly associated with extra corrections but cannot reliably identify patients requiring extra validation scans.
[MATERIAL AND METHODS] Early stage lung cancer patients (n = 167) treated with VMAT SBRT had the following image guided (IG)RT protocol: (1) CBCT, (2) CBCT to verify tumour alignment, (3) an intra-arc scan (CBCT) during both VMAT arcs. Additional corrections were made for residual misalignments ≥0.3 cm. The actual and two simulated protocols were analysed: (1) clinical (CBCT), (2) simulations without validation scans (CBCT), (3) simulations without repeat CBCTs (CBCT). Grand-mean (GM), systematic (∑) and random (σ) tumour misalignment in CBCT and CBCT were calculated. Patient characteristics were evaluated for association with extra validation scans.
[RESULTS] CBCT triggered a second correction in 20.4 % of fractions in 47 % of patients and CBCT in 14.4 % of fractions in 40 % of patients. Omitting CBCT increased ∑ and σ ranging from 27-30 % and 20-45 % for the different directions. Omitting also CBCT further increased ∑ ranging from 55-90 %. Omitting CBCT and CBCT would require a 1-2 mm planning target volume margin increase. Respiratory amplitude and body mass index (BMI) were significantly associated with extra corrections (area under the curve: 0.75).
[CONCLUSION] This study demonstrates that CBCT and CBCT reduce geometric uncertainties in VMAT lung SBRT. Respiratory amplitude and BMI were significantly associated with extra corrections but cannot reliably identify patients requiring extra validation scans.