Both four-dimensional computed tomography and four-dimensional cone beam computed tomography under-predict lung target motion during radiotherapy.
Algorithms
Computer Simulation
Cone-Beam Computed Tomography
/ methods
Four-Dimensional Computed Tomography
/ methods
Humans
Lung
/ diagnostic imaging
Lung Neoplasms
/ diagnostic imaging
Predictive Value of Tests
Radiosurgery
/ methods
Radiotherapy Planning, Computer-Assisted
/ methods
Respiratory Mechanics
Four-dimensional computed tomography
Four-dimensional cone-beam computed tomography
Intrafraction motion
Lung stereotactic ablative body radiotherapy
Lung stereotactic body radiotherapy
Respiratory motion
Journal
Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology
ISSN: 1879-0887
Titre abrégé: Radiother Oncol
Pays: Ireland
ID NLM: 8407192
Informations de publication
Date de publication:
06 2019
06 2019
Historique:
received:
12
10
2018
revised:
21
02
2019
accepted:
24
02
2019
pubmed:
25
4
2019
medline:
4
3
2020
entrez:
25
4
2019
Statut:
ppublish
Résumé
To test the hypothesis that 4DCT and 4DCBCT-measured target motion ranges predict target motion ranges during lung cancer SABR. Ten lung SABR patients were implanted with Calypso beacons. 4DCBCT was reconstructed for 29 fractions (1-4fx/patient) from a 1 min CBCT scan. The beacon centroid motion segmented for all 4DCT and 4DCBCT bins was compared with the real-time imaging and treatment beacon centroid ("target") motion range (4SDs) for each fraction. We tested the hypotheses that (1) 4DCT and 4CBCT predict treatment motion range and (2) there is no difference between 4DCT and 4DCBCT for predicting treatment motion range. Phase-wise root-mean-square errors (RMSEs) between imaging and treatment motion and reconstructed motion (4DCT, 4DCBCT) were calculated. Relationships between motion ranges in 4DCT and 4DCBCT and imaging and treatment motion ranges were investigated for the superior-inferior (SI), left-right (LR) and anterior-posterior (AP) directions. Baseline drifts and amplitude variability were investigated as potential factors leading to motion misrepresentation. SI 4DCT, 4DCBCT, imaging and treatment motion ranges were 6.3 ± 3.6 mm, 7.1 ± 4.5 mm, 11.1 ± 7.5 mm and 10.9 ± 6.9 mm, respectively. Similar 4DCT and 4DCBCT under-predictions were observed in the LR and AP directions. Hypothesis (1) was rejected (p < 0.0001). Treatment target motion range was under-predicted in 4DCT by factors of 1.7, 1.9 and 1.7 and in 4DCBCT by factors of 1.5, 1.6 and 1.6 in the SI, LR, and AP directions, respectively. RMSEs were generally lower for end-exhale than inhale. 4DCBCT showed higher correlations with the imaging and treatment target motion than 4DCT and testing hypothesis (2) a statistically significant difference between 4DCT and 4DCBCT was shown in the SI direction (p = 0.03). For lung SABR patients both 4DCT and 4DCBCT significantly under-predict treatment target motion ranges.
Sections du résumé
BACKGROUND AND PURPOSE
To test the hypothesis that 4DCT and 4DCBCT-measured target motion ranges predict target motion ranges during lung cancer SABR.
MATERIALS AND METHODS
Ten lung SABR patients were implanted with Calypso beacons. 4DCBCT was reconstructed for 29 fractions (1-4fx/patient) from a 1 min CBCT scan. The beacon centroid motion segmented for all 4DCT and 4DCBCT bins was compared with the real-time imaging and treatment beacon centroid ("target") motion range (4SDs) for each fraction. We tested the hypotheses that (1) 4DCT and 4CBCT predict treatment motion range and (2) there is no difference between 4DCT and 4DCBCT for predicting treatment motion range. Phase-wise root-mean-square errors (RMSEs) between imaging and treatment motion and reconstructed motion (4DCT, 4DCBCT) were calculated. Relationships between motion ranges in 4DCT and 4DCBCT and imaging and treatment motion ranges were investigated for the superior-inferior (SI), left-right (LR) and anterior-posterior (AP) directions. Baseline drifts and amplitude variability were investigated as potential factors leading to motion misrepresentation.
RESULTS
SI 4DCT, 4DCBCT, imaging and treatment motion ranges were 6.3 ± 3.6 mm, 7.1 ± 4.5 mm, 11.1 ± 7.5 mm and 10.9 ± 6.9 mm, respectively. Similar 4DCT and 4DCBCT under-predictions were observed in the LR and AP directions. Hypothesis (1) was rejected (p < 0.0001). Treatment target motion range was under-predicted in 4DCT by factors of 1.7, 1.9 and 1.7 and in 4DCBCT by factors of 1.5, 1.6 and 1.6 in the SI, LR, and AP directions, respectively. RMSEs were generally lower for end-exhale than inhale. 4DCBCT showed higher correlations with the imaging and treatment target motion than 4DCT and testing hypothesis (2) a statistically significant difference between 4DCT and 4DCBCT was shown in the SI direction (p = 0.03).
CONCLUSION
For lung SABR patients both 4DCT and 4DCBCT significantly under-predict treatment target motion ranges.
Identifiants
pubmed: 31015172
pii: S0167-8140(19)30101-X
doi: 10.1016/j.radonc.2019.02.019
pii:
doi:
Types de publication
Journal Article
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM
Pagination
65-73Informations de copyright
Copyright © 2019 Elsevier B.V. All rights reserved.