TY - JOUR
T1 - Feasibility and accuracy of quantitative imaging on a 1.5 T MR-linear accelerator
AU - Kooreman, Ernst S
AU - van Houdt, Petra J
AU - Nowee, Marlies E
AU - van Pelt, Vivian W J
AU - Tijssen, Rob H N
AU - Paulson, Eric S
AU - Gurney-Champion, Oliver J
AU - Wang, Jihong
AU - Koetsveld, Folkert
AU - van Buuren, Laurens D
AU - Ter Beek, Leon C
AU - van der Heide, Uulke A
N1 - Funding Information:
The Institute of Cancer Research (ICR) is supported by Cancer Research UK under programme C33589/A19727 and C7224/A23275. This paper represents independent research partly funded by the National Institute for Health Research (NIHR) Biomedical Research Centre at the Royal Marsden NHS Foundation Trust and the ICR. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health.Dr. van der Heide is supported by a grant from ITEA.
Funding Information:
Dr. van der Heide is supported by a grant from ITEA .
Funding Information:
The Institute of Cancer Research (ICR) is supported by Cancer Research UK under programme C33589/A19727 and C7224/A23275 . This paper represents independent research partly funded by the National Institute for Health Research (NIHR) Biomedical Research Centre at the Royal Marsden NHS Foundation Trust and the ICR . The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health.
Publisher Copyright:
© 2019 Elsevier B.V.
PY - 2019/4
Y1 - 2019/4
N2 - PURPOSE: Systems for magnetic resonance (MR-) guided radiotherapy enable daily MR imaging of cancer patients during treatment, which is of interest for treatment response monitoring and biomarker discovery using quantitative MRI (qMRI). Here, the performance of a 1.5 T MR-linac regarding qMRI was assessed on phantoms. Additionally, we show the feasibility of qMRI in a prostate cancer patient on this system for the first time.MATERIALS AND METHODS: Four 1.5 T MR-linac systems from four institutes were included in this study. T1 and T2 relaxation times, and apparent diffusion coefficient (ADC) maps, as well as dynamic contrast enhanced (DCE) images were acquired. Bland-Altman statistics were used, and accuracy, repeatability, and reproducibility were determined.RESULTS: Median accuracy for T1 ranged over the four systems from 2.7 to 14.3%, for T2 from 10.4 to 14.1%, and for ADC from 1.9 to 2.7%. For DCE images, the accuracy ranged from 12.8 to 35.8% for a gadolinium concentration of 0.5 mM and deteriorated for higher concentrations. Median short-term repeatability for T1 ranged from 0.6 to 5.1%, for T2 from 0.4 to 1.2%, and for ADC from 1.3 to 2.2%. DCE acquisitions showed a coefficient of variation of 0.1-0.6% in the signal intensity. Long-term repeatability was 1.8% for T1, 1.4% for T2, 1.7% for ADC, and 17.9% for DCE. Reproducibility was 11.2% for T1, 2.9% for T2, 2.2% for ADC, and 18.4% for DCE.CONCLUSION: These results indicate that qMRI on the Unity MR-linac is feasible, accurate, and repeatable which is promising for treatment response monitoring and treatment plan adaptation based on daily qMRI.
AB - PURPOSE: Systems for magnetic resonance (MR-) guided radiotherapy enable daily MR imaging of cancer patients during treatment, which is of interest for treatment response monitoring and biomarker discovery using quantitative MRI (qMRI). Here, the performance of a 1.5 T MR-linac regarding qMRI was assessed on phantoms. Additionally, we show the feasibility of qMRI in a prostate cancer patient on this system for the first time.MATERIALS AND METHODS: Four 1.5 T MR-linac systems from four institutes were included in this study. T1 and T2 relaxation times, and apparent diffusion coefficient (ADC) maps, as well as dynamic contrast enhanced (DCE) images were acquired. Bland-Altman statistics were used, and accuracy, repeatability, and reproducibility were determined.RESULTS: Median accuracy for T1 ranged over the four systems from 2.7 to 14.3%, for T2 from 10.4 to 14.1%, and for ADC from 1.9 to 2.7%. For DCE images, the accuracy ranged from 12.8 to 35.8% for a gadolinium concentration of 0.5 mM and deteriorated for higher concentrations. Median short-term repeatability for T1 ranged from 0.6 to 5.1%, for T2 from 0.4 to 1.2%, and for ADC from 1.3 to 2.2%. DCE acquisitions showed a coefficient of variation of 0.1-0.6% in the signal intensity. Long-term repeatability was 1.8% for T1, 1.4% for T2, 1.7% for ADC, and 17.9% for DCE. Reproducibility was 11.2% for T1, 2.9% for T2, 2.2% for ADC, and 18.4% for DCE.CONCLUSION: These results indicate that qMRI on the Unity MR-linac is feasible, accurate, and repeatable which is promising for treatment response monitoring and treatment plan adaptation based on daily qMRI.
KW - Functional MRI
KW - MR-linac
KW - Multicenter
KW - Quantitative MRI
KW - Phantom
KW - Prostate cancer
UR - http://www.scopus.com/inward/record.url?scp=85060516744&partnerID=8YFLogxK
U2 - 10.1016/j.radonc.2019.01.011
DO - 10.1016/j.radonc.2019.01.011
M3 - Article
C2 - 30935572
SN - 0167-8140
VL - 133
SP - 156
EP - 162
JO - Radiotherapy & Oncology
JF - Radiotherapy & Oncology
ER -