A framework for voxel-based assessment of biological effect after proton radiotherapy in pediatric brain cancer patients using multi-modal imaging
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A framework for voxel-based assessment of biological effect after proton radiotherapy in pediatric brain cancer patients using multi-modal imaging. / Skaarup, Mikkel; Lundemann, Michael Juncker; Darkner, Sune; Jorgensen, Morten; Marner, Lisbeth; Mirkovic, Dragan; Grosshans, David; Peeler, Christopher; Mohan, Radhe; Vogelius, Ivan Richter; Appelt, Ane.
In: Medical Physics, Vol. 48, No. 7, 4110-4121, 10.06.2021.Research output: Contribution to journal › Journal article › Research › peer-review
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TY - JOUR
T1 - A framework for voxel-based assessment of biological effect after proton radiotherapy in pediatric brain cancer patients using multi-modal imaging
AU - Skaarup, Mikkel
AU - Lundemann, Michael Juncker
AU - Darkner, Sune
AU - Jorgensen, Morten
AU - Marner, Lisbeth
AU - Mirkovic, Dragan
AU - Grosshans, David
AU - Peeler, Christopher
AU - Mohan, Radhe
AU - Vogelius, Ivan Richter
AU - Appelt, Ane
PY - 2021/6/10
Y1 - 2021/6/10
N2 - Introduction The exact dependence of biological effect on dose and linear energy transfer (LET) in human tissue when delivering proton therapy is unknown. In this study, we propose a framework for measuring this dependency using multi-modal image-based assays with deformable registrations within imaging sessions and across time.Materials and Methods 3T MRI scans were prospectively collected from 6 pediatric brain cancer patients before they underwent proton therapy treatment, and every 3 months for a year after treatment. Scans included T1-weighted with contrast enhancement (T1), T2-FLAIR (T2) and fractional anisotropy (FA) images. In addition, the planning CT, dose distributions and Monte Carlo-calculated LET distributions were collected.A multi-modal deformable image registration framework was used to create a dataset of dose, LET and imaging intensities at baseline and follow-up on a voxel-by-voxel basis. We modelled the biological effect of dose and LET from proton therapy using imaging changes over time as a surrogate for biological effect.We investigated various models to show the feasibility of the framework to model imaging changes. To account for interpatient and intrapatient variations, we used a nested generalized linear mixed regression model. The models were applied to predict imaging changes over time as a function of dose and LET for each modality.Results Using the nested models to predict imaging changes, we saw a decrease in the FA signal as a function of dose; however, the signal increased with increasing LET. Similarly, we saw an increase in T2 signal as a function of dose, but a decrease in signal with LET. We saw no changes in T1 voxel values as a function of either dose or LET.Conclusions The imaging changes could successfully model biological effect as a function of dose and LET using our proposed framework. Due to the low number of patients, the imaging changes observed for FA and T2 scans were not marked enough to draw any firm conclusions.
AB - Introduction The exact dependence of biological effect on dose and linear energy transfer (LET) in human tissue when delivering proton therapy is unknown. In this study, we propose a framework for measuring this dependency using multi-modal image-based assays with deformable registrations within imaging sessions and across time.Materials and Methods 3T MRI scans were prospectively collected from 6 pediatric brain cancer patients before they underwent proton therapy treatment, and every 3 months for a year after treatment. Scans included T1-weighted with contrast enhancement (T1), T2-FLAIR (T2) and fractional anisotropy (FA) images. In addition, the planning CT, dose distributions and Monte Carlo-calculated LET distributions were collected.A multi-modal deformable image registration framework was used to create a dataset of dose, LET and imaging intensities at baseline and follow-up on a voxel-by-voxel basis. We modelled the biological effect of dose and LET from proton therapy using imaging changes over time as a surrogate for biological effect.We investigated various models to show the feasibility of the framework to model imaging changes. To account for interpatient and intrapatient variations, we used a nested generalized linear mixed regression model. The models were applied to predict imaging changes over time as a function of dose and LET for each modality.Results Using the nested models to predict imaging changes, we saw a decrease in the FA signal as a function of dose; however, the signal increased with increasing LET. Similarly, we saw an increase in T2 signal as a function of dose, but a decrease in signal with LET. We saw no changes in T1 voxel values as a function of either dose or LET.Conclusions The imaging changes could successfully model biological effect as a function of dose and LET using our proposed framework. Due to the low number of patients, the imaging changes observed for FA and T2 scans were not marked enough to draw any firm conclusions.
KW - diffusion MRI
KW - MRI response assessment
KW - multi-modality registration
KW - proton therapy
KW - radiobiology of protons
KW - APPEARING WHITE-MATTER
KW - CLINICAL-EVIDENCE
KW - THERAPY
KW - RADIATION
KW - MODEL
KW - DIFFUSION
KW - DAMAGE
KW - HEAD
U2 - 10.1002/mp.14989
DO - 10.1002/mp.14989
M3 - Journal article
C2 - 34021597
VL - 48
JO - Medical Physics
JF - Medical Physics
SN - 0094-2405
IS - 7
M1 - 4110-4121
ER -
ID: 272408628