A framework for voxel-based assessment of biological effect after proton radiotherapy in pediatric brain cancer patients using multi-modal imaging.

Autor: Skaarup M; Department of Oncology, Rigshospitalet, Copenhagen, Denmark.; Faculty of Science, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark., Lundemann MJ; Department of Oncology, Rigshospitalet, Copenhagen, Denmark., Darkner S; Department of Computer Science, University of Copenhagen, Copenhagen, Denmark., Jørgensen M; Department of Oncology, Rigshospitalet, Copenhagen, Denmark., Marner L; Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen, Denmark.; Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital Bispebjerg, Copenhagen, Denmark., Mirkovic D; Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA., Grosshans D; Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA., Peeler C; Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA., Mohan R; Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA., Vogelius IR; Department of Oncology, Rigshospitalet, Copenhagen, Denmark.; Faculty of Health and Medical Science, Copenhagen University, Copenhagen, Denmark., Appelt A; Leeds Institute of Medical Research at St James's, University of Leeds and Leeds Cancer Centre, St. James's University Hospital, Leeds, UK.
Jazyk: angličtina
Zdroj: Medical physics [Med Phys] 2021 Jul; Vol. 48 (7), pp. 4110-4121. Date of Electronic Publication: 2021 Jun 10.
DOI: 10.1002/mp.14989
Abstrakt: 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.
(© 2021 American Association of Physicists in Medicine.)
Databáze: MEDLINE
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