Elekta Unity biology-guided Radiation Therapy

Biology-guided radiation therapy (BgRT) is an exciting area of clinical exploration assessing individual treatment response in an online setting, allowing you to adapt to the response. You can find an overview of the groundbreaking work by Elekta Unity users on the technical feasibility of BgRT, as well as clinical studies on MR biomarkers and treatment response assessment. Articles are categorized per anatomy and shown in descending order of publication date.

General articles

Recommendations for improved reproducibility of ADC derivation on behalf of the Elekta MRI-linac Consortium Image Analysis Working Group.

Radiother Oncol. 2023;186:109803. Bisgaard ALH; Keesman R; L H M W van Lier A; Coolens C; van Houdt PJ; Tree A; Wetscherek A; Romesser PB; Tyagi N; Lo Russo M; Habrich J; Vesprini D; Lau AZ; Mook S; Chung P; Kerkmeijer LGW; A R Gouw Z; Lorenzen EL; van der Heide UA; Schytte T; Brink C; Mahmood F. doi: 10.1016/j.radonc.2023.109803

Integrated MRI-linac systems: The new paradigm for precision adaptive radiotherapy and biological image-guidance?

Radiother Oncol.2022;176:249-250. van der Heide U; Thwaites DI. doi: 10.1016/j.radonc.2022.08.016

Integration of quantitative imaging biomarkers in clinical trials for MR-guided radiotherapy: Conceptual guidance for multicentre studies from the MR-Linac Consortium Imaging Biomarker Working Group

Eur J Cancer.2021;153:64-71. van Houdt PJ; Saeed H; Thorwarth D; Fuller CD; Hall WA; McDonald BA; Shukla-Dave A; Kooreman ES; Philippens MEP; van Lier ALHMW; Keesman R; Mahmood F; Coolens C; Stanescu T; Wang J; Tyagi N; Wetscherek A; van der Heide UA. doi: 10.1016/j.ejca.2021.04.041

Technical Challenges of Real-Time Adaptive MR-Guided Radiotherapy

Front Oncol.2021;11:634507. Thorwarth D; Low DA. doi: 10.3389/fonc.2021.634507

ADC measurements on the Unity MR-linac - A recommendation on behalf of the Elekta Unity MR-linac consortium

Radiother Oncol.2020;153:106-113. Kooreman ES; van Houdt PJ; Keesman R; Pos FJ; van Pelt VWJ; Nowee ME; Wetscherek A; Tijssen RHN; Philippens MEP; Thorwarth D; Wang J; Shukla-Dave A; Hall WA; Paulson ES; van der Heide UA. doi: 10.1016/j.radonc.2020.09.046

Quantitative magnetic resonance imaging on hybrid magnetic resonance linear accelerators: Perspective on technical and clinical validation

Phys Imaging Radiat Oncol.2020;16:69-73. Thorwarth D; Ege M; Nachbar M; Mönnich D; Gani C; Zips D; Boeke S. doi: 10.1016/j.phro.2020.09.007

Quantitative Magnetic Resonance Imaging for Biological Image-Guided Adaptive Radiotherapy

Front Oncol.2020;10:615643. van Houdt PJ; Yang Y; van der Heide UA. doi: 10.3389/fonc.2020.615643

Feasibility and accuracy of quantitative imaging on a 1.5 T MR-linear accelerator

Radiother Oncol.2019;133:156-162. Kooreman ES; van Houdt PJ; Nowee ME; van Pelt VWJ; Tijssen RHN; Paulson ES; Gurney-Champion OJ; Wang J; Koetsveld F; van Buuren LD; Ter Beek LC; van der Heide UA. doi: 10.1016/j.radonc.2019.01.011

Quantitative MRI on MR-Linacs: Towards Biological Image-Guided Adaptive Radiotherapy.

Semin Radiat Oncol. 2024;34:107-119. van Houdt PJ; Li S; Yang Y; van der Heide UA. doi: 10.1016/j.semradonc.2023.10.010.

Intravoxel incoherent motion magnetic resonance imaging to assess early tumor response to radiation therapy: Review and future directions.

Magn Reson Imaging. 2024;108:129-137. Mesny E; Leporq B; Chapet O; Beuf O. doi: 10.1016/j.mri.2024.02.008.

Central Nervous System

Diffusion-weighted imaging on an MRI-linear accelerator to identify adversely prognostic tumour regions in glioblastoma during chemoradiation.

Radiother Oncol. 2023;188:109873. Lawrence LSP; Chan RW; Chen H; Stewart J; Ruschin M; Theriault A; Myrehaug S; Detsky J; Maralani PJ; Tseng CL; Soliman H; Jane Lim-Fat M; Das S; Stanisz GJ; Sahgal A; Lau AZ. doi: 10.1016/j.radonc.2023.109873

Accuracy and precision of apparent diffusion coefficient measurements on a 1.5 T MR-Linac in central nervous system tumour patients

Radiother Oncol.2021;164:155-162. Lawrence LSP; Chan RW; Chen H; Keller B; Stewart J; Ruschin M; Chugh B; Campbell M; Theriault A; Stanisz GJ; MacKenzie S; Myrehaug S; Detsky J; Maralani PJ; Tseng CL; Czarnota GJ; Sahgal A; Lau AZ. doi: 10.1016/j.radonc.2021.09.020

Chemical exchange saturation transfer MRI in central nervous system tumours on a 1.5 T MR-Linac

Radiother Oncol.2021;162:140-149. Chan RW; Lawrence LSP; Oglesby RT; Chen H; Stewart J; Theriault A; Campbell M; Ruschin M; Myrehaug S; Atenafu EG; Keller B; Chugh B; MacKenzie S; Tseng CL; Detsky J; Maralani PJ; Czarnota GJ; Stanisz GJ; Sahgal A; Lau AZ. doi: 10.1016/j.radonc.2021.07.010

MR-Guided Radiotherapy for Brain and Spine Tumors

Front Oncol.2021;11:626100. Maziero D; Straza MW; Ford JC; Bovi JA; Diwanji T; Stoyanova R; Paulson ES; Mellon EA. doi: 10.3389/fonc.2021.626100

Evolving concepts in margin strategies and adaptive radiotherapy for glioblastoma: A new future is on the horizon.

Neuro Oncol. 2024;26:S3-S16. Tseng CL; Zeng KL; Mellon EA; Soltys SG; Ruschin M; Lau AZ; Lutsik NS; Chan RW; Detsky J; Stewart J; Maralani PJ; Sahgal A. doi: 10.1093/neuonc/noad258.

Head and Neck

Longitudinal diffusion and volumetric kinetics of head and neck cancer magnetic resonance on a 1.5 T MR-linear accelerator hybrid system: A prospective R-IDEAL stage 2a imaging biomarker characterization/pre-qualification study

Clin Transl Radiat Oncol. 2023;42:100666. Joint Head and Neck Radiation Therapy-MRI Development Cooperative; MR-Linac Consortium Head and Neck Tumor Site Group. doi: 10.1016/j.ctro.2023.100666

Prospective Evaluation of In Vivo and Phantom Repeatability and Reproducibility of Diffusion-Weighted MRI Sequences on 1.5T MRI-Linear Accelerator (MR-Linac) and MR Simulator Devices for Head and Neck Cancers

Radiother Oncol.2023;185:109717. McDonald BA; Salzillo T; Mulder S; Ahmed S; Dresner A; Preston K; He R; Christodouleas J; Mohamed ASR; Philippens M; van Houdt P; Thorwarth D; Wang J; Shukla-Dave A, Boss M, Fuller CD. doi.org/10.1016/j.radonc.2023.109717

First-in-human technique translation of oxygen-enhanced MRI to an MR Linac system in patients with head and neck cancer

Radiother Oncol.2023;183:109592. Dubec MJ; Buckley DL; Berks M; Clough A; Gaffney J; Datta A; McHugh DJ; Porta N; Little RA; Cheung S; Hague C; Eccles CL; Hoskin PJ; Bristow RG; Matthews JC; van Herk M; Choudhury A; Jm Parker G; McPartlin A; Pb O'Connor J doi: 10.1016/j.radonc.2023.109592

Review of functional magnetic resonance imaging in the assessment of nasopharyngeal carcinoma treatment response

Precision Radiation Oncology.2022;6:177-185. Wong Kwun; Cheng Ka; Lam Sai; Liu Chenyang; Cai Jing. doi: 10.1002/pro6.1161

Repeatability of diffusion-weighted magnetic resonance imaging in head and neck cancer at a 1.5 T MR-Linac

Radiother Oncol.2022;174:141-148. Habrich J; Boeke S; Nachbar M; Nikolaou K; Schick F; Gani C; Zips D; Thorwarth D. doi: 10.1016/j.radonc.2022.07.020

Target Volume Delineation Using Diffusion-weighted Imaging for MR-guided Radiotherapy: A Case Series of Laryngeal Cancer Validated by Pathology

Cureus.2018;10:e2465. Ligtenberg H; Schakel T; Dankbaar JW; Ruiter LN; Peltenburg B; Willems SM; Kasperts N; Terhaard CHJ; Raaijmakers CPJ Philippens MEP. doi: 10.7759/cureus.2465


Feasibility of cardiac-synchronized quantitative T1 and T2 mapping on a hybrid 1.5 Tesla magnetic resonance imaging and linear accelerator system

Phys Imaging Radiat Oncol.2022;21:153-159. Akdag O; Mandija S; van Lier ALHMW; Borman PTS; Schakel T; Alberts E; van der Heide O; Hassink RJ; Verhoeff JJC; Mohamed Hoesein FAA; Raaymakers BW; Fast MF. doi: 10.1016/j.phro.2022.02.017


Longitudinal monitoring of Apparent Diffusion Coefficient (ADC) in patients with prostate cancer undergoing MR-guided radiotherapy on an MR-Linac at 1.5 T: a prospective feasibility study

Radiol. Oncol. 2023;57(2):184-190. Almansour H; Schick F; Nachbar M; Afat S; Fritz V; Thorwarth D; Zips D; Bertram F; Muller AC; Nikolaou K; Othman AE; Wegener D. doi: 10.2478/raon-2023-0020

Longitudinal Correlations Between Intravoxel Incoherent Motion (IVIM) and Dynamic Contrast-Enhanced (DCE) MRI During Radiotherapy in Prostate Cancer Patients

Front Oncol.2022;12:897130. Kooreman ES; van Pelt V; Nowee ME; Pos F; van der Heide UA; van Houdt PJ. doi: 10.3389/fonc.2022.897130

Daily Intravoxel Incoherent Motion (IVIM) In Prostate Cancer Patients During MR-Guided Radiotherapy-A Multicenter Study

Front Oncol.2021;11:705964. Kooreman ES; van Houdt PJ; Keesman R; van Pelt VWJ; Nowee ME; Pos F; Sikorska K; Wetscherek A; Muller AC; Thorwarth D; Tree AC; van der Heide UA. doi: 10.3389/fonc.2021.705964

Serial T2-Weighted Magnetic Resonance Images Acquired on a 1.5 Tesla Magnetic Resonance Linear Accelerator Reveal Radiomic Feature Variation in Organs at Risk: An Exploratory Analysis of Novel Metrics of Tissue Response in Prostate Cancer

Cureus.2019;11:e4510. Lorenz JW; Schott D; Rein L; Mostafaei F; Noid G; Lawton C; Bedi M; Li XA; Schultz CJ; Paulson E; Hall WA. doi: 10.7759/cureus.4510

Longitudinal Correlations Between Intravoxel Incoherent Motion (IVIM) and Dynamic Contrast-Enhanced (DCE) MRI During Radiotherapy in Prostate Cancer Patients

Front Oncol.2022;12:897130. Kooreman ES; van Pelt V; Nowee ME; Pos F; van der Heide UA; van Houdt PJ. doi: 10.3389/fonc.2022.897130

Reliability of MRI radiomics features in MR-guided radiotherapy for prostate cancer: Repeatability, reproducibility, and within-subject agreement

Med Phys.2021;48:6976–6986. Xue C, Yuan J, Poon DM, Zhou Y, Yang B, Yu SK, Cheung YK. doi: 10.1002/mp.15232

Prospective Image Quality and Lesion Assessment in the Setting of MR-Guided Radiation Therapy of Prostate Cancer on an MR-Linac at 1.5 T: A Comparison to a Standard 3 T MRI

Cancers (Basel).2021;13: Almansour H; Afat S; Fritz V; Schick F; Nachbar M; Thorwarth D; Zips D; Muller AC; Nikolaou K; Othman AE; Wegener D. doi: 10.3390/cancers13071533


Quantitative analysis of diffusion weighted imaging in rectal cancer during radiotherapy using a magnetic resonance imaging integrated linear accelerator

Phys Imaging Radiat Oncol.2022;23:32-37. Ingle M; Blackledge M; White I; Wetscherek A; Lalondrelle S; Hafeez S; Bhide S. doi: 10.1016/j.phro.2022.06.003

T for Radiotherapy Treatment Response Monitoring in Rectal Cancer Patients: A Pilot Study

J Clin Med.2022;11. Kooreman ES; Tanaka M; Ter Beek LC; Peters FP; Marijnen CAM; van der Heide UA; van Houdt PJ. doi: 10.3390/jcm11071998

Technical articles

Quality assurance assessment of Intra-Acquisition Diffusion-Weighted and T2-Weighted magnetic resonance imaging registration and contour propagation for head and neck cancer radiotherapy

Med Phys.2022. Naser MA; Wahid KA; Ahmed S; Salama V; Dede C; Edwards BW; Lin R; McDonald B; Salzillo TC; He R; Ding Y; Abdelaal MA; Thill D; O'Connell N; Willcut V; Christodouleas JP; Lai SY; Fuller CD; Mohamed ASR. doi: 10.1002/mp.16128

Potential of Deep Learning in Quantitative Magnetic Resonance Imaging for Personalized Radiotherapy

Semin Radiat Oncol.2022;32:377-388. Gurney-Champion OJ; Landry G; Redalen KR; Thorwarth D. doi: 10.1016/j.semradonc.2022.06.007

Longitudinal assessment of quality assurance measurements in a 1.5 T MR-linac: Part II-Magnetic resonance imaging

J Appl Clin Med Phys.2022;23:e13586.Subashi E; Dresner A; Tyagi N. doi: 10.1002/acm2.13586

A convolutional neural network for contouring metastatic lymph nodes on diffusion-weighted magnetic resonance images for assessment of radiotherapy response

Phys Imaging Radiat Oncol.2020;15:1-7. Gurney-Champion OJ; Kieselmann JP; Wong KH; Ng-Cheng-Hin B; Harrington K; Oelfke U. doi: 10.1016/j.phro.2020.06.002

Technical feasibility of magnetic resonance fingerprinting on a 1.5T MRI-linac

Phys Med Biol.2020;65:22NT01. Bruijnen T; van der Heide O; Intven MPW; Mook S; Lagendijk JJW; van den Berg CAT; Tijssen RHN. doi: 10.1088/1361-6560/abbb9d