Generating synthetic computed tomography for radiotherapy: SynthRAD2023 challenge report

Medical Image Analysis, vol. 97, pp. 103276

Abstract

Radiation therapy plays a crucial role in cancer treatment, necessitating precise delivery of radiation to tumors while sparing healthy tissues over multiple days. Computed tomography (CT) is integral for treatment planning, offering electron density data crucial for accurate dose calculations. However, accurately representing patient anatomy is challenging, especially in adaptive radiotherapy, where CT is not acquired daily. Magnetic resonance imaging (MRI) provides superior soft-tissue contrast. Still, it lacks electron density information, while cone beam CT (CBCT) lacks direct electron density calibration and is mainly used for patient positioning. Adopting MRI-only or CBCT-based adaptive radiotherapy eliminates the need for CT planning but presents challenges. Synthetic CT (sCT) generation techniques aim to address these challenges by using image synthesis to bridge the gap between MRI, CBCT, and CT. The SynthRAD2023 challenge was organized to compare synthetic CT generation methods using multi-center ground truth data from 1080 patients, divided into two tasks: (1) MRI-to-CT and (2) CBCT-to-CT. The evaluation included image similarity and dose-based metrics from proton and photon plans. The challenge attracted significant participation, with 617 registrations and 22/17 valid submissions for tasks 1/2. Top-performing teams achieved high structural similarity indices (≥0.87/0.90) and gamma pass rates for photon (≥98.1%/99.0%) and proton (≥97.3%/97.0%) plans. However, no significant correlation was found between image similarity metrics and dose accuracy, emphasizing the need for dose evaluation when assessing the clinical applicability of sCT. SynthRAD2023 facilitated the investigation and benchmarking of sCT generation techniques, providing insights for developing MRI-only and CBCT-based adaptive radiotherapy. It showcased the growing capacity of deep learning to produce high-quality sCT, reducing reliance on conventional CT for treatment planning.

Authors 57

1. Evi M. C. Huijben

   Eindhoven University of Technology

   Affiliation as printed

   Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands

   TU/e - Eindhoven University of Technology [Eindhoven] (Den Dolech 2 5612 AZ Eindhoven - Netherlands)

2. Maarten L. Terpstra

   Utrecht University · University Medical Center Utrecht

   Affiliation as printed

   Radiotherapy Department, University Medical Center Utrecht, Utrecht, The Netherlands; Computational Imaging Group for MR Diagnostics & Therapy, University Medical Center Utrecht, Utrecht, The Netherlands

   UMCU - University Medical Center [Utrecht] (Heidelberglaan 100 3584 CX Utrecht - Netherlands)

3. Arthur Galapon

   University Medical Center Groningen · University of Groningen

   Affiliation as printed

   Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands

   UMCG - University Medical Center Groningen [Groningen] (PO box 30.001 9700 RB Groningen - Netherlands)

   University of Groningen [Groningen] (PO Box 72 , 9700 AB Groningen - Netherlands)

4. Suraj Pai

   Maastricht University Medical Centre

   Affiliation as printed

   Department of Radiation Oncology (Maastro), GROW School for Oncology, Maastricht University Medical Centre, Maastricht, The Netherlands

   MUMC - Maastricht University Medical Centre (Maastricht - Netherlands)

5. Adrian Thummerer

   University Medical Center Groningen · University of Groningen · LMU Klinikum · Ludwig-Maximilians-Universität München

   Affiliation as printed

   Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands; Department of Radiation Oncology, LMU University Hospital, LMU Munich, Munich, Germany

   LMU - Ludwig Maximilian University [Munich] = Ludwig Maximilians Universität München (Professor-Huber-Platz 2, 80539 München, Allemagne - Germany)

   UMCG - University Medical Center Groningen [Groningen] (PO box 30.001 9700 RB Groningen - Netherlands)

   University of Groningen [Groningen] (PO Box 72 , 9700 AB Groningen - Netherlands)

6. Peter J. Koopmans

   Radboud University Nijmegen · Radboud University Medical Center

   Affiliation as printed

   Department of Radiation Oncology, Radboud University Medical Center, Nijmegen, The Netherlands

   Radboud University Medical Center [Nijmegen] (6500 HB Nijmegen - Netherlands)

7. Manya V. Afonso

   Wageningen University & Research

   Affiliation as printed

   Wageningen University & Research, Wageningen Plant Research, Wageningen, The Netherlands

   WUR - Wageningen University and Research [Wageningen] (Droevendaalsesteeg 4, 6708 PB Wageningen - Netherlands)

8. Maureen A.J.M. van Eijnatten

   Eindhoven University of Technology

   Affiliation as printed

   Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands

   TU/e - Eindhoven University of Technology [Eindhoven] (Den Dolech 2 5612 AZ Eindhoven - Netherlands)

9. Oliver J. Gurney‐Champion

   Amsterdam UMC Location University of Amsterdam · Amsterdam University Medical Centers · Cancer Center Amsterdam · University of Amsterdam

   Affiliation as printed

   Department of Radiology and Nuclear Medicine, Amsterdam UMC, location University of Amsterdam, Amsterdam, The Netherlands; Cancer Center Amsterdam, Imaging and Biomarkers, Amsterdam, The Netherlands

   Amsterdam UMC - Amsterdam University Medical Centers (1105 AZ Amsterdam - Netherlands)

   UvA - University of Amsterdam [Amsterdam] = Universiteit van Amsterdam (Spui 21 1012 WX Amsterdam - Netherlands)

10. Zeli Chen

    Southern Medical University · China Medical University

    Affiliation as printed

    School of Biomedical Engineering, Southern Medical University, Guangzhou, China

    Shenying Medical Technology (Shenzhen) Co., Ltd., Shenzhen, Guangdong, China

    Southern Medical University [Guangzhou] (Guangdong, China - China)

11. Yiwen Zhang

    Paul Scherrer Institute · ETH Zurich · Southern Medical University

    Affiliation as printed

    Center for Proton Therapy, Paul Scherrer Institut, Villigen, Switzerland; Department of Computer Science, ETH Zurich, Zurich, Switzerland

    School of Biomedical Engineering, Southern Medical University, Guangzhou, China

    Southern Medical University [Guangzhou] (Guangdong, China - China)

12. Chuanpu Li

    Southern Medical University

    Affiliation as printed

    School of Biomedical Engineering, Southern Medical University, Guangzhou, China

    Southern Medical University [Guangzhou] (Guangdong, China - China)

13. Haowen Pang

    Beijing Institute of Technology

    Affiliation as printed

    School of Integrated Circuits and Electronics, Beijing Institute of Technology, Beijing, China

    BIT - Beijing Institute of Technology (5 South Zhongguancun Street, Haidian District, Beijing Postcode: 100081 - China)

14. Chuyang Ye

    Beijing Institute of Technology

    Affiliation as printed

    School of Integrated Circuits and Electronics, Beijing Institute of Technology, Beijing, China

    BIT - Beijing Institute of Technology (5 South Zhongguancun Street, Haidian District, Beijing Postcode: 100081 - China)

15. Runqi Wang

    ShanghaiTech University

    Affiliation as printed

    School of Biomedical Engineering, ShanghaiTech University, Shanghai, China

    ShanghaiTech University [Shanghai] (- Zhangjiang Campus, 393 Middle Huaxia Road, Pudong, Shanghai, 201210 - Yueyang Campus, 319 Yueyang Road, Puxi, Shanghai 200031 - China)

16. Fuxin Fan

    Friedrich-Alexander-Universität Erlangen-Nürnberg

    Affiliation as printed

    Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany

    FAU - Friedrich-Alexander Universität Erlangen-Nürnberg = University of Erlangen-Nuremberg (Schlossplatz 4, 91054 Erlangen, Germany - Germany)

17. Jingna Qiu

    Friedrich-Alexander-Universität Erlangen-Nürnberg

    Affiliation as printed

    Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany

    FAU - Friedrich-Alexander Universität Erlangen-Nürnberg = University of Erlangen-Nuremberg (Schlossplatz 4, 91054 Erlangen, Germany - Germany)

18. Yixing Huang

    Friedrich-Alexander-Universität Erlangen-Nürnberg

    Affiliation as printed

    Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany

    FAU - Friedrich-Alexander Universität Erlangen-Nürnberg = University of Erlangen-Nuremberg (Schlossplatz 4, 91054 Erlangen, Germany - Germany)

19. Juhyung Ha

    Indiana University Bloomington · Indiana University

    Affiliation as printed

    Indiana University, Bloomington, USA

    Indiana University [Bloomington] (107 S. Indiana Avenue, Bloomington, IN 47405-7000 - United States)

20. Jong Sung Park

    Indiana University Bloomington · Indiana University

    Affiliation as printed

    Indiana University, Bloomington, USA

    Indiana University [Bloomington] (107 S. Indiana Avenue, Bloomington, IN 47405-7000 - United States)

21. Alexandra Alain-Beaudoin

    Elekta (United States)

    Affiliation as printed

    Advanced Development Engineering, Elekta Ltd, Montreal, Canada

    Elekta Inc. [Maryland Heights] (United States)

22. Silvain Bériault

    Elekta (United States)

    Affiliation as printed

    Advanced Development Engineering, Elekta Ltd, Montreal, Canada

    Elekta Inc. [Maryland Heights] (United States)

23. Pengxin Yu

    InferVision (China)

    Affiliation as printed

    Infervision Medical Technology Co., Ltd. Beijing, China

    Infervision Technology

24. Hongbin Guo

    Shantou University

    Affiliation as printed

    Department of Biomedical Engineering, Shantou University, China

    Shantou University [Shantou, China] (243 Daxue Road, Shantou, Guangdong, P.R.China, Postal Code: 515063 - China)

25. Zhanyao Huang

    Shantou University

    Affiliation as printed

    Department of Biomedical Engineering, Shantou University, China

    Shantou University [Shantou, China] (243 Daxue Road, Shantou, Guangdong, P.R.China, Postal Code: 515063 - China)

26. Gengwan Li
    Affiliation as printed

    Independent researchers

    Chercheur indépendant (France)

27. Xueru Zhang
    Affiliation as printed

    Independent researchers

    Chercheur indépendant (France)

28. Yubo Fan

    Vanderbilt University

    Affiliation as printed

    Department of Computer Science, Vanderbilt University, Nashville, USA

    Vanderbilt University [Nashville] (Nashville, Tennessee, TN 37240 - United States)

29. Han Liu

    Vanderbilt University

    Affiliation as printed

    Department of Computer Science, Vanderbilt University, Nashville, USA

    Vanderbilt University [Nashville] (Nashville, Tennessee, TN 37240 - United States)

30. Bowen Xin

    Commonwealth Scientific and Industrial Research Organisation · Australian e-Health Research Centre

    Affiliation as printed

    Australian e-Health Research Centre, CSIRO, Herston, Queensland, Australia

    The Australian e-Health Research centre (Herston - Australia)

31. Aaron Nicolson

    Commonwealth Scientific and Industrial Research Organisation · Australian e-Health Research Centre

    Affiliation as printed

    Australian e-Health Research Centre, CSIRO, Herston, Queensland, Australia

    The Australian e-Health Research centre (Herston - Australia)

32. Lujia Zhong

    University of Southern California

    Affiliation as printed

    Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California (USC), Los Angeles, CA, USA

    USC - University of Southern California (Los Angeles, CA, 90089-0484, USA - United States)

33. Zhiwei Deng

    University of Southern California

    Affiliation as printed

    Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California (USC), Los Angeles, CA, USA

    USC - University of Southern California (Los Angeles, CA, 90089-0484, USA - United States)

34. Gustav Anton Müller‐Franzes Aachen

    Universitätsklinikum Aachen · RWTH Aachen University

    Affiliation as printed

    University Hospital Aachen, Aachen, Germany

    UKA - Universitätsklinikum RWTH Aachen - University Hospital Aachen [Aachen, Germany] (Universitätsklinikum Aachen, AöR - Pauwelsstraße 30 - 52074 Aachen - Germany)

35. Firas Khader Aachen

    Universitätsklinikum Aachen · RWTH Aachen University

    Affiliation as printed

    University Hospital Aachen, Aachen, Germany

    UKA - Universitätsklinikum RWTH Aachen - University Hospital Aachen [Aachen, Germany] (Universitätsklinikum Aachen, AöR - Pauwelsstraße 30 - 52074 Aachen - Germany)

36. Xia Li

    Paul Scherrer Institute · ETH Zurich

    Affiliation as printed

    Center for Proton Therapy, Paul Scherrer Institut, Villigen, Switzerland; Department of Computer Science, ETH Zurich, Zurich, Switzerland

    D-INFK - Department of Computer Science [ETH Zürich] (Haldeneggsteig 4 / Weinbergstrasse 8092 Zürich - Switzerland)

    PSI - Paul Scherrer Institute (Villigen PSI, CH5232 Villigen, Suisse - Switzerland)

37. Ye Zhang

    Paul Scherrer Institute · ETH Zurich · Southern Medical University

    Affiliation as printed

    Center for Proton Therapy, Paul Scherrer Institut, Villigen, Switzerland; Department of Computer Science, ETH Zurich, Zurich, Switzerland

    School of Biomedical Engineering, Southern Medical University, Guangzhou, China

    D-INFK - Department of Computer Science [ETH Zürich] (Haldeneggsteig 4 / Weinbergstrasse 8092 Zürich - Switzerland)

    PSI - Paul Scherrer Institute (Villigen PSI, CH5232 Villigen, Suisse - Switzerland)

38. Cédric Hémon

    Inserm · Laboratoire Traitement du Signal et de l'Image · Centre Eugène Marquis · Université de Rennes

    Affiliation as printed

    University Rennes 1, CLCC Eugène Marquis, INSERM, LTSI, Rennes, France

    CRLCC - CRLCC Eugène Marquis (Avenue Bataille Flandres-Dunkerque 35042 RENNES CEDEX - France)

    LTSI - Laboratoire Traitement du Signal et de l'Image (Campus Universitaire de Beaulieu - Bât 22 - 35042 Rennes - France)

39. Valentin Boussot

    Inserm · Laboratoire Traitement du Signal et de l'Image · Centre Eugène Marquis · Université de Rennes

    Affiliation as printed

    University Rennes 1, CLCC Eugène Marquis, INSERM, LTSI, Rennes, France

    CRLCC - CRLCC Eugène Marquis (Avenue Bataille Flandres-Dunkerque 35042 RENNES CEDEX - France)

    LTSI - Laboratoire Traitement du Signal et de l'Image (Campus Universitaire de Beaulieu - Bât 22 - 35042 Rennes - France)

40. Zhihao Zhang

    Southern Medical University

    Affiliation as printed

    Subtle Medical, Shanghai, China

    School of Biomedical Engineering, Southern Medical University, Guangzhou, China

41. Long Wang

    ShanghaiTech University

    Affiliation as printed

    Subtle Medical, Shanghai, China

    School of Biomedical Engineering, ShanghaiTech University, Shanghai, China

42. Lu Bai
    Affiliation as printed

    MedMind Technology Co. Ltd., Beijing, China

43. Shaobin Wang

    ShanghaiTech University

    Affiliation as printed

    MedMind Technology Co. Ltd., Beijing, China

    School of Biomedical Engineering, ShanghaiTech University, Shanghai, China

44. Derk Mus
    Affiliation as printed

    MRI Guidance BV, Utrecht, The Netherlands

45. Bram Kooiman
    Affiliation as printed

    MRI Guidance BV, Utrecht, The Netherlands

46. Chelsea A. H. Sargeant

    University of Manchester

    Affiliation as printed

    Division of Cancer Sciences, The University of Manchester, United Kingdom

    University of Manchester [Manchester] (Oxford Rd, Manchester M13 9PL - United Kingdom)

47. E HENDERSON

    University of Manchester

    Affiliation as printed

    Division of Cancer Sciences, The University of Manchester, United Kingdom

    University of Manchester [Manchester] (Oxford Rd, Manchester M13 9PL - United Kingdom)

48. Satoshi Kondo

    Muroran Institute of Technology

    Affiliation as printed

    Muroran Institute of Technology, Hokkaido, Japan

    Muroran Institute of Technology (27-1 Mizumoto-cho, Muroran, Hokkaido, 050-8585 - Japan)

49. Satoshi Kasai

    Niigata University of Health and Welfare · Niigata University

    Affiliation as printed

    Niigata University of Health and Welfare, Niigata, Japan

    Niigata University (Japan)

50. Reza Karimzadeh

    University of Copenhagen

    Affiliation as printed

    Image Analysis, Computational Modelling and Geometry, University of Copenhagen, Denmark

    UCPH - University of Copenhagen = Københavns Universitet (Nørregade 10, 1165 København, Danemark - Denmark)

51. Bulat Ibragimov

    University of Copenhagen

    Affiliation as printed

    Image Analysis, Computational Modelling and Geometry, University of Copenhagen, Denmark

    UCPH - University of Copenhagen = Københavns Universitet (Nørregade 10, 1165 København, Danemark - Denmark)

52. Thomas Helfer

    Stony Brook University

    Affiliation as printed

    IACS, Stony Brook University, NY, USA

    SBU - Stony Brook University [SUNY] (100 Nicolls Road, Stony Brook, NY 11794 - United States)

53. Jessica Dafflon

    National Institute of Mental Health · National Institute of Mental Health

    Affiliation as printed

    Data Science and Sharing Team, Functional Magnetic Resonance Imaging Facility, National Institute of Mental Health, Bethesda, USA; Machine Learning Team, Functional Magnetic Resonance Imaging Facility National Institute of Mental Health, Bethesda, USA

    NIMH - National Institute of Mental Health (Tokyo, Japan - Japan)

54. Zijie Chen

    Southern Medical University · China Medical University

    Affiliation as printed

    School of Biomedical Engineering, Southern Medical University, Guangzhou, China

    Shenying Medical Technology (Shenzhen) Co., Ltd., Shenzhen, Guangdong, China

55. Enpei Wang

    ShanghaiTech University · China Medical University

    Affiliation as printed

    Shenying Medical Technology (Shenzhen) Co., Ltd., Shenzhen, Guangdong, China

    School of Biomedical Engineering, ShanghaiTech University, Shanghai, China

56. Zoltán Perkó

    Delft University of Technology

    Affiliation as printed

    Delft University of Technology, Faculty of Applied Sciences, Department of Radiation Science and Technology, Delft, The Netherlands

    TU Delft - Delft University of Technology (Postbus 5, 2600 AA Delft - Netherlands)

57. Matteo Maspero

    University Medical Center Utrecht

    Affiliation as printed

    Radiotherapy Department, University Medical Center Utrecht, Utrecht, The Netherlands; Computational Imaging Group for MR Diagnostics & Therapy, University Medical Center Utrecht, Utrecht, The Netherlands. Electronic address: m.maspero@umcutrecht.nl

    UMCU - University Medical Center [Utrecht] (Heidelberglaan 100 3584 CX Utrecht - Netherlands)