Cone beam computed tomography guided online adaptive radiotherapy for cervical Cancer: Two-year single-Centre implementation and clinical experience

Technical Innovations & Patient Support in Radiation Oncology, vol. 40, pp. 100442

Abstract

Purpose: Managing inter- and intrafraction motion remains a major challenge in cervical cancer radiotherapy. This study reports a two-year, single-centre experience with daily CBCT-guided cervical online adaptive radiotherapy (oART), evaluating the workflow feasibility of a radiation therapist (RTT)-led adaptive workflow, including treatment session duration and target coverage. Materials and methods: Thirty patients with cervical cancer were treated with CBCT-guided oART between October 2023 and December 2025. After initial supervised sessions, treatment delivery transitioned to an RTT-led workflow supported by a traffic-light protocol with on-call multidisciplinary backup. Cervical oART was introduced in phases, progressing from single-isocentre cases to more complex treatments including two isocentres and para-aortic lymph nodes. Workflow evaluation was based on retrospective analysis of session logs, process timing and oART workflow-related interventions. Results: A total of 744 adaptive sessions were analysed. Median total session duration was 33.0 min (interquartile range 13.0). Imaging and beam delivery times were stable, whereas decision-intensive steps showed greater variability, requiring corrections to AI-generated contours in all patients. Median total session duration was comparable between the first five supervised sessions and the subsequent RTT-led sessions (32.5 vs. 32.0 min). Contour review showed the strongest correlation with total session duration (ρ = 0.73). Uterus displacement outside the PTV due to intrafraction motion was observed in approximately 11% of all post-treatment CBCT-verifications and was typically limited to small fundal regions. Conclusion: Daily CBCT-guided cervical oART can be efficiently implemented within an RTT-led workflow, demonstrating workflow feasibility while maintaining target coverage despite intra-fraction anatomical variability.

Authors 13

1. Danique L.J. Barten

   Amsterdam UMC Location University of Amsterdam · Cancer Center Amsterdam

   Affiliation as printed

   Amsterdam UMC, location University of Amsterdam, Department of Radiation Oncology, Meibergdreef 9, Amsterdam, the Netherlands

   Cancer Center Amsterdam, Imaging and Biomarkers, Amsterdam, the Netherlands

2. Karin Goudschaal

   Amsterdam UMC Location University of Amsterdam

   Affiliation as printed

   Amsterdam UMC, location University of Amsterdam, Department of Radiation Oncology, Meibergdreef 9, Amsterdam, the Netherlands

3. Karel A. Hinnen

   Amsterdam UMC Location University of Amsterdam · Cancer Center Amsterdam

   Affiliation as printed

   Amsterdam UMC, location University of Amsterdam, Department of Radiation Oncology, Meibergdreef 9, Amsterdam, the Netherlands

   Cancer Center Amsterdam, Imaging and Biomarkers, Amsterdam, the Netherlands

4. Rianne de Jong Aachen Department of Radiation Oncology

   Leiden University Medical Center

   Affiliation as printed

   Leiden University Medical Center, Department of Radiation Oncology, Postbus, 9600 Leiden, the Netherlands

5. J. Wiersma

   Amsterdam UMC Location University of Amsterdam

   Affiliation as printed

   Amsterdam UMC, location University of Amsterdam, Department of Radiation Oncology, Meibergdreef 9, Amsterdam, the Netherlands

6. Niek Van Wieringen

   Amsterdam UMC Location University of Amsterdam

   Affiliation as printed

   Amsterdam UMC, location University of Amsterdam, Department of Radiation Oncology, Meibergdreef 9, Amsterdam, the Netherlands

7. Z. van Kesteren

   Amsterdam UMC Location University of Amsterdam

   Affiliation as printed

   Amsterdam UMC, location University of Amsterdam, Department of Radiation Oncology, Meibergdreef 9, Amsterdam, the Netherlands

8. Arjan Bel

   Amsterdam UMC Location University of Amsterdam

   Affiliation as printed

   Amsterdam UMC, location University of Amsterdam, Department of Radiation Oncology, Meibergdreef 9, Amsterdam, the Netherlands

9. Angelique R.W. van Vlaenderen

   Amsterdam UMC Location Vrije Universiteit Amsterdam

   Affiliation as printed

   Amsterdam UMC location, Vrije Universiteit Amsterdam, Department of Radiation Oncology, De Boelelaan 1117, Amsterdam, the Netherlands

10. Sandy Loopeker

    Amsterdam UMC Location Vrije Universiteit Amsterdam

    Affiliation as printed

    Amsterdam UMC location, Vrije Universiteit Amsterdam, Department of Radiation Oncology, De Boelelaan 1117, Amsterdam, the Netherlands

11. Bradley Rumwell Pieters

    Amsterdam UMC Location University of Amsterdam · Cancer Center Amsterdam

    Affiliation as printed

    Amsterdam UMC, location University of Amsterdam, Department of Radiation Oncology, Meibergdreef 9, Amsterdam, the Netherlands

    Cancer Center Amsterdam, Imaging and Biomarkers, Amsterdam, the Netherlands

12. Jorrit Visser corresponding

    Amsterdam UMC Location University of Amsterdam

    Affiliation as printed

    Amsterdam UMC, location University of Amsterdam, Department of Radiation Oncology, Meibergdreef 9, Amsterdam, the Netherlands

13. Colette B. M. van den Broek

    Amsterdam UMC Location University of Amsterdam · Cancer Center Amsterdam

    Affiliation as printed

    Amsterdam UMC, location University of Amsterdam, Department of Radiation Oncology, Meibergdreef 9, Amsterdam, the Netherlands

    Cancer Center Amsterdam, Imaging and Biomarkers, Amsterdam, the Netherlands