Local control and patient reported outcomes after online MR guided stereotactic body radiotherapy of liver metastases

Laura Uder; Marcel Nachbar; Sarah Butzer; Jessica Boldt; Sabrina Baumeister; Michael Bitzer; Alfred Königsrainer; Thomas Seufferlein; Rüdiger Hoffmann; Sergios Gatidis; Konstantin Nikolaou; Daniel Zips; Daniela Thorwarth; Cihan Gani; Simon Boeke

doi:10.3389/fonc.2022.1095633

Local control and patient reported outcomes after online MR guided stereotactic body radiotherapy of liver metastases

Front Oncol. 2023 Jan 16:12:1095633. doi: 10.3389/fonc.2022.1095633. eCollection 2022.

Authors

Laura Uder¹, Marcel Nachbar², Sarah Butzer¹, Jessica Boldt¹, Sabrina Baumeister¹, Michael Bitzer³, Alfred Königsrainer⁴, Thomas Seufferlein⁵, Rüdiger Hoffmann⁶, Sergios Gatidis⁶, Konstantin Nikolaou⁶, Daniel Zips^{1

7

8}, Daniela Thorwarth^{2

7}, Cihan Gani^{1

7}, Simon Boeke^{1

7}

Affiliations

¹ Department of Radiation Oncology, University Hospital and Medical Faculty, Eberhard Karls University Tübingen, Tübingen, Germany.
² Section for Biomedical Physics, Department of Radiation Oncology, University Hospital and Medical Faculty, Eberhard Karls University Tübingen, Tübingen, Germany.
³ Department of Internal Medicine I, University Hospital Tübingen, Tübingen, Germany.
⁴ Department of General, Visceral and Transplant Surgery, University Hospital Tübingen, Tübingen, Germany.
⁵ Department of Internal Medicine I, Ulm University Hospital Medical Center, Ulm, Germany.
⁶ Department of Diagnostic and Interventional Radiology , University of Tübingen, Tübingen, Germany.
⁷ German Cancer Consortium (DKTK), partner site Tübingen; and German Cancer Research Center (DKFZ), Heidelberg, Germany.
⁸ Department of Radiation Oncology, Berlin Institute of Health, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany.

Abstract

Introduction: Stereotactic body radiotherapy (SBRT) is used to treat liver metastases with the intention of ablation. High local control rates were shown. Magnetic resonance imaging guided radiotherapy (MRgRT) provides the opportunity of a marker-less liver SBRT treatment due to the high soft tissue contrast. We report herein on one of the largest cohorts of patients treated with online MRgRT of liver metastases focusing on oncological outcome, toxicity, patient reported outcome measures (PROMs), quality of life.

Material and methods: Patients treated for liver metastases with online MR-guided SBRT at a 1,5 T MR-Linac (Unity, Elekta, Crawley, UK) between March 2019 and December 2021 were included in this prospective study. UK SABR guidelines were used for organs at risk constraints. Oncological endpoints such as survival parameters (overall survival, progression-free survival) and local control as well as patient reported acceptance and quality of life data (EORTC QLQ-C30 questionnaire) were assessed. For toxicity scoring the Common Toxicity Criteria Version 5 were used.

Results: A total of 51 patients with 74 metastases were treated with a median of five fractions. The median applied BED GTV D98 was 84,1 Gy. Median follow-up was 15 months. Local control of the irradiated liver metastasis after 12 months was 89,6%, local control of the liver was 40,3%. Overall survival (OS) after 12 months was 85.1%. Progression free survival (PFS) after 12 months was 22,4%. Local control of the irradiated liver lesion was 100% after three years when a BED ≥100 Gy was reached. The number of treated lesions did not impact local control neither of the treated or of the hepatic control. Patient acceptance of online MRgSBRT was high. There were no acute grade ≥ 3 toxicities. Quality of life data showed no significant difference comparing baseline and follow-up data.

Conclusion: Online MR guided radiotherapy is a noninvasive, well-tolerated and effective treatment for liver metastases. Further prospective trials with the goal to define patients who actually benefit most from an online adaptive workflow are currently ongoing.

Keywords: image guided radiation therapy; liver metastases; magnetic resonance guided radiotherapy; online adaptive radiation therapy; stereotactic body radiation therapy.

Grants and funding

The MRgRT program in Tübingen is funded by the German Research Council (DFG ZI 736/2-1; PAK 997/1: GA 2996/1-1, ZI 736/4-1), the University Hospital Tübingen and the Medical Faculty Tübingen. CG, DZ, SG and DT received funding by the German Research Council (DFG ZI 736/2-1; PAK 997/1: GA 2996/1-1, ZI 736/4-1). We acknowledge support by Open Access Publishing Fund of University of Tübingen.