Comparative analysis of target volume coverage and liver exposure in high-dose-rate interstitial brachytherapy and in silico MR LINAC-based stereotactic body radiotherapy plans for colorectal liver metastases

Mansoorian S, Hering S, Hofmaier J, Xiong Y, Weingandt H, Rottler M, Walter F, Rogowski P, Seidensticker M, Ricke J, Belka C, Corradini S, Eze C (2026)

Publication Type: Journal article

Publication year: 2026

Journal

Clinical and Translational Radiation Oncology Elsevier

Book Volume: 56

Article Number: 101030

DOI: 10.1016/j.ctro.2025.101030

Abstract

Background: This study compared the plan quality and dosimetric parameters of single-fraction (SF) MR-LINAC (MRL)-based stereotactic body radiotherapy (SBRT) with delivered high-dose-rate interstitial brachytherapy (HDR-iBT) for colorectal liver metastases (CRLM). Methods: Between August 2017 and March 2019, 26 patients with a total of 45 CRLM were treated in 28 sessions using HDR-iBT with 1 × 25 Gy and were retrospectively included in this study. For each patient, an in silico MRL-based SBRT plan was generated using the corresponding iBT CT dataset. In the iBT plans, a single fraction of 25 Gy was prescribed to the periphery of the gross tumor volumes (GTVs), while in the SBRT plans, the same dose was prescribed to the 80% isodose line covering the planning target volumes (PTVs). We compared the dosimetric properties of the delivered HDR-iBT and MRL-based SBRT plans. Results: Median GTV was 3.83 cc (range: 0.13–92.58 cc) and median PTVSBRT was 15.47 cc (range: 2.68–164.17 cc). Both HDR-iBT and SBRT demonstrated excellent GTV coverage, with no statistically significant differences in GTV D98% (28.82 ± 2.57 Gy vs. 28.92 ± 0.88 Gy, p = 0.9). HDR-iBT achieved superior GTV D95% (31.62 ± 3.20 Gy vs. 29.22 ± 0.74 Gy, p < 0.01) and GTV D50% (64.71 ± 12.78 Gy vs. 30.22 ± 0.52 Gy, p < 0.01). Uninvolved liver dose metrics were higher in the SBRT plans compared to iBT, with a median relative difference in V5Gy of 5.29% (range: −13.69% to + 17.89%, p < 0.01) and a smaller relative difference in V10Gy of 1.5% (range: −7.74% to + 11.26%, p < 0.01). Conclusion: Our comparison indicates MRL-based SBRT to liver lesions is feasible, achieving adequate target volume coverage without clinically relevant violations of organ-at-risk (OAR) constraints.

Involved external institutions

Klinikum der Universität München (LMU Klinikum) DE Germany (DE)

How to cite

APA:

Mansoorian, S., Hering, S., Hofmaier, J., Xiong, Y., Weingandt, H., Rottler, M.,... Eze, C. (2026). Comparative analysis of target volume coverage and liver exposure in high-dose-rate interstitial brachytherapy and in silico MR LINAC-based stereotactic body radiotherapy plans for colorectal liver metastases. Clinical and Translational Radiation Oncology, 56. https://doi.org/10.1016/j.ctro.2025.101030

MLA:

Mansoorian, Sina, et al. "Comparative analysis of target volume coverage and liver exposure in high-dose-rate interstitial brachytherapy and in silico MR LINAC-based stereotactic body radiotherapy plans for colorectal liver metastases." Clinical and Translational Radiation Oncology 56 (2026).

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