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Multicenter Study
. 2025 Feb;35(2):1046-1056.
doi: 10.1007/s00330-024-10956-5. Epub 2024 Aug 2.

Multicenter and inter-software evaluation of ablative margins after thermal ablation of colorectal liver metastases

Gregor Laimer #  1 , Koen H M Verdonschot #  2 , Lina Kopf  1 , Susan van der Lei  3 , Yannick Scharll  1 , Gerjon Hannink  2 , Sjoerd F M Jenniskens  2 , Martijn R Meijerink  3 , Reto Bale  1 , Christiaan G Overduin  4
Affiliations
Multicenter Study

Multicenter and inter-software evaluation of ablative margins after thermal ablation of colorectal liver metastases

Gregor Laimer et al. Eur Radiol. 2025 Feb.

Abstract

Purpose: To assess the association between minimal ablative margin (MAM) and local tumor progression (LTP) following CT-guided thermal ablation of colorectal liver metastases (CRLM) in a multicenter cohort and across two confirmation software.

Materials and methods: This multicenter retrospective study included patients who underwent CT-guided radiofrequency or microwave ablation for CRLM between 2009 and 2021 in three institutions. Three-dimensional (3D) MAM was retrospectively assessed using dedicated ablation confirmation software by automatic non-rigid (Ablation-fit) or semi-automatic rigid co-registration (SAFIR) of intraprocedural pre- and post-ablation contrast-enhanced CT scans by two independent reader teams blinded to patient outcomes. LTP was assessed on a per-tumor basis. Factors associated with LTP-free survival were assessed using multivariable Cox regression analysis.

Results: Overall, 113 patients (mean age: 67 ± 10 years; 78 men) who underwent thermal ablation for 189 CRLM (mean diameter: 1.9 ± 1.1 cm) met the inclusion criteria. 173/189 (92%) CRLM could be successfully analyzed using both software. Over a median follow-up of 31 months (IQR: 22-47), 21 of 173 CRLM (12.1%) developed LTP. On multivariable analysis, 3D MAM was independently associated with LTP in both software (Ablation-fit: HR 0.47, 95% CI: 0.36-0.61, p < 0.001; SAFIR: HR 0.42, 95% CI: 0.32-0.55, p < 0.001). No LTP was observed in CRLM ablated with MAM ≥ 4 mm (Ablation-fit) and ≥ 5 mm (SAFIR). The per-tumor median absolute difference in MAM quantification between both software was 2 mm (IQR: 1-3).

Conclusion: MAM was independently associated with LTP after thermal ablation of CRLM across multicenter data and two confirmation software. Ablations achieving a MAM ≥ 5 mm were associated with local control in both software.

Clinical relevance statement: MAMs from intraprocedural contrast-enhanced CT were independently associated with LTP after thermal ablation of CRLM across multicenter data and two confirmation software, with a margin ≥ 5 mm associated with local control in both software.

Key points: Sufficient ablative margins are critical for local control following thermal ablation of CRLM. Intraprocedural CT-derived MAM was the only independent factor associated with LTP across two confirmation software. No LTP was observed in CRLM ablated with a MAM ≥ 5 mm.

Keywords: Imaging (three-dimensional); Liver neoplasms; Radiofrequency ablation; Treatment outcome.

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Conflict of interest statement

Compliance with ethical standards. Guarantor: The scientific guarantor of this publication is Dr. Christiaan G. Overduin. Conflict of interest: The authors of this manuscript declare relationships with the following companies: M.R.M. Medtronic-Covidien, Johnson & Johnson, Angiodynamics, Philips, Immunophotonics, and Guerbet. R.B. with Interventional Systems. The remaining authors declare no conflicts of interest. Statistics and biometry: One of the authors has significant statistical expertise. Informed consent: Only if the study is on human subjects: written informed consent was waived by the Institutional Review Board. For this retrospective study, informed consent to use and exchange pseudonymized data was waived by the local institutional review board at each institution (2018–2053; 2020.077; 1316/2021) for all study participants. All data was shared under data sharing agreements (A20-0423; A21-0442) in compliance with local regulations. Ethical approval: Institutional Review Board approval was obtained. Study subjects or cohorts overlap: In a prior study (Laimer 2021—PMID: 33447860), we reported on 45 of 113 patients included in the current study. The previous study was a single-center study utilizing one confirmation software (Ablation-fit). The current study expands on this by having a multicenter cohort and all data analyzed by a second confirmation software, providing a significantly increased study population and additional and new analyses per software, including inter-software agreement. The extent of overlap has been explicitly mentioned in the Materials and Methods section of the manuscript (Page 4, 1st paragraph), including reference to the prior study. Methodology: Retrospective Observational Multicenter study

Figures

Fig. 1
Fig. 1
Flowchart of patient selection and criteria
Fig. 2
Fig. 2
Schematic overview of MAM quantification steps for each software. Semi-automatic segmentation of the liver, tumor, and ablation zone is performed on the pre- and post-ablation CE-CT. Automatic non-rigid (Ablation-fit) or semi-automatic rigid (SAFIR) co-registration is performed to align the image volumes. Finally, MAM calculation is performed and visualized in two-dimensional and 3D views
Fig. 3
Fig. 3
LTPFS curves stratified by MAM 0, > 0 and < 5, and > 5 mm for Ablation-fit (A) and SAFIR (B)
Fig. 4
Fig. 4
ROC-curves (left) and LTP detection rate (sensitivity) and false positive rate (1-specificity) for different MAM thresholds (right) for MAM measured by Ablation-fit (A) and SAFIR (B). Dashed lines indicate 95% CI
See this image and copyright information in PMC

Comment in

References

    1. Crocetti L, de Baére T, Pereira PL, Tarantino FP (2020) CIRSE standards of practice on thermal ablation of liver tumours. Cardiovasc Intervent Radiol 43:951–962 - PubMed
    1. Van Cutsem E, Cervantes A, Adam R et al (2016) ESMO consensus guidelines for the management of patients with metastatic colorectal cancer. Ann Oncol 27:1386–1422 - PubMed
    1. Ahmed M, Solbiati L, Brace CL et al (2014) Image-guided tumor ablation: standardization of terminology and reporting criteria-a 10-year update. Radiology 273:241–260 - PMC - PubMed
    1. Livraghi T, Meloni F, Solbiati L, Zanus G, Collaborative Italian Group using AMICA system (2012) Complications of microwave ablation for liver tumors: results of a multicenter study. Cardiovasc Intervent Radiol 35:868–874 - PubMed
    1. Schullian P, Johnston E, Laimer G et al (2021) Frequency and risk factors for major complications after stereotactic radiofrequency ablation of liver tumors in 1235 ablation sessions: a 15-year experience. Eur Radiol 31:3042–3052 - PMC - PubMed

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