• Media type: E-Article
  • Title: Minimal ablative margin (MAM) assessment with image fusion: an independent predictor for local tumor progression in hepatocellular carcinoma after stereotactic radiofrequency ablation
  • Contributor: Laimer, Gregor; Schullian, Peter; Jaschke, Nikolai; Putzer, Daniel; Eberle, Gernot; Alzaga, Amilcar; Odisio, Bruno; Bale, Reto
  • imprint: Springer Science and Business Media LLC, 2020
  • Published in: European Radiology
  • Language: English
  • DOI: 10.1007/s00330-019-06609-7
  • ISSN: 0938-7994; 1432-1084
  • Origination:
  • Footnote:
  • Description: <jats:title>Abstract</jats:title><jats:sec><jats:title>Objectives</jats:title><jats:p>To assess the minimal ablative margin (MAM) by image fusion of intraprocedural pre- and post-ablation contrast-enhanced CT images and to evaluate if it can predict local tumor progression (LTP) independently. Furthermore, to determine a MAM with which a stereotactic radiofrequency ablation (SRFA) can be determined successful and therefore used as an intraprocedural tool to evaluate treatment success.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>A total of 110 patients (20 women, 90 men; mean age 63.7 ± 10.2) with 176 hepatocellular carcinomas were assessed by retrospective analysis of prospectively collected data. The MAM was determined through image fusion of intraprocedural pre- and post-ablation images using commercially available rigid imaging registration software. LTP was assessed in contrast-enhanced CTs or MR scans at 3–6-month intervals.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>The MAM was the only significant independent predictor of LTP (<jats:italic>p</jats:italic> = 0.036). For each millimeter increase of the MAM, a 30% reduction of the relative risk for LTP was found (OR = 0.7, 95% CI 0.5–0.98,<jats:italic>p</jats:italic> = 0.036). No LTP was detected in lesions with a MAM &gt; 5 mm. The overall LTP rate was 9 of 110 (8.2%) on a patient level and 10 of 173 (5.7%) on a lesion level. The median MAM was 3.4 (1.7–6.9) mm. The mean overall follow-up period was 26.0 ± 10.3 months.</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>An immediate assessment of the minimal ablative margin (MAM) can be used as an intraprocedural tool to evaluate the treatment success in patients treated with stereotactic RFA. A MAM &gt; 5 mm has to be achieved to consider an ablation as successful.</jats:p></jats:sec><jats:sec><jats:title>Key Points</jats:title><jats:p><jats:italic>• An intraoperatively measured minimal ablative margin (MAM) &gt; 5 mm correlates with complete remission.</jats:italic></jats:p><jats:p><jats:italic>• MAM is the only significant independent predictor of LTP (OR = 0.7, 95% CI 0.5–0.98, p = 0.036) after stereotactic RFA of hepatocellular carcinoma.</jats:italic></jats:p><jats:p><jats:italic>• Image fusion using commercially available rigid imaging registration software is possible, even though considerably complex. Therefore, improved (semi-)automatic fusion software is highly desirable.</jats:italic></jats:p></jats:sec>