Percutaneous Radiofrequency Ablation of Colorectal Cancer Liver Metastases: Factors Affecting Outcomes--A 10-year Experience at a Single Center

Radiology. 2016 Feb;278(2):601-11. doi: 10.1148/radiol.2015142489. Epub 2015 Aug 12.

Abstract

Purpose: To identify predictors of oncologic outcomes after percutaneous radiofrequency ablation (RFA) of colorectal cancer liver metastases (CLMs) and to describe and evaluate a modified clinical risk score (CRS) adapted for ablation as a patient stratification and prognostic tool.

Materials and methods: This study consisted of a HIPAA-compliant institutional review board-approved retrospective review of data in 162 patients with 233 CLMs treated with percutaneous RFA between December 2002 and December 2012. Contrast material-enhanced CT was used to assess technique effectiveness 4-8 weeks after RFA. Patients were followed up with contrast-enhanced CT every 2-4 months. Overall survival (OS) and local tumor progression-free survival (LTPFS) were calculated from the time of RFA by using the Kaplan-Meier method. Log-rank tests and Cox regression models were used for univariate and multivariate analysis to identify predictors of outcomes.

Results: Technique effectiveness was 94% (218 of 233). Median LTPFS was 26 months. At univariate analysis, predictors of shorter LTPFS were tumor size greater than 3 cm (P < .001), ablation margin size of 5 mm or less (P < .001), high modified CRS (P = .009), male sex (P = .03), and no history of prior hepatectomy (P = .04) or hepatic arterial infusion chemotherapy (P = .01). At multivariate analysis, only tumor size greater than 3 cm (P = .01) and margin size of 5 mm or less (P < .001) were independent predictors of shorter LTPFS. Median and 5-year OS were 36 months and 31%. At univariate analysis, predictors of shorter OS were tumor size larger than 3 cm (P = .005), carcinoembryonic antigen level greater than 30 ng/mL (P = .003), high modified CRS (P = .02), and extrahepatic disease (EHD) (P < .001). At multivariate analysis, tumor size greater than 3 cm (P = .006) and more than one site of EHD (P < .001) were independent predictors of shorter OS.

Conclusion: Tumor size of less than 3 cm and ablation margins greater than 5 mm are essential for satisfactory local tumor control. Tumor size of more than 3 cm and the presence of more than one site of EHD are associated with shorter OS.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Aged
  • Catheter Ablation / methods*
  • Colorectal Neoplasms / pathology*
  • Contrast Media
  • Female
  • Hepatectomy / methods
  • Humans
  • Liver Neoplasms / secondary*
  • Liver Neoplasms / surgery*
  • Magnetic Resonance Imaging, Interventional / methods*
  • Male
  • Prognosis
  • Radiography, Interventional / methods*
  • Retrospective Studies
  • Survival Rate
  • Tomography, X-Ray Computed
  • Treatment Outcome

Substances

  • Contrast Media