Factors Predicting Development of New Distant Intrahepatic Metastases (NDIM) after Radiofrequency Ablation (RFA) of Liver Metastases

  • Dr Jordan Genov, Clinic of Gastroenterology, University Hospital, Bulgaria
  • Prof Nikola Grigorov, Clinic of Gastroenterology, University Hospital, Bulgaria
  • Dr Rumiana Mitova, Clinic of Gastroenterology, University Hospital, Bulgaria
  • Dr Branimir Golemanov, Clinic of Gastroenterology, University Hospital, Bulgaria
  • Prof Ljudmil Dinkov, Clinic of Gastroenterology, University Hospital, Bulgaria
  • Dr Marin Donov, Clinic of Gastroenterology, University Hospital, Bulgaria

    • Aim: To research on the factors influencing subsequent development of NDIM after percutaneous RFA of liver metastases.
    Methods: 168 patients with 341 metastases (size 3.38±1.82cm) were treated with RFA in a 6-year period (133 patients, 276 metastases - monopolar RFA; 36 patients, 65 metastases – multipolar RFA). The achieved destruction was assessed with US/CT and biopsy. Patients were followed up for 1-47 months. The influence of age, gender, tumor origin, number of lesions, size of the largest lesion, RFA type, completed tumor destruction (CD) and additional chemotherapy after RFA on the development and time to NDIM was evaluated.
    Results: CD was achieved in 70.7% of the lesions. 24-month cumulative survival was 91%. The local tumor progression rate was 29%. NDIM developed in 25% of the patients and were retreated when feasible. 95% of NDIM occurred during the first 18 months. The 3-year cumulative probability of non-development of NDIM estimated by Kaplan-Meier curve was 42%. There was significant influence on development and time to NDIM of: Number of treated metastases (<3 vs. >3), size of the largest metastasis (<5.0cm vs. >5.0cm), CD of all lesions and additional chemotherapy. By multivariate analysis only the number of metastases and CD of all lesions were predictive for development of NDIM.
    Conclusions: The number of metastases before RFA is the strongest predictor for NDIM, while CD of all lesions has the strongest protective role. Multipolar RFA is preferable to monopolar for medium-sized and large lesions. The role of adjuvant chemotherapy deserves further evaluation.