title: Five-year survival following radiofrequency ablation of small, solitary, hepatic colorectal metastases.
abstract: OBJECTIVE
  Radiofrequency (RF) ablation is an increasingly accepted treatment for nonsurgical candidates with a limited number of colorectal hepatic metastases. RF ablation is most effective in tumors smaller than 4.0 cm. This report describes 5-year survival in patients with single tumors with a maximum diameter of 4 cm.
  
  
  METHODS
  Forty of 291 patients (14%; 24 men, 16 women; mean age, 67 years; age range, 34-86 y) with no or treated extrahepatic disease were identified who were not candidates for resection and who had a minimum follow-up of 6 months. Sixteen had undergone hepatic resection and two had undergone lung resection and lung ablation. Thirty-two (80%) received chemotherapy. Thirty-five were treated under general anesthesia and five under conscious sedation. Our standard ablation protocol used internally water-cooled electrodes introduced percutaneously with ultrasonography and computed tomography guidance and monitoring. Follow-up data were obtained from primary care physicians or oncologists.
  
  
  RESULTS
  Mean tumor diameter was 2.3 cm (range, 0.8-4.0 cm). There were two successfully treated systemic complications: a chest infection and an exacerbation of asthma. There were no local complications. Mean follow-up was 38 months (range, 6-132 months). The median survival duration and 1-, 3-, and 5-year survival rates were 59 months and 97%, 84%, 40%, respectively, after ablation; and 63 months, 100%, 88%, and 54%, respectively, from the diagnosis of liver metastases. History of liver resection did not impact survival.
  
  
  CONCLUSIONS
  RF ablation of solitary liver metastases 4 cm or smaller can be performed with minimal morbidity and results in excellent long-term survival, approaching that of surgical resection, even in patients who are not surgical candidates.
authors.affiliation: Centre for Medical Imaging, University College Hospital, 235 Euston Road, Special X-Ray, Podium 2, London NW1 2BU, United Kingdom. a.gillams@medphys.ucl.ac.uk
authors.forename: Alice R
authors.initials: AR
authors.lastname: Gillams
authors.forename: William R
authors.initials: WR
authors.lastname: Lees
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000473:pathology*; D016292:Procedural Sedation; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000401:mortality / Q000556:secondary* / Q000601:surgery*; D053783:Magnetic Resonance Imaging, Interventional; D008297:Male; D008875:Middle Aged; D015996:Survival Rate; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional