title: Intraoperative radiofrequency ablation using a 3D navigation tool for treatment of colorectal liver metastases.
abstract: BACKGROUND
  Resection as the only potential cure for colorectal liver metastasis is limited by the size and the intrahepatic localization of lesions. Radiofrequency ablation (RFA) may extend the limitations of surgery.
  
  
  METHODS
  23 consecutive patients suffering from a total of 128 colorectal liver metastases were treated by resection and intraoperative RFA. All of these patients were irresectable by standard surgery due to volume and distribution of the lesions. 17 patients were treated by chemotherapy before RFA, with only 1 patient showing partial regression of liver metastases. In 12 lesions a new 3D navigation tool was used, that allows a virtual overlay of the RFA probe in real-time.
  
  
  RESULTS
  60 metastases were resected, 68 metastases were treated by RFA. There was no mortality, and complications occurred in 4 patients only (1??temporary encephalopathy, 3x cholangitis). Local tumor control according to CT scan was achieved by RFA in 93% of lesions up to 30 mm diameter (n = 45) and in 44% of lesions larger than 30 mm (n = 23). All ablations using the navigation tool were successful. After a mean follow-up of 8 +/- 5 months 12 patients are free of disease, 8 patients have either recurrent or new metastases, and 3 patients died of progressive disease. The estimated median survival time is 18 months (95% confidence interval 13-22 months).
  
  
  CONCLUSIONS
  Intraoperative RFA of colorectal liver metastases in combination with hepatic resection is safe. Up to a lesion size of 30 mm a reliable treatment with RFA is possible. The navigation aid increases the reproducibility of the procedure.
authors.affiliation: Klinik und Poliklinik für Visceral- und Gefässchirurgie, Universität zu Köln, Germany. Dirk.Stippel@uni-koeln.de
authors.forename: D L
authors.initials: DL
authors.lastname: Stippel
authors.forename: S
authors.initials: S
authors.lastname: Böhm
authors.forename: K T E
authors.initials: KT
authors.lastname: Beckurts
authors.forename: H G
authors.initials: HG
authors.lastname: Brochhagen
authors.forename: A H
authors.initials: AH
authors.lastname: Hölscher
mesh_terms: D000368:Aged; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006979:Hyperthermia, Induced / Q000295:instrumentation*; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation*; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000556:secondary* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011183:Postoperative Complications / Q000209:etiology / Q000401:mortality; D011446:Prospective Studies; D025321:Surgery, Computer-Assisted / Q000295:instrumentation*; D015996:Survival Rate; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography / Q000295:instrumentation*; D014584:User-Computer Interface