title: Outcomes of microwave ablation for colorectal cancer liver metastases: a single center experience.
abstract: OBJECTIVE
  Surgical management of colorectal cancer liver metastases continues to evolve to optimize oncologic outcomes while maximizing parenchymal preservation. Long-term data after intraoperative microwave ablation are limited. This study investigates outcomes and patterns of recurrence in patients who underwent intraoperative microwave ablation.
  
  
  METHODS
  A retrospective analysis of 33 patients who underwent intraoperative microwave ablation of colorectal cancer liver metastases from 2009 to 2013 at our institution was performed. Perioperative and long-term data were reviewed to determine outcomes and patterns of recurrence.
  
  
  RESULTS
  A total of 49 tumors were treated, ranging 0.5-5.5 cm in size. Median Clavien-Dindo classification was one. Median follow-up was 531 days, with 13 (39.4%) patients presenting with a recurrence. Median time to first recurrence was 364 days. In those patients, 1 (7.8%) presented with an isolated local recurrence in the liver. Only 1 of 7 ablated tumors greater than 3 cm recurred (14.3%). Overall survival was 35.2% at 4 years, with a 19.3% disease-free survival at 3.5 years. No perioperative variables predicted systemic or local recurrence.
  
  
  CONCLUSIONS
  Intraoperative microwave ablation is a safe and effective modality for use in the treatment of colorectal cancer liver metastases in tumors as large as 5.5 cm in size.
authors.affiliation: Department of Surgery, Division of Surgical Oncology, Rutgers-Robert Wood Johnson Medical School/Rutgers Cancer Institute of New Jersey, New Brunswick, New Jersey.
authors.forename: Oliver S
authors.initials: OS
authors.lastname: Eng
authors.forename: Ashley T
authors.initials: AT
authors.lastname: Tsang
authors.forename: Dirk
authors.initials: D
authors.lastname: Moore
authors.forename: Chunxia
authors.initials: C
authors.lastname: Chen
authors.forename: Sumana
authors.initials: S
authors.lastname: Narayanan
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Gannon
authors.forename: David A
authors.initials: DA
authors.lastname: August
authors.forename: Darren R
authors.initials: DR
authors.lastname: Carpizo
authors.forename: Laleh G
authors.initials: LG
authors.lastname: Melstrom
mesh_terms: D055011:Ablation Techniques; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000473:pathology*; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008113:Liver Neoplasms / Q000401:mortality / Q000473:pathology / Q000556:secondary* / Q000601:surgery*; D008297:Male; D008872:Microwaves / Q000627:therapeutic use*; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D012189:Retrospective Studies
keywords: colorectal cancer; liver metastases; microwave ablation