title: Microwave ablation of focal hepatic malignancies regardless of size: A 9-year retrospective study of 64 patients.
abstract: OBJECTIVE
  To retrospectively evaluate the safety and efficacy of microwave ablation (MWA) as treatment for single, focal hepatic malignancies.
  
  
  METHODS
  Institutional review board approval was obtained for this HIPAA-compliant study. From December 2003 to May 2012, 64 patients were treated with MWA for a single hepatic lesion, in 64 sessions. Hepatocellular carcinoma (HCC) was treated in 25 patients (geometric mean tumor size, 3.33-cm; 95% CI, 2.65-4.18-cm; range, 1.0-12.0-cm), metastatic colorectal cancer (CRC) was treated in 27 patients (geometric mean tumor size, 2.7-cm; 95% CI, 2.20-3.40-cm; range, 0.8-6.0-cm), and other histological-types were treated in 12 patients (geometric mean tumor size, 3.79-cm; 95% CI, 2.72-5.26-cm; range, 1.7-8.0-cm). Kaplan-Meier (K-M) method was used to analyze time event data. Chi-square and correlation evaluated the relationship between tumor size and treatment parameters.
  
  
  RESULTS
  Technical success rate was 95.3% (61/64). Treatment parameters were tailored to tumor size; as size increased more antennae were used (p<0.001), treatment with multiple activations increased (p<0.028), and treatment time increased (p<0.001). There was no statistically significant relationship between time to recurrence and tumor size, number of activations, number of antennae, and treatment time. At one-year, K-M analysis predicted a likelihood of local recurrence of 39.8% in HCC patients, 45.7% in CRC metastases patients, and 70.8% in patients with other metastases. Median cancer specific survivals for patients were 38.3 months for HCC patients, 36.3 months for CRC metastases, and 13.9 months for other histological-types. Complications occurred in 23.4% (15/64) of sessions.
  
  
  CONCLUSIONS
  In our sample, tumor size did not appear to impact complete ablation rates or local recurrence rates for focal hepatic malignancies treated with MWA.
authors.affiliation: Rhode Island Hospital, Department of Diagnostic Imaging, 593 Eddy Street, Providence, RI 02903, United States. Electronic address: erica_alexander@brown.edu.
authors.forename: Erica S
authors.initials: ES
authors.lastname: Alexander
authors.affiliation: Rhode Island Hospital, Department of Diagnostic Imaging, 593 Eddy Street, Providence, RI 02903, United States. Electronic address: fwolf@lifespan.org.
authors.forename: Farrah J
authors.initials: FJ
authors.lastname: Wolf
authors.affiliation: Rhode Island Hospital, Department of Diagnostic Imaging, 593 Eddy Street, Providence, RI 02903, United States. Electronic address: jmachan@lifespan.org.
authors.forename: Jason T
authors.initials: JT
authors.lastname: Machan
authors.affiliation: Rhode Island Hospital, Department of Diagnostic Imaging, 593 Eddy Street, Providence, RI 02903, United States. Electronic address: kcharpentier@usasurg.org.
authors.forename: Kevin P
authors.initials: KP
authors.lastname: Charpentier
authors.affiliation: Rhode Island Hospital, Department of Diagnostic Imaging, 593 Eddy Street, Providence, RI 02903, United States. Electronic address: mbeland@lifespan.org.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Beland
authors.affiliation: Rhode Island Hospital, Department of Diagnostic Imaging, 593 Eddy Street, Providence, RI 02903, United States. Electronic address: jiannuccilli@lifespan.org.
authors.forename: Jason D
authors.initials: JD
authors.lastname: Iannuccilli
authors.affiliation: Rhode Island Hospital, Department of Diagnostic Imaging, 593 Eddy Street, Providence, RI 02903, United States. Electronic address: rhaas@lifespan.org.
authors.forename: Richard H
authors.initials: RH
authors.lastname: Haas
authors.affiliation: Rhode Island Hospital, Department of Diagnostic Imaging, 593 Eddy Street, Providence, RI 02903, United States. Electronic address: ddupuy@lifespan.org.
authors.forename: Damian E
authors.initials: DE
authors.lastname: Dupuy
mesh_terms: D055011:Ablation Techniques / Q000379:methods*; D000328:Adult; D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000601:surgery*; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000601:surgery*; D008297:Male; D008872:Microwaves; D008875:Middle Aged; D012189:Retrospective Studies; D016896:Treatment Outcome
keywords: Colorectal cancer; Hepatic metastasis; Hepatocellular carcinoma; Microwave ablation