title: Percutaneous microwave coagulation therapy in liver tumors. A 3-year experience.
abstract: OBJECTIVE
  Percutaneous microwave coagulation therapy (PMCT) is an interventional alternative for inoperable malignant liver tumors. In this paper, we report the results of our 3-year experience of PMCT in order to establish suitable indications for this treatment.
  
  
  METHODS
  We studied a total of 27 inoperable liver tumors in 24 patients. Histology of the tumors showed 20 hepatocellular carcinomas (HCCs) (13 well differentiated, 4 moderately differentiated, and 3 poorly differentiated) and 7 metastases. These tumors were treated by PMCT and were followed for 4-40 months (average 18 months). Under US guidance, the tumors were coagulated by microwaves emitted from an electrode. The changes of tumor size after PMCT were evaluated by CT. When the tumors disappeared or were reduced in size after treatment, PMCT was regarded as effective. Complications from PMCT were also evaluated. The patient survival rate was obtained by means of the Kaplan-Meier method.
  
  
  RESULTS
  In tumors of 30 mm or less, treatment response was obtained in 70% of cases, while 55% of tumors larger than 30 mm responded. The tumor became smaller or disappeared in 85% of the well differentiated HCCs, and in 25% of the moderately differentiated HCCs, but none of the poorly differentiated HCCs responded. In metastatic tumors, PMCT was effective in 57% of cases. Slight pain (24%), fever (20%) and subcutaneous hematoma (8%) were experienced immediately after PMCT. In 2 poorly differentiated HCCs, needle tract seeding was observed. No case of liver dysfunction was seen after PMCT. The overall survival rate was 83.1% at 1 year and 68.7% at 2 years.
  
  
  CONCLUSIONS
  Good therapeutic results were achieved with PMCT in lesions of 30 mm or less, and in well differentiated HCCs.
authors.affiliation: Department of Radiology, Kumamoto University School of Medicine, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Matsukawa
authors.forename: Y
authors.initials: Y
authors.lastname: Yamashita
authors.forename: A
authors.initials: A
authors.lastname: Arakawa
authors.forename: T
authors.initials: T
authors.lastname: Nishiharu
authors.forename: J
authors.initials: J
authors.lastname: Urata
authors.forename: R
authors.initials: R
authors.lastname: Murakami
authors.forename: M
authors.initials: M
authors.lastname: Takahashi
authors.forename: S
authors.initials: S
authors.lastname: Yoshimatsu
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging / Q000556:secondary / Q000601:surgery*; D004564:Electrocoagulation / Q000009:adverse effects / Q000295:instrumentation; D004566:Electrodes; D005260:Female; D005334:Fever / Q000209:etiology; D005500:Follow-Up Studies; D006406:Hematoma / Q000209:etiology; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008872:Microwaves / Q000627:therapeutic use*; D008875:Middle Aged; D009366:Neoplasm Seeding; D010149:Postoperative Pain / Q000209:etiology; D012074:Remission Induction; D012871:Skin Diseases / Q000209:etiology; D015996:Survival Rate; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional