title: Clinical assessment of percutaneous radiofrequency ablation for painful metastatic bone tumors.
abstract: OBJECTIVE
  To investigate the pain-alleviating effects of radiofrequency ablation (RFA) on metastatic bone tumors in relation to tumor size, combined therapy, and percent tumor necrosis rate following RFA.
  
  
  METHODS
  Subjects comprised 24 patients with 28 painful metastatic bone tumors. A 17G internally cooled electrode was inserted into the tumor for CT guidance and ablation was performed. Bone cement was injected following RFA for 4 tumors involving a weight-bearing bone, while 5 tumors were treated using combined RFA and external irradiation. Percent necrosis rate of the tumor was measured using contrast-enhanced computed tomography 1 week after RFA.
  
  
  RESULTS
  Improvement in the visual analog scale (VAS) score was 4.6 +/- 2.2 for large tumors (> 5 cm, n = 12), 3.7 +/- 1.8 for medium-sized tumors (3.1-5.0 cm, n = 11), and 3.5 +/- 1.7 for small tumors (< or = 3 cm, n = 4), with no significant differences noted among tumor sizes. Improvement in the VAS score was 3.5 +/- 1.3 for the 4 tumors in the RFA + bone cement group, 3.2 +/- 1.9 for the 5 tumors in the RFA + radiation therapy group, and 4.8 +/- 2.2 for the 18 tumors in the RFA group. No significant differences were identified between groups. The improvement in the VAS score was 3.8 +/- 2.3, 4.0 +/- 1.9, and 4.7 +/- 2.6 in patients with tumor necrosis rates of 0-49%, 50-74%, and 75-100%, respectively. No significant association was observed among these three groups.
  
  
  CONCLUSIONS
  Percutaneous RFA therapy was effective in relieving pain due to metastatic bone tumors. No relationships appear to exist between initial response and tumor size, combined therapy, and percent tumor necrosis.
authors.affiliation: Department of Radiology, Kansai Medical University Takii Hospital, 10-15 Fumizono, Moriguchi, Osaka, 570-8507, Japan. kojimah@takii.kmu.ac.jp
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kojima
authors.forename: Noboru
authors.initials: N
authors.lastname: Tanigawa
authors.forename: Shuji
authors.initials: S
authors.lastname: Kariya
authors.forename: Atsushi
authors.initials: A
authors.lastname: Komemushi
authors.forename: Yuzo
authors.initials: Y
authors.lastname: Shomura
authors.forename: Satoshi
authors.initials: S
authors.lastname: Sawada
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001843:Bone Cements / Q000627:therapeutic use; D001859:Bone Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy / Q000556:secondary* / Q000601:surgery*; D017115:Catheter Ablation; D003131:Combined Modality Therapy; D003287:Contrast Media / Q000008:administration & dosage; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D009336:Necrosis; D010146:Pain / Q000209:etiology* / Q000601:surgery*; D010147:Pain Measurement; D016019:Survival Analysis; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D001843:Bone Cements; D003287:Contrast Media