title: Combination acetabular radiofrequency ablation and cementoplasty using a navigational radiofrequency ablation device and ultrahigh viscosity cement: technical note.
abstract: BACKGROUND
  Percutaneous radiofrequency ablation and cementoplasty is an alternative palliative therapy for painful metastases involving axial load-bearing bones. This technical report describes the use of a navigational radiofrequency probe to ablate acetabular metastases from an anterior approach followed by instillation of ultrahigh viscosity cement under CT-fluoroscopic guidance.
  
  
  METHODS
  The tumor ablation databases of two institutions were retrospectively reviewed to identify patients who underwent combination acetabular radiofrequency ablation and cementoplasty using the STAR Tumor Ablation and StabiliT Vertebral Augmentation Systems (DFINE; San Jose, CA). Pre-procedure acetabular tumor volume was measured on cross-sectional imaging. Pre- and post-procedure pain scores were measured using the Numeric Rating Scale (10-point scale) and compared. Partial pain improvement was categorically defined as ≥ 2-point pain score reduction. Patients were evaluated for evidence of immediate complications. Electronic medical records were reviewed for evidence of delayed complications.
  
  
  RESULTS
  During the study period, 12 patients with acetabular metastases were treated. The median tumor volume was 54.3 mL (range, 28.3-109.8 mL). Pre- and post-procedure pain scores were obtained from 92% (11/12) of the cohort. The median pre-procedure pain score was 8 (range, 3-10). Post-procedure pain scores were obtained 7 days (82%; 9/11), 11 days (9.1%; 1/11) or 21 days (9.1%; 1/11) after treatment. The median post-treatment pain score was 3 (range, 1-8), a statistically significant difference compared with pre-treatment (P = 0.002). Categorically, 73% (8/11) of patients reported partial pain relief after treatment. No immediate symptomatic complications occurred. Three patients (25%; 3/12) were discharged to hospice within 1 week of treatment. No delayed complications occurred in the remaining 75% (9/12) of patients during median clinical follow-up of 62 days (range, 14-178 days).
  
  
  CONCLUSIONS
  Palliative percutaneous acetabular radiofrequency ablation and cementoplasty can be feasibly performed from an anterior approach using a navigational ablation probe and ultrahigh viscosity cement instilled under CT-fluoroscopic guidance.
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 South Kingshighway Boulevard, Saint Louis, MO, 63110, USA. wallacea@mir.wustl.edu.
authors.forename: Adam N
authors.initials: AN
authors.lastname: Wallace
authors.affiliation: Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Yawkey 6E, Boston, MA, 02114, USA.
authors.forename: Ambrose J
authors.initials: AJ
authors.lastname: Huang
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 South Kingshighway Boulevard, Saint Louis, MO, 63110, USA.
authors.forename: Devin
authors.initials: D
authors.lastname: Vaswani
authors.affiliation: Washington University School of Medicine, 660 South Euclid Avenue, Saint Louis, MO, 63110, USA.
authors.forename: Randy O
authors.initials: RO
authors.lastname: Chang
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 South Kingshighway Boulevard, Saint Louis, MO, 63110, USA.
authors.forename: Jack W
authors.initials: JW
authors.lastname: Jennings
mesh_terms: D065526:Acetabuloplasty / Q000295:instrumentation / Q000379:methods; D000077:Acetabulum / Q000601:surgery*; D000328:Adult; D001843:Bone Cements / Q000737:chemistry / Q000627:therapeutic use*; D001859:Bone Neoplasms / Q000000981:diagnostic imaging / Q000601:surgery*; D017115:Catheter Ablation / Q000295:instrumentation* / Q000379:methods; D060826:Cementoplasty / Q000379:methods*; D003131:Combined Modality Therapy / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D008297:Male; D015641:Radiography, Interventional / Q000379:methods; D012189:Retrospective Studies; D013817:Thermography / Q000295:instrumentation* / Q000379:methods; D014159:Transducers; D016896:Treatment Outcome; D014783:Viscosity
chemical_list: D001843:Bone Cements
keywords: Acetabulum; Cementoplasty; Metastatic bone disease; Radiofrequency ablation