title: Palliation of painful metastatic disease involving bone with imaging-guided treatment: comparison of patients' immediate response to radiofrequency ablation and cryoablation.
abstract: OBJECTIVE
  The purpose of this article was to compare periprocedural analgesic requirements and hospital length of stay for treatment of patients with painful metastatic tumors involving bone using either percutaneous radiofrequency ablation (RFA) or cryoablation.
  
  
  METHODS
  A retrospective review was conducted of patients who underwent either imaging-guided cryoablation or imaging-guided RFA for painful metastatic tumors involving bone. The total analgesic usage for 24 hours after the procedure was expressed as a standard morphine-equivalent dose. Analgesic usage at admission served as a baseline for comparison. Total hospital stay was used as an additional measurement of procedure-related morbidity.
  
  
  RESULTS
  Fifty-eight patients underwent either cryoablation (n = 36) or RFA (n = 22) for painful metastatic tumors involving bone. Twenty-two primary tumors were treated. The most common treatment site was the pelvis (n = 31). There was no significant difference between the two groups with regard to tumor histologic type (p = 0.52) and location (p = 0.72). The median tumor diameter was 4.4 cm for the cryoablation group and 5.0 cm for the RFA group (p = 0.63). Pretreatment pain scores, measured on a scale of 0 to 10, were not significantly different between the two groups: 6.5 for cryoablation and 6.0 for RFA (p = 0.78). Analgesic use in the 24 hours immediately after the procedure decreased significantly by 24 morphine-equivalent doses after cryoablation, whereas it increased by a median of 22 morphine-equivalent doses after RFA (p = 0.03). Total hospital length of stay for patients undergoing cryoablation was a median of 2.5 days less than that for patients receiving RFA (p = 0.003).
  
  
  CONCLUSIONS
  The use of cryoablation compared with RFA is associated with a greater reduction in analgesic dose and shorter hospital stays after the procedure in the perioperative time frame.
authors.affiliation: Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA.
authors.forename: Paul G
authors.initials: PG
authors.lastname: Thacker
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Callstrom
authors.forename: Timothy B
authors.initials: TB
authors.lastname: Curry
authors.forename: Jayawant N
authors.initials: JN
authors.lastname: Mandrekar
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Atwell
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Goetz
authors.forename: Joseph
authors.initials: J
authors.lastname: Rubin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000698:Analgesia / Q000379:methods*; D001859:Bone Neoplasms / Q000556:secondary* / Q000601:surgery*; D017115:Catheter Ablation; D016009:Chi-Square Distribution; D003452:Cryosurgery; D005260:Female; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D010166:Palliative Care / Q000379:methods*; D015641:Radiography, Interventional / Q000379:methods*; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D016896:Treatment Outcome