title: Efficacy of magnetic thermoablation using SPIO in the treatment of osteoid osteoma in a bovine model compared to radiofrequency and microwave ablation.
abstract: OBJECTIVE
  To evaluate heating efficacy of superparamagnetic iron oxide nanoparticles (SPIO) for electromagnetic ablation (EMA) of osteoid osteoma (OO) using an ex vivo model compared to radiofrequency ablation (RFA) and microwave ablation (MWA).
  
  
  METHODS
  A model for OO using sliced bovine tibia and sliced muscle tissue was developed. A bone cavity filled with either a mixture of SPIO and agarose or pure agarose (control group) was established. EMA was performed using an experimental system, RFA and MWA using clinically approved systems, and the ablation protocols recommended by the vendor. For temperature measurements, fiberoptic temperature probes were inserted inside the cavity, on the outside of the periosteum, and at a 5 mm distance to the periosteum.
  
  
  RESULTS
  Maximum temperatures with or without SPIO in the nidus were as follows: EMA: 79.9 ± 2.5/22.3 ± 0.7 °C; RFA: 95.1 ± 1.8/98.6 ± 0.9 °C; MWA: 85.1 ± 10.8/83.4 ± 9.62 °C. In RFA with or without SPIO significantly higher temperatures were achieved in the nidus compared to all other groups (p < 0.05). In MWA significantly higher temperatures were observed in the 5 mm distance to the periosteum compared to EMA and RFA with or without SPIO (p < 0.05). In MWA temperature decrease between nidus and the 5 mm distance to the periosteum was significantly lower than in RFA with or without SPIO (p < 0.0001). In MWA without SPIO temperature decrease was significantly lower than in the EMA group (p < 0.05).
  
  
  CONCLUSIONS
  In the experimental setting, ablation of OO is safe and effective using EMA. It is less invasive than RFA and MWA, and it theoretically allows repeated treatments without repeated punctures. In comparison, the highest temperatures in the nidus are reached using RFA.
authors.affiliation: Department of Diagnostic and Interventional Radiology, RWTH Aachen University Hospital, Pauwelsstrasse 30, 52074, Aachen, Germany, isfort@ukaachen.de.
authors.forename: Peter
authors.initials: P
authors.lastname: Isfort
authors.forename: H
authors.initials: H
authors.lastname: Witte
authors.forename: I
authors.initials: I
authors.lastname: Slabu
authors.forename: T
authors.initials: T
authors.lastname: Penzkofer
authors.forename: M
authors.initials: M
authors.lastname: Baumann
authors.forename: T
authors.initials: T
authors.lastname: Braunschweig
authors.forename: L N
authors.initials: LN
authors.lastname: Kennes
authors.forename: C K
authors.initials: CK
authors.lastname: Kuhl
authors.forename: T
authors.initials: T
authors.lastname: Schmitz-Rode
authors.forename: A H
authors.initials: AH
authors.lastname: Mahnken
authors.forename: P
authors.initials: P
authors.lastname: Bruners
mesh_terms: D000818:Animals; D017115:Catheter Ablation / Q000379:methods*; D002417:Cattle; D003911:Dextrans / Q000494:pharmacology*; D004195:Disease Models, Animal; D004574:Electromagnetic Fields; D004867:Equipment Design; D058185:Magnetite Nanoparticles; D008872:Microwaves / Q000627:therapeutic use*; D010017:Osteoma, Osteoid / Q000601:surgery*; D013696:Temperature; D013977:Tibia
chemical_list: D003911:Dextrans; D058185:Magnetite Nanoparticles; C065507:ferumoxides