title: Particular imaging features and customized thermal ablation treatment for intramedullary osteoid osteoma in pediatric patients.
abstract: OBJECTIVE
  To report on the particular imaging features and high success rate of cold mode radio-frequency thermal ablation (RFTA) as the treatment of choice for intramedullary osteoid osteoma.
  
  
  METHODS
  The study population consisted of 51 patients (39 males, 12 females; mean age 7.2 years; 11 patients under 6 years of age, including 7 males and 4 females) who underwent RFTA for osteoid osteoma and were retrospectively observed. The affected sites were the tibia (n = 22, 43%), femur (n = 13, 25%), pelvis (n = 5, 10%), anklebone (n = 3, 6%), humerus (n = 2, 4%), sacrum (n = 2, 4%), heel, radium, patella ,and rib (n = 1, 2%), respectively. Three patients had tibial intramedullary osteoid osteoma (14% of the tibial lesions, 6% of all cases). Cold mode RFTA was performed for these three patients to obtain a large ablation area without positioning two probes. The noncooled mode was used to treat cortical and subperiosteal lesions.
  
  
  RESULTS
  Following RFTA, all patients were pain-free and in good clinical condition. In the intramedullary osteoid osteoma group, no recurrences were observed during the 24-month follow-up period, but one patient, who was affected by cortical osteoid osteoma, required two RFTA treatments to heal completely.
  
  
  CONCLUSIONS
  Children less than 6 years of age with recurrent nocturnal pain and limb swelling should be investigated for intramedullary osteoid osteoma. Once confirmed, CT-guided RFTA should be the first treatment for intramedullary osteoid osteomas because of the high success rate and reduced invasivity, especially with cold mode RFTA.                         The outcome is related to the disappearance of pain, and the efficacy may be checked shortly after treatment with MR imaging to evaluate the absence of lesion in the ablation area.
authors.affiliation: Vascular and Interventional Radiology Unit, Pediatric Hospital Bambino Gesù, Piazza S. Onofrio 4, 00165 Rome, Italy. falappa@opbg.net
authors.forename: Piergiorgio
authors.initials: P
authors.lastname: Falappa
authors.forename: Maria Carmen
authors.initials: MC
authors.lastname: Garganese
authors.forename: Alessandro
authors.initials: A
authors.lastname: Crocoli
authors.forename: Renato Maria
authors.initials: RM
authors.lastname: Toniolo
authors.forename: Antonio
authors.initials: A
authors.lastname: Lembo
authors.forename: Fabio
authors.initials: F
authors.lastname: Marconi
authors.forename: Andrea
authors.initials: A
authors.lastname: Campana
authors.forename: Rita
authors.initials: R
authors.lastname: De Vito
authors.forename: Gianclaudio
authors.initials: G
authors.lastname: Ciofetta
authors.forename: Antonio
authors.initials: A
authors.lastname: Leone
mesh_terms: D000293:Adolescent; D001859:Bone Neoplasms / Q000175:diagnosis / Q000628:therapy*; D017115:Catheter Ablation; D002648:Child; D002675:Child, Preschool; D005260:Female; D056973:Four-Dimensional Computed Tomography; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D010017:Osteoma, Osteoid / Q000175:diagnosis / Q000628:therapy*; D012189:Retrospective Studies; D055815:Young Adult