title: Phase I/II Multi-Institutional Study of Percutaneous Radiofrequency Ablation for Painful Osteoid Osteoma (JIVROSG-0704).
abstract: OBJECTIVE
  This multicenter prospective study was conducted to evaluate the safety and efficacy of percutaneous radiofrequency ablation (RFA) for painful osteoid osteoma (OO).
  
  
  METHODS
  Patients with OO (femur: n = 17, tibia: n = 2, humerus: n = 1, rib: n = 1) were enrolled and treated with RFA. In phase I, nine patients were evaluated for safety. In phase II, 12 patients were accrued, and an intent-to-treat analysis was performed on all patients. The primary endpoint was to evaluate the treatment safety. The secondary endpoint was to evaluate the efficacy for pain relief by the visual analogue scale (VAS) at 4 weeks after RFA. Treatment efficacy was classified as significantly effective (SE) when VAS score decreased by ≥5 or score was <2, moderately effective when VAS score decreased by <5-≥2 and score was ≥2, and not effective (NE) when VAS score decreased by <2 or score was increased. Cases where the need for analgesics increased after treatment were also NE.
  
  
  RESULTS
  RFA procedures were completed in all patients. Minor adverse effects (AEs) were observed as 4.8-14.3 % in 12 patients, and no major AEs were observed. Mean VAS score was 7.1 before treatment, 1.6 at 1 week, 0.3 at 4 weeks, and 0.2 at 3 months. All procedures were classified as SE. Pain recurrence was not noted in any patient during follow-up (mean: 15.1 months).
  
  
  CONCLUSIONS
  RFA is a safe, highly effective, and fast-acting treatment for painful extraspinal OO. Future studies with a greater number of patients are needed.
authors.affiliation: Department of Interventional Radiology and Clinical Ultrasound Center, Gunma University Hospital, 3-39-15, Showa-machi, Maebashi, Gunma, 371-8511, Japan. mmiyazak@gunma-u.ac.jp.
authors.forename: Masaya
authors.initials: M
authors.lastname: Miyazaki
authors.affiliation: Division of Diagnostic Radiology, National Center Hospital, 5-1-1, Tsukiji, Chuo-ku, Tokyo, 104-0045, Japan.
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Arai
authors.affiliation: Medical Center for Translational Research, Osaka University Hospital, 2-15 Yamadaoka, Suita, Osaka, 565-0871, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Myoui
authors.affiliation: Department of Radiology, Okayama University Medical School, 2-5-1 Shikatacho, Kita-ku, Okayama, 700-8558, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Gobara
authors.affiliation: Division of Diagnostic Radiology, National Center Hospital, 5-1-1, Tsukiji, Chuo-ku, Tokyo, 104-0045, Japan.
authors.forename: Miyuki
authors.initials: M
authors.lastname: Sone
authors.affiliation: Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Boston, MA, 02114, USA.
authors.forename: Daniel I
authors.initials: DI
authors.lastname: Rosenthal
authors.affiliation: Department of Interventional Radiology and Clinical Ultrasound Center, Gunma University Hospital, 3-39-15, Showa-machi, Maebashi, Gunma, 371-8511, Japan.
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Tsushima
authors.affiliation: Department of Radiology, Okayama University Medical School, 2-5-1 Shikatacho, Kita-ku, Okayama, 700-8558, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Kanazawa
authors.affiliation: Department of Radiology, Iwate Medical University School of Medicine, 19-1 Uchimaru, Morioka, 020-8505, Japan.
authors.forename: Shigeru
authors.initials: S
authors.lastname: Ehara
authors.affiliation: Department of Interventional Radiology and Clinical Ultrasound Center, Gunma University Hospital, 3-39-15, Showa-machi, Maebashi, Gunma, 371-8511, Japan.
authors.forename: Keigo
authors.initials: K
authors.lastname: Endo
mesh_terms: D000328:Adult; D001859:Bone Neoplasms / Q000473:pathology / Q000601:surgery*; D000072716:Cancer Pain / Q000473:pathology / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods*; D005260:Female; D006801:Humans; D057194:Intention to Treat Analysis; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000601:surgery; D010017:Osteoma, Osteoid / Q000473:pathology / Q000601:surgery*; D010147:Pain Measurement; D011183:Postoperative Complications / Q000209:etiology; D011446:Prospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods; D016896:Treatment Outcome
keywords: Clinical trial; Osteoid osteoma; Radiofrequency ablation