title: Pain palliation in patients with bone metastases using magnetic resonance-guided focused ultrasound with conformal bone system: a preliminary report.
abstract: OBJECTIVE
  We evaluated the safety and effectiveness of the Magnetic Resonance-guided Focused Ultrasound (MRgFUS) with the ExAblate Conformal Bone System for the palliation of painful bone metastases.
  
  
  METHODS
  Our Institutional Review Board approved this study, and all patients gave informed consent prior to enrollment. A total of six painful metastatic bone lesions in five patients were treated using MRgFUS with the ExAblate Conformal Bone System for pain palliation. The follow-up sessions were at 3 days, 2 weeks, 1, 2, and 3 months, and 1 year after treatment. Efficacy was evaluated by the changes in visual analog scale (VAS) scores. At 3-months and 1-year follow-ups, unenhanced computed tomography and contrast-enhanced MR imaging examinations were performed. All adverse events were assessed to evaluate treatment safety.
  
  
  RESULTS
  All patients showed significant pain relief within 2 weeks. Two patients experienced complete pain reduction that lasted for 1 year. Two other patients showed pain relief measured as VAS scores of 2 and 4 on their last follow-up. Although the remaining patient had experienced significant pain relief in two lesions, the VAS score re-increased on his last follow-up. The size of the enhancing soft tissue mass in metastatic lesions decreased, and new bone formation was seen on follow-up images. Although adverse events were not serious, non-specific leg pain and second degree skin burn were noted.
  
  
  CONCLUSIONS
  MRgFUS was demonstrated to be effective palliative treatment within 2 weeks in selected patients with painful bone metastases.
authors: Department of Diagnostic Radiology, Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors: Bio
authors: B
authors: Joo
authors: Department of Diagnostic Radiology, Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea. radpms@yuhs.ac.
authors: Mi-Suk
authors: MS
authors: Park
authors: Pfizer Oncology, Seoul, Korea.
authors: Soo Hyeon
authors: SH
authors: Lee
authors: Institute of Oncology, Yonsei University College of Medicine, Seoul, Korea.
authors: Hye Jin
authors: HJ
authors: Choi
authors: Institute of Oncology, Yonsei University College of Medicine, Seoul, Korea.
authors: Seung Tack
authors: ST
authors: Lim
authors: Institute of Oncology, Yonsei University College of Medicine, Seoul, Korea.
authors: Sun Young
authors: SY
authors: Rha
authors: InSightec, Haifa, Israel.
authors: Itay
authors: I
authors: Rachmilevitch
authors: Department of Diagnostic Radiology, Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors: Young Han
authors: YH
authors: Lee
authors: Department of Diagnostic Radiology, Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors: Jin-Suck
authors: JS
authors: Suh
mesh_terms: D000328:Adult; D000368:Aged; D001859:Bone Neoplasms / Q000556:secondary / Q000628:therapy*; D003287:Contrast Media; D005260:Female; D057086:High-Intensity Focused Ultrasound Ablation / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D053783:Magnetic Resonance Imaging, Interventional / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D010146:Pain; D059408:Pain Management; D010166:Palliative Care; D011446:Prospective Studies; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D003287:Contrast Media
keywords: Magnetic Resonance-guided Focused Ultrasound; bone metastases; high-intensity focused ultrasound; pain palliation