title: Pediatric Sarcomas Are Targetable by MR-Guided High Intensity Focused Ultrasound (MR-HIFU): Anatomical Distribution and Radiological Characteristics.
abstract: Despite intensive therapy, children with metastatic and recurrent sarcoma or neuroblastoma have a poor prognosis. Magnetic resonance guided high intensity focused ultrasound (MR-HIFU) is a noninvasive technique allowing the delivery of targeted ultrasound energy under MR imaging guidance. MR-HIFU may be used to ablate tumors without ionizing radiation or target chemotherapy using hyperthermia. Here, we evaluated the anatomic locations of tumors to assess the technical feasibility of MR-HIFU therapy for children with solid tumors.
  
  
  
  Patients with sarcoma or neuroblastoma with available cross-sectional imaging were studied. Tumors were classified based on the location and surrounding structures within the ultrasound beam path as (i) not targetable, (ii) completely or partially targetable with the currently available MR-HIFU system, and (iii) potentially targetable if a respiratory motion compensation technique was used.
  
  
  
  Of the 121 patients with sarcoma and 61 patients with neuroblastoma, 64% and 25% of primary tumors were targetable at diagnosis, respectively. Less than 20% of metastases at diagnosis or relapse were targetable for both sarcoma and neuroblastoma. Most targetable lesions were located in extremities or in the pelvis. Respiratory motion compensation may increase the percentage of targetable tumors by 4% for sarcomas and 10% for neuroblastoma.
  
  
  
  Many pediatric sarcomas are localized at diagnosis and are targetable by current MR-HIFU technology. Some children with neuroblastoma have bony tumors targetable by MR-HIFU at relapse, but few newly diagnosed children with neuroblastoma have tumors amenable to MR-HIFU therapy. Clinical trials of MR-HIFU should focus on patients with anatomically targetable tumors.
authors.affiliation: Department of Pediatrics, Children's Health, Dallas, Texas.
authors.forename: Jenny
authors.initials: J
authors.lastname: Shim
authors.affiliation: Department of Radiology, University of Texas Southwestern Medical Center and Children's Health, Dallas, Texas.|Clinical Sites Research Program, Philips Research North America, Cambridge, Massachusetts.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Staruch
authors.affiliation: Department of Radiology, University of Texas Southwestern Medical Center and Children's Health, Dallas, Texas.
authors.forename: Korgun
authors.initials: K
authors.lastname: Koral
authors.affiliation: Department of Clinical Sciences, Simmons Comprehensive Cancer Center, Dallas, Texas.
authors.forename: Xian-Jin
authors.initials: XJ
authors.lastname: Xie
authors.affiliation: Department of Radiology, University of Texas Southwestern Medical Center and Children's Health, Dallas, Texas.|Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Texas.
authors.forename: Rajiv
authors.initials: R
authors.lastname: Chopra
authors.affiliation: Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas.|Pauline Allen Gill Center for Cancer and Blood Disorders, Children's Health, Dallas, Texas.
authors.forename: Theodore W
authors.initials: TW
authors.lastname: Laetsch
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D057086:High-Intensity Focused Ultrasound Ablation / Q000379:methods*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging; D008297:Male; D009068:Movement; D012509:Sarcoma / Q000000981:diagnostic imaging / Q000473:pathology / Q000628:therapy*
keywords: MR-HIFU; ablation; hyperthermia; neuroblastoma; sarcoma