title: MRI-guided radiotherapy of the SK-N-SH neuroblastoma xenograft model using a small animal radiation research platform.
abstract: OBJECTIVE
  Neuroblastoma has one of the lowest survival rates of all childhood cancers, despite the use of intensive treatment regimens. Preclinical models of neuroblastoma are essential for testing new multimodality protocols, including those that involve radiotherapy (RT). The aim of this study was to develop a robust method for RT planning and tumour response monitoring based on combined MRI and cone-beam CT (CBCT) imaging and to apply it to a widely studied mouse xenograft model of neuroblastoma, SK-N-SH.
  
  
  METHODS
  As part of a tumour growth inhibition study, SK-N-SH xenografts were generated in BALB/c nu/nu mice. Mice (n = 8) were placed in a printed MR- and CT-compatible plastic cradle, imaged using a 4.7-T MRI scanner and then transferred to a small animal radiation research platform (SARRP) irradiator with on-board CBCT. MRI/CBCT co-registration was performed to enable RT planning using the soft-tissue contrast afforded by MRI prior to delivery of RT (5 Gy). Tumour response was assessed by serial MRI and calliper measurements.
  
  
  RESULTS
  SK-N-SH xenografts formed soft, deformable tumours that could not be differentiated from surrounding normal tissues using CBCT. MR images, which allowed clear delineation of tumours, were successfully co-registered with CBCT images, allowing conformal RT to be delivered. MRI measurements of tumour volume 4 days after RT correlated strongly with length of survival time.
  
  
  CONCLUSIONS
  MRI allowed precision RT of SK-N-SH tumours and provided an accurate means of measuring tumour response. Advances in knowledge: MRI-based RT planning of murine tumours is feasible using an SARRP irradiator.
authors.affiliation: 1 CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, UK.
authors.forename: Aurélien
authors.initials: A
authors.lastname: Corroyer-Dulmont
authors.affiliation: 1 CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, UK.
authors.forename: Nadia
authors.initials: N
authors.lastname: Falzone
authors.affiliation: 1 CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, UK.
authors.forename: Veerle
authors.initials: V
authors.lastname: Kersemans
authors.affiliation: 1 CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, UK.
authors.forename: James
authors.initials: J
authors.lastname: Thompson
authors.affiliation: 1 CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, UK.
authors.forename: Mark
authors.initials: M
authors.lastname: Hill
authors.affiliation: 1 CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, UK.
authors.forename: P Danny
authors.initials: PD
authors.lastname: Allen
authors.affiliation: 1 CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, UK.
authors.forename: John
authors.initials: J
authors.lastname: Beech
authors.affiliation: 1 CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, UK.
authors.forename: Stuart
authors.initials: S
authors.lastname: Gilchrist
authors.affiliation: 1 CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, UK.
authors.forename: Paul
authors.initials: P
authors.lastname: Kinchesh
authors.affiliation: 1 CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, UK.
authors.forename: Boris
authors.initials: B
authors.lastname: Vojnovic
authors.affiliation: 1 CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, UK.
authors.forename: Iain
authors.initials: I
authors.lastname: Tullis
authors.affiliation: 2 University College London Hospitals NHS Foundation Trust, London, UK.
authors.forename: Mark N
authors.initials: MN
authors.lastname: Gaze
authors.affiliation: 1 CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, UK.
authors.forename: Sean
authors.initials: S
authors.lastname: Smart
authors.affiliation: 1 CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, UK.
authors.forename: Katherine A
authors.initials: KA
authors.lastname: Vallis
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D004195:Disease Models, Animal; D042241:Early Diagnosis; D064593:Heterografts; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D051379:Mice; D008819:Mice, Nude; D009447:Neuroblastoma / Q000175:diagnosis / Q000532:radiotherapy*; D011237:Predictive Value of Tests; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D018570:Risk Assessment; D047368:Tumor Burden