title: Novel platform for MRI-guided convection-enhanced delivery of therapeutics: preclinical validation in nonhuman primate brain.
abstract: OBJECTIVE
  A skull-mounted aiming device and integrated software platform has been developed for MRI-guided neurological interventions. In anticipation of upcoming gene therapy clinical trials, we adapted this device for real-time convection-enhanced delivery of therapeutics via a custom-designed infusion cannula. The targeting accuracy of this delivery system and the performance of the infusion cannula were validated in nonhuman primates.
  
  
  METHODS
  Infusions of gadoteridol were delivered to multiple brain targets and the targeting error was determined for each cannula placement. Cannula performance was assessed by analyzing gadoteridol distributions and by histological analysis of tissue damage.
  
  
  RESULTS
  The average targeting error for all targets (n = 11) was 0.8 mm (95% CI = 0.14). For clinically relevant volumes, the distribution volume of gadoteridol increased as a linear function (R(2) = 0.97) of the infusion volume (average slope = 3.30, 95% CI = 0.2). No infusions in any target produced occlusion, cannula reflux or leakage from adjacent tracts, and no signs of unexpected tissue damage were observed.
  
  
  CONCLUSIONS
  This integrated delivery platform allows real-time convection-enhanced delivery to be performed with a high level of precision, predictability and safety. This approach may improve the success rate for clinical trials involving intracerebral drug delivery by direct infusion.
authors.affiliation: Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA. richardsonma@neurosurg.ucsf.edu
authors.forename: R Mark
authors.initials: RM
authors.lastname: Richardson
authors.forename: Adrian P
authors.initials: AP
authors.lastname: Kells
authors.forename: Alastair J
authors.initials: AJ
authors.lastname: Martin
authors.forename: Paul S
authors.initials: PS
authors.lastname: Larson
authors.forename: Philip A
authors.initials: PA
authors.lastname: Starr
authors.forename: Peter G
authors.initials: PG
authors.lastname: Piferi
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Bates
authors.forename: Lisa
authors.initials: L
authors.lastname: Tansey
authors.forename: Kathryn H
authors.initials: KH
authors.lastname: Rosenbluth
authors.forename: John R
authors.initials: JR
authors.lastname: Bringas
authors.forename: Mitchel S
authors.initials: MS
authors.lastname: Berger
authors.forename: Krystof S
authors.initials: KS
authors.lastname: Bankiewicz
mesh_terms: D000818:Animals; D001921:Brain; D057785:Catheters; D018481:Convection; D016503:Drug Delivery Systems / Q000295:instrumentation*; D008253:Macaca mulatta; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*