title: Selective ablation of rat brain tumors by boron neutron capture therapy.
abstract: OBJECTIVE
  Damage to the surrounding normal brain tissue limits the amount of radiation that can be delivered to intracranial tumors. Boron neutron capture therapy (BNCT) is a binary treatment that allows selective tumor irradiation. This study evaluates the damage imparted to the normal brain during BNCT or x-irradiation.
  
  
  METHODS
  The brains of rats with implanted 9L gliosarcomas were examined 1 year after tumor-curative doses of either 250 kV X rays or BNCT. Histopathologic techniques included hematoxylin and eosin staining, horseradish peroxidase perfusion, and electron microscopy.
  
  
  RESULTS
  Longterm X ray survivors showed extensive cortical atrophy, loss of neurons, and widespread leakage of the blood-brain barrier (BBB), particularly around the tumor scar. In contrast, the brains and the BBB of longterm BNCT survivors appeared relatively normal under both light- and electron-microscopic examination. Intact blood vessels were observed running directly through the avascular, collagenous tumor scar.
  
  
  CONCLUSIONS
  The selective therapeutic effect of BNCT is evident in comparison to x-irradiation. Both groups of animals showed no evidence of residual tumor at 1 year. However, with x-irradiation there is no therapeutic ratio and tumor eradication severely injures the remaining brain parenchyma. These observations indicate a substantial therapeutic gain for BNCT.
authors.affiliation: Medical Department, Brookhaven National Laboratory, Upton, NY 11973.
authors.forename: J
authors.initials: J
authors.lastname: Coderre
authors.forename: P
authors.initials: P
authors.lastname: Rubin
authors.forename: A
authors.initials: A
authors.lastname: Freedman
authors.forename: J
authors.initials: J
authors.lastname: Hansen
authors.forename: T S
authors.initials: TS
authors.lastname: Wooding
authors.forename: D
authors.initials: D
authors.lastname: Joel
authors.forename: D
authors.initials: D
authors.lastname: Gash
mesh_terms: D000818:Animals; D001812:Blood-Brain Barrier / Q000528:radiation effects; D016754:Boron Neutron Capture Therapy; D001921:Brain / Q000528:radiation effects; D001932:Brain Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D018316:Gliosarcoma / Q000473:pathology / Q000532:radiotherapy*; D051381:Rats; D011916:Rats, Inbred F344