title: Perfusion CT of the brain in the assessment of flow alterations during brachytherapy of meningioma.
abstract: OBJECTIVE
  The aim was to investigate the use of perfusion CT of the brain in the assessment of flow alterations during brachytherapy of meningiomas.
  
  
  METHODS
  Six patients with an intracranial meningioma were investigated during brachytherapy treatment by stereotactic implantation of I-125 seeds. Cerebral blood flow (CBF) in the tumour centre and the tumour periphery as well as in the normal brain parenchyma was determined by perfusion CT. Follow-up examinations were performed during the first year after the implantation. The CBF of the normal brain parenchyma was used as control.
  
  
  RESULTS
  In the beginning of therapy, the mean+/-SEM blood flow in the tumour centre was 231.4+/-58.1 ml/100 g/min and in the periphery 223.5+/-53.8 ml/100 g/min. Within three months after the iodine seed implantation, the tumour blood flow had decreased 41%. At the one-year follow-up, the tumour blood flow in the centre had decreased to 68.7+/-45.9 ml/100 g/min. In the periphery of the tumour, it remained nearly unchanged (199.3+/-101.0 ml/100 g/min). The CBF values obtained from normal brain parenchyma did not decrease during the treatment. Throughout the study, the mean CBF for the normal grey matter was 38.5+/-2.9 ml/100 g/min, and 22.3+/-1.2 ml/100 g/min for the normal white matter.
  
  
  CONCLUSIONS
  Perfusion CT seems to enable accurate monitoring of the blood flow of meningiomas during brachytherapy, and could be used in clinical situations where blood flow changes in brain and tumours should be investigated.
authors.affiliation: Department of Diagnostic Radiology, Helsinki University Central Hospital, Finland.
authors.forename: S
authors.initials: S
authors.lastname: Bondestam
authors.forename: J T
authors.initials: JT
authors.lastname: Halavaara
authors.forename: J E
authors.initials: JE
authors.lastname: Jääskeläinen
authors.forename: J J
authors.initials: JJ
authors.lastname: Kinnunen
authors.forename: L M
authors.initials: LM
authors.lastname: Hamberg
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity; D001918:Brachytherapy; D001921:Brain / Q000098:blood supply / Q000000981:diagnostic imaging*; D002560:Cerebrovascular Circulation; D005240:Feasibility Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D008297:Male; D008577:Meningeal Neoplasms / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000532:radiotherapy; D008579:Meningioma / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000532:radiotherapy; D008875:Middle Aged; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome
chemical_list: D007457:Iodine Radioisotopes