title: Intraoperative radiation therapy (IORT) for previously untreated malignant gliomas.
abstract: BACKGROUND
  Intraoperative radiation therapy (IORT) is one of the methods used to deliver a large single dose to the tumor tissue while reducing the exposure of normal surrounding tissue. However, the usefulness of intraoperative electron therapy for malignant gliomas has not been established.
  
  
  METHODS
  During the period from 1987 to 1997, 32 patients with malignant gliomas were treated with IORT. The histological diagnoses were anaplastic astrocytoma in 11 patients and glioblastoma in 21 patients. Therapy consisted of surgical resection and intraoperative electron therapy using a dose of 12--15 Gy (median, 15 Gy). The patients later underwent postoperative external radiation therapy (EXRT) with a median total dose of 60 Gy. Each of the 32 patients treated with IORT was randomly matched with patients who had been treated with postoperative EXRT alone (control). Patients were matched according to histological grade, age, extent of tumor removal, and tumor location.
  
  
  RESULTS
  In the anaplastic astrocytoma group, the one-, two- and five-year survival rates were 81%, 51% and 15%, respectively in the IORT patients and 54%, 43% and 21%, respectively in the control patients. In the glioblastoma group, one-, two- and five-year survival rates were 63%, 26% and 0%, respectively in the IORT patients and 70%, 18% and 6%, respectively in the control patients. There was no significant difference between survival rates in the IORT patients and control patients in either the anaplastic astrocytoma group or glioblastoma group.
  
  
  CONCLUSIONS
  IORT dose not improve survival of patients with malignant gliomas compared to that of patients who have received EXRT alone.
authors.affiliation: Department of Radiation Oncology, Tohoku University School of Medicine, Sendai, Japan. knemoto@rad.med.tohoku.ac.jp
authors.forename: Kenji
authors.initials: K
authors.lastname: Nemoto
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Ogawa
authors.forename: Haruo
authors.initials: H
authors.lastname: Matsushita
authors.forename: Ken
authors.initials: K
authors.lastname: Takeda
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Takai
authors.forename: Shogo
authors.initials: S
authors.lastname: Yamada
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Kumabe
mesh_terms: D000328:Adult; D000368:Aged; D001254:Astrocytoma / Q000401:mortality / Q000532:radiotherapy / Q000601:surgery; D001610:Beta Particles / Q000627:therapeutic use; D001932:Brain Neoplasms / Q000401:mortality / Q000532:radiotherapy / Q000601:surgery; D016543:Central Nervous System Neoplasms / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery*; D005260:Female; D005625:Frontal Lobe / Q000473:pathology / Q000528:radiation effects / Q000601:surgery; D005909:Glioblastoma / Q000401:mortality / Q000532:radiotherapy / Q000601:surgery; D005910:Glioma / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery*; D006801:Humans; D007432:Intraoperative Period / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009778:Occipital Lobe / Q000473:pathology / Q000528:radiation effects / Q000601:surgery; D010296:Parietal Lobe / Q000473:pathology / Q000528:radiation effects / Q000601:surgery; D011182:Postoperative Care / Q000379:methods; D011879:Radiotherapy Dosage; D015996:Survival Rate; D013702:Temporal Lobe / Q000473:pathology / Q000528:radiation effects / Q000601:surgery