title: Impact of targeting deviations on outcome in medulloblastoma: study of the French Society of Pediatric Oncology (SFOP).
abstract: OBJECTIVE
  To correlate targeting deviation in external beam radiation therapy with site of relapse in a prospective study of 174 patients treated for medulloblastoma.
  
  
  METHODS
  Between February 1992 and February 1998 the radiotherapy treatment records were reviewed by a panel of radiation oncologists for 174 children treated with radiation therapy for medulloblastoma. The review was done without knowledge of patient outcome. Patterns of relapse were correlated with the results of the quality control review.
  
  
  RESULTS
  Among the 174 patients five relapsed before the start of radiotherapy. One hundred sixty-nine patients were evaluable for correlation between targeting deviation and site of relapse. Number of major deviations in radiation therapy treatment is strongly correlated with the risk of tumor relapse (67% [95% CI: 28-91] of 3-year relapse rate in patient group with 2 major deviations and 78% [95% CI: 35-96] with 3 major deviations). This is particularly correlated with relapse in the frontal region of the brain: 5 relapses occurred in the frontal region in patients with major deviation in this area. An erroneous choice of electron beam energy is also linked with craniospinal fluid (CSF) relapse (3-year relapse rate of 68% [95% CI: 42-86]). Minor deviations in therapy technique are slightly associated with an increased risk of relapse in the same range as the group with only one major deviation.
  
  
  CONCLUSIONS
  The quality of medulloblastoma radiation therapy technique is strongly correlated with outcome. Pretreatment central quality assurance review or standardized computer-designed blocks would improve survival to an extent equivalent to that attributed to adjuvant chemotherapy.
authors.affiliation: Radiotherapy Department, Centre Léon Bérard, Lyon, France.
authors.forename: C
authors.initials: C
authors.lastname: Carrie
authors.forename: S
authors.initials: S
authors.lastname: Hoffstetter
authors.forename: F
authors.initials: F
authors.lastname: Gomez
authors.forename: V
authors.initials: V
authors.lastname: Moncho
authors.forename: F
authors.initials: F
authors.lastname: Doz
authors.forename: C
authors.initials: C
authors.lastname: Alapetite
authors.forename: X
authors.initials: X
authors.lastname: Murraciole
authors.forename: J P
authors.initials: JP
authors.lastname: Maire
authors.forename: M
authors.initials: M
authors.lastname: Benhassel
authors.forename: S
authors.initials: S
authors.lastname: Chapet
authors.forename: P
authors.initials: P
authors.lastname: Quetin
authors.forename: H
authors.initials: H
authors.lastname: Kolodie
authors.forename: J L
authors.initials: JL
authors.lastname: Lagrange
authors.forename: J C
authors.initials: JC
authors.lastname: Cuillere
authors.forename: J L
authors.initials: JL
authors.lastname: Habrand
mesh_terms: D000293:Adolescent; D001932:Brain Neoplasms / Q000556:secondary; D002528:Cerebellar Neoplasms / Q000532:radiotherapy*; D002648:Child; D002675:Child, Preschool; D005602:France; D006801:Humans; D008495:Medical Oncology; D008527:Medulloblastoma / Q000532:radiotherapy* / Q000556:secondary; D011446:Prospective Studies; D011786:Quality Control; D011878:Radiotherapy / Q000592:standards; D012955:Societies, Medical