title: Radiotherapy in pediatric pilocytic astrocytomas. A subgroup analysis within the prospective multicenter study HIT-LGG 1996 by the German Society of Pediatric Oncology and Hematology (GPOH).
abstract: OBJECTIVE
  We evaluated clinical outcomes in the subset of patients who underwent radiotherapy (RT) due to progressive pilocytic astrocytoma within the Multicenter Treatment Study for Children and Adolescents with a Low Grade Glioma HIT-LGG 1996.
  
  
  METHODS
  Eligibility criteria were fulfilled by 117 patients. Most tumors (65 %) were located in the supratentorial midline, followed by the posterior fossa (26.5 %) and the cerebral hemispheres (8.5 %). Median age at the start of RT was 9.2 years (range 0.7-17.4 years). In 75 cases, external fractionated radiotherapy (EFRT) was administered either as first-line nonsurgical treatment (n = 58) or after progression following primary chemotherapy (n = 17). The median normalized total dose was 54 Gy. Stereotactic brachytherapy (SBT) was used in 42 selected cases.
  
  
  RESULTS
  During a median follow-up period of 8.4 years, 4 patients (3.4 %) died and 33 (27.4 %) experienced disease progression. The 10-year overall (OS) and progression-free survival (PFS) rates were 97 and 70 %, respectively. No impact of the RT technique applied (EFRT versus SBT) on progression was observed. The 5-year PFS was 76 ± 5 % after EFRT and 65 ± 8 % after SBT. Disease progression after EFRT was not influenced by gender, neurofibromatosis type 1 (NF1) status, tumor location (hemispheres versus supratentorial midline versus posterior fossa), age or prior chemotherapy. Normalized total EFRT doses of more than 50.4 Gy did not improve PFS rates.
  
  
  CONCLUSIONS
  EFRT plays an integral role in the treatment of pediatric pilocytic astrocytoma and is characterized by excellent tumor control. A reduction of the normalized total dose from 54 to 50.4 Gy appears to be feasible without jeopardizing tumor control. SBT is an effective treatment alternative.
authors.affiliation: Department of Radiotherapy and Radiation-Oncology, University of Leipzig, Stephanstr. 9A, 04103, Leipzig, Germany. Klaus.Mueller@medizin.uni-leipzig.de
authors.forename: K
authors.initials: K
authors.lastname: Müller
authors.forename: A
authors.initials: A
authors.lastname: Gnekow
authors.forename: F
authors.initials: F
authors.lastname: Falkenstein
authors.forename: J
authors.initials: J
authors.lastname: Scheiderbauer
authors.forename: I
authors.initials: I
authors.lastname: Zwiener
authors.forename: T
authors.initials: T
authors.lastname: Pietsch
authors.forename: M
authors.initials: M
authors.lastname: Warmuth-Metz
authors.forename: J
authors.initials: J
authors.lastname: Voges
authors.forename: G
authors.initials: G
authors.lastname: Nikkhah
authors.forename: M
authors.initials: M
authors.lastname: Flentje
authors.forename: S E
authors.initials: SE
authors.lastname: Combs
authors.forename: D
authors.initials: D
authors.lastname: Vordermark
authors.forename: M
authors.initials: M
authors.lastname: Kocher
authors.forename: R-D
authors.initials: RD
authors.lastname: Kortmann
mesh_terms: D000293:Adolescent; D001254:Astrocytoma / Q000453:epidemiology* / Q000532:radiotherapy*; D001918:Brachytherapy / Q000706:statistics & numerical data*; D001932:Brain Neoplasms / Q000453:epidemiology* / Q000532:radiotherapy*; D002648:Child; D018572:Disease-Free Survival; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D008297:Male; D015995:Prevalence; D011446:Prospective Studies; D016896:Treatment Outcome; D055815:Young Adult