title: Timing of radiation in children with medulloblastoma/PNET.
abstract: BACKGROUND
  To evaluate the importance of timing of radiation therapy in children with PNET/medulloblastoma, treated at the Brazilian National Cancer Institute (INCA).
  
  
  METHODS
  The records of 101 children with confirmed diagnosis of medulloblastoma were retrospectively reviewed. Patients had a median follow-up of 48 months (0.5-241 months). The age varied from 0.8 to 17.5 years (median: 7.6 years) and 21.7% were 3 years old or younger.
  
  
  RESULTS
  According to the data collected from patients that received treatment for medulloblastoma from 1983 to 2001, the overall survival (OS) rate was 53% and the Disease Free Survival (DFS) rate was 40%. Multivariate analysis showed that under age 3 years, presence of neoplasic cells in the cerebrospinal fluid (CSF) at presentation or subtotal tumor resection resulted in a worse OS. The patients that received a biological effective dose (BED) greater than 44 Gy10 had better prognosis. Two-thirds of the patients had complete response after the initial treatment. Among them, 50% (34 patients) recurred, and of those 34 patients, 42% of them (14 patients) had recurrence in the posterior fossa.
  
  
  CONCLUSIONS
  Surgery with total resection of the tumor and absence of neoplasic cells in the CSF are effective predictors of better OS. Radiotherapy was more effective when a BED was greater than 44 Gy10.
authors.affiliation: Department of Radiation Oncology, Instituto Nacional de Câncer (INCA), Rio de Janeiro, Brazil. mrcsantos@uol.com.br
authors.forename: Marcos A
authors.initials: MA
authors.lastname: Santos
authors.forename: Célia M P
authors.initials: CM
authors.lastname: Viégas
authors.forename: Renata A
authors.initials: RA
authors.lastname: Servidoni
authors.forename: Mario H M
authors.initials: MH
authors.lastname: Barros
authors.forename: Maria Isabel
authors.initials: MI
authors.lastname: Pinel
authors.forename: Carlos M M
authors.initials: CM
authors.lastname: Araújo
mesh_terms: D000293:Adolescent; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D002528:Cerebellar Neoplasms / Q000188:drug therapy / Q000532:radiotherapy* / Q000601:surgery; D002648:Child; D002675:Child, Preschool; D002945:Cisplatin / Q000008:administration & dosage; D003131:Combined Modality Therapy; D016371:Cranial Irradiation / Q000379:methods*; D019583:Dose Fractionation, Radiation; D005260:Female; D006801:Humans; D007223:Infant; D053208:Kaplan-Meier Estimate; D008130:Lomustine / Q000008:administration & dosage; D008297:Male; D008527:Medulloblastoma / Q000188:drug therapy / Q000532:radiotherapy* / Q000601:surgery; D016016:Proportional Hazards Models; D011882:Radiotherapy, High-Energy / Q000379:methods*; D012189:Retrospective Studies; D015173:Supratentorial Neoplasms / Q000188:drug therapy / Q000532:radiotherapy / Q000601:surgery; D013997:Time Factors; D016896:Treatment Outcome; D014750:Vincristine / Q000008:administration & dosage
chemical_list: D014750:Vincristine; D008130:Lomustine; D002945:Cisplatin