title: Ototoxicity evaluation in medulloblastoma patients treated with involved field boost using intensity-modulated radiation therapy (IMRT): a retrospective review.
abstract: BACKGROUND
  Ototoxicity is a known side effect of combined radiation therapy and cisplatin chemotherapy for the treatment of medulloblastoma. The delivery of an involved field boost by intensity modulated radiation therapy (IMRT) may reduce the dose to the inner ear when compared with conventional radiotherapy. The dose of cisplatin may also affect the risk of ototoxicity. A retrospective study was performed to evaluate the impact of involved field boost using IMRT and cisplatin dose on the rate of ototoxicity.
  
  
  METHODS
  Data from 41 medulloblastoma patients treated with IMRT were collected. Overall and disease-free survival rates were calculated by Kaplan-Meier method Hearing function was graded according to toxicity criteria of Pediatric Oncology Group (POG). Doses to inner ear and total cisplatin dose were correlated with hearing function by univariate and multivariate data analysis.
  
  
  RESULTS
  After a mean follow-up of 44 months (range: 14 to 72 months), 37 patients remained alive, with two recurrences, both in spine with CSF involvement, resulting in a disease free-survival and overall survival of 85.2% and 90.2%, respectively.Seven patients (17%) experienced POG Grade 3 or 4 toxicity. Cisplatin dose was a significant factor for hearing loss in univariate analysis (p < 0.03). In multivariate analysis, median dose to inner ear was significantly associated with hearing loss (p < 0.01). POG grade 3 and 4 toxicity were uncommon with median doses to the inner ear bellow 42 Gy (p < 0.05) and total cisplatin dose of less than 375 mg/m2 (p < 0.01).
  
  
  CONCLUSIONS
  IMRT leads to a low rate of severe ototoxicity. Median radiation dose to auditory apparatus should be kept below 42 Gy. Cisplatin doses should not exceed 375 mg/m2.
authors.affiliation: Department of Radiation Oncology, Hospital Israelita Albert Einstein-HIAE, São Paulo, Brazil. wilson.vieira@usp.br.
authors.forename: Wilson Albieri
authors.initials: WA
authors.lastname: Vieira
authors.forename: Eduardo
authors.initials: E
authors.lastname: Weltman
authors.forename: Michael Jenwei
authors.initials: MJ
authors.lastname: Chen
authors.forename: Nasjla Saba
authors.initials: NS
authors.lastname: da Silva
authors.forename: Andrea Maria
authors.initials: AM
authors.lastname: Cappellano
authors.forename: Liliane Desgualdo
authors.initials: LD
authors.lastname: Pereira
authors.forename: Maria Ines Rabelo
authors.initials: MI
authors.lastname: Gonçalves
authors.forename: Robson
authors.initials: R
authors.lastname: Ferrigno
authors.forename: Rodrigo Morais
authors.initials: RM
authors.lastname: Hanriot
authors.forename: Wladimir
authors.initials: W
authors.lastname: Nadalin
authors.forename: Vicente
authors.initials: V
authors.lastname: Odone Filho
authors.forename: Antonio Sergio
authors.initials: AS
authors.lastname: Petrilli
mesh_terms: D000293:Adolescent; D000328:Adult; D002528:Cerebellar Neoplasms / Q000532:radiotherapy*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006309:Hearing / Q000528:radiation effects*; D034381:Hearing Loss / Q000175:diagnosis* / Q000209:etiology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008527:Medulloblastoma / Q000532:radiotherapy*; D011379:Prognosis; D011836:Radiation Tolerance; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects*; D012189:Retrospective Studies; D055815:Young Adult