title: Disease control and ototoxicity using intensity-modulated radiation therapy tumor-bed boost for medulloblastoma.
abstract: OBJECTIVE
  We previously reported excellent local control for treating medulloblastoma with a limited boost to the tumor bed. In order to decrease ototoxicity, we subsequently implemented a tumor-bed boost using intensity-modulated radiation therapy (IMRT), the clinical results of which we report here.
  
  
  METHODS
  A total of 33 patients with newly diagnosed medulloblastoma, 25 with standard risk, and 8 with high risk, were treated on an IMRT tumor-bed boost following craniospinal irradiation (CSI). Six standard-risk patients were treated with an institutional protocol with 18 Gy CSI in conjunction with intrathecal iodine-131-labeled monoclonal antibody. The majority of patients received concurrent vincristine and standard adjuvant chemotherapy. Pure-tone audiograms were graded according to National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0.
  
  
  RESULTS
  Median age was 9 years old (range, 4-46 years old). Median follow-up was 63 months. Kaplan-Meier estimates of progression-free survival (PFS) and overall survival (OS) rates for standard-risk patients who received 23.4 or 36 Gy CSI (not including those who received 18 Gy CSI with radioimmunotherapy) were 81.4% and 88.4%, respectively, at 5 years; 5-year PFS and OS rates for high-risk patients were both 87.5%. There were no isolated posterior fossa failures outside of the boost volume. Posttreatment audiograms were available for 31 patients, of whom 6%, at a median follow-up of 19 months, had developed Grade 3 hearing loss.
  
  
  CONCLUSIONS
  An IMRT tumor-bed boost results in excellent local control while delivering a low mean dose to the cochlea, resulting in a low rate of ototoxicity.
authors.affiliation: Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA.
authors.forename: William R
authors.initials: WR
authors.lastname: Polkinghorn
authors.forename: Ira J
authors.initials: IJ
authors.lastname: Dunkel
authors.forename: Mark M
authors.initials: MM
authors.lastname: Souweidane
authors.forename: Yasmin
authors.initials: Y
authors.lastname: Khakoo
authors.forename: David C
authors.initials: DC
authors.lastname: Lyden
authors.forename: Stephen W
authors.initials: SW
authors.lastname: Gilheeney
authors.forename: Oren J
authors.initials: OJ
authors.lastname: Becher
authors.forename: Amy S
authors.initials: AS
authors.lastname: Budnick
authors.forename: Suzanne L
authors.initials: SL
authors.lastname: Wolden
mesh_terms: D000293:Adolescent; D000328:Adult; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D002528:Cerebellar Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000532:radiotherapy*; D017024:Chemotherapy, Adjuvant / Q000379:methods; D002648:Child; D002675:Child, Preschool; D003051:Cochlea / Q000528:radiation effects*; D016371:Cranial Irradiation / Q000379:methods; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006309:Hearing / Q000502:physiology / Q000528:radiation effects; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008297:Male; D008527:Medulloblastoma / Q000188:drug therapy / Q000401:mortality / Q000532:radiotherapy*; D008875:Middle Aged; D009519:New York City; D016499:Radioimmunotherapy / Q000379:methods; D011879:Radiotherapy Dosage; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects* / Q000379:methods; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D000911:Antibodies, Monoclonal; D007457:Iodine Radioisotopes