title: Intensity-modulated radiotherapy (IMRT) in pediatric low-grade glioma.
abstract: BACKGROUND
  The objective of this study was to evaluate local control and patterns of failure in pediatric patients with low-grade glioma (LGG) who received treatment with intensity-modulated radiation therapy (IMRT).
  
  
  METHODS
  In total, 39 children received IMRT after incomplete resection or disease progression. Three methods of target delineation were used. The first was to delineate the gross tumor volume (GTV) and add a 1-cm margin to create the clinical target volume (CTV) (Method 1; n = 19). The second was to add a 0.5-cm margin around the GTV to create the CTV (Method 2; n = 6). The prescribed dose to the GTV was the same as dose to the CTV for both Methods 1 and 2 (median, 50.4 grays [Gy]). The final method was dose painting, in which a GTV was delineated with a second target volume (2TV) created by adding 1 cm to the GTV (Method 3; n = 14). Different doses were prescribed to the GTV (median, 50.4 Gy) and the 2TV (median, 41.4 Gy).
  
  
  RESULTS
  The 8-year progression-free and overall survival rates were 78.2% and 93.7%, respectively. Seven failures occurred, all of which were local in the high-dose (≥95%) region of the IMRT field. On multivariate analysis, age ≤5 years at time of IMRT had a detrimental impact on progression-free survival.
  
  
  CONCLUSIONS
  IMRT provided local control rates comparable to those provided by 2-dimensional and 3-dimensional radiotherapy. Margins ≥1 cm added to the GTV may not be necessary, because excellent local control was achieved by adding a 0.5-cm margin (Method 2) and by dose painting (Method 3).
authors: Department of Radiation Oncology, The Methodist Hospital and Weil-Cornell Medical College, Houston, Texas, USA. apaulino@tmhs.org
authors: Arnold C
authors: AC
authors: Paulino
authors: Ali
authors: A
authors: Mazloom
authors: Keita
authors: K
authors: Terashima
authors: Jack
authors: J
authors: Su
authors: Adekunle M
authors: AM
authors: Adesina
authors: M Faith
authors: MF
authors: Okcu
authors: Bin S
authors: BS
authors: Teh
authors: Murali
authors: M
authors: Chintagumpala
mesh_terms: D000293:Adolescent; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001932:Brain Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D016190:Carboplatin / Q000008:administration & dosage; D002490:Central Nervous System / Q000528:radiation effects; D002648:Child; D002675:Child, Preschool; D003071:Cognition / Q000528:radiation effects; D018450:Disease Progression; D018572:Disease-Free Survival; D005260:Female; D005910:Glioma / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D015999:Multivariate Analysis; D060787:Neoplasm Grading; D018365:Neoplasm, Residual / Q000532:radiotherapy; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D018714:Radiotherapy, Adjuvant; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects / Q000379:methods; D012189:Retrospective Studies; D014750:Vincristine / Q000008:administration & dosage
chemical_list: D014750:Vincristine; D016190:Carboplatin
keywords: dose painting; intensity modulated radiotherapy; low grade glioma; pediatric