title: Feasibility and outcomes of hypofractionated simultaneous integrated boost-intensity modulated radiotherapy for malignant gliomas: a preliminary report.
abstract: OBJECTIVE
  The aim of this study was to assess the feasibility and efficacy of hypofractionated simultaneous integrated boost-intensity modulated radiotherapy (SIB-IMRT) using three-layered planning target volumes (PTV) for malignant gliomas.
  
  
  METHODS
  We conducted a retrospective analysis of 12 patients (WHO grade IV-10; III-2) postoperatively treated with SIB-IMRT with concurrent temozolomide. Three-layered PTVs were contoured based on gadolinium-enhanced magnetic resonance imaging as follows; high risk PTV (H-PTV) as the area of surgical bed including residual gross tumor with a 0.5 cm margin; low risk PTV (L-PTV) as the area surrounding the high risk PTV with 1.5 cm margin; moderate risk PTV (M-PTV) as a line at one-third the distance from high risk PTV to low risk PTV. Total dose to high risk PTV was 70 Gy in 8 and 62.5 Gy in 4 patients.
  
  
  RESULTS
  The median follow-up time was 52 months in surviving patients. The 2- and 5-year overall survival (OS) rates were 66.6% and 47.6%, respectively. The 2- and 5-year progression-free survival (PFS) rates were 57.1% and 45.7%, respectively. The median OS and PFS were 48 and 31 months, respectively. Six patients (50%) progressed: in-field only in one, out-field or disseminated in 4, and both in one patient. All patients completed planned treatments without a toxicity-related gap. Asymptomatic radiation necrosis was observed in 4 patients at post-radiotherapy 9-31 months.
  
  
  CONCLUSIONS
  An escalated dose of hypofractionated SIB-IMRT using three-layered PTVs can be safely performed in patients with malignant glioma, and might contribute to better tumor control and survival.
authors: Department of Radiation Oncology, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea. jjhmd@yuhs.ac.
authors: Jihye
authors: J
authors: Cha
authors: Chang-Ok
authors: CO
authors: Suh
authors: Kwangwoo
authors: K
authors: Park
authors: Jong Hee
authors: JH
authors: Chang
authors: Kyu Sung
authors: KS
authors: Lee
authors: Se Hoon
authors: SH
authors: Kim
authors: Jee Suk
authors: JS
authors: Chang
authors: Joo Ho
authors: JH
authors: Kim
authors: Yang-Gun
authors: YG
authors: Suh
authors: Jun Won
authors: JW
authors: Kim
authors: Jaeho
authors: J
authors: Cho
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005910:Glioma / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D012189:Retrospective Studies; D055815:Young Adult
keywords: Radiotherapy; hypofractionation; intensity-modulated; malignant glioma; simultaneous integrated boost