title: Integration method of 3D MR spectroscopy into treatment planning system for glioblastoma IMRT dose painting with integrated simultaneous boost.
abstract: BACKGROUND
  To integrate 3D MR spectroscopy imaging (MRSI) in the treatment planning system (TPS) for glioblastoma dose painting to guide simultaneous integrated boost (SIB) in intensity-modulated radiation therapy (IMRT).
  
  
  METHODS
  For sixteen glioblastoma patients, we have simulated three types of dosimetry plans, one conventional plan of 60-Gy in 3D conformational radiotherapy (3D-CRT), one 60-Gy plan in IMRT and one 72-Gy plan in SIB-IMRT. All sixteen MRSI metabolic maps were integrated into TPS, using normalization with color-space conversion and threshold-based segmentation. The fusion between the metabolic maps and the planning CT scans were assessed. Dosimetry comparisons were performed between the different plans of 60-Gy 3D-CRT, 60-Gy IMRT and 72-Gy SIB-IMRT, the last plan was targeted on MRSI abnormalities and contrast enhancement (CE).
  
  
  RESULTS
  Fusion assessment was performed for 160 transformations. It resulted in maximum differences <1.00 mm for translation parameters and ≤1.15° for rotation. Dosimetry plans of 72-Gy SIB-IMRT and 60-Gy IMRT showed a significantly decreased maximum dose to the brainstem (44.00 and 44.30 vs. 57.01 Gy) and decreased high dose-volumes to normal brain (19 and 20 vs. 23% and 7 and 7 vs. 12%) compared to 60-Gy 3D-CRT (p < 0.05).
  
  
  CONCLUSIONS
  Delivering standard doses to conventional target and higher doses to new target volumes characterized by MRSI and CE is now possible and does not increase dose to organs at risk. MRSI and CE abnormalities are now integrated for glioblastoma SIB-IMRT, concomitant with temozolomide, in an ongoing multi-institutional phase-III clinical trial. Our method of MR spectroscopy maps integration to TPS is robust and reliable; integration to neuronavigation systems with this method could also improve glioblastoma resection or guide biopsies.
authors.affiliation: Department of Radiation Oncology and Medical Physics, Institut Claudius Regaud, Toulouse, 31052, France. Ken.Soleakhena@claudiusregaud.fr
authors.forename: Soléakhéna
authors.initials: S
authors.lastname: Ken
authors.forename: Laure
authors.initials: L
authors.lastname: Vieillevigne
authors.forename: Xavier
authors.initials: X
authors.lastname: Franceries
authors.forename: Luc
authors.initials: L
authors.lastname: Simon
authors.forename: Caroline
authors.initials: C
authors.lastname: Supper
authors.forename: Jean-Albert
authors.initials: JA
authors.lastname: Lotterie
authors.forename: Thomas
authors.initials: T
authors.lastname: Filleron
authors.forename: Vincent
authors.initials: V
authors.lastname: Lubrano
authors.forename: Isabelle
authors.initials: I
authors.lastname: Berry
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Cassol
authors.forename: Martine
authors.initials: M
authors.lastname: Delannes
authors.forename: Pierre
authors.initials: P
authors.lastname: Celsis
authors.forename: Elizabeth Moyal
authors.initials: EM
authors.lastname: Cohen-Jonathan
authors.forename: Anne
authors.initials: A
authors.lastname: Laprie
mesh_terms: D001932:Brain Neoplasms / Q000473:pathology* / Q000532:radiotherapy*; D003287:Contrast Media / Q000494:pharmacology; D003606:Dacarbazine / Q000031:analogs & derivatives / Q000627:therapeutic use; D005909:Glioblastoma / Q000473:pathology* / Q000532:radiotherapy*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008875:Middle Aged; D011874:Radiometry / Q000379:methods; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D020266:Radiotherapy, Conformal / Q000379:methods; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D012008:Recurrence; D000077204:Temozolomide; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D003287:Contrast Media; D003606:Dacarbazine; D000077204:Temozolomide