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Integration method of 3D MR spectroscopy into treatment planning system for glioblastoma IMRT dose painting with integrated simultaneous boost

Soléakhéna Ken12*, Laure Vieillevigne1, Xavier Franceries2, Luc Simon1, Caroline Supper1, Jean-Albert Lotterie23, Thomas Filleron1, Vincent Lubrano23, Isabelle Berry23, Emmanuelle Cassol23, Martine Delannes1, Pierre Celsis2, Elizabeth Moyal Cohen-Jonathan14 and Anne Laprie12

Author Affiliations

1 Department of Radiation Oncology and Medical Physics, Institut Claudius Regaud, Toulouse, 31052, France

2 INSERM UMR 825 Imagerie cérébrale et handicaps neurologiques, Toulouse, 31059, France

3 Centre Hospitalier Universitaire de Rangueil, Université Toulouse III Paul Sabatier, Toulouse, 31059, France

4 INSERM UMR1037, CRCT, Institut Claudius Regaud, Toulouse, 31052, France

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Radiation Oncology 2013, 8:1  doi:10.1186/1748-717X-8-1

Published: 2 January 2013

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.

Keywords:
MR spectroscopy imaging (MRSI); Glioblastoma; Simultaneous integrated boost intensity modulation radiation therapy (SIB-IMRT),Dose painting