Faculty of Physics - University of Bucharest

UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS

Guest
2024-11-22 1:21

HOME CONFERENCES SEARCH LOGIN NEW USER IMAGES

Conference: Bucharest University Faculty of Physics 2015 Meeting

Section: Biophysics; Medical Physics

Title:

CT-MRI image fusion – the role and benefits of imaging in 3D radiation therapy planning

Authors:

Maria VLASCEANU (1,2), Alina TANASE (1,2), Mihai DUMITRACHE (1,2)

Affiliation:

1)Emergency Central Military Hospital ”Dr. Carol Davila” Bucharest, Romania,

2)University of Bucharest, Faculty of Physics, Romania

E-mail

mv_ky@yahoo.com

Keywords:

image fusion, benefits, imaging, 3D radiation therapy planning, clinical target volume

Abstract:

The aim of radiation therapy is to eradicate tumor cells without seriously damaging of normal tissue, especially without seriously damaging radiation sensitive structures, and to improve the physical dose distribution, which is not automatically the same as an improvement in patient treatment. An appropriate way to determining the clinical target volume and also the volume of organ at risk (OAR) is based on multiple-modality 3D image data sets, like X-ray computed tomography (CT), magnetic resonance imaging (MRI), positron emission computed tomography (PET) and single photon emission computed tomography (SPECT). Routinely X-ray CT is the most common tomographic imaging method. The definition of the clinical target volume and of critical structures is a complex process in three-dimensional conformal radiation therapy (3D CRT). 3D CRT planning requires sophisticated imaging modalities. For this reason, MRI has become an important imaging modality in radiotherapy planning, complementing the use of CT and introducing several additional and important benefits. In our clinic, we often apply fusion procedure using Eclipse v.11 software tools, especially for head, head and neck and prostate cases. The patients are scanned on a Somatom Spirit CT simulator for treatment planning, in the treatment position. CT images obtained are then placed in MRI image rigid registration procedure (fusion), following the bones anatomy. Image fusion showed that CTV delineated on a CT image study set is mainly inadequate for treatment planning, in comparison with CTV delineated on CT-MRI fused image study set, and consequently, treatment planning is more appropriate, in dosimetry terms. In conclusion, the registration and image fusion allows precise target localization in terms of CTV and PTV and also in local disease control, minimizing uncertainties within acceptable treatment planning limits.