Clinical target volume definition for glioblastoma radiotherapy planning: magnetic resonance imaging and computed tomography.
OBJECTIVE
To assess the differences between the target delineation using computed tomography (CT) and imaging fusion CT/magnetic resonance imaging (MRI) for the radiotherapy planning of glioblastoma.


METHODS
One hundred-twenty gross tumor volume and clinical target volume on CT and MRI (GTVCT/CTVCT, GTVMRI/CTVMRI, respectively) were contoured and evaluated. The treatments planning (total dose 60 Gy) based on CTVCT were analysed in terms of percentage of CTVCT and CTVMRI receiving 95 % of the prescribed dose (V95-CTVCT, V95-CTVMRI).


RESULTS
GTVs and CTVs contoured on MRI were significantly larger than those delineated on CT (p = 0.0003, p = 0.0006, respectively). Nighty-two percent of CTVCT was coincident with the CTVMRI and 8 % was normal tissue; 20 % of CTVMRI, considered as tumor volume, was not included on CTVCT. The V95-CTVMRI was significantly lower than the V95-CTVCT (p = 0.0005).


CONCLUSIONS
In the delineation of glioblastoma target volume, fusion CT/MRI was preferred. The CT only is insufficient for the CTV dose coverage.
Department of Radiation Oncology, IRCCS/CROB, via San Pio 1, 85028, Rionero in Vulture, PZ, Italy. albafiorentino@hotmail.it
A
A
Fiorentino
R
R
Caivano
P
P
Pedicini
V
V
Fusco
D001932:Brain Neoplasms / Q000532:radiotherapy*; D005260:Female; D005909:Glioblastoma / Q000532:radiotherapy*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D011829:Radiation Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D015203:Reproducibility of Results; D012306:Risk; D014057:Tomography, X-Ray Computed