Implications of contrast-enhanced CT-based and MRI-based target volume delineations in radiotherapy treatment planning for brain tumors.
J Cancer Res Ther
;
2008 Jan-Mar; 4(1): 9-13
Article
in English
| IMSEAR
| ID: sea-111411
ABSTRACT
Delineation of various target volumes using contrast-enhanced magnetic resonance imaging (MRI) and/or computed tomography (CT) constitutes the primary step for radiation therapy planning (RTP) in brain tumors. This study presents a quantification and comparative evaluation of the various clinical target volumes (CTV) and gross target volumes (GTV) as outlined by contrast-enhanced CT and MRI, along with its implications for postoperative radiotherapy of brain tumors. Twenty-one patients of gliomas were considered for this prospective study. Peritumoral edema as CTV and residual tumor as GTV were delineated separately in postoperative contrast-enhanced CT and MRI. These volumes were estimated separately and their congruence studied for contrast-enhanced CT and MRI. Compared to MRI, CT underestimated the volumes, with significant differences seen in the mean CTV (mean +/- SD -62.92 +/- 93.99 cc; P = 0.006) and GTV (mean +/- SD -21.08 +/- 36.04 cc; P = 0.014). These differences were found to be significant for high-grade gliomas (CTV P = 0.045; GTV P = 0.044), while they were statistically insignificant for low-grade gliomas (CTV P = 0.080; GTV P = 0.117). The mean differences in the volumes for CTV and GTV were estimated to be -106.7% and -62.6%, respectively, taking the CT volumes as the baseline. Thus, even though, electron density information from CT is essential for RTP, target delineation during postoperative radiotherapy of brain tumors, especially for high-grade tumors, should be based on MRI so as to avoid inadvertent geographical misses, especially in the regions of peritumoral edema.
Full text:
Available
Index:
IMSEAR (South-East Asia)
Main subject:
Radiotherapy Planning, Computer-Assisted
/
Brain Neoplasms
/
Aged
/
Humans
/
Magnetic Resonance Imaging
/
Tomography, X-Ray Computed
/
Prospective Studies
/
Adolescent
/
Contrast Media
/
Adult
Type of study:
Observational study
Language:
English
Journal:
J Cancer Res Ther
Journal subject:
Neoplasms
/
Therapeutics
Year:
2008
Type:
Article
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