Evaluation of the Impact of Magnetic Resonance Imaging (MRI) on Gross Tumor Volume (GTV) Definition for Radiation Treatment Planning (RTP) of Inoperable High Grade Gliomas (HGGs)

Table 2

Volumetric comparison of GTVs defined by CT-simulation images only, CT-simulation and MR images, and consensus of the treatment team.

	Imaging data used for GTV definition			Median % increase in GTV based on CT-simulation images only with incorporation of MRI in target definition (range)	Median % increase in GTV based on CT-simulation images only with incorporation of consensus of the treatment team (range)	Median % decrease in GTV based on CT-simulation and MR images with incorporation of consensus of the treatment team (range)
	CT-simulation images only	CT-simulation and MR images	Consensus of the treatment team
Median GTV in cc (range)	65.3 (39.6-94.3) cc	76.1 (46.8-108.9) cc	75.7 (46.3-108.5) cc	12.61% (6%-19%); p < 0.05	12.11% (5.6%-18.63%); p < 0.05	0.49% (0.37%-0.95%); p > 0.05