Evaluation CT with MRI image fusion technique on delineation GTV for glioma / 肿瘤研究与临床

ABSTRACT

Objective To investigate the way to accurately delineate gross tumor volume (GTV) of high grade gliomas(HGG) for intensity modulated radiation therapy (IMRT) by using computed tomography (CT) and magnetic resonance imaging (MRI) image fusion technique. Methods CT and MRI images were fused from 19 patients. The GTV of each patient were independently delineated by one chief doctor and one resident doctor on CT and MRI image. The GTV contoured on CT (GTVCT), MRI (GTVMRI) were measured, and composite volumes (GTVCT+MRI) were the sum of CT-defined GTV and MRI-defined GTV. The differences of these volumes were compared. Results Whether chief or resident doctors delineated, all were GTVMRI ＞GTVCT(P ＜0.050). The percentages of GTVMRI on GTVCT+MRI were (98.57±7.00)% by chief doctors, and (97.84±10.00)% by resident doctors. Compared the difference between GTVCT and GTVMRI in postoperative patients and preoperative patients, P =0.046, and the difference between chief doctors and resident doctors was statistically significant for GTV defined by CT (P =0.020), but not by MRI and composite image (P ＞0.050).Conclusion The GTV of HGG patients must be delineated on both CT image and MRI image, including using CT and MRI image fusion. But the composite volumes(GTVCT+MRI) should be the sum of CT-defined GTV and MRI-defined GTV. Especially for the postoperative patients,delineating GTV should be taken more attention. And the GTV should be delineated by doctors with full experiences.