CT-MRI Image Fusion Effect on Dose Delivered and Distribution for Astrocytoma Radiation Therapy

Aim: This study described the benefits of CT-MRI fusion to consolidate the accuracy of conformal radiation therapy for Egyptian astrocytoma patients. Materials and methods: Thirty four patients with astrocytoma tumor who underwent 3D conformal radiotherapy were included in this study. CT and MRI imaging was done for all the patients after surgery. The PTVCT and PTVMRI tumor were measured and compared with each other. The center of mass (CM) of the PTV delineated on CT and MRI were computed and the shift between the two CMs was determined. Results and Discussion: The mean and median for PTV measured by CT-MRI was 66.77cm3±48.77 and 43.65 (range 8.6 to 162.2) respectively. For CT the mean and median for PTV was 53.82cm3± 45.66 and 31.7 (range 12.4 to 180.1) respectively. The differences between the centers of mass (CM) of the two PTV’s detected spatial 3D shifts ranging from (-4mm to 5mm) with an average of 0.3 mm for x direction, (-2mm to 5mm) with an average of 1.3 mm for y, and (-2mm to 4mm) with an average of 0.7 mm for z direction respectively. The prescribed dose was fitted on PTVCT. The V95-PTVMRI was lower than the V95-PTVCT by 22.5%. Conclusion: The result showed that MRI is an essential modality in radiotherapy for planning astrocytoma tumors. Research Article CT-MRI Image Fusion Effect on Dose Delivered and Distribution for Astrocytoma Radiation Therapy Tamer Dawod1, EM Abdelrazek2, Hend Ahmed El-Hadaad1 and Mariam Isam3* 1Department of Clinical Oncology and Nuclear Medicine, Mansoura University, Egypt 2Department of Physics, Mansoura University, Egypt 3Department of Science, Mansoura University, Egypt