Comparison of computed tomography and magnetic resonance based target volume in brain tumors.

PURPOSE: This study was mainly framed to study the difference in tumor volumes as seen on computed tomography (CT) and magnetic resonance (MR) and their significance in planning. MATERIALS AND METHODS: Twenty-five patients with brain tumor of different diagnoses who underwent stereotactic radiotherapy were included in this study. CT and MR imaging was done for all the patients with 2.5 mm slice thickness. The CT tumor volume and MR tumor volume were measured and compared with each other. The center of mass (CM) of the tumor volume delineated on CT and MR were computed and the shift between the two CMs was determined. RESULTS: The mean and median volume of the tumor as measured from MR scans was 19.67 cc +/- 13.73 and 16.13 cc (range: 3.25 cc-50.37 cc). Similarly, the mean and median volume of the tumor as measured from CT scans was 15.05 cc +/- 10.13 and 11.63 cc (range: 3.0 cc-36.25 cc) respectively. The mean and median CM shift between CT and MR was 5.47 mm and 5.21 mm respectively. CONCLUSION: The study demonstrates that MR is an indispensable imaging modality in radiotherapy for planning brain tumors.

Role of radiation therapy in the treatment of benign ocular diseases.

Radiation therapy, although a prime treatment modality for malignant disease, has few definitive indications for some benign ocular diseases too. Orbital pseudotumour, Graves ophthalmopathy and pterygium are the conditions where the radiation oncologist has got an important role to play. This article reviews the current status of the role of radiation and its effectiveness in the management of these diseases.