Feasibility of using MRI alone for 3D radiation treatment planning in brain tumors.

OBJECTIVE

The aim of this study was to establish whether radiation treatment planning using MRI alone could replace CT-based planning for brain tumors while retaining the dosimetric accuracy. This would help to provide a single imaging modality for both target delineation as well as treatment planning, thus saving time and resources.

METHODS

Twenty-five patients with brain tumors were scanned on a spiral CT scanner and 1.5 T MRI scanner. Three treatment plans were generated for all patients. The first plan was generated using the CT scan images with inhomogeneity correction (CT + IC); the second plan used the CT scan without inhomogeneity correction (CT-IC) and the third plan was generated using the MRI scan (MRI alone).

RESULTS

The maximum distortion in the MRI phantom study was less than 1 mm. There were no statistically significant differences in any of the target coverage parameters analysed in this study. Similarly, the maximum antero-posterior and lateral dimensions for the CT-based and MRI-based planning did not show any statistical difference.

CONCLUSION

MRI-based treatment planning for brain lesions is feasible and gives equivalent dosimetric results compared to CT-based treatment planning.