Program Information
Evaluation of Dose to Spinal Cord for SBRT Spine Patients and the Role of MRIs
J Muenkel*, D Pearson , University of Toledo, Toledo, OH
Presentations
SU-I-GPD-T-595 (Sunday, July 30, 2017) 3:00 PM - 6:00 PM Room: Exhibit Hall
Purpose: To determine a method for estimating the dose to the spinal cord for SBRT vertebra patients without using a MRI.
Methods: Fourteen T-spine SBRT vertebra patients were analyzed. The planning CT was fused to the axial T2 MRI, and contours for the vertebra, canal, and cord were drawn. The doses were exported to MIM from Pinnacle and used to attempt to find a correlation between the dose to the PTV or canal and dose to the cord. Attempts were also made to find a correlation between the distance from the vertebra to the cord and dose to the cord. Finally, measurements for the dimensions of the cord were made and used with the average distance from the vertebra to contour a model cord. The dose to the model cord was then compared to the dose to the fake cord.
Results: Examining the doses to the PTV, canal, and cord indicated little correlation between the maximum dose to the PTV or canal and the maximum dose to the cord. There was also little correlation between the distance from the vertebra to the cord and the dose to the cord. When the dose to the model cord was compared to the real cord, the model cord underestimated the dose for T6-T9, overestimated the dose for T11 and T12, and was comparable for T1 and T10. By taking measurements for the distance between the vertebra and cord for different vertebrae the model cord can be made even more accurate.
Conclusion: This work will give physicians the option to forgo getting a MRI that will only be used to find the dose to the spinal cord for SBRT vertebra patients, so the patients can be treated sooner. This model cord can also be used to estimate the dose for treatments in other areas.
Contact Email: