Authors: Zhao Zhang, M.S., Michael Wahl, M.D., Julia Owen Ph.D., Pratik Mukherjee, M.D. Ph.D.
Program: Nova Southeastern University Dr. Kiran C. Patel College of Osteopathic Medicine, Fort Lauderdale, FL
Background: Glioma is a type of brain tumor, originating in the glial cells in the brain and accounts for about one third of all brain tumors. Because glial cells are the tissues that surround and supports neurons in the brain, gliomas are called intrinsic brain tumors and tend to grow preferentially along the white matter tracts of the brain. Current treatment methods include surgery for resection of tumor and adjunct chemotherapy with radiation therapy. However current radiation therapy involves wide margins and nonspecific coverage of both white matter and grey matter.
Objective: To implement a new algorithm for more accurate radiation contouring in treating glioblastoma with radiation oncology.
Methods: Patient data was received for three individuals with GBM. MR Imaging was performed using a 3 Tesla scanner with T2 weighting parameters (TR =9800ms, TE=82.1ms, Slice Thickness 2mm and Flip Angle of 90). Acquisition matrix of 128 x 128 was used during image acquisition. Diffusion weighting was set at b-value of 1000 s/mm^2 with 55 gradient diffusion directions. A FLAIR sequence was run to suppress CSF. Data quality was acceptable in all cases and models for radiotherapy were established using FSL preprocessing, BedpostX and Probtrackx of patient tumor seed.
Results: A total of three patients with GBM were imaged using a 3 Tesla MRI. For patient 1 the DTI method decreased volume of grey matter irradiated by 8.34x10^4 mm^3 while decreasing the volume of white matter irradiated by 1.37x10^5 mm^3. For patients 2 and 3 total volume was increased in the DTI Tractography method by 3.41x10^4mm^3 and 4.43x10^4mm^3 respectively which was the result of making sure our method reached the corpus callosum. We addressed this issue by applying a smoothing kernel, which decreased the total volume radiated compared with the original DTI volume by 1.18x10^5mm^3 for both patient 2 and 3.
Conclusion: Current radiotherapy treatment using a 2cm isotropic expansion of tumor margins is nonspecific and potentially results in over-radiation, especially in areas of the brain responsible for cognitive function. This study utilizes Tractography in targeting pathways of high probable tumor recurrence while attempting to minimize total treatment volume to prevent over radiation of patients. Use of DTI in predicting GBM growth can be a more automated and methodological approach that may one day supersede the current method of 2cm isotropic expansion and hopefully be used as the gold standard in the clinic.
Program: Nova Southeastern University Dr. Kiran C. Patel College of Osteopathic Medicine, Fort Lauderdale, FL
Background: Glioma is a type of brain tumor, originating in the glial cells in the brain and accounts for about one third of all brain tumors. Because glial cells are the tissues that surround and supports neurons in the brain, gliomas are called intrinsic brain tumors and tend to grow preferentially along the white matter tracts of the brain. Current treatment methods include surgery for resection of tumor and adjunct chemotherapy with radiation therapy. However current radiation therapy involves wide margins and nonspecific coverage of both white matter and grey matter.
Objective: To implement a new algorithm for more accurate radiation contouring in treating glioblastoma with radiation oncology.
Methods: Patient data was received for three individuals with GBM. MR Imaging was performed using a 3 Tesla scanner with T2 weighting parameters (TR =9800ms, TE=82.1ms, Slice Thickness 2mm and Flip Angle of 90). Acquisition matrix of 128 x 128 was used during image acquisition. Diffusion weighting was set at b-value of 1000 s/mm^2 with 55 gradient diffusion directions. A FLAIR sequence was run to suppress CSF. Data quality was acceptable in all cases and models for radiotherapy were established using FSL preprocessing, BedpostX and Probtrackx of patient tumor seed.
Results: A total of three patients with GBM were imaged using a 3 Tesla MRI. For patient 1 the DTI method decreased volume of grey matter irradiated by 8.34x10^4 mm^3 while decreasing the volume of white matter irradiated by 1.37x10^5 mm^3. For patients 2 and 3 total volume was increased in the DTI Tractography method by 3.41x10^4mm^3 and 4.43x10^4mm^3 respectively which was the result of making sure our method reached the corpus callosum. We addressed this issue by applying a smoothing kernel, which decreased the total volume radiated compared with the original DTI volume by 1.18x10^5mm^3 for both patient 2 and 3.
Conclusion: Current radiotherapy treatment using a 2cm isotropic expansion of tumor margins is nonspecific and potentially results in over-radiation, especially in areas of the brain responsible for cognitive function. This study utilizes Tractography in targeting pathways of high probable tumor recurrence while attempting to minimize total treatment volume to prevent over radiation of patients. Use of DTI in predicting GBM growth can be a more automated and methodological approach that may one day supersede the current method of 2cm isotropic expansion and hopefully be used as the gold standard in the clinic.