Using diffusion-tensor imaging and tractography (DTT) to study biological characteristics of glyoma in brain stem for neurosurgical planning Poster No.: C-0016 Congress: ECR 2014 Type: Authors: Keywords: DOI: Scientific Exhibit W. Wu; Chengdu/CN Neuroradiology brain, Oncology, MR-Diffusion/Perfusion, Radiation therapy / Oncology, Surgery, Image guided radiotherapy 10.1594/ecr2014/C-0016 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. www.myesr.org Page 1 of 5
Aims and objectives Glyoma in brain stem is difficult to be resected due to the unclear relationship between tumor and neighboring neuro-fiber tracts. It is also not clear about how the glyoma injure the tracts, which is one of the important biological characteristics. This research is to study the relationship using diffusion-tensor imaging and tractography (DTT), understand biological characteristics of glyoma to fiber tracts, and apply the results for neurosurgical planning. Methods and materials Fourty patients were recruited into this study. DTT was processed in Slicer 4.2 (www.slicer.org) before and after surgery for every patient. The pyramidal tracts and cerebellar peduncle tracts were reconstructed individually. The 3D models of glyoma were also reconstructed individually. Then, the neurosurgical planning was made individually based on the results of DTT to decide the surgical approach. The images and processed models were input in the surgical navigation system to guide the surgery. According to the relationship between resection area and results from pre-surgical planning during the surgery, we can predict if the tracts were injured or not, and the degree of the injury. The predictable effect of planning was verified individually by comparing clinical neuro-function deficit with DTT results pre- and post-surgically. Results Three biological characteristics of glyoma in brain stem to fiber tracts are illustrated in Figure 1. The first one refers to the tumor pushing, partially embedding and destroying the tracts (Figure 1A); the second one refers to the tumor pushing and partially embedding, but without destroying the tracts (Figure 1B); the third one refers to the tumor totally embedding, but without destroying the tracts (Figure 1C). Based on the way of pushing and embedding tracts, two surgical approaches are suggested by neurosurgical planning, which are approach through cerebellopontine angle (Figure 2D) and approach through infratentorial midline (Figure 2E). The decision of the surgical approach is made according to the location of tumor area where few tracts were in the way to resect the tumor. After removing over 90% of tumor, the neuro-function deficit didn't get worse in 32 patients of the first and second kind of glyoma, with the help of neurosurgical planning (Figure 3F). However, The third kind of glyoma in the rest 8 patients was not suitable for surgery, and had to receive radio-therapy. Page 2 of 5
Images for this section: Fig. 1: Three biological characteristics of glyoma to fiber tracts in brain stem Fig. 2: Two surgical approaches are suggested by neurosurgical planning Page 3 of 5
Fig. 3: Compare with figure 1A, the neuro-function deficit didn't get worse with the help of neurosurgical planning. Page 4 of 5
Conclusion DTT offers a non-invasive method to study the biological characteristics of glyoma in brain stem. With the help of neurosurgical planning based on DTT, resection of glyoma in brain stem will become less risky to destroy fiber tracts and aggravate the neuro-function deficit. Personal information Wentao Wu, M.D. Ph.D. Department of radiology, West China Hospital, Chengdu, China wentao_wu1981@163.com Yan Ju, M.D. Department of neurosurgery, West China Hospital, Chengdu, China References 1. Basser PJ, Mattiello J, LeBihan D. MRdiffusion tensor spectroscopy and imaging. Biophys J. 1994(66):259-267. 2. Pierpaoli C, Jezzard P, Basser PJ, Barnett A, Di Chiro G. Diffusion tensor MR imaging of the human brain. Radiology. 1996(201):637-648. 3. Pataky TC, Goulermas JY, Crompton RH. A comparison of seven methods of within-subjects rigid-body pedobarographic image registration. J Biomech. 2008;41(14):3085-3089. Page 5 of 5