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Magnetic resonance in neuro-oncology: Achievements and challenges
Published in Dževad Belkić, Karen Belkić, Signal Processing in Magnetic Resonance Spectroscopy with Biomedical Applications, 2010
Complete surgical resection is the aim for successful treatment of brain tumors. Realization of this goal vitally depends upon the grade and histopathologic characteristics of the tumor and anatomical location. If accessible, low-grade astrocytomas are usually surgically resected with RT often also employed. Protocols vary substantially across centers, and strategies also differ greatly in relation to the clinical considerations. Since high-grade gliomas only rarely have clearly defined margins, total surgical resection is not possible in most cases. Partial resection to control mass effect is often performed, as well as RT, chemotherapy and glucocorticoids. Overall survival is poor, generally below 1 year. Total surgical resection represents a curative treatment for meningiomas. If the resection is sub-total, local RT is usually given and reduces recurrence rates to fewer than 10%. If the meningioma is not surgically accessible, targeted radio surgery with the gamma knife or heavy particle radiation may be considered. Accurate grading of intra-cerebral neoplasms can be very difficult, due especially to tumor heterogeneity. For this reason, brain biopsy may not provide the definitive answer, besides being associated with substantial morbidity, as noted. Thus, there has been interest in using in vivo MRSI with full volumetric coverage for grading brain tumors.
A position- and time-dependent pressure profile to model viscoelastic mechanical behavior of the brain tissue due to tumor growth
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2023
Fatemeh Abdolkarimzadeh, Mohammad Reza Ashory, Ahmad Ghasemi-Ghalebahman, Alireza Karimi
The mass-effect plays a key role in defining the premise for justifying surgery of the cerebrum (Bullock et al. 2006; McKenna et al. 2012; Gonda et al. 2013). In neurologic diseases, ranging from trauma (Bullock et al. 2006; Kim and Gean 2011), stroke (Zazulia et al. 1999; McKenna et al. 2012), to tumor (Gamburg et al. 2000), increased mass-effect is consistently associated with poor prognosis. Our results revealed that considering a variable pressure boundary causes a more realistic pressure contour around the tumor region, so it would result in a more accurate prediction of mass-effect in ventricles. Our results herein showed the mass-effect of ∼5-11 mm in the regions around the brain cavity (Figure 7), which is lower than that of brain shift reported during tumor resection ∼24 mm (Nimsky et al. 2000; Chen et al. 2011; Miga et al. 2016; Bayer et al. 2017; Gerard et al. 2017). This difference could be related to the stiffness of the tissues at the vicinity of the tumor that affect the mass-effect. In addition, herein we only modeled two cases while more cases would be required if a wider range of mass-effect estimation is the goal.