DTI fiber-tracking parameters adjacent to gliomas: the role of tract irregularity value in operative planning, resection and outcome

Background: The goal of glioma surgery is maximal tumor resection associated with minimal post-operative morbidity. DTI-FT is a standard application of white-matter (WM) visualization for diagnosis and surgical planning but assumes a descriptive role since the main DTI parameters showed limitations in clinical use. New quantitative measurements were recently applied to describe WM architecture adjacent the tumor that can be adopted as predictive values and guide for safe tumor resection. Methods: This is a prospective multicentric study on a series of glioma-patient who performed magnetic resonance imaging (MRI) with pre-operative diffusion tensor imaging-tractography (DTI-FT). We examined DTI parameters of FA (mean, min-max), MD, and the shape-metric TI grade measured in the brain adjacent tumor area, comparing it with the surgical series' clinical, radiological, and outcome data. Results: The population consisted of 118 patients, with a mean age of 60.6 years. 82 patients suffering from high-grade gliomas (69.5%), and 36 from low-grade gliomas (30.5%). A significant inverse relationship exists between the FA mean value and grading (p=0.001). The relationship appears directly proportional regarding MD values (p=0.003) and TI values (p=0.005). FA mean and MD values are susceptible to significant variations with tumor and edema volume (p=0.05). TI showed an independent relationship with grading regardless of tumor radiological features and dimensions, with a direct relationship with grading, ki67% (p=0,05), PFS (p<0.001), and EOR (p<0.01). Conclusion: FA, MD and TI are useful predictive measures of clinical behavior of glioma and especially TI could potentially be helpful for tumor grading identification and surgical planning.