Clinical Professor of Neurosurgical Oncology, Hon. Consultant Neurosurgeon University of Cambridge Cambridge, United Kingdom
Introduction: Despite improvements made in the multimodal treatment of Glioblastoma (GBM), the likelihood of progression and recurrence beyond an initial resection cavity is nearly inescapable. Diffusion tensor imaging (DTI) is a sensitive technique for detecting occult white matter tract disruptions that conventional MR imaging falls short of, making DTI a valuable tool for early predictions of extent and pathways of recurrence/progression. The aim of this study was to systematically review the literature to date on the use of DTI in characterizing and predicting recurrence/progression of GBM.
Methods: Three databases (PubMed, Web of Science, and Scopus) were queried with the following search terms: “(diffusion tensor imaging OR DTI) AND (glioblastoma OR GBM) AND (recurrence OR progression)”. Three hundred sixty-nine results populated from this search and were systematically reviewed with the following inclusion criteria: (1) original articles (excluding reviews); (2) written in English; (3) specified data for GBM patients; and (4) provided DTI data on characterizing or predicting the recurrence/progression of GBM as a primary endpoint. Sixteen articles met these criteria and were included in this review.
Results: Amongst these 16 studies, some similar trends in DTI metrics and patterns were found regarding GBM recurrence/progression, including: decreased fractional anisotropy (FA) in regions of recurrent tumor; tractography delineating the path of tumor migration along disrupted white matter tracts before recurrence is detected by conventional MR imaging; and decreased isotropic and increased anisotropic diffusion maps correlating with the rate of tumor progression.
Conclusion : DTI metrics can be reliable predictive values for the recurrence/progression of GBM. Knowing and understanding these metrics and patterns, as well as using this imaging modality for surgical planning, may inform the extent of resection and better guide post-operative surveillance and management. Moreover, further research into DTI patterns of recurrence/progression may unveil unique GBM profiles that portend local versus distant spread.
