Correlation of Preoperative Cranial Nerve Diffusion Tensor Tractography with Intraoperative Findings in Surgery of...

Imaging to visualize nerves around tumors preoperatively could help the surgeon to plan the surgery and excise the tumor with preservation or improvement in patients' quality of life. In the present prospective study, we attempted to correlate the preoperative cranial nerves (i.e., trigeminal, abducens, facial, and vestibulocochlear diffusion tensor tractography and anatomic magnetic resonance imaging [MRI] findings) with intraoperative findings during cerebellopontine angle (CPA) tumor surgery.

The 40 enrolled patients had CPA tumors (31 vestibular schwannomas, 5 epidermoid tumors, 2 meningiomas, 2 trigeminal schwannomas). All the patients were undergoing microsurgery for the first time. They underwent preoperative MRI for anatomic and diffusion tensor imaging (DTI) data. The imaging series were postprocessed, and 3-dimensional images were obtained. The location of the involved nerves around the tumors was recorded during surgery by the senior surgeon, who was kept unaware of the results of the fiber tracking, and a correlation was performed.

We evaluated the correlation between the DTI and intraoperative findings for the nerve location in relation to the tumor in the CPA. The correlation between the DTI and intraoperative findings for the facial, trigeminal, and vestibulocochlear nerves was 85% (34 of 40), 85% (34 of 40), and 75% (12 of 16), respectively.

The modified technical parameters proposed could lead to better preservation of cranial nerve function, especially for patients with large tumors. To the best of our knowledge, the present study is the first systematic study of relevant cranial nerves in 40 patients with demonstration of the vestibulocochlear bundle by preoperative MRI in the most common CPA tumors using advanced MRI sequences such as diffusion tensor tractography and capturing the data in a multiplanar format.