ARTICLE REVIEW 4

Name

E.P. Lin, B.T. Crane

Article Title

The Management and Imaging of Vestibular Schwannomas

Journal Name

“The Lateral Skull Base: Historical, Surgical and Radiologic Perspectives.”

1)       Bibliography

Lin, X. E. P., & Crane, X. B. T. (2017). The Management and Imaging of Vestibular Schwannomas.

2)   Purpose of the Article

This article outlines the treatment management of vestibular schwannoma in terms of surgical approaches, role of radiation therapy, observation, imaging differential and pre- and post-treatment findings. This article also wanted to highlight the importance of imaging the vestibular schwannoma for screening, evaluation and follow-up assessment.

3)    Brief Description of Procedure and Findings/Results

 Imaging of vestibular schwannoma is crucial for screening, evaluation and follow-up assessment as it can differentiate VS from tumor, cyst and others. MRI is the first option to evaluate the VS while contrast-enhanced CT of temporal bone is an alternative for those who could not undergo MRI. The most common symptom of the VS is chronic asymmetric sensorineural hearing loss with equal incidence on the right and left. Due to slow tumor growth, true vertigo, sudden hearing loss, facial pain, numbness, and weakness are uncommon. Historically, new approaches of VS treatment which mostly improve cranical nerve preservation do decrease the mortality rate. As for the surgical management of VS, there are either being total resection, subtotal resection, surgery or SRS is depending on the center. Further observation is needed to balance the option of treatment planning as they have advantages and disadvantages. Surgical approaches that have been highlighted are translabyrinthine (TL), retrosigmoid (RS), or middle fossa (MF) craniotomy. The approaches, how it is being performed, what can be assess, advantaged and disadvantages are illustrated in pictures below. Next, there is radiation therapy which are SRS, stereotactic radiation therapy and conventional fractionated radiation therapy as another approach to manage VS. SRS is the most commonly used technique and converges multiple beams onto a delineated volume by using cross-sectional imaging to minimize injury to adjacent tissues. This approach has some conflict where the radiation could gives harm when the exposure is not appropriate. At the same time, the is observation approach that available and suitable for patients who are indicated as follows; patients older than 60 years old with significant comorbidity, small tumor size, and absence of the symptoms. However, if hearing preservation is the main objective, other approach should be applied. Lastly, there are two modalities of imaging that can detect the VS which are CT and MRI. Both can detect moderate-large VS. But, MRI give a way better image of VS especially small-moderate VS due to its superior contrast resolution. MR imaging is now the standard of care in evaluating the VS.

    4) Conclusions and Comments

VS can be managed by surgical resection, radiation therapy, and observation, depending on how its association with hearing loss. The treatment objectives of VS have shifted from total resection to long-term tumor control with maximum functional preservation. Different sizes of tumor have different approaches of treatment. Lateral skull base surgery approaches include the TL, RS, and MF and have been applied to other skull base and PF pathologies. Knowledge of the management objectives and options allows the radiologist to provide imaging findings pertinent to initial management and to recognize expected post-therapeutic findings.

5)   Opinion of the Article

This article is equipped with comprehensive knowledge of vestibular schwannoma management. It covers all the treatment planning, surgical approaches, pre- and post-treatment image findings and other associated risks. It explains that management objectives must be clear so that appropriate and correct planning is approached. All the points are neatly arranged hence it is easy to understand. this article helps in getting better pictures of vestibular schwannoma management.