Magnetic Resonance Imaging Surveillance for Vestibular Schwannoma After Microsurgical Resection Using a Retrosigmoid...

Area of Science:

• Neurosurgery
• Radiology
• Oncology

Background:

• Vestibular schwannoma (VS) is a benign tumor often surgically resected.
• Radical resection can lead to neurologic injury, sometimes necessitating leaving a tumor remnant.
• Predicting regrowth of VS remnants is crucial for patient management.

Purpose of the Study:

• To evaluate the prognostic value of MRI enhancement patterns post-vestibular schwannoma resection.
• To identify MRI features associated with tumor regrowth risk.

Main Methods:

• Retrospective analysis of 30 patients undergoing microsurgical VS resection.
• Post-operative MRI assessment at 6 months to define enhancement patterns (linear vs. nodular).
• Annual follow-up MRI for at least 6 years to monitor tumor remnant changes.

Main Results:

• Nodular enhancement in the internal auditory canal (IAC) was observed in 36.7% of patients, indicating a tumor remnant.
• Most nodular remnants remained stable, with a few showing slight decrease or increase.
• Linear enhancement in the IAC or cerebellopontine angle (CPA) was seen in 60% of patients and was not associated with nodular enhancement.

Conclusions:

• Post-operative MRI findings at 6 months can inform monitoring strategies for vestibular schwannoma remnants.
• Indefinite long-term follow-up is recommended due to the potential for very late regrowth, even if slight.