Surgical outcomes of premeatal and retromeatal cerebellopontine angle meningioma in Vietnam: a single-center prospective cross-sectional study

Cerebellopontine angle (CPA) meningiomas are the second most common tumor of the CPA. Depending on the site of dural attachment, the relationship between the tumor and critical neurovascular structures of the CPA is variable. This study aims to evaluate the influence of CPA meningioma location in relation to the internal auditory canal (IAC) on clinical symptoms, radiological presentations, and surgical treatments and outcomes which has been rarely reported in Vietnam.

Patients and methods

A prospective study on 33 patients treated with microsurgery from August 2020 to May 2022 at the Neurosurgery Center, Viet Duc University Hospital.

Results

The mean age of 27 females (85%) and 6 (15%) males was 54±12 years. Based on their location to the IAC, there were 16 premeatal cases (49%) (anterior to the IAC) and 17 retromeatal cases (15%) (posterior to the IAC). The time of diagnosis of the retromeatal group was later (16.5 vs. 9.7 months), the average tumor size of the 2 groups was not different, but when there was brainstem compression, the average tumor size of retromeatal group was larger (49 vs. 44 mm). The clinical presentations of the retromeatal group were related to the cerebellar symptoms, while trigeminal neuropathy symptoms all came from the premeatal group. Gross total resection of the premeatal group was 31% and of the retrometal group was 71%. The results of preserving the facial nerve function of the premeatal group were lower (44 vs. 82%). Postoperative Karnofsky score of the retromeatal group improved, while the premeatal group did not change.

Conclusions

Classification of CPA meningiomas according to their location to the IAC plays an important role in diagnosis and treatment, affecting clinical symptoms, surgical strategy as well as surgical outcomes.

Stereotactic radiosurgery for cerebellopontine meningiomas: a systematic review and meta-analysis

OBJECTIVE

To (1) measure surgical outcomes associated with stereotactic radiosurgery treatment of cerebellopontine angle meningiomas, and (2) determine if differences in radiation dosages or preoperative tumor volumes affect surgical outcomes.

METHODS

A systematic search was performed on the PubMed, Medline, Embase and Cochrane Library databases searching for patients under stereotactic radiosurgery for meningiomas of the cerebellopontine angle. After data extraction and Newcastle-Ottawa scale quality assessment, meta-analysis of the data was performed with Review Manager 3.4.5.

RESULTS

In total, 6 studies including 406 patients were included. Postprocedure, patients had minimal cranial nerve complications while having an overall tumor control rate of 95.6%. Complications were minimal with facial nerve deficits occurring in 2.4%, sensation deficits of the trigeminal nerve in 4.0%, hearing loss in 5.9%, hydrocephalus in 2.0% and diplopia in 2.6% of all patients. Individuals with tumors extending into the internal auditory canal extension did not have significantly increases in hearing loss. There was a higher likelihood of tumor regression on postprocedure imaging in studies with a median prescription dose of >13 Gy (RR 1.27 [95% CI 1.04-1.56, p = 0.0225). There was no evidence of publication bias detected.

CONCLUSIONS

Radiosurgery is an effective modality for offering excellent tumor control of CPA meningiomas while allowing for only minimal complications postprocedure. A higher prescription dose may achieve higher tumor regression at follow up. Future studies should aim at establishing and optimizing accurate dosimetric guidelines for this patient population.