KẾT QUẢ XẠ PHẪU GAMMA KNIFE KIỂM SOÁT U BAO SỢI THẦN KINH VIII TỒN LƯU SAU PHẪU THUẬT

Abstract

Background: Vestibular Schwannoma (VS), a benign tumor located at the cerebellopontine angle, is typically treated with surgery when the tumor is large or symptomatic. However, residual tumor tissue may remain after surgery due to the need to preserve critical functional structures, such as the facial nerve and cochlea. Gamma Knife radiosurgery is a minimally invasive adjuvant treatment that helps control tumor growth while minimizing neurological complications. Although international reports have demonstrated the effectiveness of Gamma Knife, domestic data on residual VS after surgery is still limited. This study aims to evaluate the outcomes of Gamma Knife radiosurgery in managing residual tumor, contributing to the optimization of a multimodal treatment strategy for these patients. Aim: To evaluate tumor control efficacy and safety of Gamma Knife radiosurgery in patients with residual vestibular schwannoma after surgery. Patients and methods: This retrospective descriptive study included 50 patients with residual vestibular schwannoma after surgery, treated between May 2022 and December 2023 at Cho Ray Hospital. The mean age was 53.5 ± 12.4 years. Radiosurgical planning followed practical dose recommendations (typically a peripheral dose of 12 Gy and a maximum dose of approximately 24 Gy), followed by periodic clinical and MRI follow-up. Post-treatment follow-up was scheduled at 6, 12, 24, and 36 months; at each visit, symptom progression, complications, and tumor size changes were assessed. Results: In this cohort, the mean interval from surgery to radiosurgery was 9.6 ± 4.1 months; 82% of patients underwent radiosurgery within the first 12 postoperative months. Before treatment, common symptoms included headache (84%), hearing loss (70%), tinnitus (30.61%), facial palsy (28%), and imbalance (18%). On imaging, left-sided tumors accounted for 72%, with a mean size of 27.9 ± 8.4 mm and a mean volume of 6.5 ± 6.4 cm³. After radiosurgery, the tumor control rate was 98% (stable or decreased tumor size), with only 1 case (2%) showing enlargement at 6 months. Regarding safety, 2 cases of trigeminal neuralgia (4%) were recorded; no new hearing loss or new facial palsy occurred after treatment. Survival at the time of assessment was 100%. Conclusion: Gamma Knife radiosurgery is an effective and safe adjuvant treatment for residual vestibular schwannoma after surgery, with a high tumor control rate, favorable clinical improvement, and a low rate of severe complications. These findings support integrating Gamma Knife into a multimodality treatment strategy to optimize disease control and quality of life in this patient population.