A Proposed Method to Comprehensively Define Outcomes in Acoustic Tumor Patients Undergoing CyberKnife Management

Abstract

Background: Vestibular assessment in patients with acoustic tumor (so-called vestibular schwannoma, VS) via ocular vestibular-evoked myogenic potential (oVEMP) and cervical VEMP (cVEMP) tests are not often discussed in the neurosurgical literature. Objectives: This study conducted physiological and morphological assessments for VS patients before and after CyberKnife radiosurgery. Methods: Twenty patients with unilateral VS underwent a battery of tests comprising facial nerve function test, audiometry, and caloric, oVEMP and cVEMP tests before and 2 years after CyberKnife treatment at a mean dosage of 18 Gy in 3 fractions. Results: The abnormal percentages of caloric, oVEMP and cVEMP tests did not significantly differ before and after Cyberknife treatment, indicating that preservation of the superior and inferior vestibular nerves can be achieved after radiosurgery. Median tumor volumes, 1.49 cm³ before treatment versus 0.97 cm³ at 2 years after treatment, differed significantly. Conclusions: The use of oVEMP and cVEMP tests in VS patients before stereotactic radiosurgery may help to evaluate the tumor origin from the superior or inferior vestibular nerve. It takes a short time and costs less, and it would be practical to make this a routine examination in VS patients having stereotactic radiosurgery.

The Role of Cervical and Ocular Vestibular Evoked Myogenic Potentials in the Assessment of Patients with Vestibular Schwannomas

“…VEMPs were done systematically in patients suffering from vertigo or imbalance and an MRI centered on the IAC was requested in the case of isolated abnormal cervical or ocular VEMPs. Finally, cVEMPs and oVEMPs allow evaluation of the effects of treatment on VS patients who undergo stereotactic radiosurgery [21]. The role of the VEMPs in VS is not primarily in diagnosis, although some patients were detected this way.…”

Correlating Vestibular Schwannoma Size With Vestibular-Evoked Myogenic Potential Results

“…A recent investigation showed that the cVEMP test evaluates the ipsilateral sacculo-collic reflex, via the inferior vestibular nerve (IVN) to the motor neurons of the neck muscles. Both tests thus can be adopted in VS patients to assess the afflictions of SVN and IVN (Ushio et al 2009;Lin et al 2013b). Both tests thus can be adopted in VS patients to assess the afflictions of SVN and IVN (Ushio et al 2009;Lin et al 2013b).…”

Optimized treatment with RF thermotherapy and immunotherapy combined with CyberKnife for advanced high-risk tumors: A clinical trial report

“…Although the condition of patients with multiple metastatic tumors may be timely controlled, oncolytic reaction and abnormal metabolism of bilirubin must be prevented during the early stages. Previous clinical trials reported that the hemogram was persistently normal during treatment with CyberKnife; however, the sudden decrease in granulocyte numbers after 2 weeks cannot be ignored, since it may lead to serious complications (7)(8). Thus, it is advocated to keep the patients who undergo CyberKnife therapy with more than two treatment plans hospitalized with symptomatic treatment for >2 weeks, until the hemogram returns to normal.…”

“…Furthermore, there is a lack of theoretical basis and practical experience on deducing the additional dose and optimizing dosage. Due to its accuracy and flexibility, CyberKnife therapy may alleviate the pain symptoms, relieve the compression syndrome, improve the quality of life and increase the chances of overcoming advanced multiple tumors (2,7). In addition, CyberKnife exhibits significant radiosurgical value.…”