Posts Tagged ‘acoustic neuroma’
Background: Cochlear dose has been identified as a potentially modifiable contributor to hearing loss following stereotactic radiosurgery (SRS) for vestibular schwannoma (VS).
Objective: (1) to evaluate the association between CT-based volumetric cochlea dose and loss of serviceable hearing following SRS; 2) to assess intra- and interobserver reliability when determining modiolar point dose using MRI and CT; 3) and to discuss the clinical significance of the cochlea dose with regard to radiosurgical planning strategy.
Methods: Patients with serviceable pre-treatment hearing who underwent SRS for sporadic VS between using Gamma Knife Perfexion were studied. Univariate and multivariate associations with the primary outcome of time to non-serviceable hearing were evaluated.
Background: Management of neurofibromatosis type 2 (NF2)—associated vestibular schwannomas (VSs) remains controversial. Stereotactic radiosurgery (SRS) with conventional dosing is less effective for NF2-related VS compared with sporadic lesions.
Objective: To evaluate optimal SRS dose parameters for NF2-related VS and to report long-term outcomes.
Methods: A prospective database was reviewed and outcome measures, including radiographic progression, American Academy of Otolaryngology—Head and Neck Surgery hearing class, and facial nerve function, were analyzed. Progression-free survival was estimated with Kaplan-Meier methods. Associations between tumor progression and radiosurgical treatment parameters, tumor volume, and patient age were explored with the use of Cox proportional hazards regression.
Background: Fractionated Stereotactic Radiotherapy (FSRT) is a non-invasive treatment for acoustic neuromas (AN). Initial reports from our institution demonstrated that reduction of treatment dose to 46.8 Gy resulted in improved preservation of functional hearing status.
Objective: We now report the tumor control (TC), symptomatic outcome, and hearing preservation rate (HP) in patients treated with reduced-dose FSRT.
Methods: We analyzed all patients with AN treated from 2002 to 2011. All patients received 46.8 Gy in 1.8 Gy fractions. Follow-up audiogram and MRI were performed in = one-year intervals. TC and HP were calculated by the Kaplan-Meier method. Analysis of HP, defined as Gardner-Robertson value = 2, was determined by audiometric data. Non-hearing related symptoms were defined by Common Terminology Criteria for Adverse Events version 4.
Background: Radiosurgery is increasingly used to treat vestibular schwannomas (VSs). Increasing the sensitivity of VS cells to irradiation (IR) could allow for lower and/or more effective doses of IR, improving safety and efficacy. Persistent c-Jun N-terminal kinase (JNK) activity in VS cells reduces cell death by suppressing accumulation of reactive oxygen species (ROS), raising the possibility that JNK activity protects against IR-induced VS cell death, which is mediated by ROS.
Objective: To determine the extent to which JNK signaling contributes to VS cell radiosensitivity.
Methods: Primary human VS cultures, derived from acutely resected tumors, received single doses (5-40 Gy) of [gamma]-irradiation. Histone 2AX phosphorylation, a marker of IR-induced DNA damage, was assayed by western blot and immunostaining. ROS levels were quantified by measuring 2′,7′-dichlorodihydrofluorescein diacetate (CM-H2DCFDA) fluorescence. Cell apoptosis was determined by terminal deoxynucleotidyl transferase dUTP nick end labeling.
Background: Despite advanced microsurgical techniques, more refined instrumentation, and expert team management, there is still a significant incidence of complications in vestibular schwannoma surgery.
Objective: To analyze complications from the microsurgical treatment of vestibular schwannoma by an expert surgical team and to propose strategies for minimizing such complications.
Methods: Surgical outcomes and complications were evaluated in a consecutive series of 410 unilateral vestibular schwannomas treated from 2000 to 2009. Clinical status and complications were assessed postoperatively (within 7 days) and at the time of follow-up (range, 1-116 months; mean, 32.7 months).