Effects of CyberKnife therapy for vestibular schwannoma on hearing: a retrospective study

The safety and efficacy of robotic radiosurgery and radiotherapy in the management of skull base tumors: a systematic review and meta-analysis

Stereotactic radiosurgery (SRS) and radiotherapy (SRT) have gained prominence as both adjuvant and primary treatment options for patients with skull base tumors that are either inoperable or present as residual or recurrent lesions post-surgery. The object of the current study is to evaluate the safety and efficacy of robotic-assisted SRS and SRT across various skull base pathologies. The study was conducted under PRISMA guidelines and involved a comprehensive evaluation of databases, including PubMed, Scopus, Embase, Web-of-Science, and the Cochrane Library. The data collection period was extended up to 30 September. Statistical analyses were executed using Comprehensive Meta-Analysis software. Furthermore, Cochran's Q test assessed statistical heterogeneity within the findings. From an initial pool of 1,792 articles, 69 studies were included in the systematic review, with 60 qualifying for meta-analysis, encompassing 3,046 participants. Meta-analysis revealed tumor control rates were significantly enhanced with the use of CyberKnife (95% CI: 0.901-0.928, p < 0.001) and robotic Gamma Knife radiosurgery (GKRS) (95% CI: 0.897-0.959, p < 0.001). Meningiomas and schwannomas exhibited higher treatment responsiveness (ES: 0.960 and 0.949, respectively), whereas chordomas displayed lower responsiveness (ES: 0.743). The overall major adverse event rate was between 5.6% and 8.3% (95% CI: 0.056-0.083, p < 0.001). Adverse events exhibited a higher incidence in patients with adenomas (95% CI: 0.122-0.217, p < 0.001), while they were least prevalent in those with schwannomas (95% CI: 0.019-0.041, p < 0.001). Robotic SRS and SRT, employing both gamma-knife and cyber-knife, have demonstrated promising outcomes characterized by high efficacy and safety in managing various skull base tumors.

Hearing Function after CyberKnife for Vestibular Schwannoma: A Systematic Review

Introduction  CyberKnife (CK) radiosurgery is a treatment strategy for vestibular schwannoma (VS). Objectives  To evaluate hearing preservation (HP) after CK for VS. Data Synthesis  The study was conducted following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement, and it was registered at the International Prospective Register of Systematic Reviews (PROSPERO, under number CRD42021250300). The inclusion criteria were based on the population, intervention, comparison, outcome, timing and study design (PICOTS) strategy: population - patients with VS; intervention - CK; Comparison - none; Outcome - serviceable HP defined by Gardner and Robertson as grades I or II, or by the American Academy of Otolaryngology and Head and Neck Surgery as classes A or B; timing - mean follow-up longer than 1 year; and study design - retrospective or prospective studies. The exclusion criteria were: studies not published in English; studies published before January 2000 and after October 2021; and studies only including patients with neurofibromatosis type 2 or submitted to a previous treatment. The PubMed/MEDLINE, EMBASE, Web of Science, Cochrane Library, LILACS, and IBECS databases were used and last searched on October 27th, 2021. Statistical heterogeneity was assessed using I 2 statistics. The appraisal checklist was used to assess the risk of bias in the included studies. A total of 222 studies were analyzed, and 13 were included in the synthesis, which represents 493 participants with serviceable hearing before intervention. The mean HP rate after CK using a random effects model was of 68% (95% confidence interval [95%CI]: 59-76%) at a mean follow-up of 42.96 months. Conclusion  The longer follow-up period was associated with a lower HP rate after CK radiosurgery for VS in the qualitative synthesis.

Hearing Preservation in Stereotactic Radiosurgery for Vestibular Schwannoma

Despite no universally accepted definition of hearing preservation following vestibular schwannoma (VS) treatment, numerous variables have been identified as possible factors that may affect hearing outcomes following radiotherapy. Age, pretreatment hearing, radiation dose, tumor location and size, length of follow-up, fractionation, and timing of radiation have all been explored, among other variables, as factors related to hearing outcomes following radiation. These variables and associated hearing outcomes will be explored in detail, summarizing the literature to date to improve patient counseling for those patients who present with serviceable hearing and are considering their VS management options.