Stereotactic radiosurgery for head and neck paragangliomas: a systematic review and meta-analysis

Head and neck paragangliomas (HNPs) are rare, usually benign hyper vascularized neuroendocrine tumors that traditionally have been treated by surgery, with or without endovascular embolization, or, more recently stereotactic radiosurgery (SRS). The aim of our study is to determine the clinical and radiographic effectiveness of SRS for treatment of HNPs. A systematic search of electronic databases was performed, and 37 articles reporting 11,174 patients (1144 tumors) with glomus jugulare (GJT: 993, 86.9%), glomus tympanicum (GTT: 94, 8.2%), carotid body tumors (CBTs: 28, 2.4%), and glomus vagale (GVT: 16, 1.4%) treated with SRS definitively or adjuvantly were included. The local control (LC) was estimated from the pooled analysis of the series, and its association with SRS technique as well as demographic and clinical factors was analyzed. The median age was 56 years (44-69 years). With a median clinical and radiological follow-up of 44 months (9-161 months), LC was 94.2%. Majority of the patients (61.0%) underwent Gamma Knife Radiosurgery (GKS), but there was no statistically significant difference in LC depending upon the SRS technique (p = 0.9). Spearmen's correlation showed that LC was strongly and negatively correlated with multiple parameters, which included female gender (r = - 0.4, p = 0.001), right-sided tumor (r = - 0.3, p = 0.03), primary SRS (r = - 0.5, p ≤ 0.001), and initial clinical presentation of hearing loss (r = - 0.4, p = 0.001). To achieve a LC ≥ 90%, a median marginal dose (Gy) of 15 (range, 12-30 Gy) was required. The results corroborate that SRS in HNPs is associated with good clinical and radiological outcome.