Current evidence and future perspectives in the treatment of head and neck vagal paragangliomas: a systematic review

BACKGROUND: Vagal paragangliomas (VPGs) are rare neuroendocrine tumors, typically benign but with unpredictable growth and local invasiveness. Their management is debated, particularly in asymptomatic or elderly patients, due to the lack of clear predictive indicators for progression and treatment response. This systematic review aimed to assess the clinical features and treatment outcomes of VPGs. METHODS: We conducted a systematic review of the literature, screening studies at multiple levels. A total of 41 articles were included, comprising data from 501 patients. Treatments were categorized as surgery, radiotherapy (RT), both, or observation (wait-and-scan). Due to study heterogeneity and generally low evidence levels, a statistical comparison between treatment modalities was not feasible. RESULTS: Among 501 patients, 325 underwent surgery, 101 received RT, 9 had combined treatment, and 66 were managed conservatively. Surgical resection achieved effective tumor removal and long-term control but was almost always associated with vagal nerve injury, leading to dysphonia and dysphagia. There was a 2.6-fold increase in postoperative impairment of at least one additional cranial nerve (IX, XII) or the sympathetic chain compared to preoperative status. RT and stereotactic radiosurgery (SRS) offered high tumor control rates with generally mild side effects, though long-term radiation risks-especially in younger patients-remain a concern. These modalities were often preferred for small, non-secreting tumors with preserved nerve function. The wait-and-scan approach was mainly used in elderly patients with asymptomatic or slow-growing tumors. No definitive predictors of tumor growth or treatment complications emerged from the literature. CONCLUSIONS: Surgery offers curative resection but carries a high risk of cranial nerve morbidity. RT and SRS are effective, less invasive alternatives with favorable safety profiles, particularly suitable for small, stable tumors. While observation remains appropriate in select cases, emerging options such as proton therapy, partial resection, and theranostics require further research to clarify their roles. The overall quality of evidence remains low, highlighting the need for prospective, comparative studies.