Staged stereotactic radiosurgery for bilateral trigeminal neuralgia: a systematic review and clinical decision framework

This project presents a systematic review evaluating the use of stereotactic radiosurgery (SRS) for the treatment of medically refractory bilateral trigeminal neuralgia (BTN). BTN is an exceptionally rare and debilitating condition, affecting both sides of the face. Its management is uniquely challenging because any surgical intervention carries the risk of causing bilateral facial numbness, which can lead to severe functional impairments (chewing, speaking, corneal protection). Stereotactic radiosurgery, including Gamma Knife, CyberKnife, and LINAC-based platforms, offers a minimally invasive alternative, but the evidence base for its use specifically in bilateral disease is limited and scattered. Purpose: The primary purpose of this review is to systematically identify, appraise, and synthesize all available evidence on the efficacy, durability, and safety of SRS for patients with bilateral trigeminal neuralgia. We aim to provide clinicians with a clear summary of: Initial pain relief rates. Long-term pain control and recurrence rates. The nature and frequency of complications, particularly sensory disturbances. The influence of underlying conditions like Multiple Sclerosis (MS) on outcomes. The role of specialized treatment strategies, such as staged procedures and adaptive dose reduction, to minimize bilateral nerve injury. Methods: A comprehensive literature search was conducted in MEDLINE (PubMed), Embase, Scopus, and the Cochrane Library up to November 15, 2025, following the PRISMA 2020 guidelines. Studies were included if they reported outcomes specifically for adult BTN patients treated with SRS. Due to the rarity of the condition and the heterogeneity of the included studies (different SRS platforms, doses, patient populations), a quantitative meta-analysis was not feasible. Instead, a structured narrative synthesis was performed. The risk of bias in the included studies was assessed using a tailored tool, and the certainty of the evidence was evaluated using principles adapted from the GRADE framework. Expected Outcomes and Significance: This review represents the first systematic synthesis of evidence on this topic. The expected outcomes include: A comprehensive summary of the current state of knowledge regarding SRS for BTN. Identification of evidence gaps and limitations in the existing literature. Practical, evidence-informed recommendations for clinical practice, such as the importance of staged treatments and individualized dose planning. A foundation for guiding future research, including the need for prospective, multi-center registries. The findings will be of direct relevance to neurosurgeons, radiation oncologists, and other healthcare professionals involved in the care of patients with this challenging condition.