Simultaneous Tumor and Bilateral Medial Thalamic Radiosurgery for Tumor-Trigeminal Neuralgia With Concomitant Continuous Pain: A Case Report.

Tumor-related trigeminal neuralgia (TN) may present with concomitant continuous pain (CCP), a persistent burning background pain between paroxysmal crises that can be particularly difficult to manage. When caused by skull base tumors involving the cavernous sinus and posterior fossa, complete encasement of the trigeminal nerve markedly increases therapeutic complexity, often rendering conventional options, such as microsurgical decompression, nerve-targeted radiosurgery, or percutaneous procedures, impractical or unsafe. In such settings, radiosurgical management may offer an alternative strategy capable of addressing both tumor control and pain relief. We report the case of a 41-year-old woman with severe refractory secondary TN and CCP caused by a right cavernous sinus meningioma extending into the temporal, infratemporal, and posterior fossae, with complete encasement of the trigeminal nerve along its entire intracranial course. Treatment consisted of simultaneous irradiation of the tumor and bilateral medial thalamic structures, delivering a maximum dose (Dmax) of 125 Gy to both thalami and a prescription dose of 14 Gy to the meningioma. Symptomatic improvement began within 35 hours of treatment, with complete pain relief (Visual Analog Scale (VAS) 0) achieved by day 6 and sustained throughout 39 months of follow-up. This case suggests that simultaneous tumor radiosurgery and bilateral medial thalamic irradiation may represent a feasible rescue strategy in selected patients with anatomically inaccessible tumor-related TN with CCP. Further study is needed to define the role of focal thalamic irradiation in the acute and long-term control of this challenging pain phenotype.