Radiation exposure to deep brain stimulation leads during multiple cranial radiation courses: illustrative case.

backgroundDeep brain stimulation (DBS) is an established treatment for Parkinson's disease (PD). Concurrently, brain tumors are increasing in incidence, creating complex clinical scenarios when both conditions coexist. The safety of delivering radiation therapy to patients with active DBS devices remains poorly documented, with limited guidelines available. OBSERVATIONS: This case report describes a 69-year-old male PD patient with bilateral DBS leads who developed metastatic melanoma with brain metastases. He underwent multiple radiation treatments, including stereotactic radiosurgery and hippocampal avoidance whole-brain radiation therapy, receiving a cumulative dose exceeding 47 Gy to the DBS device. Throughout treatment, the DBS device remained fully functional with no impedance changes or symptom deterioration. A review of similar cases indicates that radiation doses to DBS components, including leads and implantable pulse generators, are generally well tolerated, although no standardized safety protocols currently exist. LESSONS: This case reinforces the feasibility and safety of multiple radiation treatments in patients with implanted DBS devices when carefully planned and monitored. Cumulative high radiation doses may not impair DBS functionality, but attention to neutron contamination and dose distribution remains essential. Multidisciplinary collaboration and individualized planning are crucial to optimize tumor control while preserving device integrity in this emerging patient population. https://thejns.org/doi/10.3171/CASE25600.