GKRS is a safe and effective treatment modality for the management of ELSTs, particularly in residual or recurrent disease, offering excellent radiological control and symptom stabilization as both a primary and adjunctive treatment option.
Gamma knife radiosurgery achieved stable disease in all five patients with endolymphatic sac tumors, with no increase in tumor size on follow-up MRI.
Two of five patients received primary GKRS while three received secondary GKRS following prior surgical resection.
Marginal doses used for GKRS treatment of ELSTs ranged from 20 to 25 Gy across the five patients.
No patients experienced worsening or emergence of new neurological symptoms following GKRS.
ELSTs are rare, locally aggressive tumors often associated with von Hippel-Lindau disease, for which complete surgical excision is challenging due to their location and hypervascularity.
This research suggests that a specialized form of radiation treatment called Gamma Knife radiosurgery (GKRS) can effectively control endolymphatic sac tumors (ELSTs), which are rare and aggressive tumors that grow near the inner ear and are often linked to a genetic condition called von Hippel-Lindau disease. Because of where these tumors are located and how blood-rich they are, surgeons often cannot remove them completely, and they tend to come back. This study followed five patients treated at a single hospital over about 11 years, some of whom received GKRS as their first treatment and others who received it after surgery had already been attempted. This research suggests that GKRS stopped tumor growth in all five patients, with no tumors getting larger on follow-up MRI scans, and no patients developing new or worsening neurological problems. Importantly, no patients experienced complications from the radiation, such as radiation-induced tissue damage (necrosis), and none needed steroid medications to manage side effects. The radiation doses used ranged from 20 to 25 Gray units across patients. This research suggests that GKRS represents a safe and viable option for managing these difficult tumors, whether used as the main treatment or as a follow-up after surgery. Because ELSTs are so rare, large clinical trials are very difficult to conduct, making this kind of single-institution case series valuable for understanding how patients respond to treatment. The findings support considering GKRS for patients with residual, recurrent, or inoperable ELSTs.
Mahajan V, Mishra S, Garg K, Garg A, Singh M, Chandra P. (2026). Gamma Knife Radiosurgery for Endolymphatic Sac Tumors: A Single-Institution Experience.. Neurology India. https://doi.org/10.4103/neurol-india.Neurol-India-D-25-00986