Related Experiment Video
Updated: Jun 30, 2025
Microvascular Decompression: Salient Surgical Principles and Technical Nuances
Published on: July 5, 2011
Radiosurgical Decompression of Trigeminal Nerve and Its Correlation with Functional Outcome in Tumor-Related
Sushanta Kumar Sahoo1, Joginder Singh1, Anurodh Kumar1
1Department of Neurosurgery, Post Graduate Institute of Medical Education and Research, Chandigarh, India.
Background:
Target selection during Gamma Knife radiosurgery (GKRS) in cases of tumor-related trigeminal neuralgia is always debatable. We analyzed the correlation of regression of tumor size and degree of release of the nerve with long-term pain control.
Methods:
Between March 2012 and March 2023, 50 cases of tumor-related trigeminal neuralgia were treated with GKRS (tumor was targeted). Radiological findings after GKRS were categorized into 3 types: 1) tumor volume remained same or decreased, additional segment of nerve not seen; 2) tumor volume decreased, additional segment of trigeminal nerve seen, but tumor still adherent to the nerve; 3) tumor volume decreased, adjacent nerve seen completely separated from tumor. Pain score before and after GKRS (Barrow Neurological Institute I-III: good; Barrow Neurological Institute IV and V: poor) was correlated with these subgroups.
Results:
At median follow-up of 46.5 months, 18 cases showed type 1 radiological response, 23 showed type 2 response, and 9 showed type 3 response. Good pain control was achieved in 10 (55.5%) patients with type 1, 15 (65.21%) with type 2, and 7 (77.8%) with type 3 responses. The outcome differences among these 3 groups were not statistically significant (P = 0.519). Five patients with type 3 radiological response were off medication, which was statistically better than type 1 and type 2 radiological responses, with 3 patients (P = 0.012) and 2 patients (P = 0.002), respectively, still receiving medication.
Conclusions:
Tumor volume reduction after GKRS may be associated with good pain control in tumor-related trigeminal neuralgia. Further, this allows visualization of additional segment of nerve that can be targeted in a second session for treating recurrent or failed cases.
Insights
Gamma Knife radiosurgery (GKRS) for tumor-related trigeminal neuralgia shows tumor shrinkage correlates with pain relief. Complete nerve separation after GKRS offers the best chance for patients to become medication-free.
Area of Science:
- Neurosurgery
- Radiology
- Pain Management
Background:
- Trigeminal neuralgia (TN) caused by tumors presents challenges for Gamma Knife radiosurgery (GKRS) target selection.
- The correlation between tumor size reduction, nerve decompression, and long-term pain control in TN is debated.
Purpose of the Study:
- To analyze the relationship between tumor volume regression and nerve decompression after GKRS.
- To evaluate the impact of these radiological changes on long-term pain control in patients with tumor-related TN.
Main Methods:
- A retrospective analysis of 50 patients with tumor-related TN treated with GKRS between March 2012 and March 2023.
- Patients were categorized into three radiological response groups based on tumor volume changes and nerve visualization post-GKRS.
- Pain scores (Barrow Neurological Institute scale) were correlated with these radiological subgroups.
Main Results:
- At a median follow-up of 46.5 months, 18 patients had type 1, 23 had type 2, and 9 had type 3 radiological responses.
- Good pain control rates were 55.5% (type 1), 65.21% (type 2), and 77.8% (type 3), with no statistically significant difference between groups (P=0.519).
- Significantly more patients with type 3 response (complete nerve separation) became medication-free (P=0.012 for type 1, P=0.002 for type 2).
Conclusions:
- Tumor volume reduction following GKRS may contribute to favorable pain control outcomes in tumor-related TN.
- Achieving complete separation of the trigeminal nerve from the tumor post-GKRS is associated with higher rates of medication independence.
- This approach may guide retreatment strategies for recurrent or refractory cases by allowing targeting of visualized nerve segments.
