Gamma Knife radiosurgery for trigeminal neuralgia provides greater pain relief at higher dose rates

Authors

Andrew I. Yang, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
Kobina G. Mensah-Brown, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
Emily F. Shekhtman, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
Svetlana Kvint, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
Connor A. Wathen, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
Frederick L. Hitti, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
Michelle Alonso-Basanta, Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
Stephen M. Avery, Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
Jay F. Dorsey, Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
John Y K Lee, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.

Document Type

Article

Abstract

In Gamma Knife (GK) radiosurgery, dose rate decreases during the life cycle of its radiation source, extending treatment times. Prolonged treatments influence the amount of sublethal radiation injury that is repaired during exposure, and is associated with decreased biologically-equivalent dose (BED). We assessed the impact of treatment times on clinical outcomes following GK of the trigeminal nerve - a rare clinical model to isolate the effects of treatment times. This is a retrospective analysis of 192 patients with facial pain treated across three source exchanges. All patients were treated to 80 Gy with a single isocenter. Treatment time was analyzed in terms of patient anatomy-specific dose rate, as well as BED calculated from individual patient beam-on times. An outcome tool measuring pain in three distinct domains (pain intensity, interference with general and oro-facial activities of daily living), was administered before and after intervention. Multivariate linear regression was performed with dose rate/BED, brainstem dose, sex, age, diagnosis, and prior intervention as predictors. BED was an independent predictor of the degree of improvement in all three dimensions of pain severity. A decrease in dose rate by 1.5 Gy/min corresponded to 31.8% less improvement in the overall severity of pain. Post-radiosurgery incidence of facial numbness was increased for BEDs in the highest quartile. Treatment time is an independent predictor of pain outcomes, suggesting that prescription dose should be customized to ensure iso-effective treatments, while accounting for the possible increase in adverse effects at the highest BEDs.

Publication Date

1-1-2022

Publication Title

Journal of radiosurgery and SBRT

E-ISSN

2156-4647

Volume

8

Issue

2

First Page

117

Last Page

125

PubMed ID

36275137

Recommended Citation

Yang, Andrew I.; Mensah-Brown, Kobina G.; Shekhtman, Emily F.; Kvint, Svetlana; Wathen, Connor A.; Hitti, Frederick L.; Alonso-Basanta, Michelle; Avery, Stephen M.; Dorsey, Jay F.; and Y K Lee, John, "Gamma Knife radiosurgery for trigeminal neuralgia provides greater pain relief at higher dose rates" (2022). Neurosurgery. 1869.
https://scholar.barrowneuro.org/neurosurgery/1869