Effect of beam channel plugging on the outcome of gamma knife radiosurgery for trigeminal neuralgia

Journal Article · Sat Jul 15 04:00:00 EDT 2006 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/j.ijrobp.2006.01.043· OSTI ID:20849997

Massager, Nicolas ^[1]; Nissim, Ouzi ^[1]; Murata, Noriko ^[2]; Devriendt, Daniel ^[1]; Desmedt, Francoise ^[1]; Vanderlinden, Bruno ^[1]; Regis, Jean ^[2]; Levivier, Marc ^[1]

---

1. Gamma Knife Center, Universite Libre de Bruxelles, Brussels (Belgium)
2. Gamma Knife Center, CHU La Timone, Marseilles (France)

Purpose: We studied the influence of using plugs for brainstem protection during gamma knife radiosurgery (GKR) of trigeminal neuralgia (TN), with special emphasis on irradiation doses delivered to the trigeminal nerve, pain outcomes, and incidence of trigeminal dysfunction. Methods and Materials: A GKR procedure for TN using an anterior cisternal target and a maximum dose of 90 Gy was performed in 109 patients. For 49 patients, customized beam channel blocking (plugs) were used to reduce the dose delivered to the brainstem. We measured the mean and integrated radiation doses delivered to the trigeminal nerve and the clinical course of patients treated with and without plugs. Results: We found that blocking increases the length of trigeminal nerve exposed to high-dose radiation, resulting in a significantly higher mean dose to the trigeminal nerve. Significantly more of the patients with blocking achieved excellent pain outcomes (84% vs. 62%), but with higher incidences of moderate and bothersome trigeminal nerve dysfunction (37% mild/10% bothersome with plugs vs. 30% mild/2% bothersome without). Conclusions: The use of plugs to protect the brainstem during GKR treatment for TN increases the dose of irradiation delivered to the intracisternal trigeminal nerve root and is associated with an important increase in the incidence of trigeminal nerve dysfunction. Therefore, beam channel blocking should be avoided for 90 Gy-GKR of TN.

• OSTI ID: 20849997
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 4 Vol. 65; ISSN IOBPD3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
BEAMS
IRRADIATION
PAIN
PATIENTS
RADIATION DOSES
RADIOTHERAPY
SAFETY
SURGERY