Dedicated linear accelerator radiosurgery for trigeminal neuralgia: a single-center experience in 179 patients with varied dose prescriptions and treatment plans

Int J Radiat Oncol Biol Phys. 2011 Sep 1;81(1):225-31. doi: 10.1016/j.ijrobp.2010.05.058. Epub 2011 Jan 13.

Abstract

Purpose: Dedicated linear accelerator radiosurgery (D-LINAC) has become an important treatment for trigeminal neuralgia (TN). Although the use of gamma knife continues to be established, few large series exist using D-LINAC. The authors describe their results, comparing the effects of varied target and dose regimens.

Methods and materials: Between August 1995 and January 2008, 179 patients were treated with D-LINAC radiosurgery. Ten patients (5.58%) had no clinical follow-up. The median age was 74.0 years (range, 32-90 years). A total of 39 patients had secondary or atypical pain, and 130 had idiopathic TN. Initially, 28 patients received doses between 70 and 85 Gy, with the 30% isodose line (IDL) touching the brainstem. Then, using 90 Gy, 82 consecutive patients were treated with a 30% IDL and 59 patients with a 50% IDL tangential to the pons.

Results: Of 169 patients, 134 (79.3%) experienced significant relief at a mean of 28.8 months (range, 5-142 months). Average time to relief was 1.92 months (range, immediate to 6 months). A total of 31 patients (19.0%) had recurrent pain at 13.5 months. Of 87 patients with idiopathic TN without prior procedures, 79 (90.8%) had initial relief. Among 28 patients treated with 70 Gy and 30% IDL, 18 patients (64.3%) had significant relief, and 10 (35.7%) had numbness. Of the patients with 90 Gy and 30% IDL at the brainstem, 59 (79.0%) had significant relief and 48.9% had numbness. Among 59 consecutive patients with similar dose but the 50% isodoseline at the brainstem, 49 patients (88.0%) had excellent/good relief. Numbness, averaging 2.49 on a subjective scale of 1 to 5, was experienced by 49.7% of the patients,

Conclusions: Increased radiation dose and volume of brainstem irradiation may improve clinical outcomes with the trade-off of trigeminal dysfunction. Further study of the implications of dose and target are needed to optimize outcomes and to minimize complications.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Brain Stem / radiation effects
  • Female
  • Humans
  • Hypesthesia / etiology
  • Magnetic Resonance Imaging / methods
  • Male
  • Middle Aged
  • Pons / radiation effects
  • Radiosurgery / adverse effects
  • Radiosurgery / methods*
  • Radiotherapy Dosage
  • Radiotherapy Planning, Computer-Assisted / methods
  • Recurrence
  • Remission Induction
  • Time Factors
  • Tomography, X-Ray Computed / methods
  • Trigeminal Neuralgia / surgery*