title: Fractionated stereotactic radiotherapy in patients with benign or atypical intracranial meningioma: long-term experience and prognostic factors.
abstract: OBJECTIVE
  To analyze our long-term experience and prognostic factors after fractionated stereotactic radiotherapy (FSRT) in patients with benign or atypical intracranial meningioma.
  
  
  METHODS
  Between January 1985 and December 2001, 317 patients with a median age of 55.7 years were treated with FSRT for intracranial meningioma. The tumor distribution was World Health Organization (WHO) Grade 1 in 48.3%, WHO Grade 2 in 8.2%, and unknown in 43.5%. Of the 317 patients, 97 underwent RT as their primary treatment, 79 underwent postoperative RT (subtotal resection in 38 and biopsy only in 41), and 141 were treated for recurrent disease. The median target volume was 33.6 cm(3) (range, 1.0-412.6 cm(3)). The median total dose was 57.6 Gy at 1.8 Gy/fraction five times weekly.
  
  
  RESULTS
  The median follow-up was 5.7 years (range, 1.2-14.3 years). The overall local tumor control rate was 93.1% (295 of 317). Of the 317 patients, 72 had a partial response on CT/MRI and 223 (70.4%) remained stable. At a median of 4.5 years after FSRT, 22 patients (6.9%) had local tumor progression on MRI. Local tumor failure was significantly greater in patients with WHO Grade 2 meningioma (p <0.002) than in patients with WHO Grade 1 or unknown histologic features. Patients treated for recurrent meningioma showed a trend toward decreased progression-free survival compared with patients treated with primary therapy, after biopsy, or after subtotal resection (p <0.06). Patients with a tumor volume >60 cm(3) had a recurrence rate of 15.5% vs. 4.3% for those with a tumor volume of < or =60 cm(3) (p <0.001). In 42.9% of the patients, preexisting neurologic deficits improved. Worsening of preexisting neurologic symptoms occurred in 8.2%. Eight patients developed new clinical symptoms, such as reduced vision, trigeminal neuralgia, and intermittent tinnitus located at the side of the irradiated meningioma after FSRT.
  
  
  CONCLUSIONS
  These data have demonstrated that FSRT is an effective and safe treatment modality for local control of meningioma with a low risk of significant late toxicity. We identified the tumor volume, indication for FSRT, and histologic features of the meningioma as statistically significant prognostic factors.
authors.affiliation: Department of Clinical Radiology, Radiation Therapy, University of Heidelberg, INF 400, D-69120 Heidelberg, Germany. stefanie_milker-zabel@med.uni-heidelberg.de
authors.forename: Stefanie
authors.initials: S
authors.lastname: Milker-Zabel
authors.forename: Angelika
authors.initials: A
authors.lastname: Zabel
authors.forename: Daniela
authors.initials: D
authors.lastname: Schulz-Ertner
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Schlegel
authors.forename: Michael
authors.initials: M
authors.lastname: Wannenmacher
authors.forename: Jürgen
authors.initials: J
authors.lastname: Debus
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D018450:Disease Progression; D019583:Dose Fractionation, Radiation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008577:Meningeal Neoplasms / Q000401:mortality / Q000532:radiotherapy*; D008579:Meningioma / Q000401:mortality / Q000532:radiotherapy*; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000532:radiotherapy; D011379:Prognosis; D011880:Radiotherapy Planning, Computer-Assisted; D013238:Stereotaxic Techniques; D015996:Survival Rate