Intensity-modulated radiotherapy for complex-shaped meningioma of the skull base: long-term experience of a single institution.
OBJECTIVE
We analyzed our long-term experience with intensity-modulated radiotherapy (IMRT) in patients with complex-shaped meningioma of the skull base.


METHODS
Between January 1998 and December 2004, 94 patients with complex-shaped meningioma were treated using IMRT at our institution. Tumor distribution was: World Health Organization (WHO) Grade 1 in 54.3%, WHO Grade 2 in 9.6%, and WHO Grade 3 in 4.2%. In 31.9% of patients, the clinical and radiologic characteristics of the tumor were consistent with the diagnosis of meningioma. Twenty-six patients received radiotherapy as primary treatment and 14 patients postoperative for residual disease. Fifty-four patients were treated after local recurrence. Median target volume was 81.4 mL, median total dose was 57.6 Gy given in 32 fractions.


RESULTS
Median follow-up was 4.4 years. Overall local control was 93.6%. Sixty-nine patients had stable disease based on computed tomography/magnetic resonance imaging (MRI), whereas 19 had a tumor volume reduction after IMRT. Six patients showed local tumor progression on MRI 22.3 months' median after IMRT. Three patients died from non-treatment-related conditions after IMRT. In 39.8% of the patients, preexisting neurologic deficits improved. Worsening of preexisting neurologic symptoms was seen in 4 patients and 2 patients developed new clinical symptoms from local tumor progression. Transient side effects such as headache were seen in 7 patients. Treatment-induced loss of vision was seen in 1 of 53 reirradiated patients with a Grade 3 meningioma 9 months after retreatment with IMRT.


CONCLUSIONS
These data demonstrate that IMRT is an effective and safe treatment modality for long-term local control of complex-shaped and otherwise difficult to treat meningioma.
Milker-Zabel
Stefanie
S
Department of Clinical Radiology, Radiation Therapy, University of Heidelberg, Germany. Stefanie_Milker-Zabel@med.uni-heidelberg.de
Zabel-du Bois
Angelika
A
Huber
Peter
P
Schlegel
Wolfgang
W
Debus
Jürgen
J
D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008577:Meningeal Neoplasms / Q000401:mortality* / Q000532:radiotherapy*; D008579:Meningioma / Q000401:mortality* / Q000532:radiotherapy*; D008875:Middle Aged; D011379:Prognosis; D020266:Radiotherapy, Conformal / Q000401:mortality*; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D019292:Skull Base Neoplasms / Q000401:mortality* / Q000532:radiotherapy*; D016019:Survival Analysis; D015996:Survival Rate; D016896:Treatment Outcome