title: Long-term control of petroclival meningiomas through radiosurgery.
abstract: OBJECTIVE
  Because of their critical location adjacent to brain, cranial nerve, and vascular structures, petroclival meningiomas remain a clinical challenge. The authors evaluated outcomes in 168 patients with petroclival meningiomas who underwent Gamma Knife surgery (GKS) during a 21-year interval.
  
  
  METHODS
  Gamma Knife surgery was used as either primary or adjuvant treatment of 168 petroclival meningiomas involving the region between the petrous apex and the upper two-thirds of the clivus. The most common presenting symptoms were trigeminal nerve dysfunction, balance problems, diplopia, and hearing loss. The median tumor volume was 6.1 cm3 (range 0.3-32.5 cm3), and the median radiation dose to the tumor margin was 13 Gy (range 9-18 Gy).
  
  
  RESULTS
  During a median follow-up of 72 months, neurological status improved in 44 patients (26%), remained stable in 98 (58%), and worsened in 26 (15%). Tumor volume decreased in 78 patients (46%), remained stable in 74 (44%), and increased in 16 (10%), all of whom were subjected to additional management strategies. Overall 5- and 10-year progression-free survival rates were 91 and 86%, respectively. Patients followed up for at least 10 years (31 patients) had tumor and symptom control rates of 97 and 94%, respectively. Eight patients had repeat radiosurgery, 4 underwent delayed resection, and 4 had fractionated radiation therapy. Cerebrospinal fluid diversion was performed in 7 patients (4%). Significant risk factors for tumor progression were a tumor volume > or = 8 cm3 (p = 0.001) and male sex (p = 0.02).
  
  
  CONCLUSIONS
  In this 21-year experience, GKS for petroclival meningiomas obviated initial or further resection in 98% of patients and was associated with a low risk of adverse radiation effects. The authors believe that radiosurgery should be considered as an initial option for patients with smaller-volume, symptomatic petroclival meningiomas.
authors.affiliation: Department of Neurological Surgery, University of Pittsburgh, Pennsylvania 15213, USA.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Flannery
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Kano
authors.forename: L Dade
authors.initials: LD
authors.lastname: Lunsford
authors.forename: Sait
authors.initials: S
authors.lastname: Sirin
authors.forename: Matthew
authors.initials: M
authors.lastname: Tormenti
authors.forename: Ajay
authors.initials: A
authors.lastname: Niranjan
authors.forename: John C
authors.initials: JC
authors.lastname: Flickinger
authors.forename: Douglas
authors.initials: D
authors.lastname: Kondziolka
mesh_terms: D001259:Ataxia / Q000453:epidemiology / Q000209:etiology; D003388:Cranial Fossa, Posterior / Q000473:pathology* / Q000601:surgery*; D004172:Diplopia / Q000453:epidemiology / Q000209:etiology; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006311:Hearing Disorders / Q000453:epidemiology / Q000209:etiology; D006801:Humans; D008297:Male; D008579:Meningioma / Q000473:pathology* / Q000601:surgery*; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D010579:Petrous Bone / Q000473:pathology* / Q000601:surgery*; D016634:Radiosurgery / Q000009:adverse effects / Q000295:instrumentation*; D012307:Risk Factors; D012888:Skull Neoplasms / Q000473:pathology* / Q000601:surgery*; D016896:Treatment Outcome; D014277:Trigeminal Neuralgia / Q000453:epidemiology / Q000209:etiology