title: Fractionated stereotactic conformal radiotherapy for large benign skull base meningiomas.
abstract: OBJECTIVE
  To assess the safety and efficacy of fractionated stereotactic radiotherapy (FSRT) for large skull base meningiomas.
  
  
  METHODS
  Fifty-two patients with large skull base meningiomas aged 34-74 years (median age 56 years) were treated with FSRT between June 2004 and August 2009. All patients received FSRT for residual or progressive meningiomas more than 4 centimeters in greatest dimension. The median GTV was 35.4 cm3 (range 24.1-94.9 cm3), and the median PTV was 47.6 cm3 (range 33.5-142.7 cm3). Treatment volumes were achieved with 5-8 noncoplanar beams shaped using a micromultileaf collimator (MLC). Treatment was delivered in 30 daily fractions over 6 weeks to a total dose of 50 Gy using 6 MV photons. Outcome was assessed prospectively.
  
  
  RESULTS
  At a median follow-up of 42 months (range 9-72 months) the 3-year and 5-year progression-free survival (PFS) rates were 96% and 93%, respectively, and survival was 100%. Three patients required further debulking surgery for progressive disease. Hypopituitarism was the most commonly reported late complication, with a new hormone pituitary deficit occurring in 10 (19%) of patients. Clinically significant late neurological toxicity was observed in 3 (5.5%) patients consisting of worsening of pre-existing cranial deficits.
  
  
  CONCLUSIONS
  FSRT as a high-precision technique of localized RT is suitable for the treatment of large skull base meningiomas. The local control is comparable to that reported following conventional external beam RT. Longer follow-up is required to assess long term efficacy and toxicity, particularly in terms of potential reduction of treatment-related late toxicity.
authors.affiliation: Department of Radiation Oncology, Sant' Andrea Hospital, Università degli Studi di Roma La Sapienza, Rome, Italy. giuseppe.minniti@ospedalesantandrea.it
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Minniti
authors.forename: Enrico
authors.initials: E
authors.lastname: Clarke
authors.forename: Luigi
authors.initials: L
authors.lastname: Cavallo
authors.forename: Mattia Falchetto
authors.initials: MF
authors.lastname: Osti
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Esposito
authors.forename: Gianpaolo
authors.initials: G
authors.lastname: Cantore
authors.forename: Paolo
authors.initials: P
authors.lastname: Cappabianca
authors.forename: Riccardo Maurizi
authors.initials: RM
authors.lastname: Enrici
mesh_terms: D000328:Adult; D000368:Aged; D019583:Dose Fractionation, Radiation; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008579:Meningioma / Q000401:mortality / Q000532:radiotherapy*; D008875:Middle Aged; D016634:Radiosurgery / Q000009:adverse effects*; D020266:Radiotherapy, Conformal / Q000009:adverse effects*; D019292:Skull Base Neoplasms / Q000401:mortality / Q000532:radiotherapy*; D016896:Treatment Outcome