title: Is Fractionated Gamma Knife Radiosurgery a Safe and Effective Treatment Approach for Large-Volume (>10 cm3) Intracranial Meningiomas?
abstract: BACKGROUND
  Even with great advances in surgery and improved clinical outcome, morbidity and mortality are still high for large-volume intracranial meningiomas (MNGs). Recently, Gamma Knife radiosurgery (GKS) has proven to be a safe and effective treatment for many patients with intracranial MNGs. However, single-session GKS may increase the risk of radiation-induced toxicity for large MNGs. Recently, fractionated GKS (FGKS) has been performed for an increasing number of patients with surgically high-risk and large intracranial tumors. In this study, we report our results on the efficacy and safety of FGKS for large MNGs.
  
  
  METHODS
  The authors performed a retrospective review of 70 patients who underwent GKS for large-volume (>10 cm3) intracranial MNGs between 2004 and 2015, with a minimum follow-up of 12 months. The authors classified these patients into 2 groups of single-session GKS, FGKS. The patients were followed by clinical examination and serial imaging with magnetic resonance imaging.
  
  
  RESULTS
  In the single-session GKS group (42 patients), the median tumor volume was 15.2 cm3(range 10.3-48.3 cm3); the median prescription dose was 12 Gy (range 8-14 Gy), and the median follow-up duration was 57.8 months (range 14.5-128.4 months). In the FGKS group (28 patients), the median tumor volume was 21 cm3(range 10.2-54.7 cm3), and the median prescription was 7.5 Gy in 2 fractions (range 5-8 Gy), 6 Gy in 3 fractions (range 5-6.5 Gy), and 4.5 Gy in 4 fractions. The median follow-up duration for the FGKS group was 50 months (range 12.5-90.6 months). The overall 5-year tumor control rate was 92.9% in the FGKS group and 88.1% in the single-session GKS group. Fourteen (33.3%) symptomatic complications after single-session GKS were noted, including 5 cases of hemiparesis, 4 of seizure, 3 of peritumoral edema, and 2 of hydrocephalus. Two (7.1%) symptomatic complications after FGKS were noted, including 2 cases of hemiparesis. The FGKS group had higher progression-free survival (PFS) rate at 5 years (92.9% vs. 88.1%), but the differences did not reach statistical significance (P = 0.389). The patients in the FGKS group, however, experienced a lower complication rate compared with patients with a single-session GKS group (P = 0.017, hazard ratio, 5.7:1).
  
  
  CONCLUSIONS
  When the large-volume (>10 cm3) intracranial MNGs are expected to have high morbidity after microsurgery and for patients that have a poor medical status for surgery, FGKS can be considered an alternative with good tumor control and lower complications rates compared with single-session GKS (P = 0.017).
authors.affiliation: Department of Neurosurgery, Brain Tumor Clinic & Gamma Knife Center, Chonnam National University Research Institute of Medical Sciences, Chonnam National University Hwasun Hospital & Medical School, Gwangju, South Korea.
authors.forename: Moon-Soo
authors.initials: MS
authors.lastname: Han
authors.affiliation: Department of Neurosurgery, Brain Tumor Clinic & Gamma Knife Center, Chonnam National University Research Institute of Medical Sciences, Chonnam National University Hwasun Hospital & Medical School, Gwangju, South Korea.
authors.forename: Woo-Youl
authors.initials: WY
authors.lastname: Jang
authors.affiliation: Department of Neurosurgery, Brain Tumor Clinic & Gamma Knife Center, Chonnam National University Research Institute of Medical Sciences, Chonnam National University Hwasun Hospital & Medical School, Gwangju, South Korea.
authors.forename: Kyung-Sub
authors.initials: KS
authors.lastname: Moon
authors.affiliation: Department of Neurosurgery, Brain Tumor Clinic & Gamma Knife Center, Chonnam National University Research Institute of Medical Sciences, Chonnam National University Hwasun Hospital & Medical School, Gwangju, South Korea.
authors.forename: Sa-Hoe
authors.initials: SH
authors.lastname: Lim
authors.affiliation: Department of Neurosurgery, Brain Tumor Clinic & Gamma Knife Center, Chonnam National University Research Institute of Medical Sciences, Chonnam National University Hwasun Hospital & Medical School, Gwangju, South Korea.
authors.forename: In-Young
authors.initials: IY
authors.lastname: Kim
authors.affiliation: Department of Neurosurgery, Brain Tumor Clinic & Gamma Knife Center, Chonnam National University Research Institute of Medical Sciences, Chonnam National University Hwasun Hospital & Medical School, Gwangju, South Korea.
authors.forename: Tae-Young
authors.initials: TY
authors.lastname: Jung
authors.affiliation: Department of Neurosurgery, Brain Tumor Clinic & Gamma Knife Center, Chonnam National University Research Institute of Medical Sciences, Chonnam National University Hwasun Hospital & Medical School, Gwangju, South Korea. Electronic address: sjung@chonnam.ac.kr.
authors.forename: Shin
authors.initials: S
authors.lastname: Jung
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001932:Brain Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D019583:Dose Fractionation, Radiation; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008279:Magnetic Resonance Imaging; D008297:Male; D008577:Meningeal Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D008579:Meningioma / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology*; D016016:Proportional Hazards Models; D016634:Radiosurgery / Q000379:methods*; D012189:Retrospective Studies; D016896:Treatment Outcome; D047368:Tumor Burden
keywords: Fractionation; Gamma Knife radiosurgery; Meningioma