title: The role of surgery in the management of patients with diffuse low grade glioma: A systematic review and evidence-based clinical practice guideline.
abstract: OBJECTIVE
  Should patients with imaging suggestive of low grade glioma (LGG) undergo observation versus treatment involving a surgical procedure?
  
  
  METHODS
  These recommendations apply to adults with imaging suggestive of a WHO grade 2 glioma (oligodendroglioma, astrocytoma, or oligo-astrocytoma).
  
  
  CONCLUSIONS
  Surgical resection is recommended over observation to improve overall survival for patients with diffuse low-grade glioma (Level III) although observation has no negative impact on cognitive performance and quality of life (Level II).
  
  
  OBJECTIVE
  What is the impact of extent of resection on progression free survival (PFS) or overall survival (OS) in LGG patients?
  
  
  METHODS
  These recommendations apply to adults with imaging suggestive of a WHO grade 2 glioma (oligodendroglioma, astrocytoma, or oligo-astrocytoma).
  
  
  CONCLUSIONS
  IMPACT OF EXTENT OF RESECTION ON PFS:
  
  
  METHODS
  It is recommended that GTR or STR be accomplished instead of biopsy alone when safe and feasible so as to decrease the frequency of tumor progression recognizing that the rate of progression after GTR is fairly high.
  
  
  
  METHODS
  Greater extent of resection can improve OS in LGG patients.
  
  
  OBJECTIVE
  What tools are available to increase extent of resection in LGG patients?
  
  
  METHODS
  These recommendations apply to adults with imaging suggestive of a WHO grade 2 glioma (oligodendroglioma, astrocytoma, or oligo-astrocytoma).
  
  
  CONCLUSIONS
  INTRAOPERATIVE MRI DURING SURGERY:
  
  
  METHODS
  The use of intraoperative MRI should be considered as a method of increasing the extent of resection of LGGs.
  
  
  OBJECTIVE
  What is the impact of surgical resection on seizure control and accuracy of pathology in low grade glioma patients?
  
  
  METHODS
  These recommendations apply to adults with imaging suggestive of a WHO grade 2 glioma (oligodendroglioma, astrocytoma, or oligo-astrocytoma).
  
  
  CONCLUSIONS
  SURGICAL RESECTION AND SEIZURE CONTROL:
  
  
  METHODS
  After taking into account the patient's clinical status and tumor location, gross total resection is recommended for patients with diffuse LGG as a way to achieve more favorable seizure control.
  
  
  
  METHODS
  Taking into account the patient's clinical status and tumor location, surgical resection should be carried out to maximize the chance of accurate diagnosis.
  
  
  OBJECTIVE
  What tools can improve the safety of surgery for LGGs in eloquent locations?
  
  
  METHODS
  These recommendations apply to adults with imaging suggestive of a WHO grade 2 glioma (oligodendroglioma, astrocytoma, or oligo-astrocytoma).
  
  
  CONCLUSIONS
  PREOPERATIVE IMAGING:
  
  
  METHODS
  It is recommended that preoperative functional MRI and diffusion tensor imaging be utilized in the appropriate clinical setting to improve functional outcome after surgery for LGG.
  
  
  
  METHODS
  Intraoperative mapping is recommended for patients with diffuse LGGs in eloquent locations compared to patients with non-eloquently located diffuse LGGs as a way of preserving function.
authors.affiliation: Department of Neurosurgery, University of California, 505 Parnassus Avenue, Room M779, San Francisco, CA, 94143-0112, USA. aghim@neurosurg.ucsf.edu.
authors.forename: Manish K
authors.initials: MK
authors.lastname: Aghi
authors.affiliation: Department of Neurosurgery, Massachusetts General Hospital, Boston, MA, USA.
authors.forename: Brian V
authors.initials: BV
authors.lastname: Nahed
authors.affiliation: Department of Neurosurgery, University Hospitals, Cleveland, OH, USA.
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Sloan
authors.affiliation: Department of Neurosurgery, Kansas University Medical Center, Kansas City, KS, USA.
authors.forename: Timothy C
authors.initials: TC
authors.lastname: Ryken
authors.affiliation: Department of Neurosurgery, Henry Ford Health System, Detroit, MI, USA.
authors.forename: Steven N
authors.initials: SN
authors.lastname: Kalkanis
authors.affiliation: Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA, USA.
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Olson
mesh_terms: D006801:Humans; D001921:Brain / Q000473:pathology / Q000601:surgery; D001932:Brain Neoplasms / Q000175:diagnosis / Q000473:pathology / Q000601:surgery; D019317:Evidence-Based Medicine; D005910:Glioma / Q000175:diagnosis / Q000473:pathology / Q000601:surgery; D060787:Neoplasm Grading; D019635:Neurosurgical Procedures
keywords: Astrocytoma; Low grade glioma; Observation; Oligodendroglioma; Practice guideline; Surgery; Systematic review