Updated June 2006

Clinical practice guidelines are systematically developed statements to assist practitioner and patient decisions about appropriate health care for specific individual circumstances.  An advantage of utilizing guidelines in clinical decision-making over sole reliance on randomized clinical trial (RCT) results, is that they take professional experience into account in an aggregate and more systematic manner, rather than on an individual or ad hoc basis. Not only are more “experts” involved in the consensus process (diluting out outliers in opinion) but in an evidence-based guidelines development process, the opinions solicited are the experts’ opinions about the collected evidence in the literature, rather than simply their own personal opinion regarding the subject.

Construction of guidelines involves, first, a systematic means of identifying evidence and ranking the relative strengths, or quality of each study as evidence, and then, second, achieving panel agreement on a strength of recommendation linked to the analysis of the strength of evidence for each intervention in question. Both steps are critically important and have their own drawbacks and limitations.  The ultimate validity of any guideline is critically related to three key factors: (1) the composition of the guideline panel and its process, (2) the identification and synthesis of the evidence, and (3) method of guideline construction applied. 

The panel composition is crucial, both for ultimate acceptance of the guidelines by practicing physicians and for its critical influence on the recommendation step of guideline construction.  Panelists recommendations can differ even when analyzing the same data.  In general, studies have observed that U.S. experts tend to be more action oriented than those from the UK, surgeons tend to be more certain about surgery than non-surgeons, and generalists tend to be more conservative than specialists.  Guidelines produced by advocacy groups and subspecialty societies tend to be most problematic and suspect, due to both problems with unbalanced panel representation and methodological concerns.  There is a natural tendency for advocacy groups to use evidence selectively for their cause.  Panels that over-represent certain disciplines or exclude other key disciplines, or dissenting voices may be seen as less credible.  Recommendations made by specialists sometimes are more influenced by the specialty to which they belong, rather than by the scientific evidence. 

Ultimately, the quality and effectiveness of resultant guidelines depends at least as much on the quality of the consensus development involved in deciding the strength of recommendation (the second step of guidelines construction), as on the quality of the evidence base.  Strength of recommendations is a complex topic that implies value judgments on top of methodological assessments of evidence. It should incorporate subjective considerations such as patient- or setting-specific applicability, trade-offs among risks, benefits, costs, etc.  Strong evidence for an intervention should not always translate into equally strong recommendations for use.

Not all guidelines are equivalent in quality.  There are three main methods of guideline development – informal consensus, formal consensus, and evidence-linked development.  From the standpoint of evidence-based medicine (EBM), only the latter have evidentiary status for EBM decision-making. Indeed, the U.S. Institute of Medicine has stated that it hopes to eventually restrict the use of the term ‘guideline’ to systematically developed advisory statements created according to validated methodology. 

The Joint Tumor Section recognizes four levels of authority and validity among current sources of guidelines related to the care of patients nervous system tumors.  Each varies on such parameters as to their level of adherence to EBM clinical practice parameter methodology, method of guidelines development, source of panel composition, and the breadth of expert panel representation.  They are listed and introduced below in descending order of priority, and links are provided for navigation to the actual guidelines produced.


AANS and CNS Endorsed Guidelines

The AANS established a Guidelines Committee in 1992, which became a subcommittee of AANS-CNS Joint Committee on Assessment of Quality in 1993.  In 2006, the Joint Guidelines Committee was re-established under the auspices of the joint Washington Committee to better link the national initiative to health policy and legislative “pay for performance” concerns.  Chaired for the first twelve years by Beverly Walters, the guidelines committee chose a valid and very stringent EBM evidence-linked guidelines development methodology that is a modification of the original American Medical Association approach first published in 1990.  Neurosurgery guidelines initiatives are developed through the various Joint AANS-CNS Sections.  They require careful attention to breadth of expert representation across medical and surgical disciplines on the generating panels and follow a strict EBM methodology for evidence synthesis and strength of recommendation.  [Walters BC. Clinical practice parameter development in neurosurgery. In Bean JR, (ed). Neurosurgery in Transition: The Socioeconomic Transformation of Neurological Surgery. Baltimore, Williams & Wilkins, 1998, pp 99-111.]  Guidelines development utilizing this process is an intensive exercise than can take 1-3 years to complete.  Below is a link to the AANS-CNS guidelines construction checklists. 


Guidelines Description of Process

Guidelines Development Summary Format

Guidelines Development Checklist

Currently, the Joint Tumor Section has three EBM clinical practice parameter guidelines development efforts in process. They are listed below along with the name of their project leaders:

Pituitary Adenoma Guidelines

Initiative Leader:  Nelson, Oyesiku
Project begun:    2002
Projected completion: 2006
Number of Topics/Questions Addressed: 7

Newly Diagnosed GBM Guidelines

Initiative Leader:  

Metastatic Brain Tumor Guidelines

Initiative Leader: Stephen Kalkanis
Project begun:    2005
Projected completion: 2008
Number of Topics/Questions Addressed: 16


The National Comprehensive Cancer Network (NCCN) is a group of 20 of the 39 National Cancer Institute (NCI) comprehensive cancer centers in the U.S. that produce consensus recommendations for clinical care of patients with cancer in the U.S. under the designation – NCCN Clinical Practice Guidelines in Oncology TM. 


More accurately termed clinical treatment algorithms rather than clinical practice parameter guidelines, these “guidelines” are formed by a panel of multidisciplinary experts representing the NCI-designated comprehensive cancer centers participating in the NCCN.  Their construction is a hybrid of evidence-linked construction and formal consensus.  The evidence is collected and ranked along EBM criteria, but the resultant recommendations are consensus based and are not ranked according to strength of recommendation based on the level of evidence available to support the recommendation. Their have been two versions of NCCN guidelines produced so far, and the most recent dates from January 2006.  There are currently eight NCCN guidelines on nervous system tumor topics, and another two on principles of brain tumor therapy, and they are listed below.

  • Adult Low Grade Infiltrative Supratentorial Astrocytoma/Oligodendroglioma (excluding Pilocytic astrocytoma) (ASTR-1)
  • Adult Intracranial Ependymoma (EPEN-1)
  • Anaplastic Astrocytoma / Anaplastic Oligodendroglioma / Glioblastoma Multiforme (GLIO-1)
  • Limited (1-3) Metastatic Lesions (LTD-1)
  • Multiple (<3) Metastatic Lesions (MU-1)
  • Carcinomatous/Lymphomatous Meningitis (CLMEN-1)
  • Nonimmunosuppressed Primary Central Nervous SYtem Lymphoma (PCNS-1)
  • Metastatic Spine Tumors (SPINE-1)
  • Surgical Issues (BRAIN-1)
  • Radiation Therapy Guidelines (BRAIN-2)


Each of the ten listed above can be accessed for free through the NCCN Clinical Practice Guidelines in Oncology TM  section of the NCCN website through the link below




In 1999, the National Health Service (NHS) of Great Britain launched the National Institute for Health and Clinical Excellence (NICE) which is responsible for providing patients, health professionals and the public with authoritative, robust and reliable evidence-based guidance on current ‘best practices’ in relation to new and existing health technologies by establishing and maintaining clinical guidelines for the NHS. 


Their first sanctioned guideline was published in 2001.  Unlike guidelines published by the US National Guidelines Clearinghouse (NGC), NICE guidelines are required to resolve conflict between pre-existing association and stakeholder guidelines and take into consideration cost-effectiveness and practicality along with clinical effectiveness, prior to acceptance as NICE-sanctioned guidelines.  NICE “subcontracts” the actual guideline generation task to approved collaborating centers across Great Britain.  The NHS only recognizes guidelines produced by their National Collaborating Centers. These centers are each individually tasked with establishing representative panels, following validated guidelines methodology, surveying existing guidelines relevant to the topic and resolving any apparent conflict, and including both cost-effectiveness and practicality as part of the final recommendation process.  As of June 2006, the NICE website listed one clinical guideline, one interventional procedure guidance, and two technology appraisals related to nervous system tumors.

As of June 2006, according to the NICE website, the Brain Tumoursproject started in 2002, is now in is seventh iteration, and is due to complete and disseminate in 2006.  An draft of the document in progress can be viewed at:


Guidance on Endoscopic Pituitary Adenoma Resection was finalized issued in December 2003


A technology appraisal on the use of temozolomide in brain cancer (No.23) was issued in 2001 and re-reviewed in 2004


A combined technology appraisal on the use of bothtemozolomide and carmustine implants for the treatment of newly diagnosed high-grade glioma was issued in April 2006


The inclusion of including both cost-effectiveness and practicality as part of the final recommendation process in NICE guidance publications has led to controversy form the perspective of some health care providers as well as patient advocacy groups.



The U.S. National Guidelines Clearinghouse (NGC) is a repository of clinical guidelines maintained by the Agency for Healthcare Research and Quality (AHRQ) of the Department of Health and Human Services (HHS) in a joint initiative with the American Medical Association (AMA) and America’s Health Insurance Plans (AHIP). 


The NGC currently includes guidelines that have been formed through informal and as well as formal expert consensus alongside those based in systematic evidence-based methodology. It also includes guidelines that have been created by special interest and advocacy groups, subspecialty organizations, insurance companies, private consulting firms, cross-representative panels designed to include representatives from all potential stakeholders, and evidence-based practice centers (EPCs) established and endorsed by the AHRQ.  Many of these guidelines conflict with one another, and there is currently no means of resolving or adjudicating these conflicts other than individual providers or oversight organizations making their own decision(s) as to which should take a position of supremacy or authority. As of June 2006 there were 17 “guidelines potentially related to nervous system tumors listed with the NGC.  Their names and associated links are listed below”

American Academy of Neurology:

Practice Parameter: Anticonvulsant prohylaxis in patients with newly diagnosed brain tumors

American Academy of Pediatrics:

Guidelines for pediatric cancer centers

American Association of Clinical Endocrinologists:

Medical guidelines for clinical practice for the diagnosis and treatment of acromegaly

American College of Chest Physicians:

Lung cancer palliative care

Presentations of lung cancer with special treatment considerations

The noninvasive staging of non small cell lung cancer – The guidelines

American College of Radiology:

ACR appropriateness criteria for imaging work-up for stage I  breast cancer

Pre-irradiation evaluation and management of brain metastases

Renal cell carcinoma staging

Staging of bronchogenic cancer, non small cell and small cell lung cancer

Finnish Medical Society Duodecim:

Palliative treatment of cancer

International Radiosurgery Support Association (IRSA):

Stereotactic radiosurgery for patients with pituitary adenoma

Program in Evidence-Based Care (Cancer Care Ontario & Ontario Ministry of Health and Long-Term Care):

Adjuvant systemic chemotherapy, following surgery and external beam radiotherapy, for adults with newly diagnosed malignant glioma

Management of brain metastases: Role of radiotherapy alone or in combination with other treatment modalities

Management of single brain metastases

Prophylactic cranial irradiation in small cell lung cancer

Radiotherapy for newly diagnosed malignant glioma in adults



The Department of Education and Practice Management of the AANS maintains a repository of clinical guidelines pertinent to neurosurgical diagnoses at


The listing includes guidelines from agencies and organizations other than the AANS or CNS, but as of June 2006, this site appeared to be in need of updating.



The AANS, CNS and the Joint Tumor Section are not engaged in rendering professional medical services and assume no responsibility for patient outcomes resulting from application of these general recommendations in specific patient circumstances. Adherence to these clinical practice parameter guidelines does not necessarily assure a successful medical outcome. The information contained in these guidelines reflects published scientific evidence at the time of completion of the guidelines and cannot anticipate subsequent findings and/or additional evidence and, therefore, should not be considered inclusive of all proper procedures and tests or exclusive of other procedures and tests that are reasonably directed to obtaining the same result. Medical advice and decisions are appropriately made only by a competent and licensed physician who must make decisions in light of all the facts and circumstances in each individual and particular case and on the basis of availability of resources and expertise. Guidelines are not intended to supplant physician judgment with respect to particular patients or special clinical situations and are not a substitute for physician-patient consultation. Accordingly, the AANS and CNS and Joint Tumor Section consider adherence to these guidelines to be voluntary, with the ultimate determination regarding their application to be made by the physician in light of each patient's individual circumstances.