An Assessment of the Reliability of the Enneking and Weinstein-Boriani-Biagini Classifications for Staging of Primary Spinal Tumors by the Spine Oncology Study Group

• Published in: Spine (Philadelphia, Pa. 1976) Vol. 34; no. 4; pp. 384 - 391
• Main Authors: CHAN, Patrick, BORIANI, Stefano, SCHMIDT, Meic H, VIALLE, Luis R, GERSZTEN, Peter C, RHINES, Laurence D, ONDRA, Stephen L, PRATT, Stuart R, FISHER, Charles G, FOURNEY, Daryl R, BIAGINI, Roberto, DEKUTOSKI, Mark B, FEHLINGS, Michael G, RYKEN, Timothy C, GOKASLAN, Ziya L, VRIONIS, Frank D, HARROP, James S
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD Lippincott Williams & Wilkins 15-02-2009
• Subjects: Biological and medical sciences; Biopsy; Brazil; Canada; Cerebrospinal fluid. Meninges. Spinal cord; Female; Humans; Injuries of the nervous system and the skull. Diseases due to physical agents; Italy; Magnetic Resonance Imaging; Medical sciences; Middle Aged; Neoplasm Staging - methods; Nervous system (semeiology, syndromes); Neurology; Neurosurgical Procedures; Observer Variation; Patient Selection; Predictive Value of Tests; Reproducibility of Results; Spinal Neoplasms - classification; Spinal Neoplasms - pathology; Spinal Neoplasms - surgery; Tomography, X-Ray Computed; Traumas. Diseases due to physical agents; United States; Brazil; Canada; Italy; United States; Nervous system diseases; intraobserver reliability; Vertebral canal; Staging; Spine; oncological staging; Osteoarticular system; classification system; Central nervous system disease; Classification; primary tumors of spine; Tumor; Reliability; Spinal cord disease
• ISSN: 0362-2436; 1528-1159
• DOI: 10.1097/BRS.0b013e3181971283

Reliability analysis based on expert panel case series review and grading per the Enneking and Weinstein-Boriani-Biagini classification systems.
To assess the reliability of the Enneking and Weinstein-Boriani-Biagini classification systems.
The Enneking and Weinstein-Boriani-Biagini (WBB) classifications were developed to stage and facilitate treatment planning in patients with primary spine tumors. To date, their interobserver and intraobserver reliability has not been assessed-a fundamental step in facilitating broader clinical and research use.
Clinical information, imaging studies, and biopsy results were compiled from 15 selected patients with primary spinal tumors. Eighteen spine surgeons independently estimated and scored the cases for Enneking grade, tumor and metastasis categories, Enneking stage, Enneking-recommended surgical margin, WBB zones and layers, and WBB-recommended surgical procedures, with a second assessment performed after random resorting of cases. Interobserver and intraobserver reliability of each category were assessed by percent agreement or proportional overlap. The Fleiss, Cohen, and Mezzich kappa statistics (kappa) were then applied, determined by the type of variable analyzed.
The kappa statistics for interobserver reliability were 0.82, 0.22, 0.00, 0.57, 0.47, 0.31, 0.58, and 0.54 for the fields of Enneking grade, tumor and metastasis categories, Enneking stage, Enneking-recommended surgical margin, WBB zones and layers, and WBB-recommended surgical procedures, respectively. The kappa statistics for intraobserver reliability were 0.97, 0.53, 0.47, 0.82, 0.67, 0.63, 0.79, and 0.79 for the same respective fields. According to Landis and Koch, the ranges of kappa values of 0.00 to 0.20, 0.21 to 0.40, 0.41 to 0.60, 0.61 to 0.80, and >0.80 imply slight, fair, moderate, substantial, and near-perfect agreement, respectively.
Results indicate moderate interobserver reliability and substantial and near-perfect intraobserver reliability for both the Enneking and WBB classification in terms of staging and guidance for treatment, despite a less than moderate interobserver reliability in interpreting the Enneking local tumor extension and WBB sector. Before incorporating the classifications in the clinical practice and research studies, further work is required to investigate the validity of the classifications.