Filling A Critical Gap in Metastatic Spine Care: A Novel Classification System for Neoplastic Cauda Equina...

Area of Science:

• Spinal oncology
• Radiology
• Neurosurgery

Background:

• Metastatic epidural spinal-cord compression is well-characterized, but epidural cauda-equina compression (ECEC) is poorly understood.
• A novel grading system is needed to standardize ECEC assessment.

Purpose of the Study:

• To develop a novel grading system for ECEC.
• To determine the inter/intrarater reliability of this new system.
• To assess its ability to predict preoperative neurologic status.

Main Methods:

• A cross-sectional survey and retrospective-cohort study (2010-21) included patients undergoing ECEC surgery.
• Severity was graded on axial MRI using a novel 4-point scale (Grade-0 to Grade-3) with a +F modifier for foraminal stenosis.
• Inter/intrarater reliability was assessed among spine surgeons, trainees, and radiation oncologists using intraclass correlation coefficient.

Main Results:

• The novel ECEC grading system (Grades 0-3) demonstrated good inter/intrarater reliability (0.635 and 0.676, respectively) across all assessed specialties.
• The +F modifier for foraminal stenosis showed poor reliability (0.350 and 0.391, respectively).
• Compression grade was not associated with neurologic deficits, though bowel/bladder deficits were non-significantly higher in Grades 2/3.

Conclusions:

• The novel ECEC grading system offers a reliable framework for characterizing neoplastic ECEC, with good reliability for Grades 0-3.
• The system may improve communication regarding neoplastic ECEC.
• The poor reliability of the foraminal modifier highlights limitations of static MRI for assessing foraminal stenosis.