The CGCG response assessment criteria for spinal cord gliomas

The RANO criteria remain the cornerstone for evaluating adult gliomas; however, they often fail in spinal cord gliomas due to anatomical constraints, molecular heterogeneity, and distinct biological behavior. Firstly, central nervous system (CNS) dissemination is a hallmark feature of spinal cord gliomas and a critical driver of mortality, distinguishing them from their brain counterparts where such spread is rare. ‌Moreover, T1-weighted contrast-enhanced MRI typically reveals non-enhancing primary lesions‌, a characteristic feature of ‌H3 K27M-mutant diffuse midline gliomas (DMG)‌ that constitute over 40% of spinal cord gliomas, while ‌non-contrast T2-weighted imaging demonstrates sensitivity and reproducibility. Given the narrow and elongated anatomy of the spinal cord and the unique surgical strategy required for spinal cord gliomas, we advocate for volumetric assessment as the primary evaluation method, utilizing millimeters (mm) rather than centimeters (cm) as the measurement unit, and consider all visually identifiable lesions as measurable. Furthermore, the spinal cord exhibits super-functional integration across motor, sensory, and reflex pathways, thereby accentuating the importance of clinical manifestations and neurological functional assessment in accurately and promptly tracking disease progression. Our objective is to develop the specialized response assessment criteria for spinal cord gliomas to serve clinical trials.