Strategy of adult thalamic glioma surgery: Thoughts and practices based on thalamic glioma classification
摘要
Adult thalamic gliomas (ATGs) present a significant surgical challenge due to their deep location and proximity to critical brain structures. To standardize the surgical approaches, we proposed a novel anatomically-guided classification that divides thalamic gliomas into four distinct zones, each associated with specific surgical approaches. This retrospective study included 201 patients (median age 40 years) with WHO grade 2–4 thalamic gliomas treated at West China Hospital from 2012 to 2024. Utilizing two vertical lines transecting the internal capsule genu and the third ventricle midpoint, we categorized thalamic gliomas into Zone I (anterolateral), Zone II (posterolateral), Zone III (dorsomedial), and Zone IV (ventromedial). Survival analysis was performed using multivariable Cox regression with bidirectional stepwise selection, Kaplan–Meier analysis and log-rank testing. Intervariable associations were quantified using Cramer's V. Tumors invading multiple zones were the most frequent, representing 23.88% of cases, whereas only 1.98% involved both cerebral hemispheres. Supra-tentorial lateral approaches were most commonly employed (51.4%), and no patients required a supracerebellar infratentorial approach. Median overall survival was 10 months. After adjusting for molecular markers, adjuvant therapy and WHO grading, extent of resection (EOR) remained an independent prognostic factor (vs. gross total resection: subtotal HR = 1.62, p = 0.04; partial HR = 1.87, p < 0.001). Surgical approach significantly correlated with EOR in Zones I + II and II + III (p < 0.05), while Zones IV and III + IV demonstrated strong effect sizes (Cramer's V = 0.516 and 0.356, respectively), although these associations did not reach statistical significance. Maximal safe resection is a clinically justified first-line treatment for ATG patients. The transcallosal anterior approach is recommended for midline tumors located in Zones III, IV, or III + IV, particularly in cases involving obstructive hydrocephalus. For posterolateral tumors in Zones II and II + III, the approach should be determined by the direction of tumor extension. Nevertheless, further research with larger sample sizes is warranted to refine and optimize treatment strategies for thalamic gliomas. Clinical trial number: not applicable.