Thalamic gliomas in adults: a systematic review of clinical characteristics, treatment strategies, and survival outcomes

Purpose: Thalamic gliomas are rare neoplasms that pose significant surgical challenges. The literature is limited to single-institution retrospective case series. We systematically review the literature and describe the clinical characteristics, treatment strategies, and survival outcomes of adult thalamic gliomas. Methods: Relevant articles were identified on PubMed, Scopus, and Cochrane databases. Papers containing cases of adult thalamic gliomas with clinical outcome data were included. A comprehensive review of clinical characteristics and survival analysis was conducted. Results: We included 25 studies comprising 617 patients. The median age was 45 years (male = 58.6%). Glioblastoma was the most frequent histological type (47.2%), and 82 tumors were H3 K27M-mutant. Motor deficit was the most common presenting symptom (51.8%). Surgical resection was performed in 69.1% of cases while adjuvant chemotherapy and radiotherapy were administered in 56.3% and 72.6%, respectively. Other treatments included laser interstitial thermal therapy, which was performed in 15 patients (2.4%). The lesion laterality (P = 0.754) and the surgical approach (P = 0.111) did not correlate with overall survival. The median progression-free survival was 9 months, and the overall two-year survival rate was 19.7%. The two-year survival rates of low-grade and high-grade thalamic gliomas were 31.0% and 16.5%, respectively. H3 K27M-mutant gliomas showed worse overall survival (P = 0.017). Conclusion: Adult thalamic gliomas are associated with poor survival. Complete surgical resection is associated with improved survival rates but is not always feasible. H3 K27M mutation is associated with worse survival and a more aggressive approach should be considered for mutant neoplasms.