Primary and radiation induced skull base osteosarcoma: a systematic review of clinical features and treatment outcomes

Purpose: We aim to systematically review and summarize the demographics, clinical features, management strategies, and clinical outcomes of primary and radiation-induced skull-base osteosarcoma (SBO). Methods: PubMed, Scopus, and Cochrane databases were used to identify relevant articles. Papers including SBO cases and sufficient clinical outcome data were included. A comprehensive clinical characteristic review and survival analysis were also conducted. Results: Forty-one studies describing 67 patients were included. The median age was 31 years (male = 59.7%). The middle skull-base was most commonly involved (52.7%), followed by anterior (34.5%) and posterior (12.7%) skull-base. Headache (27%), exophthalmos (18%), and diplopia (10%) were common presenting symptoms. Sixty-eight percent of patients had primary SBO, while 25% had radiation-induced SBO. Surgery was the main treatment modality in 89% of cases. Chemotherapy was administered in 65.7% and radiotherapy in 50%. Median progression-free survival (PFS) was 12 months, and the overall 5-year survival was 22%. The five-year survival rates of radiation-induced SBO and primary SBO were 39% and 16%, respectively (P < 0.05). Conclusion: SBO is a malignant disease with poor survival outcomes. Surgical resection is the primary management modality, in conjunction with chemotherapy and radiotherapy. Radiation-induced SBO has a superior survival outcome as compared to its primary counterpart. Complete surgical resection showed a statistically insignificant survival benefit as compared to partial resection.