Clinical Characteristics and Prognostic Factors of Treatment in Pediatric Posterior Cranial Fossa Ependymoma

Objective: The purpose of this study was to explore the clinical features and risk factors of outcomes in pediatric posterior cranial fossa ependymoma. We aim to provide evidence-based recommendations for the improvement of prognoses.

Patients and methods: The clinical data, treatment modalities, approaches performed, recurrence rates and times, as well as the outcomes of 94 cases were analyzed retrospectively. The characters of neuroimaging were further studied.

Results: In data from the most recent follow-up, 27 cases had tumor recurrence. The time for tumor recurrence was 13.7 ± 7.7 months. The estimated overall survival and progression-free survival, based on Kaplan-Meier analysis, was 42.2 ± 2.9 months and 38.7 ± 3.4 months, respectively. Univariate analysis showed that being free of recurrence is closely related to the high tumor sphericity (p = 0.018), homogeneity of tumor texture (p = 0.001), and gross total resection (GTR; p < 0.001). Mortality is linked to low sphericity (p = 0.017) and brain stem edema (p = 0.005). Cerebellar mutism is correlated with posterosuperior compression of the 4th ventricle roof by the tumor. The incidence rate of cerebellar ataxia, cerebellar mutism, and cerebellar dysarthria is related to the rostral extension of the tumor within the 4th ventricle. The recurrence rate is higher in subtotal resection (STR) than in GTR, and the difference is significant (p < 0.001). Although there is no significant difference between the recurrence rates in the three types, an earlier recurrence is prone with tumors located in the paramidline-lateral compared to the midline (p = 0.021) and paramidline-medial areas (p = 0.042).

Conclusions: Based on our data, GTR is indicated as the most optimal choice. Recurrence is linked to lower tumor sphericity, inhomogeneous tumor texture, and STR/partial resection. Tumor located on the lateral side might be prone for an early recurrence.