Tectal plate low-grade gliomas (LGGs) most often present with increased intracranial pressure and sometimes as incidental findings from brain imaging. Prognostic factors predicting outcome are largely unknown.
From 2004 until 2012, 71 patients with tectal plate LGG from Germany and Switzerland were followed within the SIOP-LGG 2004 study. Median age at diagnosis was 9.7 (range: 0.1–17.5) years, and median follow-up time of surviving patients was 6.3 (interquartile range: 4.9–8.3) years.
A total of 41 out of 71 patients received no tumor treatment (12 with and 29 without biopsy). The 10-year event-free survival (EFS) rate (± standard error ) for patients with an initial tumor volume of ≤3 cm3 was 56% (±7%), as opposed to 12% (±8%) for those with tumors >3 cm3 (p < 0.001). The 10-year EFS for patients without contrast enhancement on initial magnetic resonance imaging (MRI) was 52% (±9%), and for those with enhancement, it was 23% (±9%) (p = 0.003). The 10-year overall survival rate was 96% (±3%) (death due to disease, 1; ventriculoperitoneal shunt infection, 1). Sixty-three (89%) patients had at least one cerebrospinal fluid diversion procedure.
More than half of patients were managed without tumor treatment. Favorable prognostic factors for EFS were small initial tumor volume (≤3cm3) and the absence of initial contrast enhancement on MRI. Overall survival was excellent.