Management of Primary Tectal Plate Low-Grade Glioma in Pediatric Patients: Results of the Multicenter Treatment Study SIOP-LGG 2004.

BACKGROUND: 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.

METHODS: 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.

RESULTS: 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.

CONCLUSIONS: 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.