Tectal Plate Glioma: A Clinical and Radiological Analysis of Progression and Management in Adults

BACKGROUND:Tectal Plate Gliomas (TPG) are a heterogeneous group of uncommon brain tumours. TPGs are considered indolent and are usually managed conservatively but they have the potential to transform into higher grade tumours. The aims of this study were to investigate the natural history of adult TPG, treatment outcomes, and overall survival. METHODS:This was a retrospective cohort analysis of adult patients with TPG between 1993 and 2021. Baseline clinical, radiological and management characteristics were collected. The primary outcome was tumour progression, defined as increasing size on radiological assessment or new gadolinium contrast enhancement. Secondary outcomes included: management and mortality. RESULTS:Thirty-nine patients were included, of which 23 (52.2%) were males. Median age at diagnosis was 35 years (Interquartile Range [IQR] 27-53). Radiological tumour progression was observed in eight (20.5%) patients. The 10-year PFS rate was 72.6% (95% Confidence Interval [CI] 0.58-0.91). The 10-year OS rate was 86.5% (95% CI 0.75-1.0). CSF diversion procedures were used in 62% of the cohort (n=24). Seventeen (43.6%) patients underwent at least one Endoscopic Third Ventriculostomy, while only six (15.4%) patients underwent at least one Ventriculoperitoneal Shunt. CONCLUSIONS:TPG has an overall favourable clinical prognosis, although progression occurs in 1 in 5 patients. Demonstrating accurate factors by which TPG patients may be risk stratified should be a key area of further research. A follow up duration of 10 years would be a reasonable window based on the radiological progression rates in this study however, larger cohort studies are needed to answer both questions definitively.