Patterns of response following gamma knife radiosurgery for tectal plate gliomas.

purposeTectal plate gliomas are slow-growing brainstem tumors often causing obstructive hydrocephalus. This study evaluates radiological response patterns and clinical outcomes of Gamma Knife radiosurgery (GKRS), a minimally invasive alternative for tumor control with lower risks than surgery.

methodsA retrospective analysis was conducted on 10 patients treated with GKRS for tectal plate gliomas between January 2014 and November 2023 at a tertiary Gamma Knife Centre. Inclusion criteria required a minimum follow-up of one year with radiological assessment. Tumor volume, dose parameters, radiological responses, and clinical outcomes were documented.

resultsThe cohort comprised six females and four males, with a median age of 13 years (range: 2-31 years). Hydrocephalus was managed with endoscopic third ventriculostomy (50%) or ventriculoperitoneal shunting (40%). Histopathological confirmation, available in 40% of cases, revealed WHO Grade 2 diffuse astrocytoma. The median tumor volume was 2.18 cc, and a marginal dose of 12 Gy was delivered at a 50% isodose line. Radiological follow-up (median: 24 months) demonstrated a gradual reduction in tumor size in 90% of cases, with a median volume reduction of 56.7%. One patient exhibited pseudoprogression, and no cases of cystic degeneration or sustained tumor growth were observed. Clinically, 80% of patients reported symptomatic improvement, while 20% remained stable. Minor adverse effects, primarily headaches, were noted in four patients.

conclusionGKRS is a safe, effective treatment for tectal plate gliomas, offering significant tumor control with minimal complications. It primarily results in gradual tumor shrinkage, making it a viable alternative when surgery is not feasible.