Subependymal Giant Cell Astrocytoma (SEGA) Treatment Update

Opinion statement

Rates of regrowth after resection of subependymal giant cell astrocytoma (SEGA) are low, making surgical resection a successful and permanent therapeutic strategy. In addition to surgical resection of SEGAs, other treatment options now include medications and Gamma Knife™ therapy. Advising patients on medical versus surgical management of SEGAs is currently not easy. SEGAs have been reported to regrow if mTOR inhibitor therapy is stopped, raising the possibility that long-term medication may be required to prevent tumor growth and hydrocephalus. The question of regrowth following medication withdrawal will need to be addressed in more patients to help establish the optimal duration of therapy. The risks of surgery include acute morbidity and the permanent need for ventriculoperitoneal shunting, which must be balanced against the adverse effects of mTOR inhibitors, including immunosuppression (infections, mouth sores), hypercholesterolemia, and the need for chronic drug monitoring. Some additional benefits of mTOR inhibition in patients with tuberous sclerosis complex, however, may include shrinkage of angiofibromas and angiomyolipomas as well as a possible decrease in seizure burden. Recent reports of successful nonsurgical treatment of SEGAs are promising, and it is hoped that further specifics on dosing, duration, and long-term outcome will help patients and physicians to make informed therapeutic choices.

Present treatment recommendations for SEGAs include routine surveillance neuroimaging and close clinical follow-up, paying particular attention to signs and symptoms of acute hydrocephalus. If symptoms arise, or if serial neuroimaging demonstrates tumor growth, neurosurgical intervention is recommended. When gross total resection is impossible, rapamycin and everolimus should be considered, but may not offer a durable response.