Current trends in the management of subependymal giant cell astrocytomas in tuberous sclerosis.

Abstract

The management of subependymal giant cells astrocytomas (SEGAs) has been traditionally represented by surgical treatment through an open craniotomic approach. Though open surgery still represents a major option in the management of this kind of tumors, the introduction of mTOR inhibitors in the clinical practice, technological advances in neuroendoscopy and the more recent use of laser interstitial therapy have significantly enlarged the range of available management opportunities. A thorough review of the literature has been performed. Accordingly, current views in open surgical treatment, medical therapy, endoscopic tumor removal and new trends (such as laser interstitial thermal therapy) are discussed. The risk of significant neurological morbidity (5-50%) complicating open surgery has been for a long time representing a main drawback in the management of SEGAs. More recent series report a significant reduction of morbidity and mortality. The mTOR inhibitors have demonstrated efficacy in both warranting a tumor reduction by up to 60% of the tumor size and helping the control of seizures. However, the reported rate of side effects is as high as 30% and tumor recurrence is a documented occurrence at the time of mTOR inhibitor discontinuation. Endoscopic tumor removal has been more extensively considered an option due to the acquisition of new tools. Limits are still represented by tumor size (< 3 cm) and broad attachment of the tumor to the basal ganglia. Laser interstitial thermal therapy (LITT)is the more recently considered option. Though promising, only short follow-up is available so far, while data on medium- and long-term results of this treatment are completely lacking to date. Surgical treatment remains a mainstay of the management of SEGAs. The indication for an open craniotomic approach should be balanced with an endoscopic tumor removal or LITT according to patient conditions, presence or not of an active hydrocephalus and extension of the attachment of the tumor to the basal ganglia. The mTOR inhibitors do have a definite role both as primary and as adjuvant treatment, but consistent limitations are represented up to now by a not negligible rate of complications and the uncertainties related to the possibility of tumor recurrence once the medical treatment is discontinued.