Gamma Knife surgery for subependymal giant cell astrocytomas

Abstract

Object. The authors report their experience of using Gamma Knife surgery (GKS) in patients with subependymal giant cell astrocytoma (SEGA).Methods. Over a 20-year period, the authors identified 6 patients with SEGAs who were eligible for GKS. The median patient age was 16.5 years (range 7-55 years). In 4 patients, GKS was used as a primary management therapy. One patient underwent radiosurgery for recurrent tumors after prior resection, and in 1 patient GKS was used as an adjunct after subtotal resection. The median tumor volume at GKS was 2.75 cm 3 (range 0.7-5.9 cm 3 ). A median radiation dose of 14 Gy (range 11-20 Gy) was delivered to the tumor margin.Results. The median follow-up duration was 73 months (range 42-90 months). Overall local tumor control was achieved in 4 tumors (67%) with progression-free periods of 24, 42, 57, and 66 months. Three tumors regressed and one remained unchanged. In 2 patients the tumors progressed, and in 1 of these patients the lesion was managed by repeated GKS with subsequent tumor regression. The other relatively large tumor (5.9 cm 3 ) was excised 9 months after GKS. The progression-free period for all GKS-managed tumors varied from 9 to 66 months. There were no cases of hydrocephalus or GKS-related morbidity.Conclusions. Gamma Knife surgery may be an additional minimally invasive management option for SEGA in a patient who harbors a small but progressively enlarging tumor when complete resection is not safely achievable. It may also benefit patients with a residual or recurrent tumor that has progressed after surgery. Key WorDs • Gamma Knife surgery • glioma • radiosurgery • subependymal giant cell astrocytomaAbbreviations used in this paper: GKS = Gamma Knife surgery; SEGA = subependymal giant cell astrocytoma; SRS = stereo tactic radiosurgery.

Stereotactic laser ablation for hypothalamic and deep intraventricular lesions

“…Overall, this rate compares similarly with rates seen after radiosurgery or everolimus alone. 13,17 No complications were noted during these treatments. While no tumor was completely extirpated after laser ablation, there were marked reductions in tumor volumes up to 70%.…”

“…However, in incompletely resected SEGAs, up to 100% reoperation rates are noted. 1 Radiosurgery has also been used for inoperable tumors with reported long-term control rates of 67%, 17 and recent introduction of everolimus, an mTOR inhibitor, has provided new options for medical management. 13 Again, there exists a potential role for laser ablation for management of inoperable, symptomatic SEGAs, especially with its potential to reduce tumor volume and improve associated mass effect and/or CSF outlet obstruction.…”

Subependymal Giant Cell Astrocytoma Presenting with Tumoral Bleeding: A Case Report

“…GKR revealed good outcomes for many types of benign brain tumors, including gliomas, with a low incidence of side effects [22]. Out of reported cases of SEGA after GKR, half of them showed tumor volume reduction 70–80% within 6 months, and another shown tumor progression [22232425]. Even though the role of GKR in SEGAs was limited by the sporadic cases, these reported results suggest GKR may be an additional option for SEGAs that are small but progressively enlarging tumors where complete resection has not been safely achieved, residual or recurrent tumors.…”

Advances in the management of subependymal giant cell astrocytoma

“…An additional study that included two patients with SEGAs observed a radiographic response in one patient and progression in the other after a median dose of 13 Gy [18]. More recently, a study of six TSC patients with SEGA who received a median dose of 14 Gy reported local tumor control in four patients with progression-free intervals of 24, 42, 57, and 66 months [19]. Importantly, "tumor control" was defined as <25 % increase in enhancing or nonenhancing tumor volume, whereas "tumor progression" was defined as ≥25 % increase in tumor volume.…”