gms | German Medical Science

Objective: Despite advances in preoperative (functional) imaging and the use of intraoperative guidance and mapping techniques, gliomas located in the area of the central sulcus are still a big challenge for resective surgery due to a high risk of severe neurological deficits. Stereotactic brachytherapy (SBT) after implantation of ¹²⁵Iodine seeds has been reported to be a minimally invasive, safe and effective treatment alternative to resection, especially for small tumours located in eloquent brain areas. With the present retrospective analysis, we determined the value of SBT for the therapy of gliomas infiltrating the area of the pre- or post-central sulcus.

Methods: Almost 500 patients underwent SBT (¹²⁵Iodine seeds, surface dose 50Gy, permanent implantation) for supratentorial WHO° II and III gliomas in our institution from 1997 through 2010. For this retrospective analysis, we selected those patients with circumscribed tumours (<4 cm diameter) located within the area of the central sulcus. For patients with WHO°III gliomas receiving SBT as first-line therapy, adjuvant percutaneous radiotherapy (boost-dose: 15-30 Gy) was added. We evaluated procedure-related complications in the early postoperative period and in the long-term run, as well as time to tumour progression stratified by WHO grade. For statistical analysis, Kaplan-Meier estimates and the Log-rank test were used.

Results: Sixty patients (WHO°II: 29 patients; WHO°III: 31 patients) fulfilled the selection criteria. There was no procedure-related mortality. Within 30-days after seed implantation 3/60 patients (5%) had transient neurological deficits and 6/60 patients (10%) had temporarily increased seizure activity improving in all cases after adaptation of the anticonvulsive medication. After a median of 66.6 months (range, 39-114 months), three patients (5.0%) developed space-occupying cysts requiring surgical intervention. The median time to tumour progression was 53.6 months for WHO°II and 26.2 months for WHO°III gliomas.

Conclusions: Compared to neurosurgical resection, SBT is a safe and minimal invasive treatment option with a low rate of transient complications for patients with circumscribed WHO grade II and III gliomas located in the area of the central sulcus. The achieved tumour control is well comparable with results after resection.