CIRCUMSCRIBED LOW-GRADE ASTROCYTOMAS IN THE DOMINANT OPERCULAR AND INSULAR REGION - A PILOT-STUDY

Intraoperative mapping techniques allow a reliable identification or e xclusion of eloquent brain areas and are well tolerated by the patient s. In dominant opercular tumours radical surgery can only be achieved without lasting deficits with intraoperative histological examination of the resection line and mapping. If an early postoperative MRI shows residual opercular tumour in non-eloquent areas re-operation is recom mended. In large dominant insular or opercular-insular tumours only bi opsy is recommended, because only an incomplete removal can be accompl ished, because the trial of radical removal carries a high risk of pos toperative deficits due to possible vascular damage of the lenticulo-s triate arteries or internal capsule. Because subtotal removal of low g rade gliomas does not increase the progression free interval, we would not recommend surgery in these cases, as they carry a significant ris k of a further deficit.