Operative treatment of subcortical metastatic tumours in the central region

Abstract

The operative treatment of subcortical metastatic tumours within the paracentral area is still under discussion. Against the background of possible new postoperative neurological deficits and of evolving new radio oncological techniques, the indication for surgery is limited only to a subgroup of patients. In this retrospective study we present the clinical results after operative treatment of metastases within the central and paracentral brain region, with an emphasis on the short-term and mid-term functional outcome. We report on 20 patients suffering from subcortical brain metastases within the primary sensorimotor area, with a median volume on MRI-scans of 8.18 cm³. Patients were admitted to our department with a progressive hemiparesis (n = 11), focal seizures (n = 6) or other unspecific symptoms (n = 3) like headache, nausea, and neuropsychological disturbances, respectively. After updated MRI- and fMRI-scanning, intensive electrophysiological testing including MEP-brain mapping and interdisciplinary tumour-board discussion of each case, those patients were evaluated for surgery. Early postoperative control was done by MRI within the first 48 h. Follow-up took place in our outpatient department, assessing clinical criteria two and 6 weeks postoperatively, followed by clinical control and MRI-scans every 3 months. In all patients, surgery was performed under general anaesthesia, cranial neuro navigation and intraoperative motor cortex stimulation. Surgery and the early postoperative course were uneventful in all cases. After a 6 months follow-up, two patients had died. The motor deficits improved in seven patients and remained unchanged in four cases. One patient suffered from a new persistent hemiparesis. A temporary paresis occurred in two cases. In five patients there was no motor deficit pre- and postoperatively. The Karnofsky Performance Status improved in ten patients 6 months after surgery. Quality of Life, measured by the FACT-Br score, improved in 12 patients and remained unchanged in one patient. With modern techniques like fMRI-guided cranial neuronavigation and intraoperative neuromonitoring including direct stimulation of the motor cortex, microsurgical resection of subcortical paracentral metastases is feasible with an acceptable risk of neurological deterioration. Even preexistent deficits can improve with positive influence on the quality of life for oncological patients, being disabled by the symptoms caused by the cerebral lesion.

Surgery on motor area metastasis

“…This improvement in KPS strengthens data available from other smaller series [7,20,21] and plays an important meaning from an oncological point of view since it has a great impact on the response to adjuvant therapies and the overall survival [10,18].…”

“…Infiltration aspect was assessed by the macroscopical impression during microscopic resection. Tumor volume was analyzed on T1-weighted images after gadolinium administration and was set into two groups (<9 and ≥9 cm 3 ) according to the median volume calculated through an estimated spherical shape of the lesion [20]. The extent of resection was assessed by an expert neuroradiologist through the evaluation of a postoperative gadolinium MRI performed within 1 month after surgery and reported as gross total resection (GTR) or subtotal resection (STR) if resection was judged < or ≥ of 90 %, respectively.…”

“…The role of surgery in the treatment of central area metastases represents an emerging issue in the current neuro-oncological setting [1,3,5,7,14,20,21]. Indeed, even if boundaries of surgery have recently moved forward thanks to the intraoperative assistance of neurophysiologic monitoring and more in general by new technologies [4,9,15], only few data are available on the real impact of surgery on this specific subgroup of patients and on criteria of patient selection.…”

Surgical Management of Glioblastoma

“…Clinical factors that cause shift of the brain or a lesion, such as cerebrospinal fluid loss, cyst decompression, and cerebral edema, may diminish navigational accuracy (44). Neuronavigation is most useful as an adjunct to other brain-mapping techniques such as awake mapping and electrocorticography in the resection of lesions within eloquent motor and language areas (45). Intraoperative MRI has become more widespread and the evidence supporting the use of intraoperative MRI to maximize resection has also grown.…”

Resection of supratentorial gliomas: the need to merge microsurgical technical cornerstones with modern functional mapping concepts. An overview

“…Classically, the most frequently used routes were trans-sulcal, trans-fissural, or trans-gyral depending on the individual anatomy [53][54][55][56]. In those brain areas presumptively defined as "non-eloquent", navigation devices can precisely localize a purely subcortical lesion, and the most direct path is then exploited.…”