technical issues

The purpose of the study is to determine whether intraoperative ultrasound guided resection of glioma without contrast enhancement in magnetic resonance imaging can achieve higher extent of resection than surgery without intraoperative sonography

Gliomas, not enhancing contrast agent in magnetic resonance imaging (MRI), are usually low-grade gliomas. They rarely show intraoperative fluorescence using 5-aminolevulinic acid or fluorescein. Intraoperative high-field MRI, sonography and navigation are the only ways to assess extent of their resection during surgery. MRI is the gold standard, but interrupts surgical workflow and only few hospitals are equipped with device like that. Navigation eventually looses it's precision due to brainshift. Ultrasound allows assess tumor remnants in real time but has worse imaging quality. Currently no randomized trials published their results about efficiency of intraoperative sonography in removing low-grade gliomas.

Objective of the study is to determine whether intraoperative ultrasound guided resection of non-enhancing gliomas can achieve higher extent of resection than surgery without intraoperative sonography.

Participants of the study will be randomly operated with and without intraoperative ultrasound. Extent of resection will be assessed in postoperative MRI by blinded radiologists.

Inclusion Criteria:

• single supratentorial gliomas without contrast enhancement in preoperative magnetic resonance imaging (presumed low-grade gliomas)
• newly diagnosed
• previously untreated
• Karnofsky Performance Status 60-100%
• age 18-79 years
• performed magnetic resonance imaging with contrast enhancement

Exclusion Criteria:

• glioma spreading to brainstem
• previously performed radiotherapy, chemotherapy or immunotherapy
• planned supratotal tumor resection until neurophysiologically revealed eloquent areas

Glioma extent of resection will be assessed by radiologists blinded for the treatment arm