P14.15.A INTRAOPERATIVE ASPIRATE TISSUE MONITORING DURING 5-ALA GUIDED HIGH-GRADE GLIOMA SURGERY

Abstract BACKGROUND The first-line treatment for high-grade gliomas (HGG) is maximal safe resection, which is limited by diffuse tumor margins and nearby eloquent areas. Intraoperative detection of tumor cells is improved with fluorescence-guided surgery using 5-ALA, but its visual detection is limited by blood, obstacles and weakness of the fluorescence. Aspirate tissue monitoring (ATM) of fluorescence from surgical suction waste could improve surgical performance by providing objective feedback while maintaining a natural white light anatomical view. This observational study compared the visual detection of 5-ALA fluorescence to feedback from an ATM device. MATERIALS AND METHODS Twelve (n=12) patients’ suspected HGG resection with (n=9) and without (n=3) prescribed 5-ALA were recorded while a prototype ATM, was attached to the tube of an ultrasonic aspirator. Seven (7) neurosurgeons viewed the white and blue light operation videos with and without ATM feedback and responded to a questionnaire assessing the safety and benefit-risk ratio of ATM. According to the averaged experts’ analysis, the resected tissues were categorized to visually perceivable fluorescence (yes/no) and compared to the ATM signals. RESULTS In total 42 video sequences were analyzed. The sensitivity and specificity of ATM in comparison to visual analysis was 100% and 80%, respectively. The positive predictive value (PPV) of ATM was 92% and the negative predictive value (NPV) was 100%. The ATM detected fluorescence under white light in 11 of the resected areas, whereas experts in 0 areas (p