SURG-19. EVALUATION OF SERUM NEURON SPECIFIC ENOLASE, INTERFERON-ALPHA, AND INTERFERON-GAMMA IN RESPONSE TO LASER ABLATION OF HIGH GRADE GLIOMAS

Abstract

Abstract BACKGROUND The blood-brain barrier (BBB) is a formidable obstacle in the treatment of gliomas. It has been speculated that the BBB may be temporarily disrupted in laser ablation, a relatively new treatment used for newly diagnosed and recurrent high grade gliomas (HGG). BBB disruption can be measured non-invasively through serum neuron specific enolase (NSE) levels. In addition to disrupting the BBB, laser ablation could trigger an immune response in brain that has yet to be studied. Interferon-alpha (IFN-α) and interferon-gamma (IFN-ɣ) are cytokines used as serum markers for an immune response. OBJECTIVE To measure NSE and IFN-α and IFN-ɣ as serum markers for BBB disruption and brain immune response activation, respectively, in patients undergoing laser ablation for recurrent high grade gliomas. METHODS Sixteen patients with recurrent HGG underwent laser ablation from 2/2017 to 12/2019. All 16 patients had gross total ablation of the contrast enhancing mass. Serum levels of NSE, IFN-α, IFN-ɣ were measured pre-operatively and at 24 hours, 2 weeks, and 8-16 weeks post-operatively, depending on adjuvant treatment received post-operatively. RESULTS Levels of NSE consistently increased 24 hours post-operatively (2.28±0.37 ng/ml) compared to pre-operative levels (1.62±0.29 ng/ml), p=0.032. Afterwards, NSE decreased and reached baseline by 2 weeks postoperatively (2 weeks- 1.67±0.29 ng/ml, 8 weeks- 1.85±0.91 ng/ml, 12 weeks- 0.81±0.33 ng/ml, 16 weeks- 1.23±0.93 ng/ml). Compared to their pre-operative levels, IFN-α and IFN-ɣ (85.46±35.29 and 1.62±0.47 pg/ml, respectively) did not display a significant difference in their serum levels (p=0.26-0.72 and 0.14-0.60, respectively, for IFN-α and IFN-ɣ) at any post-operative measurement time. Conclusions: Elevated NSE levels following laser ablation in HGG indicate a temporary disruption of the BBB that persists for approximately 2 weeks without eliciting an accompanying immune reaction in brain. Correlation studies with DCE-MRI are on-going.