Аннотация:We applied reflection-mode terahertz (THz) pulsed spectroscopy to study ex vivo the optical properties of human brain tumors with the different World Health Organization grades, as well as of perifocal regions comprised of intact (healthy) and edematous tissues. We applied gelatin-embedding in order to fix freshly-excised tissues, thus, preserving them from hydration/dehydration and sustaining their THz response unaltered for a couple of hours after resection. We observed a contrast between the THz optical properties of intact tissues and tumors, including gliomas and meningiomas of the brain, in turn, the response of edematous tissues is close to that of a tumor. The observed contrast between intact tissues and tumors has an endogenous character and originates reportedly from increased water content in a tumor due to edema, abnormal vascularity and, in some cases, necrotic debris. The observed results justify a prospect of THz technology in the intraoperative label-free diagnosis of human brain tumors.