Endothelium changes of peritumoral zone capillaries after brain glioblastoma adjuvant radiation therapy

Abstract

Introduction. Despite the treatment methods’ improvement, the brain glioblastoma (GB) patient survival remains at the level of 12–14 months. In this regard, it is very relevant to optimize the choice of the treat-ment of recurrent GB, including using stereotactic radiosurgery (SRS). Materials and methods. Comparative analysis of the endothelial cells in the capillaries of blood vessels of the brain peritumoral zone (PZ) before (1 group – 32 capillaries) and 12 – 14 months after (2 group – 75 capillaries) adjuvant external radiation therapy (AERT) was performed using transmission electron micros-copy (TEM). Results. Apoptosis of endotheliocytes was observed in the capillaries of the brain PZ from 2 group much more often than from 1 group (60% and 12.6% of capillaries, respectively, p<0.001). Capillary death and thrombosis occurred in 4% and 1.4% of 2 group capillaries. An important finding was that only 69.3 of capillaries from 2 group revealed thickening of the basement membrane (BM), and 26.9% of them also revealed its peak deformation. Conclusion. 12–14 months after AERT, the brain PZ remains ischemic due to apoptosis of the capillary endothelium, thickening and peak deformation of the BM. The detected signs of revascularization of the brain PZ after previously performed AERT suggest that it is possible to consider SRS as a method of treat-ment for recurrent brain GB. Keywords: brain glioblastoma, peritumoral zone, endotheliocyte apoptosis, thickening of the basement membrane, stereotactic radiosurgery, glioblastoma relapse