Intraoperative Monitoring of Glial Brain Tumors Cryodestruction

Abstract

Purpose: to determine the most useful quantitative parameter of diffusion-weighted images (DWI) in the differential diagnosis of focal liver lesions. Aim: To develop and assess the technique of intraoperative sonography during cryoablation of neuroepithelial brain tumors. Materials and methods. 27 patients with brain tumors of glial cells underwent cryosurgery under control of intraoperative sonography (IS). Cryotherapy was performed using a new cryosurgical apparatus. The tumors had both superficial and deep localization in functionally important areas of the brain, the size ranged from 4.4 to 240.5 cm³ (mean 40.1 cm³). Results. Cryotherapy and intraoperative sonography were performed through a single burr hole in 20 cases, through two burr holes - in 7. Through one burr hole accurate tumor volume measurement is possible only up to 23 cm³, with larger volumes measurement error significantly increases. Two burr hole technique helps to improve the accuracy up to 80 cm³. IS allows us to control the positioning and immersion depth of the cryoprobe. The analysis showed that the intraoperative values corresponded to the calculated values obtained from the preoperative planning. It should be noted that thanks to the possibility to intraoperatively monitor the formation and size of the iceball, for the group of total cryo-therapy, the area subjected to cryogenic treatment slightly exceeded the tumor volume (by an average of 2.7 cm³) in all cases after surgery. Conclusion. IS during brain tumor cryoablation increases the accuracy of cryogenic instrument positioning, allows us to visualize the iceball in real time, confidently perform several cycles of cryotherapy, reliably monitor all stages of cryosurgery.