Promising outcome of patients with recurrent glioblastoma after Gamma Knife-based hypofractionated radiotherapy.

BACKGROUND: The role of Gamma Knife radiosurgery (GKRS) in recurrent glioblastoma remains unclear. The purpose of this study is to evaluate the effects of GKRS in a group of patients with recurrent glioblastoma, focusing on survival and safety. METHODS: Patients undergoing GKRS for recurrent glioblastoma between September 2014 and April 2019 were included in this study. Relevant clinical and radiosurgical data, including GKRS-related complications, were recorded and analyzed. Overall survival (OS), local progression free survival (LPFS) and prognostic factors for outcome were thoroughly evaluated. RESULTS: Fifty-three patients were analyzed (24 female, 29 male). The median age was 50 years (range, 19-78 years). The median GKRS treatment volume was 35.01 cm3 (range, 2.38-115.57 cm3). Twenty patients (38%) were treated with single fraction GKRS, while 33 (62%) were treated with GKRS-based hypofractionated stereotactic radiotherapy (HSRT). The median prescription dose for single fraction GKRS, 3-fractions HSRT and 5-fractions HSRT were 16 Gy (range, 10-20 Gy), 27 Gy (range, 18-33 Gy) and 25 Gy (range, 25-30 Gy), respectively. The median LPFS and OS times were 8.1 months and 11.4 months after GKRS, respectively. HSRT and Bevacizumab were associated with improved LPFS, while HSRT alone was associated with longer OS. CONCLUSION: Our findings suggested that HRST would likely improve LPFS and OS in definite settings; the addition of Bevacizumab to GKRS was associated with increased rates of local control. No major complications were reported. Further prospective studies are warranted to confirm our findings.

An Investigation into the Relationship of SUR-1TRPM4 Receptor with Peritumoral Edema in High-Grade Glial Tumors.

AIM: To investigate the presence of Sur1-Trpm4 receptors in high-grade glial tumors, and their relationship with edema volumes in preoperative magnetic resonance imaging (MRI) sequences. MATERIAL AND METHODS: MRI sections were extracted from T1-weighted (T1W) and T2-weighted (T2W) sequences and fluidattenuated inversion recovery (FLAIR) images. After that, T1W 3D magnetization-prepared rapid gradient echo (MP-RAGE) sequences were taken with and without contrast medium. Tumor and peritumoral edema volumes were calculated in cubic centimeters. Sur1- Trpm4 receptors were studied by immunohistochemical examination of tissue samples. Relationships between data were analyzed using Spearman's correlation coefficient. RESULTS: In the immunohistochemical examinations, 58% of the samples from patients with high-grade glial tumors were positive for Sur1 and 74% were positive for Trpm4. The volume of tumors was correlated with the volume of peritumoral edema. CONCLUSION: The presence of the Sur1-Trpm4 receptor complex in high-grade glial tumors was confirmed. Further preclinical or clinical studies are required to identify and validate the role of Sur1-Trpm4 in glial tumor subgroups.