Table 1.

Studies excluded from the analysis.

First author, year of publication, journal	Reason for exclusion
Westphal et al., 2003, Neuro Oncol (9)	Recurrent glioblastoma multiforme
Attenello et al., 2008, Ann Surg Oncol (25)	Glioma grade III and IV were included
Salmaggi et al., 2013, Journal of Neurosurgery (12)	Not including standard treatment (surgery + chemo-/radio-therapy) group for comparison
Jungk et al., 2016, BMC Cancer (13)	Included recurrent glioblastoma cases only, Not including Carmustine Wafer treatment group for comparison
Della Puppa et al., 2017, J Neurooncol (14)	Not including NON-Carmustine Wafer treatment group for comparison
Champeaux et al., 2019, Journal of Neuro-Oncology (22)	Not including standard treatment (surgery + chemo-/radio-therapy) group for comparison
Ius et al., 2020, Cancer (2)	Not including Carmustine Wafer treatment group for comparison
Iuchi et al., 2022, Neurooncol Adv (21)	Not including NON-Carmustine Wafer treatment group for comparison