Table 2.

Overview of the study's inclusion and exclusion criteria: Pronounced aphasia is defined as severe communication impairment that limits participation in or comprehension of study-related assessments. In cases of suspected speech disorder, a diagnostic evaluation will be performed using the modified Aachen Aphasia Test, the Aachen Aphasia Bedside Test, and the Aphasia Check List. Abbreviations: CNS = central nervous system; WHO = World Health Organization; IDH = isocitrate dehydrogenase; ICU = intensive care unit

Inclusion criteria	Exclusion criteria
At least 18 years of age	Presence of Neurodegenerative diseases (e.g. Parkinson's disease, Alzheimer's disease, Huntington's disease, Korsakoff's syndrome, Pick's disease, Shy-Drager syndrome)
Newly-diagnosed glioblastoma (CNS WHO 2021; IDH wild-type) before start of first radiotherapy	History of invasive tumors or surgery in the head or neck area, except for surgeries for non-invasive skin tumors (e.g. basal cell carcinomas)
Never received prior chemotherapy	Permanent olfactory impairment following infections (e.g., influenza, coronavirus)
Never received radiotherapy to the head or neck before	Conditions that, in the examiner’s judgment, could interfere with the participant’s study compliance (e.g., schizophrenia)
KPS ≥ 70	Language barriers likely to interfere with participation or comprehension of study procedures
No history of severe head or brain trauma requiring ICU admission or classified as Glasgow Coma Scale grade 3
No respiratory infection at the time of inclusion
No significant aphasia