Abstract OBJECTIVE Glioblastoma (GBM) is widely treated with surgery, chemoradiation and TTFields in combination with chemotherapy. Since the introduction of TTFields to first-line GBM treatment, prescribing physicians in Germany are interested to gain additional knowledge on the use in clinical practice. The TIGER study was designed to assess the therapy decision making process, safety and efficacy of TTFields in clinical routine, as well as evaluating quality of life (QoL) within 4 months after start of therapy, treatment compliance and duration. METHODS This multi-center prospective non-interventional study in Germany (NCT03258021) included newly diagnosed GBM patients eligible for TTFields therapy. Within the study, after receiving introduction to TTFields therapy, patients could decide for or against receiving TTFields. The study was designed to recruit 500 patients for each group, with and without TTFields. Demographic data, QoL and reasons for therapy decision 2–4 months after treatment start are assessed using the EORTC-QLQ-C30/BN-20 and a TTFields questionnaire, respectively, with 18 months follow-up. RESULTS At the last data cut-off (31st March, 2020), the median follow-up was 11 months (range: 0–28 months) and 581 (82%) of the 710 recruited patients in the trial had decided for TTFields therapy. According to preliminary analysis, this patient population represents a typical GBM population regarding median age (59 years, range: 19.0–85.0), gender (37 % female), median KPS (90, range: 40–100) and MGMT promoter methylation status (44% methylated). In this population 49 % received complete resection, 33 % partial resection and 19 % biopsy. CONCLUSION The TIGER study allows prospective and systematic analysis of TTFields treatment decision making and use of typical GBM patient population in routine clinical care. In addition, the study allows the evaluation of compliance and treatment duration. Here, we will present an updated analysis of the TIGER study.