Almost all GBM patients experience recurrent disease. Stereotactic radiosurgery (SRS),at recurrence, has limitations due to the invasive nature of glioblastoma. TTFields may decrease the tumor aggressiveness outside the target area potentially by multiple pathways, including immunogenic cell death and DNA repair inhibition sensitizing to radiation. We hypothesize that combined SRS and TTFields will be complementary, improving outcomes with minimal toxicity.~In this open-label, phase II trial 40 participants with recurrence will be treated with SRS and TTFields, starting in 2020. Recurrence will be defined on FET-PET or MRI using RANO criteria.~All patients will begin treatment within 14 days from baseline imaging evaluation and at maximum 42 days from screening.~The attempt to obtain the Methyl-guanine methyl-transferase (MGMT) gene promoter methylation and IDH1 and IDH2 mutation from primary tumor are made during the study whenever not defined before entering to the study.~TTFields treatment will be initiated as in clinical routine at patients home. Admission to hospital will not be necessary.~SRS must be delivered within 7 days of TTFields start. A 5-day SRS regimen is allowed. TTFields should be interrupted only during SRS. The sample size of the study was calculated for the comparison of survival against a historical control.Overall survival will be stratified by volume, PET-based treatment, SVZ invasion, MGMT methylation status, time to first progression, and TTFields compliance.
All patients will receive TTFields therapy and additionally Stereotactic Radiosurgery . Radiosurgery will be based on MRI and FET-PET or MRI alone. Addition of FET-PET will be preferred option.