title: INTRAGO: intraoperative radiotherapy in glioblastoma multiforme—a phase I/II dose escalation study.
abstract: BACKGROUND
  Glioblastoma multiforme (GBM) is the most frequent primary malignant brain tumor in adults. Despite multimodal therapies, almost all GBM recur within a narrow margin around the initial resected lesion. Thus, novel therapeutic intensification strategies must target both, the population of dispersed tumor cells around the cavity and the postoperative microenvironment. Intraoperative radiotherapy (IORT) is a pragmatic and effective approach to sterilize the margins from persistent tumor cells, abrogate post-injury proliferative stimuli and to bridge the therapeutic gap between surgery and radiochemotherapy. Therefore, we have set up INTRAGO, a phase I/II dose-escalation study to evaluate the safety and tolerability of IORT added to standard therapy in newly diagnosed GBM. In contrast to previous approaches, the study involves the application of isotropic low-energy (kV) x-rays delivered by spherical applicators, providing optimal irradiation properties to the resection cavity.
  
  
  METHODS
  INTRAGO includes patients aged 50 years or older with a Karnofsky performance status of at least 50% and a histologically confirmed (frozen sections) supratentorial GBM. Safety and tolerability (i.e., the maximum tolerated dose, MTD) will be assessed using a classical 3 + 3 dose-escalation design. Dose-limiting toxicities (DLT) are wound healing deficits or infections requiring surgical intervention, IORT-related cerebral bleeding or ischemia, symptomatic brain necrosis requiring surgical intervention and early termination of external beam radiotherapy (before the envisaged dose of 60 Gy) due to radiotoxicity. Secondary end points are progression-free and overall survival.
  
  
  BACKGROUND
  The study is registered with clinicaltrials.gov, number: NCT02104882 (Registration Date: 03/26/2014).
authors.affiliation: Department of Radiation Oncology, University Medical Center Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany. frank.giordano@umm.de.
authors.forename: Frank A
authors.initials: FA
authors.lastname: Giordano
authors.forename: Stefanie
authors.initials: S
authors.lastname: Brehmer
authors.forename: Yasser
authors.initials: Y
authors.lastname: Abo-Madyan
authors.forename: Grit
authors.initials: G
authors.lastname: Welzel
authors.forename: Elena
authors.initials: E
authors.lastname: Sperk
authors.forename: Anke
authors.initials: A
authors.lastname: Keller
authors.forename: Frank
authors.initials: F
authors.lastname: Schneider
authors.forename: Sven
authors.initials: S
authors.lastname: Clausen
authors.forename: Carsten
authors.initials: C
authors.lastname: Herskind
authors.forename: Peter
authors.initials: P
authors.lastname: Schmiedek
authors.forename: Frederik
authors.initials: F
authors.lastname: Wenz
mesh_terms: D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery*; D002985:Clinical Protocols; D003131:Combined Modality Therapy; D005909:Glioblastoma / Q000000981:diagnostic imaging* / Q000601:surgery*; D006801:Humans; D007430:Intraoperative Care; D011859:Radiography; D011879:Radiotherapy Dosage