title: FET-PET-based reirradiation and chloroquine in patients with recurrent glioblastoma: first tolerability and feasibility results.
abstract: BACKGROUND
  Treatment of recurrent glioblastoma (rGBM) remains an unsolved clinical problem. Reirradiation (re-RT) can be used to treat some patients with rGBM, but as a monotherapy it has only limited efficacy. Chloroquine (CQ) is an anti-malaria and immunomodulatory drug that may inhibit autophagy and increase the radiosensitivity of GBM.
  
  
  METHODS
  Between January 2012 and August 2013, we treated five patients with histologically confirmed rGBM with re-RT and 250 mg CQ daily.
  
  
  RESULTS
  Treatment was very well tolerated; no CQ-related toxicity was observed. At the first follow-up 2 months after finishing re-RT, two patients achieved partial response (PR), one patient stable disease (SD), and one patient progressive disease (PD). One patient with reirradiated surgical cavity did not show any sign of PD.
  
  
  CONCLUSIONS
  In this case series, we observed encouraging responses to CQ and re-RT. We plan to conduct a CQ dose escalation study combined with re-RT.
authors.affiliation: Department of Radiation Oncology, University Medical Center Freiburg, Robert Koch Strasse 3, 79106, Freiburg, Germany.
authors.forename: Angelika
authors.initials: A
authors.lastname: Bilger
authors.forename: Martin-Immanuel
authors.initials: MI
authors.lastname: Bittner
authors.forename: Anca-L
authors.initials: AL
authors.lastname: Grosu
authors.forename: Nicole
authors.initials: N
authors.lastname: Wiedenmann
authors.forename: Philipp T
authors.initials: PT
authors.lastname: Meyer
authors.forename: Elke
authors.initials: E
authors.lastname: Firat
authors.forename: Gabriele
authors.initials: G
authors.lastname: Niedermann
authors.forename: Wolfgang A
authors.initials: WA
authors.lastname: Weber
authors.forename: Dušan
authors.initials: D
authors.lastname: Milanović
mesh_terms: D000328:Adult; D001932:Brain Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D002738:Chloroquine / Q000009:adverse effects / Q000627:therapeutic use*; D005240:Feasibility Studies; D005260:Female; D005909:Glioblastoma / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging / Q000517:prevention & control*; D010865:Pilot Projects; D049268:Positron-Emission Tomography / Q000379:methods*; D011838:Radiation-Sensitizing Agents; D019275:Radiopharmaceuticals; D011879:Radiotherapy Dosage; D061089:Radiotherapy, Image-Guided / Q000379:methods*; D016896:Treatment Outcome; D014443:Tyrosine / Q000031:analogs & derivatives*
chemical_list: D011838:Radiation-Sensitizing Agents; D019275:Radiopharmaceuticals; C545932:(18F)fluoroethyltyrosine; D014443:Tyrosine; D002738:Chloroquine