Tumor Volume for Glioblastoma as Defined by Tryptophan PET Offers Superior Coverage of Recurrence Site Than Standard MRI-based GTV

Abstract

Glioblastoma is an infiltrative malignancy, for which the role of positron emission tomography (PET) in radiation therapy volume definition remains largely unexplored. In order to develop a reliable method for delineation of a high risk gross tumor volume (GTV) for glioblastoma we examined the utility of the PET radiotracer alpha[C-11]methyl-L-tryptophan (AMT) which can detect tumor mass and tumor-infiltrated brain by increased tumoral tryptophan transport and metabolism via the immunosuppressive kynurenine pathway.