Radiotherapy Planning Using Fluciclovine PET in Patients With Newly Diagnosed Glioblastoma

Overview

The purpose of the this study is to see if the use of a PET scan with 18F-fluciclovine (PET or Fluciclovine PET) in addition to the normal radiation planning imaging procedures (MRI and CT scan) will help determine the areas where the radiation therapy is to be delivered. It is also a goal of the study to determine if subjects live longer when treatment plans for radiation therapy are designed using a Fluciclovine PET scan, as well as MRI and CT scans. We will also collect information on if and where the tumor returns. Information on the side effects from the two different treatment planning imaging methods will also be collected. 18F-Fluciclovine is an FDA-approved radioactive diagnostic agent that is injected into the patient and then taken up by cancer cells, which can then be visualized with a PET/CT scan. 18F-Fluciclovine is FDA approved for the detection of recurrent prostate cancer, but is still investigational for the purposes of this study.

The goal of this study is to see if the use of PET in planning radiotherapy can reduce these local failures. Glioblastoma (GBM) is the most common primary malignant brain tumor. Newly diagnosed glioblastoma management includes maximum safe resection followed by radiotherapy with concurrent temozolomide, followed by maintenance temozolomide for 6 - 12 cycles. This postoperative chemoradiotherapy approach has resulted in a significant increase in median PFS (5.0 vs. 6.9 months) and OS (12.1 vs. 14.6 months) compared to radiotherapy alone (Stupp 2005). However, despite such multi-modality therapy, the median survival for GBM remains poor at approximately 15-16 months in contemporary series (Grossman, Ye et al. 2010, Gilbert, Wang et al. 2013 vs 2010). Recently, a randomized trial of tumor-treating fields (TTF or Optune) plus temozolomide demonstrated the benefit of this treatment in newly diagnosed glioblastoma that led to FDA approval of the device (Stupp 2015, Stupp 2017). However despite these advances, most patients still have a poor prognosis with median survival of 16-21 months. Although adjuvant chemoradiotherapy has been shown to increase survival, a predominant pattern of failure remains local (Chan, Lee et al. 2002, Milano, Okunieff et al. 2010). Therefore, better therapeutic options are needed for this disease.