AUTHOR=Hassanzadeh Comron , Rao Yuan James , Chundury Anupama , Rowe Jackson , Ponisio Maria Rosana , Sharma Akash , Miller-Thomas Michelle , Tsien Christina I. , Ippolito Joseph E. 

TITLE=Multiparametric MRI and [18F]Fluorodeoxyglucose Positron Emission Tomography Imaging Is a Potential Prognostic Imaging Biomarker in Recurrent Glioblastoma

JOURNAL=Frontiers in Oncology

VOLUME=7

YEAR=2017

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2017.00178

DOI=10.3389/fonc.2017.00178

ISSN=2234-943X

ABSTRACT=<sec id="ST1"><title>Purpose/objectives</title><p>Multiparametric advanced MR and [<sup>18</sup>F]fluorodeoxyglucose (FDG)-positron emission tomography (PET) imaging may be important biomarkers for prognosis as well for distinguishing recurrent glioblastoma multiforme (GBM) from treatment-related changes.</p></sec><sec id="ST2"><title>Methods/materials</title><p>We retrospectively evaluated 30 patients treated with chemoradiation for GBM and underwent advanced MR and FDG-PET for confirmation of tumor progression. Multiparametric MRI and FDG-PET imaging metrics were evaluated for their association with 6-month overall (OS) and progression-free survival (PFS) based on pathological, radiographic, and clinical criteria.</p></sec><sec id="ST3"><title>Results</title><p>17 males and 13 females were treated between 2001 and 2014, and later underwent FDG-PET at suspected recurrence. Baseline FDG-PET and MRI imaging was obtained at a median of 7.5 months [interquartile range (IQR) 3.7–12.4] following completion of chemoradiation. Median follow-up after FDG-PET imaging was 10 months (IQR 7.2–13.0). Receiver-operator characteristic curve analysis identified that lesions characterized by a ratio of the SUV<sub>max</sub> to the normal contralateral brain (SUV<sub>max</sub>/NB index) &gt;1.5 and mean apparent diffusion coefficient (ADC) value of ≤1,400 × 10<sup>−6</sup> mm<sup>2</sup>/s correlated with worse 6-month OS and PFS. We defined three patient groups that predicted the probability of tumor progression: SUV<sub>max</sub>/NB index &gt;1.5 and ADC ≤1,400 × 10<sup>−6</sup> mm<sup>2</sup>/s defined high-risk patients (<italic>n</italic> = 7), SUV<sub>max</sub>/NB index ≤1.5 and ADC &gt;1,400 × 10<sup>−6</sup> mm<sup>2</sup>/s defined low-risk patients (<italic>n</italic> = 11), and intermediate-risk (<italic>n</italic> = 12) defined the remainder of the patients. Median OS following the time of the FDG-PET scan for the low, intermediate, and high-risk groups were 23.5, 10.5, and 3.8 months (<italic>p</italic> &lt; 0.01). Median PFS were 10.0, 4.4, and 1.9 months (<italic>p</italic> = 0.03). Rates of progression at 6-months in the low, intermediate, and high-risk groups were 36, 67, and 86% (<italic>p</italic> = 0.04).</p></sec><sec id="ST4"><title>Conclusion</title><p>Recurrent GBM in the molecular era is associated with highly variable outcomes. Multiparametric MR and FDG-PET biomarkers may provide a clinically relevant, non-invasive and cost-effective method of predicting prognosis and improving clinical decision making in the treatment of patients with suspected tumor recurrence.</p></sec>