Page 113 - Read Online

Review Article

Positron emission tomography imaging in gliomas

Assimakis Assimakopoulos , Konstantinos Polyzoidis , Chrissa Sioka 1
1,2
1
1 Neurosurgical Research Institute, University of Ioannina, 45500 Ioannina, Ioannina, Greece.
2 Department of Neurosurgery, Aristotle University of Thessaloniki, 54124 Thessaloniki, Thessaloniki, Greece.

ABSTRA CT

Glioma, the most frequent primary brain tumor in adults, is a highly infiltrative tumor exhibiting resistance to most treatments and
associated with short survival of patients. Positron emission tomography (PET) imaging using various tracers takes advantage of
the increased metabolic rate of neoplastic cells, in order to detect tumors and validate the treatment response. The most frequently
used PET tracer, the (18)F-fluorodeoxyglucose (FDG), is useful during the initial and follow-up assessment of patients with gliomas
because it can assist in the selection of the initial biopsy site and to assess early response to a given therapeutic intervention.
Furthermore, when there is tumor re-growth after an initial remission, FDG-PET can differentiate between true tumor recurrence
versus necrosis from radiation therapy. Newly developed PET tracers may exhibit better sensitivity than FDG to diagnose primary
brain tumors, but may occasionally produce false positive results in various conditions. In any event, PET is a useful tool in patients
with central nervous system cancer during both initial assessment and follow-up.

Key words: Brain tumor, cancer, glioma, positron emission tomography

INTRODUCTION evolving since in a recent report the change in ADC
histogram skewness may be more sensitive than the
Gliomas represent the most common primary brain response assessment in RANO criteria for evaluation
tumors, with poor prognosis even with aggressive of antiangiogenic therapy. [7]
therapies such as various combinations of surgery,
radiation therapy and chemotherapies. [1,2] Earlier Nuclear medicine imaging such as positron emission
response and progression criteria in recurrent tomography (PET) and single photon emission computed
glioma relied on changes in the contrast enhancing tomography (SPECT) combined with CT are useful for
magnetic resonance imaging (MRI), [3,4] however, the diagnosis and management of a variety of neurological
dramatic response rates seen in therapies involving diseases and cancers. SPECT and PET scans may
[8]
antiangiogenic therapies as well as other insufficiencies be utilized to assess brain tumor biologic behavior,
[9]
of the previous criteria resulted in development of distinction of radiation-induced necrosis from tumor
updated response criteria that take into account the recurrence and estimation of overall prognosis. [10]
nonenhancing component of the tumor as well as other Increased tumor uptake of (99 m) Tc-tetrofosmin in
critical parameters. [4,5] The newly described response SPECT correlated with aggressive behavior and may
assessment in neuro-oncology (RANO) criteria includes be an independent prognostic factor in patients with
comprehensive recommendations to assess response to malignant glioma. [11]
a therapy taking into account various issues in gliomas,
such as imaging changes postsurgical resection of a In this article, we present an evidence-based practical
tumor or locally delivered therapies, issues-related approach for the use of PET/CT during evaluation and
to contrast enhancement of previously unenhanced therapy of patients with a malignant primary brain
[6]
areas as well as clinical parameters. This field is still tumor. We reviewed published papers during the last
decade and included some older key references and
Access this article online our own experience.
Quick Response Code:
Website: (18)F-FLURODEOXYGLUCOSE POSITRON
www.nnjournal.net
EMISSION TOMOGRAPHY
DOI:
10.4103/2347-8659.143659 (18)F-flurodeoxyglucose (FDG) PET takes advantage
of the increased glucose uptake, a characteristic of

Corresponding Author: Dr. Chrissa Sioka, Neurosurgical Research Institute, University of Ioannina, 45500 Ioannina, Ioannina,
Greece. E-mail: csioka@yahoo.com

Neuroimmunol Neuroinflammation | Volume 1 | Issue 3 | December 2014 107