Feature | June 20, 2013

Molecular Imaging Improves Care for Children with Brain Cancer

Pediatric PET imaging of gliomas gets a boost with an easier-to-manufacture imaging agent

June 20, 2013 — A relatively new weapon in the fight against childhood brain cancer has emerged that improves upon standard magnetic resonance imaging (MRI) by providing information about tumor metabolism and extent of cancer in children diagnosed with glioma, a growth caused by the abnormal division of glial cells in the brain, said researchers at the Society of Nuclear Medicine and Molecular Imaging’s 2013 Annual Meeting.

Brain cancer imaging is often conducted with conventional MRI, but there are some limitations to this imaging technique. This type of cancer accounts for approximately 80 percent of all invasive brain tumors and develops in the brain’s glial cells that protect and maintain a state of neural equilibrium. Conventional MRI can sometimes over- or underestimate the extent of these tumors and the exact shape of their outlying margins. A method of molecular imaging called positron emission tomography (PET), which provides information about physiological functions rather than structures of the brain, can be performed with a variety of imaging agents that bind to specific cellular systems to image gliomas. Two of the main types of brain imaging agents used for this purpose provide information about either glucose, or sugar, metabolism of cells or the cellular metabolism of amino acids, the brick-and-mortar components of proteins used by tissues, especially rapidly growing so-called neoplastic tumors.

Amino acid PET imaging has been shown to be better for detection of neoplastic tissue and treatment monitoring in cases of brain cancer than glucose imaging. In general, the brain requires more glucose than the body’s other tissues and organs, making brain scans “noisier” and less defined than others due to this increase in overall cellular metabolism, whereas areas of increased amino acid activity show up clearly on scans as a visual “hot spot.” This study focuses on a particular amino acid imaging agent, O-(2-[18F]-fluoroethyl)-L-tyrosine (F-18 FET), and its diagnostic benefit for imaging pediatric gliomas when conventional MRI cannot make out a clear picture of disease.

“Cancer of the brain and spinal cord are common in children and young adults, and caring for this particular group can be challenging because choice of treatment depends on specific information about the tumor. Tumors in younger patients show a greater variety in both type and size, and in many cases the tumors are located near critical brain structures that prohibit surgical removal,” said Veronika Dunkl, M.D., a research scientist at the Institute of Neuroscience and Medicine, Forschungszentrum Jülich, in Jülich, Germany. “In patients with brain tumors, contrast-enhanced structural MRI is currently the diagnostic method of choice. However, in youths with newly diagnosed cerebral lesions thought to be brain tumors, MRI’s ability to identify neoplastic tissue or tumor progression and recurrence after treatment is limited. F-18 FET is complementary and can potentially improve diagnosis and treatment of pediatric brain tumors.”

Pediatric brain imaging with PET and F-18 FET can be used not only to evaluate extent of tumors but also to help doctors plan for biopsy, surgery and radiation therapies and track response to therapy and recurrence of tumors after completion of a treatment cycle.

F-18 FET is also unique from other amino acid PET agents because the production of the drug can be centrally located and distributed by a radiopharmacy, whereas other amino acid–based PET agents must be produced by an on-site cyclotron — a massive particle accelerator that bombards particles with a target used to radiolabel the agent’s molecular compound. For F-18 FET, it is the amino acid tyrosine that allows brain cells to signal each other. The greater logistical ease of F-18 FET is due to its radioactive half-life of approximately 110 minutes, whereas many other isotopes have a half-life of only about 20 minutes and must be administered for patient imaging almost immediately.

For this study, 15 young patients suspected of glioma cerebral cancer via MRI screening underwent PET imaging with the guidance of F-18 FET. This molecular imaging technique was found to be highly effective, about 87 percent, for detecting and differentiating brain lesions in children and young adults. The method was able to pinpoint 11 out of 12 brain lesions correctly as tumors and two out of three as a non-tumorous growth. Repeated PET imaging (17 scans) for seven more pediatric patients provided meaningful information about cancer progression or remission. F-18 FET imaging was able to detect residual tumor and tumor progression in five out of six scans, and in 11 scans in which the cancer had been eradicated, for a 94 percent rate of accuracy.

“Results of the present study may improve the clinical management of this vulnerable patient population significantly, especially when a decision for further treatment is difficult or impossible on the basis of conventional MRI alone,” said Dunkl.

The National Cancer Institute estimates that brain cancers are among the most common cancers in child populations. Incidence of pediatric brain tumors is approximately 3.2 cases per 100,000 people.

Scientific Paper 474: Veronika Dunkl, Gabriele Stoffels, Gereon Fink, Nadim J. Shah, Heinz Coenen, Karl-Josef Langen and Norbert Galldiks, Institute of Neuroscience and Medicine, Forschungszentrum Jülich, Jülich, Germany; Corvin Cleff, Department of Neurology, University of Cologne, Cologne, Germany; and Sevgi Sarikaya-Seiwert, Department of Neurosurgery, University of Düsseldorf, Düsseldorf, Germany, “The use of dynamic O-(2-[18F]fluoroethyl)-L-tyrosine-PET in the clinical evaluation of brain tumors in children and young adults,” SNMMI’s 60th Annual Meeting, June 8–12, 2013, Vancouver, British Columbia.

For more information: www.snmmi.org 

Related Content

Novel PET Agent Could Help Guide Therapy for Brain Diseases

Rat brain 11C‐Me‐NB1 PET images (0‐60 min) superimposed on an MRI template. Credit: SD Krämer et al., ETH Zurich, Zurich, Switzerland

News | PET Imaging | April 10, 2018
Researchers have developed a new imaging agent that could help guide and assess treatments for people with various...
The Chalk River nuclear reactor license has been renewed, but will be decommissioned by 2028.

The Chalk River nuclear isotope reactor license has been renewed, but will be decommissioned by 2028. The reactor supplies about 50 percent of the world's supply of Tc99m.

Feature | Nuclear Imaging | April 02, 2018 | Dave Fornell
April 2, 2018 – The Canadian Nuclear Safety Commission (CNSC) announced March 29 that it renewed Canadian Nuclear Lab
Imaging agent helps predict success of lung cancer therapy
News | Oncology Diagnostics | March 08, 2018
March 8, 2018 – Doctors contemplating the best therapy for...
Axumin PET Agent Added to NCCN Guidelines for Suspected Recurrent Prostate Cancer
News | PET Imaging | February 21, 2018
Blue Earth Diagnostics announced that Axumin (fluciclovine F 18) injection has been added to the National Comprehensive...
A Tc99m SPECT cardiac exam showing myocardial perfusion in the heart.

Technetium-99m is primarily used for the detection of cancer and to assess perfusion defects in the heart caused by heart attacks or other conditions.

Feature | Radiopharmaceuticals and Tracers | February 08, 2018 | Dave Fornell
February 8, 2018 — The U.S.
PSMA PET-CT Clearly Differentiates Prostate Cancer from Benign Tissue

68Ga-PSMA PET/CT images showing multifocal PCA in peripheral zone with GS of 5 1 5 5 10. (A and C) Axial PET images. (B and D) Fused PET/CT images. SUVmax of lesion in B was 84.3 and that of lesion in D was 5.7. IRS was 3, and 80% of cells were stained. Credit: Senior author V Prasad, Charité Universitätsmedizin Berlin, Berlin, Germany.

News | PET-CT | February 05, 2018
February 5, 2018 — Using nuclear medicine...
PET Tracer Measures Damage From Multiple Sclerosis in Mouse Models
News | PET Imaging | January 24, 2018
January 24, 2018 — The loss or damage of myelin, a cellular sheath that surrounds and insulates nerves, is the hallma
Novel PET Tracer Clearly Identifies and Tracks Bacterial Lung Infection

Representative PET/CT images of 18F-FDS and 18F-FDG in inflamed mice. Mice were inoculated with dead K. pneumoniae (10^8 CFU/mL). Imaging was performed for days 1, 2, 3 and 4 using 18F-FDG and 18F-FDS. CT images showed clear inflammation on day 2 and day 3 with corresponding high 18F-FDG uptake on PET. No significant uptake of 18F-FDS was detected for any of those 4 days. Credit: J Li et al., University of Louisville School of Medicine, Louisville, Ky.

News | PET-CT | January 22, 2018
January 22, 2018 — Researchers at the University of Louisville, Kentucky, have demonstrated that a new...
PET Tracer Gauges Effectiveness of Promising Alzheimer's Treatment

Longitudinal PET imaging with 18F-AV45. PET imaging shows the average 18F-AV45 uptake per animal group at 8 and 13 months of age. A significant interaction of genotype treatment was observed in the cortex (p = 0.0248), hippocampus (p = 0.0071) and thalamus (p = 0.0084), indicating reduced [18F]-AV45 uptake in BACE1 inhibited transgenic mice. Credit: MICA, University of Antwerp, Belgium.

News | Radiopharmaceuticals and Tracers | December 28, 2017
In the December featured basic science article in The Journal of Nuclear Medicine, Belgian researchers report on the...
Michael J. Fox Foundation and Tau Consortium Developing PET Tracers for Neurodegenerative Disease
News | Radiopharmaceuticals and Tracers | October 27, 2017
The Michael J. Fox Foundation for Parkinson's Research (MJFF) and the Tau Consortium announced a funding partnership to...
Overlay Init