Features Partner Sites Information LinkXpress
Sign In

Molecular Imaging Tracers Help Determine Brain Metastases Treatment Strategies

By Medimaging International staff writers
Posted on 17 Dec 2013
Print article
Imaging with the molecular imaging tracer 18F-FDOPA (L-3,4-dihydroxy-6-[18F]fluoro-phenylalanine) can help differentiate radiation-induced lesions from new tumor growth in patients who have been treated with radiotherapy for brain metastases, according to new research.

Using this amino acid tracer, researchers discovered that physicians could effectively differentiate the two types of lesions 83% of the time. Progression-free survival could also be predicted through evaluating the 18F-FDOPA imaging findings.

Brain metastases occur in 20%–40% of all cancer patients, especially in those with melanoma, non-small-cell lung cancer, and breast cancer. They account for 170,000 new cases yearly in the United States alone, and prognosis is poor. Treatment for brain metastases usually includes a combination of surgery, radiation treatment, and chemotherapy.

“Histopathological changes in neural tissue treated with radiation could trigger clinical and imaging manifestations which are very similar to those caused by tumor growth,” said Karlo J. Lizarraga, MD, MS, from the department of neurology, Miller School of Medicine, University of Miami (FL, USA), and lead author of the study. “The challenge is then to differentiate whether these manifestations are due to radiation or to tumor progression or recurrence. Accurate and timely distinction between these two possibilities can significantly affect patient care, and outcome for treatment modalities are completely different for each case.”

In the retrospective study, published ahead of print October 28, 2013, and slated for the January 1, 2014, issue of the Journal of Nuclear Medicine, researchers analyzed images from 32 patients who had 83 earlier irradiated brain metastases and who underwent 18F-FDOPA positron emission tomography (PET). The studies were analyzed both semi-quantitatively and visually to determine whether lesions were caused by radiation injury or were recurrent or progressive brain metastases. Results were verified by histopathologic analysis or clinical follow-up. The prognostic ability of 18F-FDOPA in predicting progression-free survival and overall survival was also studied with the Kaplan-Meier and Cox regression techniques.

The best overall accuracy for differentiating between the two types of lesions was achieved using visual scoring, which had a sensitivity of 81.3%, a specificity of 84.3%, and an overall accuracy of 83.1%. The semi-quantitative analysis resulted in a sensitivity of 81.3%, a specificity of 72.5% and an overall accuracy of 75.9%.

Researchers also discovered that evaluations with 18F-FDOPA PET was highly prognostic of progression-free survival, as lesions with a negative PET result had a mean time to progression that was 4.6 times longer than lesions with positive 18F-FDOPA PET findings. Moreover, a trend toward predicting overall survival was also seen.

18F-FDOPA PET imaging is currently available in few centers. The longer physical half-life of 18F-FDOPA, when compared to other amino acid tracers, gives it the advantage of potential automated production and transport to PET centers for widespread use,” noted Dr. Lizarraga.

Related Links:

Miller School of Medicine, University of Miami

Print article
Medical Imaging Innovations



view channel
Image: New Scenaria SE 64/128-slice Computed Tomography Scanner from Hitachi Medical Systems America (Photo courtesy of Business Wire).

Two new 64/128-Slice CT Scanners Cleared by the FDA

A major diagnostic imaging equipment provider has announced US FDA clearance of two new 64/128-slice Computed Tomography (CT) scanners. The Food and Drug Administration (FDA; Silver Spring, MD, USA)... Read more


view channel

Additional Aggressive Cancers Can Be Found Using Breast MRI Following Mammography Screening

The results of a study published online in the journal Radiology have shown that performing MRI scans, after the discovery of mammography breast cancer findings, sometimes shows larger and more aggressive tumors than those discovered in mammography. Breast Magnetic Resonance Imaging (MRI) is widely used for the screening... Read more


view channel

Fast, Noninvasive Assessment of Chronic Liver Disease Announced as Alternative to Biopsies

A leading ultrasound imaging vendor has presented the clinical benefits of its innovative technology for noninvasive assessment of the severity of liver fibrosis, at the Liver Meeting 2015, in San Francisco (CA, USA). Researchers have published more than 60 items on the reliability and effectiveness of the new technology.... Read more

Imaging IT

view channel
Image: 3D scan a child’s heart born with congenital heart defects (Photo courtesy of the Phoenix Children’s Hospital).

3D Modeling System Accurately Predicts Pediatric Donor Heart Volumes

A new three dimensional (3D) computer modeling system may more accurately identify the best donor heart for a pediatric transplant patient. To develop the new 3D system, researchers at Arizona State... Read more

Industry News

view channel

Long-Term Strategic Managed Medical Equipment Services Partnership Announced

An 18-year strategic collaboration agreement, worth CAD 300 million, between a major medical imaging vendor and the Southwest York Region of Ontario in Canada, has been announced. The partnership is for managed equipment services to help advance medical technology in the Southwest York region, and to expand the accessibility... Read more
Copyright © 2000-2015 Globetech Media. All rights reserved.