Treatment plans for brain metastases more accurately determined with aid of molecular imaging trace

December 2, 2013

Imaging with the molecular imaging tracer 18F-FDOPA can help distinguish radiation-induced lesions from new tumor growth in patients who have been treated with radiation for brain metastases, according to new research published in The Journal of Nuclear Medicine. Using this amino acid tracer, researchers found that physicians could accurately differentiate the two types of lesions 83 percent of the time. Progression-free survival could also be predicted through evaluating the 18F-FDOPA imaging results.

Brain metastases occur in 20-40 percent of all cancer patients, particularly in those with non-small cell lung cancer, breast cancer and melanoma. They account for 170,000 new cases per year in the United States, and prognosis is poor. Treatment for brain metastases typically includes a combination of surgery, 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, lead author of the study "18F-FDOPA PET for Differentiating Recurrent or Progressive Brain Metastatic Tumors from Late or Delayed Radiation Injury After Radiation Treatment." "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, researchers analyzed images from 32 patients who had 83 previously irradiated brain metastases and who underwent 18F-FDOPA positron emission tomography (PET). The studies were analyzed both semiquantitatively and visually to determine whether were caused by injury or were recurrent or progressive . Results were verified by histopathological analysis or clinical follow-up. The prognostic power of 18F-FDOPA in predicting progression-free survival and overall survival was also analyzed with the Kaplan-Meier and Cox regression methods.

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

Researchers also found 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 results. Additionally, 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 Lizarraga.

Explore further: Noninvasive 18F-fluoride PET can identify culprit coronary plaques

More information: "18F-FDOPA PET for Differentiating Recurrent or Progressive Brain Metastatic Tumors from Late or Delayed Radiation Injury After Radiation Treatment" The Journal of Nuclear Medicine, 2013.

Related Stories

Noninvasive 18F-fluoride PET can identify culprit coronary plaques

November 12, 2013
(HealthDay)—Combined positron emission tomography (PET) and computed tomography (CT) using the radioactive tracer 18F-sodium fluoride (18F-NaF) can identify ruptured and high-risk coronary plaques, according to a study ...

PET/CT bests gold standard bone marrow biopsy for diagnosis and prognosis of lymphoma patients

August 1, 2013
A more precise method for determining bone marrow involvement in patients with diffuse large B-cell lymphoma (DLBCL)—a key factor in tailoring patient management plans—has been identified by researchers in a study published ...

PET/CT shows clear advantages over conventional staging for breast cancer patients

January 2, 2013
New research published in the January issue of The Journal of Nuclear Medicine shows that 18F-fludeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) imaging offers significant prognostic stratification ...

PET predicts outcomes for patients with cervical spinal cord compression

September 4, 2013
For patients with degenerative cervical myelopathy, imaging with 18F-FDG positron emission tomography (PET) could act as a marker for a potentially reversible phase of the disease in which substantial clinical improvement ...

Combined imaging agents advance PET imaging of cancer

June 6, 2011
Research presented at SNM's 58th Annual Meeting is taking targeted molecular imaging to a new level by combining two commonly used imaging agents into one molecular imaging procedure. The combination of these agents creates ...

Inflammatory bowel disease detection enhanced with PET/CT

May 1, 2013
Inflammatory bowel diseases (IBD), such as Crohn's disease and ulcerative colitis, may be detected and monitored more effectively in the future with positron emission tomography/computed tomography (PET/CT), according to ...

Recommended for you

Immune-cell numbers predict response to combination immunotherapy in melanoma

July 20, 2017
Whether a melanoma patient will better respond to a single immunotherapy drug or two in combination depends on the abundance of certain white blood cells within their tumors, according to a new study conducted by UC San Francisco ...

Discovery could lead to better results for patients undergoing radiation

July 19, 2017
More than half of cancer patients undergo radiotherapy, in which high doses of radiation are aimed at diseased tissue to kill cancer cells. But due to a phenomenon known as radiation-induced bystander effect (RIBE), in which ...

Definitive genomic study reveals alterations driving most medulloblastoma brain tumors

July 19, 2017
The most comprehensive analysis yet of medulloblastoma has identified genomic changes responsible for more than 75 percent of the brain tumors, including two new suspected cancer genes that were found exclusively in the least ...

Novel CRISPR-Cas9 screening enables discovery of new targets to aid cancer immunotherapy

July 19, 2017
A novel screening method developed by a team at Dana-Farber/Boston Children's Cancer and Blood Disorders Center—using CRISPR-Cas9 genome editing technology to test the function of thousands of tumor genes in mice—has ...

Combining CAR T cells with existing immunotherapies may overcome resistance in glioblastomas

July 19, 2017
Genetically modified "hunter" T cells successfully migrated to and penetrated a deadly type of brain tumor known as glioblastoma (GBM) in a clinical trial of the new therapy, but the cells triggered an immunosuppressive tumor ...

How CD44s gives brain cancer a survival advantage

July 19, 2017
Understanding the mechanisms that give cancer cells the ability to survive and grow opens the possibility of developing improved treatments to control or cure the disease. In the case of glioblastoma multiforme, the deadliest ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.