Radiation Type Treats Kids Gently

Brain tumors treated with proton therapy effectively controlled without cognitive decline

(RxWiki News) Radiation treatment is used to treat all different types of cancer. And there are different types of radiation that are given in various ways. Recently, researchers found a type of radiation that may be particularly helpful for young patients.

The new study discovered that proton radiation therapy was not only effective in treating brain tumors in pediatric patients, but this type of radiotherapy also helped preserve IQ and mental function.

Proton therapy has become popular for use in young children because it minimizes the amount of radiation absorbed by their still-developing brains.

"Talk to your doctor about the type of radiation therapy you’ll be receiving."

Shannon MacDonald, a pediatric radiation oncologist at the Massachusetts General Hospital in Boston, was the lead investigator of the study aimed at gathering clinical data on proton therapy use in pediatric patients.

Seventy youngsters between the ages of one and 20 years old participated in the study. They all had a common childhood brain tumor known as ependymoma and were treated at Massachusetts General between 2000 and 2011.

In terms of surgery, 66 percent of the youngsters had the entire tumor removed, while 34 percent had only a portion of the tumor removed.

After surgery, all of the participants received proton radiation — a form of external beam radiation. Protons are used to deliver precise doses of radiation to the tumor, while sparing nearby tissue from damage.

Researchers followed the participants for 46 months after their radiotherapy and found that tumors did not grow or return in 83 percent of the cases.

The three-year progression-free survival (PFS), during which the disease did not get worse, was 76 percent, and 95 percent of the patients were still alive.

Patients who had the total tumor removed had better overall outcomes than patients who had only part of the tumor removed. The three-year PFS was 54 percent in the kids who had partial removal compared to 88 percent for children who had the entire tumor removed — with overall survival 90 percent vs. 97 percent.

Cognitive function and psychological assessments were given to the youngsters before and after the proton therapy to measure total IQ. The patients’ parents completed a written questionnaire that assessed the child’s independence.

Two years after the treatment ended, the average IQ for 14 patients was 111.3 compared to 108.5 before the treatment. Independent functioning remained about the same.

Keith L. Black, MD, chair and professor of Cedars-Sinai’s Department of Neurosurgery, director of the Cochran Brain Tumor Center, director of the Maxine Dunitz Neurosurgical Institute and the Ruth and Lawrence Harvey Chair in Neuroscience, told dailyRx News, “This study reports positive benefits of proton beam therapy for tumor control in pediatric brain tumors, but it must be viewed in the context that there was no control group, so we can’t compare proton beam to other forms of focused radiation therapy.”

Dr. Black continued, “Would the results be similar if Gamma Knife®, CyberKnife® or XKnife® technology and techniques were used, or is there a unique benefit to proton beam therapy? Unfortunately, this study was not designed to answer these important questions.”

Findings from this study were presented at the American Society for Radiation Oncology’s (ASTRO’s) 55th Annual Meeting. 

Before publication in a peer-reviewed journal, all research is considered preliminary.

No conflicts of interest were reported.

Review Date: 
September 26, 2013