Encouraging outcomes for pediatric brain tumor patients treated with proton therapy

September 23, 2013

When used to treat pediatric patients with intracranial malignant tumors, proton therapy may limit the toxicity of radiation therapy while preserving tumor control, according to research presented today at the American Society for Radiation Oncology's (ASTRO's) 55th Annual Meeting.

Typically, malignancies are treated with surgical resection and post-operative radiation therapy. Proton therapy, an therapy in which protons deliver precise to a tumor, offers significant sparing of healthy tissues outside the target region, compared to conventional photon radiotherapy. Proton therapy is frequently used to treat central nervous system malignancies in young children in order to minimize the amount of to their still-developing brain. Although this therapy holds great promise, to date, published clinical data are limited.

This study evaluated the largest reported group of pediatric patients treated with -70 patients with localized ependymoma, a relatively common childhood tumor. The patients in the study ranged in age from one to 20 years and were all treated with involved-field proton radiation at the Massachusetts General Hospital in Boston from October 2000 to February 2011. Forty-six of the patients (66 percent) had a gross total resection, meaning that the tumor was completely removed; and 24 patients (34 percent) had a subtotal resection, meaning that only a portion of the tumor was removed.

Upon patient follow-up at 46 months after proton therapy treatment, the three-year local control was 83 percent; progression free survival (PFS) was 76 percent; and overall survival (OS) was 95 percent. The researchers found that subtotal resection surgery correlated with decreased PFS (54 percent) and OS (90 percent), compared to the patients who underwent complete tumor removal prior to proton therapy, who had a PFS of 88 percent and an OS of 97 percent.

In addition to , cognitive and endocrine outcomes were analyzed. Neuropsychological assessments were administered before and after proton therapy to measure total intelligence quotient (IQ). Scales of Independent Behavior (SIB-R), a written questionnaire that assessed functional independence, were completed by the patients' parents. Within a subset of 14 of the patients, the average IQ was 108.5 at baseline, and 111.3 after two years of follow-up. In a larger group of 28 of the patients, overall SIB-R score was 100.1 at baseline, and 100.8 after two years of follow-up. It was also noted that few patients developed evidence of growth hormone deficiency (GHD), hypothyroidism or hearing loss.

"This study represents the best available evidence on the use of proton radiotherapy in the pediatric population," said Shannon MacDonald, the principal investigator of the study, a pediatric radiation oncologist at the Massachusetts General Hospital. "Our analysis is the first to present auditory, endocrine and cognitive outcomes, the domains expected to benefit from this highly streamlined form of . Given the increasing numbers of proton facilities and the high cost of proton treatment, this data was urgently needed to provide evidence-based guidance on proton therapy outcomes for pediatric brain tumor patients."

Explore further: Proton therapy offers new, precise cancer treatment for children with high-risk neuroblastoma

More information: The abstract, "Proton Radiation Therapy for Pediatric Central Nervous System Ependymoma: Clinical Outcomes for 70 patients," will be presented in detail at ASTRO's 55th Annual Meeting.

Related Stories

Proton therapy offers new, precise cancer treatment for children with high-risk neuroblastoma

August 13, 2013
Proton therapy, using high-energy subatomic particles, may offer a precise, organ-sparing treatment option for children with high-risk forms of neuroblastoma. For patients in a new study of advanced radiation treatment, proton ...

Proton imaging provides more accuracy, less radiation to pediatric cancer patients

April 29, 2011
Proton radiography imaging used prior to and during proton treatments for pediatric cancer patients provides for more accurate treatment delivery and a lower dose of radiation compared to standard diagnostic X-rays and cone ...

Carbon ion radiotherapy safe and effective for treating inoperable spinal tumors

August 12, 2013
A new analysis has found that a type of radiation therapy called carbon ion radiotherapy can control cancer growth and prolong survival in patients with spinal tumors. Published early online in Cancer, a peer-reviewed journal ...

Recommended for you

Shooting the achilles heel of nervous system cancers

July 20, 2017
Virtually all cancer treatments used today also damage normal cells, causing the toxic side effects associated with cancer treatment. A cooperative research team led by researchers at Dartmouth's Norris Cotton Cancer Center ...

Molecular changes with age in normal breast tissue are linked to cancer-related changes

July 20, 2017
Several known factors are associated with a higher risk of breast cancer including increasing age, being overweight after menopause, alcohol intake, and family history. However, the underlying biologic mechanisms through ...

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 ...

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.