Predicting the Outcome of Chemotherapy in Children

Janet F. Eary, MD, and Ernest U. Conrad, MD

Janet F. Eary, MD and Ernest U. Conrad, MD are anticipating funding for a competing renewal grant that will involve collaboration with Children's Hospital.

Featured in interaction April 2006 (PDF 778KB)

University of Washington researchers Janet F. Eary, MD, and Ernest U. Conrad, MD, are anticipating funding from the National Institutes of Health (NIH) for a competing renewal grant that will involve collaboration with Children's Hospital.

This grant will allow the investigators to allocate significant resources specifically for their research on pediatric patients.

This research will be carried out using a new, state-of-the-art Positron Emissions Tomography/Computerized Tomography (PET/CT) unit that should be installed at Children's in late summer or early fall of 2007.

Dr. Eary and Dr. Conrad have been conducting research on the response of cancer patients to chemotherapy for 15 years through several NIH grants, working with their co-investigator, Dr. Finbarr O'Sullivan, a statistician from the University of Cork.

Their work has focused on patients with sarcoma, a tumor affecting connective tissue, such as bones, muscles, fat, ligaments and tendons.

A recent interest in conducting more extensive research on pediatric patients led them to obtain preliminary data for this major NIH funding renewal request, which will allow them to look at the response of children with bone tumors to chemotherapy.

There are approximately 1600 new sarcoma cases in children each year, according to the National Cancer Institute's Surveillance Epidemiology and End Results (SEER) Web site.

SEER also indicates that the peak age incidence for pediatric bone tumors is between ages 13 and 19, but they occur in younger children and young adults as well. The treatment protocols for Dr. Eary and Dr. Conrad's research include patients up to the age of 30.

PET image

State-of-the-art Positron Emissions Tomography/Computerized Tomography (PET/CT) unit.

Their work with children will focus on the pediatric and young adult population of patients with Ewings Sarcoma Family of Tumors (ESFT) and osteosarcoma, or bone tumors.

These types of sarcoma, which are treated with chemotherapy followed by surgery, are among the most common malignant tumors that affect adolescents.

"Some tumors, like Ewings and osteosarcoma, cross over between children and adults," explains Dr. Eary, the principal investigator. "So our research is a way to get an understanding of the entire disease. Often what we can find in adults will likely apply in children."

In their research, Dr. Eary and Dr. Conrad use Positron Emission Tomography, commonly known as PET scanning, to obtain images that allow them to determine the type of tumor, its rate of growth and how it will behave.

The PET images also enable them to decide where to carry out a biopsy for diagnosis, and once treatment has begun, they may assess their patients' response. Essentially, the investigators use PET images to evaluate whether or not a treatment is effective in preventing the growth, recurrence or spreading of the tumor.

PET image

FDG PET image of a 15-year-old young man who has a Ewing Sarcoma, which appears as a dark mass in his right pelvis. PET allows researchers to measure the rate of energy use in specific regions of the body. In this case, researchers measure the glucose used by the tumor. The other solid dark areas are the brain, heart and kidneys, which appear because they also use a high amount of energy.

"It can help us learn about tumor response to chemotherapy fairly early, which can help us choose treatment and determine who is responding well and who isn't.

Since PET imaging is non-invasive, we can study a patient throughout the course of their therapy, and help learn about their tumors and individualize their therapy," says Dr. Eary, who specializes in cancer imaging.

The researchers also use PET to make predictions about the outcome, obtaining data throughout the treatment.

"We can provide real time information instead of waiting to see what happens," she says. "We've found out in our preliminary data that when we determine what happens in response to treatment very early in the cycle, it's predictive of the eventual outcome."

Through this grant, Dr. Eary and Dr. Conrad will also further the development of methods of analyzing images of tumors, allowing physicians to better understand their growth. The ability to determine the aggressiveness of a tumor is critical in making decisions about a patient's treatment.

Dr. Eary explains that the information they obtain "helps plan treatment and determine what kind of treatment might be appropriate.

It might be that many patients don't require quite as much treatment as the standard treatment, or it might be that there are some who have particularly resistant tumors who need more aggressive therapy."

For Dr. Eary, the most exciting aspect of the renewal of this grant is that the researchers will be able to conduct definitive clinical trials.

"They are going to be large populations that can be analyzed using good outcome statistics to validate the use of PET to characterize the tumor and determine response," she concludes.