Results of a recent survey of 13 pediatric hospitals in North America show a lack of universally applied standards for administering radiopharmaceutical doses to children undergoing nuclear medicine examinations, according to an article in the June issue of The Journal of Nuclear Medicine.
"Modern nuclear medicine procedures are sensitive, minimally invasive, painless and safe and thus well suited for the evaluation of pediatric patients. They provide a wealth of unique and useful information that can be used to diagnose and treat many diseases of childhood," said S. Ted Treves, M.D., chief of the Division of Nuclear Medicine at Children's Hospital Boston and professor of radiology at Harvard Medical School.
In nuclear medicine, there are well-established guidelines for administering radiopharmaceutical doses for adults. However, Dr. Treves stated, "At this time, the majority of radiopharmaceutical package inserts do not provide guidance on pediatric doses. In imaging children, physicians typically base dosages on the patient's body weight, the nature and the type of problem being investigated, the equipment available and their own experience. This has led to the variations in dosage that currently exist."
This approach, however, may result in the smallest patients receiving a dose that is too small to produce adequate results. Also, according to experts, radiopharmaceuticals are handled differently in infants and young children. For example, circulation time in newborns is faster than it is in adult patients. These and other kinetic and metabolic differences can make a difference in the doses children require. The wide range of disorders, body sizes, stages of development, and level of patient cooperation require customized approaches to dosimety and to the various imaging techniques that are used in making a diagnosis.
"This survey identifies a very important question-what are the lowest radiopharmaceutical dosage levels that are compatible with quality imaging in children?" said Dr. Michael Gelfand, M.D., president of SNM's Pediatric Imaging Council. "Over the last few years, the imaging community successfully tackled the problem of computed tomography (CT) absorbed radiation doses that, in many cases, were higher than required for quality imaging. Although nuclear medicine scans are performed less frequently than CT scans and generally involve much less radiation, this report has identified a question that needs attention. As a result, the nuclear medicine community has begun to address the radiopharmaceutical dosage question by forming a work group composed of members of the Pediatric Imaging Council and the Society for Pediatric Radiology who practice nuclear medicine. This group will examine administered dosages and come up with recommended radiopharmaceutical dosages over the next year."
When a nuclear medicine procedure is appropriately administered, the benefits to the patient far outweigh any potential risks associated with the radiation. The risk from exposure to small amounts of radiation is very small. The need to reach a consensus on pediatric-administered doses is therefore of utmost importance and forms the central impetus for this critical survey.
"This report provides the data and incentive needed to work toward establishing radiopharmaceutical administration guidelines for pediatric molecular imaging patients. We will be working with the study investigators, the SNM community and the FDA to help establish such guidelines," said George Sgouros, Ph.D., vice-chairman of SNM's Medical Internal Radiation Dose (MIRD) Committee.