The ALARA concept in pediatric oncology

Abstract

For the past several years, the Society for Pediatric Radiology (SPR) has successfully conducted ALARA conferences emphasizing the importance of radiation safety in pediatric imaging, providing a valuable forum for pediatric radiologists, practicing general radiologists, and interested clinicians to review specific concepts relevant to the ALARA (as low as reasonably achievable) principle [1–4]. In 2008 the focus of the ALARA symposium was pediatric oncology imaging. Imaging endpoints and sophisticated imaging studies are increasingly being incorporated into oncologic treatment protocols and clinical trials. This symposium underscored the need for increased awareness of the potential for radiation-related injury from repeated exposure to ionizing radiation. Such a forum brought together key members of the pediatric imaging and pediatric oncology communities and highlighted the need for evidence-based methods to guide diagnostic and surveillance imaging and to identify opportunities for interdisciplinary investigation. Numerous reports have emphasized that even low doses of radiation exposure, such as those occurring during radiological examinations, can lead to long-term adverse health outcomes, most notably increases in risk of malignancy [5, 6]. The Society for Pediatric Radiology has successfully launched the Image Gently campaign, highlighting the importance of radiation safety in pediatric imaging [7]. What began largely as an initiative within the Society for Pediatric Radiology has expanded well beyond our own society and now has representation from a large number of imaging organizations, as well as representation from major manufacturers [8]. Although the ALARA concept has been widely embraced by the pediatric radiology imaging community, it is essential that this awareness be expanded outside the imaging community to our referring clinicians. Pediatric oncology patients are some of the most aggressively treated and intensively imaged patients in pediatric practice. While imaging is central to the diagnosis, treatment and management of these critically ill children, the large number of serial—and frequently high-dose—examinations has the potential to contribute to considerable cumulative radiation exposure. Two recent studies have provided direct evidence to support this concern, demonstrating significant cumulative effective doses in multiple tumor subgroups, with neuroblastoma and lymphoma patients receiving the largest radiation burden [9, 10]. These observations were attributable to the large number of nuclear medicine and CT examinations that oncology patients routinely undergo. Because these patients are concurrently receiving cytotoxic chemotherapy and frequently radiation therapy, it may be difficult to calculate an excess relative risk attributable to S. D. Voss (*) Department of Radiology, Children’s Hospital Boston, Harvard Medical School, 300 Longwood Ave., Boston, MA 02115, USA e-mail: Stephan.Voss@childrens.harvard.edu