New frontiers in pediatric oncologic imaging

As imaging technologies advance, a paradigm shift is emerging in the assessment of tumor response to therapy. The traditional method of measuring tumor size may not reflect changes in tumor viability induced by chemotherapy and radiation therapy. Today's oncologists and radiologists seek objective methods for assessing tumor metabolism and blood flow, measures that provide earlier, more accurate information about treatment effects. Pediatric imaging presents unique challenges not encountered in adult imaging, including the need for sedation and consideration of the long-term effects of radiation exposure in a growing child. Therefore, the potential risks and benefits of new imaging approaches for monitoring anticancer treatment in children require careful consideration. Several new imaging techniques are currently under investigation for use in pediatric oncology. These include dynamic enhanced magnetic resonance imaging and quantitative contrast-enhanced ultrasonography for assessment of blood flow in solid tumors such as osteosarcoma and neuroblastoma, and nuclear imaging, including positron emission tomography–computed tomography, for assessment of pediatric musculoskeletal tumors and neuroblastoma. The potential value, relative advantages, and limitations of these new methods in monitoring anticancer therapy in children are discussed.