Imaging for Staging of Pediatric Abdominal Tumors: An Update, From the AJR Special Series on Cancer Staging.

The three most common pediatric solid tumors of the abdomen are neuroblastoma, Wilms tumor, and hepatoblastoma. These embryonal tumors most commonly present in the first decade of life. Each tumor exhibits unique imaging findings, including locoregional presentation and patterns of distant spread. Neuroblastoma, Wilms tumor, and hepatoblastoma have unique staging systems that rely heavily on imaging and significantly impact surgical and oncologic management. The staging systems include image defined risk factors for neuroblastoma, Children's Oncology Group staging system for Wilms tumor, and the PRE-Treatment EXTent of tumor (PRETEXT) system for hepatoblastoma. It is important for radiologists to be aware of these staging systems to optimize image acquisition and interpretation. This article provides a practical and clinically oriented approach to the role of imaging in the staging of these common embryonal tumors of childhood. The selection among imaging modalities, key findings for determining tumor stage, and the role of imaging in posttreatment response evaluation and surveillance, are discussed. Recent updates to the relevant staging systems are highlighted, with attention to imaging findings of particular prognostic importance. The presented information will help radiologists tailor the imaging approach to the individual patient and to guide optimal oncologic management.