Cancer Predisposition Syndromes in Children: Who, When, and How to Screen?

Childhood cancer predisposition syndromes (CPSs) are individually rare but collectively account for approximately 15%-20% of pediatric cancers. Advances in genomic testing have identified more than 100 cancer susceptibility genes, enabling earlier recognition of at-risk children and prompting implementation of structured surveillance programs. Imaging is central to screening, which also typically includes physical examination and biochemical testing, guided by the syndrome-specific tumor spectrum, age-related penetrance, tumor growth kinetics, and defined risk thresholds. In general, screening is recommended when the risk of developing a malignancy exceeds 5% within a specified age window. Pediatric CPS surveillance presents unique challenges. Protocols must balance early tumor detection with minimization of potential harm, including cumulative radiation exposure, contrast material-related risks, sedation requirements, and psychosocial burden associated with repeated or lifelong imaging. Ionizing radiation-free modalities, particularly US and MRI, form the backbone of surveillance. Whole-body MRI, with its large field of view and ability to allow assessment of multiple organ systems in a single examination, is increasingly incorporated into surveillance protocols for select syndromes associated with a variety of tumors. Sequence optimization and nonsedative strategies are frequently used to mitigate prolonged acquisition. Familiarity with syndrome-specific tumor imaging characteristics is essential to optimize lesion detection and reduce false-positive and false-negative interpretations. Radiologists may also be the first to recognize characteristic tumors suggestive of an underlying hereditary condition. On the basis of the updated recommendations from the 2023 American Association for Cancer Research pediatric CPS workshop, the authors review outlines guiding principles for surveillance, summarizing imaging components of current protocols for several common or clinically significant childhood CPSs.