Appropriate Screening Modality Selection Is Critical for Surveilling Childhood Cancer Predisposition Syndromes
Unique challenges drive special consideration of capabilities, long-term consequences of possible modalities and approaches
In concert with the RadioGraphics monograph, RSNA News shares the latest on the role of imaging in disease screening.
Imaging surveillance for children with cancer predisposition syndromes (CPS) requires a tailored approach that balances diagnostic performance against the potential risks of repeated imaging.
CPS collectively account for approximately 15-20% of pediatric cancers. Because the nine major subgroups differ in their genetic causes, affected tissues, clinical features and prognoses, imaging surveillance must be tailored to each condition.
“While a team of radiologists and I prepared updates stemming from the 2023 American Association for Cancer Research (AACR) Special Childhood Cancer Predisposition Workshop, we recognized the value of bringing together the radiology components of the more common or clinically significant childhood CPS into a single document,” said Mary-Louise Greer, MBBS, FRANZCR, from the Department of Diagnostic and Interventional Radiology at The Hospital for Sick Children in Toronto.
“Our aim was to create a practical review for radiologists interested in establishing a CPS screening program—one that explains the principles of surveillance while drawing on the team’s real-world experience across a range of clinical settings,” said Kevin Fung, MBBS, FRCR, FHKCR, EBIR, from the Department of Radiology at Hong Kong Children’s Hospital in Hong Kong.
In an article published in RadioGraphics, Drs. Greer and Fung and colleagues review guidelines for who to screen and when, and they provide recommended imaging approaches for specific cancers in each of the nine subgroups.
“Imaging is central to many surveillance protocols, but the decision to screen requires a careful balance of benefit and risk. Childhood-onset CPS are increasingly recognized as more infants and children undergo genetic testing and are found to carry a pathogenic or likely pathogenic variant. Genetic testing may be prompted by a characteristic tumor or an unusually young age at presentation, as with adrenocortical carcinoma in Li-Fraumeni syndrome,” Dr. Greer said. “Or, testing may be performed in asymptomatic children, pre- or postnatally, for a known familial variant or for evaluation of non-tumor manifestations of a CPS such as café-au-lait macules in neurofibromatosis type 1 (NF1).”
The authors note that imaging is typically recommended for anyone with a 5% or greater risk of developing a childhood cancer within a defined age window, with some exceptions.
“For radiologists, the main challenges are understanding the spectrum of tumors associated with each CPS across organs and ages and selecting the most appropriate modality while accounting for sensitivity, specificity, body habitus and the potential need for sedation.” Dr. Fung said. “We must also minimize ionizing radiation whenever possible. Tumors detected through surveillance are often small and subtle, and occasionally difficult to differentiate from normal developmental changes, creating the potential for both false-negative and false-positive findings.”
Neurofibromatosis type 2–related schwannomatosis in a 14-year-old adolescent girl undergoing surveillance imaging. (A) Axial contrast-enhanced T1-weighted image shows an enhancing lesion (arrow) at the left cerebellopontine angle with extension into the internal acoustic meatus, compatible with a vestibular schwannoma. (B) Coronal T2-weighted image of the cervical spine shows the left vestibular schwannoma (arrow) and another schwannoma (arrowhead) at the left C4–C5 neural foramina, causing spinal cord displacement.
https://doi.org/10.1148/rg.260022 ©RSNA 2026
Weighing The Advantages and Risks of Imaging Approaches
US and MRI are primary imaging modalities for pediatric CPS surveillance, although each has limitations related to lesion detection, patient size and the potential need for sedation.
CT and PET/CT play more selective roles because of ionizing radiation exposure, though CT remains important for detecting pulmonary lesions, and PET/CT may help characterize suspicious findings identified on regular surveillance imaging.
Because each CPS carries a distinct tumor profile, these considerations inform syndrome-specific screening recommendations. For example, Wilms tumor, which is found in patients with Beckwith-Wiedemann Syndrome/Spectrum (BWS/BWSp), is best screened with renal US.
By contrast, Li-Fraumeni Syndrome (LFS), an autosomal dominant CPS characterized by soft tissue and bone sarcomas and CNS tumors, among others, requires whole-body MRI (WBMRI), with additional dedicated brain MRI, for screening.
Some syndromes necessitate the use of higher-radiation modalities, despite their drawbacks, the authors note. For example, screening for pleuropulmonary blastoma in DICER1-related tumor predisposition requires chest CT despite the risks associated with ionizing radiation exposure.
However, new technologies are underway to reduce the need for CT. “Lung MRI is an exciting development that may allow us to screen for pulmonary cysts in infants with DICER1-related tumor predisposition without the ionizing radiation of chest CT,” Dr. Greer said.
Looking Towards Emerging Non-Imaging Components for Surveillance
“Along with imaging, clinical examination, laboratory testing and endoscopic testing are used to detect disease early in an integrated way, with specific elements differing between syndromes,” Dr. Greer said.
“For example, while liquid biopsy is not yet in routine clinical use, we are particularly excited about its potential to detect circulating tumor DNA (ctDNA) to eventually help us triage patients,” Dr. Fung said. “It may be particularly beneficial for those living in remote or resource-limited settings.”
He noted that a positive result could prompt more comprehensive or directed imaging, while a negative result might support longer intervals between examinations such as whole-body MRI. However, he emphasized that the appropriate response to discordant results will need to be clearly defined through rigorous testing and validation.
Balancing Innovation with Family-Centered Care
Yet, even with the development of these new technologies, perhaps the most notable aspect of the field is the adaptability of everyone involved. “There is a genuine readiness to revise protocols as new evidence emerges,” Dr. Greer said. “But, above all, we remain most struck by the resilience and extraordinary grace of our patients and their families, who live with these syndromes and all they entail.”
As such, the authors note that designing screening protocols goes beyond just recommending the best imaging modality and timeline. “We also prioritize rapid report turnaround because we recognize the 'scanxiety' families experience both before the examination and while waiting for the result,” Dr. Fung said. “Together, these steps help us add value to care of this very special group of patients beyond simply interpreting the images.”
These factors highlight that screening for CPS is a complex, multifaceted task. “As guidelines continue to evolve, radiologists have an important role in shaping the scope and frequency of surveillance and coordinating it with diagnostic imaging to avoid unnecessary duplication,” Drs. Greer and Fung said.
For More Information
Access the RadioGraphics article, “Cancer Predisposition Syndromes in Children: Who, When, and How to Screen?”
Read previous RSNA News stories on pediatric imaging: