Purpose or Case Report: Imaging is crucial in the staging of primary pediatric liver tumors. Hepatoblastoma, pediatric HCC and transitional-type lesions (HCC/hepatoblastoma) should be pre-operatively staged at the time of diagnosis using the PRETEXT system. The PRETEXT (PRE-Treatment EXTent of tumor) criteria were first described in 1992 and updated most recently following an international consensus in 2017, and provide reproducible imaging-based prognostic information for patient survival prior to treatment.

The PRETEXT system consists of two criteria; the group and annotation factors. The PRETEXT stage (I-IV) describes the anatomical extent of tumor within the liver, categorized according to contiguous lesion-free liver sections, whilst the annotation factors describe associated features such as vascular involvement, extrahepatic disease and metastases. These are combined and patients are divided into two risk stratified groups. The standard risk group, mostly including Stage I and II tumors, are more likely to be managed by partial hepatectomy whilst higher risk groups including stage IV tumors are often unresectable and require liver transplantation. Its ultimate goal is to determine the feasibility of surgical resection.

At our institution, our hepatobiliary surgeons use the PRETEXT criteria for prognostication and patient management. International use of these consensus criteria is essential in order to unify management of this rare pediatric tumor subtype.

Our objective is to discuss pearls and pitfalls from our experience of using the PRETEXT criteria. Relevant imaging examples from our large specialist pediatric institute will be provided with discussion of variability of scoring between CT and MRI as well as technical challenges. Selected multi-modality case-based examples will be provided with reference to patient management and operative findings where available.
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