Image-Guided Biopsy for the Diagnosis and Molecular Profiling of Hepatoblastoma.

Introduction: Studies on the use of image-guided percutaneous biopsy for hepatoblastoma (HB), and recommendations put forth by the pediatric hepatic international tumor trial (PHITT), are limited. It is unknown if sufficient tissue can be obtained for trial enrollment as well as molecular profiling, which will likely play a key role in informing future treatment strategies.

Methods And Materials: Patients with HB who underwent percutaneous biopsy at initial diagnosis in interventional radiology (IR) over a 12-year period at a single center were included. Patient demographics, pretreatment extent of disease (PRETEXT) stage, tumor size, and procedure details were collected. Pathology reports and tumor genomic analysis, when performed, were assessed for specimen adequacy. Post-procedure records were assessed for hemoperitoneum.

Results: A total of 33 percutaneous biopsies were performed on 32 patients [17 female; median age 1.3 years (IQR: 0.7-2.5 years); median weight 10.5 kg (IQR: 7.4-12.7 kg)]. Most (n = 27) had a single liver lesion, and most (n = 18) were PRETEXT II. A total of 15 were positive for at least one annotation factor. Median longest tumor axis was 9.3 cm (IQR: 5.0-13.5 cm). A total of 16 patients had concurrent non-targeted liver biopsy, per PHITT recommendations. An 18-gauge instrument was most commonly used (n = 24, 73%) with a median of 8 cores (IQR: 6-12) obtained. There were no instances of hemoperitoneum. Tissue was adequate for histologic diagnosis in 97% (n = 32), with histologic subtyping obtained in 94% (30/32). When available (n = 29), comparison with the subsequent surgical resection specimen showed subtype concordance in 15 (52%) patients and minor variations secondary to sampling or treatment effect in 14 patients. Molecular profiling was completed on 21/21 specimens (100%), with 19/21 (90%) showing potentially clinically significant variants, most commonly in CTNNB1 (16/21).

Conclusion: In this single-center study, percutaneous biopsy resulted in no serious adverse events, a high rate of diagnosis, and successful subtyping and molecular characterization of HB.