Yttrium-90 Transarterial Radioembolization as a Bridging Therapy to Liver Transplant in a Toddler With Pretreatment Extent (PRETEXT) IV Hepatoblastoma.

Hepatoblastoma (HB) is a rare but highly malignant tumor that commonly arises in utero. The mainstay treatment is surgical resection, with adjuvant treatment options including chemotherapy, hepatic artery chemoembolization, and liver transplantation. Yttrium-90 (Y90) transarterial radioembolization (TARE Y90) is a developing treatment option that utilizes radioactive beads delivered specifically to blood vessels supplying the tumor. This treatment method has previously been utilized in the treatment of adult tumors but has rarely been utilized in the pediatric population. In this report, we discuss the case of a toddler with an unresectable HB who underwent TARE Y90 as an adjuvant treatment to chemotherapy, ending in a successful liver transplantation. This patient was a 19-month-old female who presented with an abdominal mass and laboratory findings significant for anemia, thrombocytosis, elevated lactate dehydrogenase (LDH), direct hyperbilirubinemia, and alpha-fetoprotein (AFP) elevation. A computed tomography (CT) scan and magnetic resonance imaging (MRI) displayed a large, multilobular mass involving all lobes of the liver without evidence of metastasis, and biopsy results were consistent with HB. Following four rounds of chemotherapy, an MRI of the abdomen revealed a decrease in tumor size. Due to the continued uptrend of AFP raising concern for lack of control of the tumor, treatment with TARE Y90 microspheres radioembolization as a bridging therapy was initiated. Repeat scans showed an interval increase in the HB size, likely secondary to tumor necrosis with edema and hyperemia. Nine months following the diagnosis, the patient underwent an orthotopic liver transplant and a sixth cycle of chemotherapy.  This report illustrates the use of TARE Y90 in a pediatric patient diagnosed with HB, thereby inducing a direct cytotoxic effect on tumor cells. Adjunctive therapy Y90 radioembolization worked by controlling tumor size and AFP levels, facilitating the crucial aspect of liver transplantation with tumor resection with negative margins. The patient did not suffer any of the known side effects of TARE Y90 therapy, which include, but are not limited to, post-embolization syndrome, biliary complications, stricture, cholangitis, pulmonary complications, and gastrointestinal ulcers. This therapy, along with chemotherapy, has the potential to be a novel approach as a bridge to resection or orthotopic liver transplant in HB patients. Further case reports and a manuscript compiling the use of Y90 radioembolization therapy in pediatric HB patients would be useful in evaluating the efficacy of the treatment in pediatric patients.