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Treatment of hepatocellular carcinoma with arterioportal shunting using balloon-assisted transarterial yttrium-90 radiation segmentectomy: A case report
How to cite this article: Kolyvas P, Aljundi M, Sivananthan G. Treatment of hepatocellular carcinoma with arterioportal shunting using balloon-assisted transarterial yttrium-90 radiation segmentectomy: A case report. Am J Interv Radiol 2023;7:12.
Portal vein tumor thrombus (PVTT) is a common finding associated with hepatocellular carcinoma (HCC) often further complicated by arterioportal shunting. While radioembolization with Yttrium-90 (Y-90) is the preferred treatment for HCC with PVTT, shunting can complicate particle delivery. Here, we describe a case of a 65-year-old man with HCC and significant shunting from the segment IV hepatic artery into the left and right portal veins due to a PVTT. We performed a balloon-assisted radiation segmentectomy by occluding the hepatic artery supplying the PVTT to minimize arterioportal shunting and promote redistribution of particles into the tumor bed. Post Y-90 bremsstrahlung scan correlated with appropriate uptake. One-month follow-up magnetic resonance imaging demonstrated response to treatment with decreased tumor thrombus in the left portal vein. Here, we demonstrate that balloon-occlusion-assisted transarterial radiation segmentectomy could be a beneficial approach for improving tumor response and reducing complications in individuals with HCC and arterioportal shunting.
Portal vein tumor thrombus
Radioembolization with Yttrium-90 (Y-90) is the locoregional treatment of choice in patients with hepatocellular carcinoma (HCC) and portal vein tumor thrombus (PVTT). Radiation segmentectomy, defined as radioembolization of two or fewer segments of the liver, has been shown to improve outcomes in patients with PVTT when doses >205 Gy are utilized compared with those patients who receive lower doses.[1,2] Unfortunately, arterioportal venous shunts (APS), often seen concurrently with HCC PVTT, have been hypothesized to decrease the response to treatment and increase adverse events. This is thought to be a result of poor implantation of microparticles in the tumor as the particles exit through the capillary bed without stasis, reducing the therapeutic dose, and increasing the rate of adverse events by redistributing particles to non-target liver segments. This shunting is often minor and limited to the tumor-involved segment or lobe. Rarely, a major shunt can result in shunting to both the involved and uninvolved lobes as well as the extrahepatic portal system. In these patients with major shunts, segmentectomy dosing cannot be delivered as the dose would be redistributed to the entire liver. We describe a case where we used a balloon-occlusion microcatheter in the hepatic artery supplying PVTT to minimize arterioportal shunting and promote redistribution of particles into the tumor bed, specifically the PVTT component, during Y-90 glass microspheres radiation segmentectomy in a patient with HCC and APS. The Institutional Review Board approval was not required for this report.
A 65-year-old male with hepatitis C cirrhosis, chronic kidney disease, and recently diagnosed HCC presented with abdominal pain, decreased appetite, and weight loss. He was risk stratified as Child-Pugh 5A, albumin-bilirubin grade 1, and eastern cooperative oncology group grade 1 and referred for Y-90 treatment. Magnetic resonance imaging (MRI) demonstrated extensive bilobar HCC with enhancing tumor thrombus in the left portal vein as well as porta hepatis nodal metastasis [Figure 1]. At presentation, vital signs were within normal limits, total bilirubin level was 0.2 mg/dL, and alpha-fetoprotein was 9.6 ng/mL (normal range, <10 ng/mL). Given the extensive liver-centered malignancy burden with vascular invasion in the setting of preserved liver function and functional status, the decision was made to proceed with radioembolization with planned segmentectomy dose to the PVTT and lobar treatment to the left lobe.
Digital subtraction angiogram (DSA) performed through a conventional microcatheter in the left hepatic artery demonstrated rapid shunting into the left and right portal veins. Similarly, a DSA with the sniper microcatheter (Embolix, Los Altos, California) with the balloon deflated and positioned in the segment IV branch of the left hepatic artery demonstrated subtle tumor blush in the left lobe with quick opacification of the right and left portal veins [Figure 2a]. Cone-beam computed tomography (CBCT) was performed with a rate of 1 mL/s for a total volume of 10 mL and demonstrated enhancement of the right and left hepatic lobe parenchyma [Figure 2b]. Repeat DSA and CBCT with balloon occlusion of the segment IV branch demonstrated improved tumor enhancement without arterioportal shunting into the right lobe [Figure 3a and b]. Tc-99 m macroaggregated albumin (MAA) was administered into segment IV during balloon occlusion and single-photon emission computed tomography–computed tomography demonstrated high activity in the left lobe tumor as well as the left portal vein thrombus with minimal uptake in the right hepatic lobe [Figure 4]. Pre-treatment Tc-99m MAA scintigram demonstrated a lung shunt of 10% and perfused volume of 790 mL. The left lobe of the liver, including the left PVTT, was treated with Y-90 glass microspheres (BTG International, Ottawa, Canada) utilizing balloon occlusion in the same fashion. The total activity delivered was 4.878 GBq, with a 286 Gy dose delivered to the perfused liver volume of 790 mL and a dose delivered to the lung of 24.39 Gy. Post Y-90 bremsstrahlung scan correlated with the mapping study [Figure 5]. There were no intraprocedural complications and 1-month follow-up MRI demonstrated response to treatment with decreased tumor thrombus in the left portal vein [Figure 6].
The presence of arterioportal shunts in HCC impacts the efficacy and safety of radioembolization due to particles siphoning off through the shunt, potentially leading to underdosing of the target lesion and increased deposition of radiation in normal liver tissue leading to further liver damage. The risk of adverse events after radioembolization is highest with non-segmental and large shunts. Permanent occlusion of some shunts is possible with various embolic agents including polyvinyl alcohol, lipiodol gelatin, sponge granules, cyanoacrylate, and coils and could potentially be followed by typical radioembolization.[5,6] However, these strategies carry additional risks including non-target embolization, portal vein occlusion, or proximal embolization thus preventing access to the tumor for future treatment. To date, there are no clear guidelines in management of large APS due to PVTT.
This case demonstrates a technique that allows delivery of Y-90 beads to the target tumoral tissue in the setting of significant portal vein shunting that would otherwise redistribute the particles throughout the liver, resulting in insufficient dose to the tumor and high does to non-target liver parenchyma. The occlusion balloon in the arterial side of the portal vein shunt decreases the pressure in the arterial system compared to the portal vein, thereby reversing flow away from the shunt. The degree to which this happens is dependent on the intrahepatic collaterals that perfuse the target artery distal to the balloon.
Balloon-occlusion-assisted transarterial radiation segmentectomy may be an effective method to increase tumor response and decrease the rate of complications in patients with HCC and arterioportal shunting undergoing radiation segmentectomy. Future prospective studies may be warranted to determine the feasibility and safety of adding balloon-occlusion transarterial radioembolization segmentectomy to standardized treatment algorithms.
This case was accepted as a poster at global embolization symposium technologies (GEST) 2023.
Declaration of patient consent
Patient’s consent not required as patient’s identity is not disclosed or compromised.
Conflicts of interest
Dr. Sivananthan is a consultant for Boston Scientific and on the medical advisory board for Embolix inc.
Financial support and sponsorship
We plan to apply for support from embolix to pay any publication/processing fee.