Abstract No. 7 Experience with radioembolization for hepatocellular carcinoma complicated by portal vein tumor thrombus

Abstract

Hepatocellular carcinoma (HCC) with portal vein tumor thrombus (PVTT) has a poor prognosis of 3 months without treatment. A study found that where the predicted radiation dose to PVTT was greater than 205 Gy, median overall survival was 18.2 months. Follow-up studies have been lacking. We evaluated our experience treating PVTT with radioembolization using post-radioembolization PET/CT to calculate radiation dose. We reviewed medical charts for all radioembolizations for HCC with PVTT at a large academic institution for the past 3 years. Patient demographics, labs, tumor type/location and imaging were reviewed. Mirada Simplicit90Y software was used for radiation dosimetry calculations. Sixteen patients had HCC with PVTT and were treated with TheraSphere radioembolization. Six patients were excluded from review because of no follow-up, developed PVTT during treatment or died from drug overdose. Eight of 10 patients had radiation doses to PVTT greater than 238 Gy. Two patients had PVTT radiation doses of 148 and 101 Gy and no response was seen in PVTT. One patient had a dose of 187 Gy and partial response was seen in PVTT. Three patients with radiation doses greater than 238 Gy had complete responses in the PVTT and parenchymal disease; two are living over 2.5 years from procedure, and one died from a gastrointestinal bleed at 404 days. Although these three patients had PVTT involving main/lobar portal veins, parenchymal disease was unilobar. Of remaining four patients, two had complete and two had partial responses in PVTT; however, none had complete overall imaging responses because of prior untreated hepatic vein tumor thrombus (HVTT) or bilobar parenchymal disease. Eight patients also had medical therapy. Our limited experience found that HCC with PVTT treated with radioembolization had mean survival of 778 days for those with unilobar parenchymal disease, regardless of extent of PVTT, when the PVTT was treated with a radiation dose greater than 238 Gy. Patients with bilobar parenchymal disease who had their PVTT treated with a radiation dose greater than 238 Gy had a mean survival of 181 days.