Treatment of Unresectable Primary and Metastatic Liver Cancer with Yttrium-90 Microspheres (TheraSphere®): Assessment of Hepatic Arterial Embolization

Abstract

In Canada and Europe, yttrium-90 microspheres (TheraSphere); MDS Nordion, Ottawa, Canada) are a primary treatment option for primary and secondary hepatic malignancies. We present data from 30 patients with hepatocellular carcinoma (HCC) and metastatic liver disease treated with TheraSphere from a single academic institution to evaluate the angiographically evident embolization that follows treatment. Seven interventional radiologists from one treatment center compared pretreatment and posttreatment angiograms. The reviewers were blinded to the timing of the studies. The incidence of postembolization syndrome (PES) was determined as well as objective tumor response rates by the World Health Organization (WHO), Response Evaluation Criteria in Solid Tumors (RECIST), and European Association for the Study of the Liver (EASL) criteria. There were 420 independent angiographic observations that were assessed using the chi-squared statistic. The pretreatment and posttreatment angiograms could not be correctly identified on average more than 43% of the time (p = 0.0004). The postprocedure arterial patency rate was 100%. The objective tumor response rates for all patients were 24%, 31%, and 72% for WHO, RECIST, and EASL criteria, respectively. All of the patients tolerated the procedure without complications and were treated on an outpatient basis, and four patients had evidence of PES. This treatment method does not result in macroscopic embolization of the hepatic arteries, thereby maintaining hepatic tissue perfusion. These data support the principle that the favorable response rates reported with TheraSphere are likely due to radiation and microscopic embolization rather than flow-related macroscopic embolization and ischemia.

Yttrium-90 microsphere radioembolization for the treatment of liver malignancies: a structured meta-analysis

“…It has been reported in the literature that administration of resin microspheres had to be prematurely halted, before the predetermined amount of radioactivity was instilled, due to macroscopic embolization [43]. In contrast, the relatively very low number of glass microspheres per dose is associated with microscopic embolization [39]. However, the low number of particles infused in the case of the glass microspheres may be a disadvantage when targeting a tumor type that is often diffusely spread throughout the liver at the time of diagnosis [44]; the radiation dose would be distributed in and around the tumors too heterogeneously to be able to deliver a tumoricidal dose to the entire lesion even if the total Y-RE arm alone c CT of 3 out of 36 patients not assessable amount of radioactivity of a dose of glass microspheres is at least 50% higher than is the case in the resin microspheres (Table 1).…”

“…PES is characterized by fatigue, nausea, fever, right upper quadrant pain, and/or vomitus, all of which are transitory and can be effectively controlled by outpatient medication [21, 39,[45][46][47].…”

“…In 14 articles clinical data were presented on tumor response and survival for 425 patients with HCC who had received 90 Y-RE [11,18,24,[30][31][32][33][34][35][36][37][38][39][40]. Twelve studies presented data of tumor response for a total of 318 patients.…”

Safety and efficacy of 90Y radiotherapy for hepatocellular carcinoma with and without portal vein thrombosis

“…Clinical experience with this device has shown a low incidence of post embolization syndrome, directly supporting its minimally embolic effect. 11,12 A preliminary safety analysis in 15 patients with unresectable HCC and PVT without cavernous transformation has been reported. 90 Y therapy was well tolerated, and in the absence of disease progression, no clinically significant post-treatment bilirubin elevations were noted.…”

Bridging and downstaging therapy in patients suffering from hepatocellular carcinoma waiting on the list of liver transplantation

“…The highly concentrated radioactive substance would be administrated to the tumor, while keeping the level of toxicity affecting the functional liver parenchyma at the minimal and preserving the blood supply (94,95). It was also safe for use in patients with portal vein thrombosis (96).…”