Hepatocellular carcinoma (HCC) is the most common form of primary liver cancer and affects millions worldwide. Due to the lack of effective systemic therapies for HCC, researchers have been investigating the use of locoregional tumor control with Yttrium-90 (Y90) radioembolization since the 1960s. Following the development of glass and resin Y90 microspheres in the early 1990s, Y90 radioembolization has been shown to be a safe and efficacious treatment for patients with HCC across Barcelona Clinic Liver Cancer (BCLC) stages. By demonstrating durable local control, good long term outcomes, and equivalent if not superior tumor responses and tolerability when compared to alternative therapies including transarterial chemoembolization (TACE) and sorafenib, Y90 radioembolization is being increasingly used in HCC treatment. More recently, investigations into variations in Y90 radioembolization technique including radiation segmentectomy and radiation lobectomy have further expanded its clinical utility. Here, we discuss the history and evolution of Y90 use in HCC. We outline key clinical trials that have established the safety and efficacy of Y90 radioembolization, and also summarize trials comparing its efficacy to existing HCC treatments. We conclude by reviewing the techniques of radiation segmentectomy and lobectomy, and by discussing dosimetry.

No abstract

To demonstrate postangiographic Lipiodol (LIP) in hepatocellular carcinoma (HCC) in paraffin sections, direct impregnation of formalin-fixed tissue blocks with silver nitrate (AgNO3) was followed by routine processing. LIP appeared as black globules in the sinusoids. Ninety-four tissue blocks from 13 postangiographic LIP HCCs and 69 from 8 non-LIP HCCs and 4 fatty livers were studied. Seventy-two of 73 negative controls and all positive blocks as seen on soft tissue radiographs (STRs) were correctly coded (specificity 98.6%, sensitivity 100%). Twenty-six of the 44 LIP-negative areas on STRs from LIP cases contained scanty globules of less than 10 microns in diameter. Fatty change gave no positive readings. Thus, modified AgNO3 impregnation is a simple, accurate means of detecting LIP in high-quality paraffin sections suitable for tumor diagnosis and, if applied to postangiographic LIP, ultrasonographically guided liver biopsy, can verify that a biopsy has reached a suspected tumor focus.

To study the distribution and thromboembolic effect of Ultrafluid Lipiodol, 15 surgically removed hepatocellular carcinomas with selective intraarterial Lipiodol injection 7 to 10 days before surgery and 15 noninjected controls were studied radiologically and histologically. Tissue blocks were processed with an en bloc silver impregnation technique for Lipiodol localization in histologic sections. Lipiodol was distributed evenly in tumors measuring less than 5 cm in diameter and peripherally in tumors measuring 10 cm or more. Lipiodol droplets were mainly extracellular. There was no difference in tumor architecture or in hemorrhage and necrosis scores between Lipiodol-injected cases and negative controls (1.18 versus 0.92). Similarly, in injected cases, no differences were observed between Lipiodol-positive and Lipiodol-negative areas (scores of x-ray Lipiodol-positive versus Lipiodol-negative areas: 1.17 versus 1.36; scores of microscopic Lipiodol-positive versus Lipiodol-negative areas: 1.18 versus 1.14). Lipiodol-negative but hypodense areas examined by x-ray proved to be necrosis or fibrosis with or without viable tumor islands. Lipiodol has no thromboembolic effects. The uneven Lipiodol distribution may account for its failure as a carrier for chemotherapeutic agents in large tumors.