ILCA Keynote Report | Twenty Years of Progress -- Application and Prospect of Yttrium 90 Selective Internal Radiotherapy for Liver Cancer

 Yttrium 90 microsphere selective internal radiation therapy (SIRT) has been used for nearly 20 years as a local minimally invasive treatment at home and abroad. Relevant studies have confirmed that SIRT plays a local control role in the clinical treatment of advanced liver cancer, and has reliable efficacy and safety in combination with surgery, immunotherapy and targeted drugs. At the same time, preliminary studies have shown that the radioresection effect of SIRT on liver segments has a promising application prospect in the radical treatment of liver cancer. On September 1-4, 2022, at the 16th International Liver Cancer Association Annual Meeting (ILCA 2022) held in Spain, Professor Riad Salem of Feinberg Medical School of Northwestern University was invited to give a keynote report on the progress of the clinical application of Y-90 microspheres SIRT in the treatment of liver cancer. At the meeting, Professor Riad Salem was specially invited by the magazine to conduct an exclusive interview. Now, the content is compiled into an article for the readers.

 

 Interview with Professor Riad Salem, Feinberg Medical School of Northwestern University

Hepatology Disease : Due to the combination of imaging and modern radiotherapy equipment, tumor radiotherapy technology is also changing with each passing day. Would you please introduce the progress of radiotherapy technology for HCC in recent years?

Dr Salem: The role of radiotherapy in HCC continues to evolve. There are the techniques that are internal, such as yttrium radiotherapy, and those that are external. There is certainly a lot of worldwide interest in the internal radiotherapy like yttrium radiotherapy. I think the other external radiotherapies have a lot of compelling information and data that are being published. I believe that, in the future, radiotherapy techniques, no matter how they are applied, are going to become an essential part of treating HCC.

Hepatology Disease : At present, major HCC guidelines recommend surgical resection, liver transplantation and radiofrequency ablation for the treatment of small HCC（<5cm）. Compared with these technologies above, how is the application of the recent Y90 Radiation Therapy in patients with small HCC? What are the clinical research reports?

Dr Salem: The advantages of the yttrium radiotherapy is that it is internal, and that you are injecting the radiotherapy directly into the tumor, so there is no effect on adjacent tissue. That is a big advantage compared to other modes of radiotherapy.

Guidelines do talk about resection, transplant and ablation for smaller lesions. The problem, of course, is that other factors come into play in terms of resectability, the location of the lesion, the comorbidities of the patient that may or may not allow surgical resection, and, of course, ablation is dependent on where the lesion is located.

So radiotherapy with Y90 allows you to identify the blood supply to these lesions and apply very high dose radiation therapy. There are hundreds of research reports that have been published on this. There was a 1000-patient paper that we published in Hepatology a couple of years ago. There are now many centers in Europe that have adopted this technology as part of their toolbox against HCC.

 

Hepatology Disease : For patients with HCC complicated with venous tumor thrombus, traditional surgical treatment has a high risk of metastasis and recurrence. Therefore, surgery based combination therapy is the best policy. Would you please talk about the application prospect of recent radiotherapy?

Dr Salem: When it comes to HCC with tumor thrombus, there is a higher risk of recurrence after a surgical resection, and that is why combination therapies are indeed the best. For my approach, I believe the yttrium radiotherapy, because of it’s internal delivery, is a very good tool to treat the venous tumor thrombus and apply systemic therapy to augment and improve the response to the radiotherapy. There are many studies ongoing that will continue to improve on this. These are data that will be coming out in the coming years.

Hepatology Disease : What are the main challenges of radiotherapy in the treatment of HCC? What are the possibilities of radiotherapy in the treatment of advanced liver cancer in the future?

Dr Salem: The challenges of radiotherapy in HCC have to do with the background disease and the cirrhotic liver, and the exposure of radiotherapy to other organs. When it comes to internal radiotherapy with yttrium, many of those risks are mitigated, because the radiotherapy is being applied from the inside out. That is one of the major advantages of this radiotherapy. In terms of advanced liver cancer, particularly with locally advanced disease with portal vein thrombosis, certainly the yttrium radiotherapy and other types of radiotherapy play a role in debulking and decreasing the amount of tumor thrombus. These are often married to other types of therapy, like systemic therapies, to achieve long-term responses and hopefully extend patient survival.