Yttrium-90 Radiation Segmentectomy

Advances and Emerging Techniques in Y-90 Radioembolization for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer deaths worldwide. Despite the high incidence of HCC, mortality remains high, with an estimated 5-year survival rate of less than 20%. Surgical resection represents a potential curative treatment for HCC; however, less than 20% of patients with HCC are candidates for surgical resection. In patients with unresectable HCC, Yttrium-90 (Y90) transarterial radioembolization (TARE) has emerged as an innovative treatment option. This locoregional therapy delivers high doses of radiation directly to liver tumors via intra-arterial injection, allowing for the targeted destruction of malignant cells while sparing surrounding healthy tissue. In this review, we will explore the latest advances in Y90 TARE for the treatment of HCC, focusing on key developments such as the following: (1) improvements in radiation lobectomy and segmentectomy techniques, (2) the introduction of personalized dosimetry, (3) the integration of combination therapies, (4) the use of imageable microspheres, (5) pressure-enabled Y90 delivery systems, and (6) the application of Y90 surrogates.

Radioembolization of HCC and secondary hepatic tumors: a comprehensive review

Transarterial radioembolization (TARE), also called Selective Internal Radiation Therapy (SIRT), has emerged as an effective locoregional therapy for primary and secondary hepatic tumors, utilizing yttrium-90 (Y90) microspheres and other agents such as holmium-166 and rhenium-188. TARE has various applications in the management of HCC across different BCLC stages. Radiation segmentectomy, which involves administering high doses of Y90 (>190 Gy), can be both curative and ablative, achieving complete necrosis of the tumor. In contrast, radiation lobectomy involves administering a lower dose of Y90 (80-120 Gy) as a neoadjuvant treatment modality to improve local control and induce future liver remnant (FLR) hypertrophy in patients who are planned to undergo surgery but have insufficient FLR. Modified radiation lobectomy combines both techniques and offers several advantages over portal vein embolization (PVE). Y90 is also used in downstaging HCC patients outside liver transplantation criteria, as well as bridging those awaiting liver transplantation (LT). Multiple studies and combined analyses were described to highlight the outcomes of TARE and compare it with other treatment modalities, including TACE and sorafenib. Additionally, the review delves into the efficacy and safety of radioembolization in managing metastatic colorectal cancer and other metastatic tumors to the liver. Recent studies have emphasized the role of personalized dosimetry for improved outcomes, and thus we described the different methods used for this purpose. Pretherapy imaging, estimating lung shunt, selection of therapeutic radionuclides, adverse effects, and cost-effectiveness were all discussed as well.

Conversion Therapy to Transplant or Surgical Resection in Patients with Unresectable Hepatocellular Carcinoma Treated with Boosted Dose of Yttrium-90 Radiation Segmentectomy

BACKGROUND/OBJECTIVES

The aim of this study was to assess the efficacy of boosted dose yttrium-90 radioembolization (TARE) as a modality for conversion therapy to transplant or surgical resection in patients with unresectable hepatocellular carcinoma (HCC).

METHODS

In this single-center retrospective study, all patients with a diagnosis of HCC who were treated with boosted dose TARE (>190 Gy) between January 2013 and December 2023 were reviewed. Treatment response and decrease in tumor size were assessed with the RECIST v1.1 and mRECIST criteria. Milan and University of California, San Francisco (UCSF), criteria were used to determine transplant eligibility, and Barcelona Clinic Liver Cancer (BCLC) surgical resection recommendations were used to evaluate tumor resectability.

RESULTS

Thirty-eight patients with primary HCC who were treated with boosted dose TARE were retrospectively analyzed. The majority of the patients were Child-Pugh A (n = 35; 92.1%), BCLC C (n = 17; 44.7%), and ECOG performance status 0 (n = 25; 65.8%). The mean sum of the target lesions was 6.0 cm (standard deviation; SD = 4.0). The objective response rate (ORR) was 31.6% by RECIST and 84.2% by mRECIST. The disease control rate (DCR) was 94.7% by both RECIST and mRECIST. Among patients outside of Milan or UCSF, 13/25 (52.0%, Milan) and 9/19 (47.4%, UCSF) patients were successfully converted to within transplant criteria. Of patients who were initially unresectable, conversion was successful in 7/26 (26.9%) patients.

CONCLUSIONS

This study provides further real-world data demonstrating that boosted-dose TARE is an effective modality for conversion of patients with unresectable HCC to transplant or resection.

Ablation versus Radiation Segmentectomy for Small Liver Tumors

Hepatocellular carcinoma (HCC) is a liver malignancy that affects more than a million people worldwide with a complex multifactorial etiology. After the diagnosis of HCC is made, physicians establish management using the Barcelona Clinic Liver Cancer (BCLC) guidelines revolving around tumor stage, liver function, performance status, and patient preferences. According to recent updates to these guidelines, thermal ablation is the second-best curative option apart from surgical resection for small HCC (< 2 cm). While thermal ablation is standard of care, recent studies have suggested that radiation segmentectomy (RS) has similar outcomes, limited hepatotoxicity, and ultimately a cost-efficient approach. Although there is limited literature on RS, this article compares ablation techniques against radiation segmentectomy for small HCC tumors.