Biochemical Safety of Ablative Yttrium-90 Radioembolization for Hepatocellular Carcinoma as a Function of Percent Liver Treated

Radiation Segmentectomy or Ablative External Beam Radiation Therapy as Initial Treatment for Solitary Hepatocellular Carcinoma: A Multicenter Experience

Purpose

Radiation segmentectomy (RS) and ablative external beam radiation therapy (EBRT) are now accepted, definitive, local therapies for hepatocellular carcinoma (HCC). This report aimed to describe the clinical outcomes of RS and EBRT for treatment-naïve, solitary, HCC.

Methods

A multicenter retrospective review was performed of all patients treated with RS or EBRT from March 2016 through September 2023. Inclusion criteria were initial treatment for solitary HCC ≤8 cm and absence of macrovascular invasion or extrahepatic disease. Outcomes were censored for liver transplantation (LT).

Results

Eighty-six patients (RS: 58; EBRT: 28) met inclusion criteria. The EBRT cohort had older patients (median 76 vs 66 years, p < 0.001), larger tumors (median 3.7 vs 2.4 cm, p < 0.001), and worse performance status (p = 0.02). The RS cohort had more patients with ≥ grade 3 liver fibrosis (p < 0.001). Radiologic complete response (rCR) was achieved in 97% of RS and 82% of EBRT patients (p = 0.02). Median time to rCR was 1 month (95% CI: 0.9-1.1) after RS and 7 months (95% CI: 6-7) after EBRT (p < 0.001). The 1-year local control was 97% vs 93% for RS and EBRT, respectively (p = 0.80). Subsequent LT was performed in 48% of RS and 11% of EBRT patients with tumor complete pathologic response rates of 76% (n=22/28) and 33% (n=1/3), respectively. Progression free survival at 1-year was 87% after RS vs 80% after EBRT (p = 0.26). 1- and 2-year overall survival was 88% and 85% after RS vs 84% and 59% after EBRT (p = 0.34).

Conclusion

RS and EBRT are effective therapies for solitary HCC. Treatment should be determined via multidisciplinary discussion based on individual patient characteristics.

Radiation segmentectomy for early hepatocellular carcinoma is curative

In this expert opinion, we provide the rationale for concluding that radiation segmentectomy (using the RADSEG method) - a technique involving the transarterial delivery of an ablative, complete necrosis-inducing dose of yttrium-90 radiotherapy - is curative in limited-disease burden hepatocellular carcinoma (HCC). Currently, curative options for early stage and other carefully selected HCC cases include transplantation, resection, and ablation. Because of issues with organ availability, co-morbidities preventing resection, and tumour size and location limiting ablation, other treatments are necessary for this selected patient population. The RADSEG method has evolved into an intra-arterial approach in this setting, with long-term outcomes comparable to ablation, resection, and transplantation. It is proposed that yttrium-90 radioembolisation, applying the RADSEG technique, be formally recognised as curative for early HCC.

Selective internal radiation therapy across Barcelona Clinic Liver Cancer (BCLC) stages of hepatocellular carcinoma: literature review

Background and Objective

Selective internal radiation therapy (SIRT) represents an endovascular treatment option for patients with hepatocellular carcinoma (HCC). Its use is widely recognized in the intermediate and advanced HCC, but it has become more prevalent in recent years in different Barcelona Clinic Liver Cancer (BCLC) stages. The aim of this review is to summarize the role of SIRT and its clinical implications through different stages of HCC.

Methods

A literature review of papers on this topic was performed using PubMed MEDLINE, focusing exclusively on the role of yttrium-90 SIRT across all BCLC stages and comparing it with other treatments. Only English-language papers currently available until September 2023 were considered.

Key Content and Findings

Many studies have shown that SIRT is a promising tool with multiple uses, such as tumour control in the context of bridge-to-liver transplantation or resection, tumour downstaging, and curative therapy in selected patients. Therefore, according to the recent update of BCLC staging system criteria, SIRT now emerges as a potential curative treatment for early-stage HCC patients, serving as an alternative when ablation or resection is not feasible. It is also a promising treatment compared to transarterial chemoembolization (TACE) as well as in combination with immunotherapies.

Conclusions

SIRT is a safe and effective treatment for selected patients at all BCLC stages of HCC. Therefore, due to its numerous advantages, SIRT may prove useful in many complex HCC treatment situations in the near future.

Keywords

Hepatocellular carcinoma (HCC); radioembolization; yttrium-90 (90Y); selective internal radiation therapy (SIRT); transarterial radioembolization (TARE).

Using Voxel-Based Dosimetry to Evaluate Sphere Concentration and Tumor Dose in Hepatocellular Carcinoma Treated with Yttrium-90 Radiation Segmentectomy with Glass Microspheres

PURPOSE

To utilize voxel-based dosimetry following radiation segmentectomy (RS) to understand microsphere distribution and validate current literature regarding radiologic and pathologic outcomes.

MATERIALS AND METHODS

A retrospective, single-center analysis of patients with solitary hepatocellular carcinoma (N = 56) treated with yttrium-90 (90Y) RS with glass microspheres (Therasphere; Boston Scientific, Marlborough, Massachusetts) from 2020 to 2022 was performed. Posttreatment voxel-based dosimetry was evaluated using Mirada DBx Build 1.2.0 Simplicit90Y software (Boston Scientific) and utilized to calculate sphere concentration to tumor as well as D70 (minimum dose to 70% total tumor volume), D90, and D99. Time to progression (TTP), treatment response, and adverse events were studied.

RESULTS

Fifty-six solitary tumors were analyzed with a median tumor diameter of 3.4 cm (range, 1.2-6.8 cm) and median tumor absorbed dose of 732 Gy (range, 252-1,776 Gy). Median sphere activity (SA) at the time of delivery was 1,446 Bq (range, 417-2,621 Bq). Median tumor sphere concentration was 12,868 spheres/mL (range, 2,655-37,183 spheres/mL). Sphere concentration into tumor and normal tissue was inversely correlated with perfused treatment volume (R2 = 0.21 and R2 = 0.39, respectively). Of the 51 tumors with posttreatment imaging, objective response was noted in 49 patients (96%) and complete response in 42 patients (82%). The median TTP was not reached with a 2-year progression rate of 11%. Fifteen patients underwent liver transplant. Median tumor necrosis was 99% (range, 80%-100%). Lower tumor volumes and higher D99 were associated with complete pathologic necrosis (P < .001 and P = .022, respectively).

CONCLUSIONS

Voxel-based dosimetry following 90Y radioembolization can be utilized to account for sphere deposition and distribution into tumor. Ablative RS with high SA yields durable radiologic and pathologic outcomes.

Radiation Segmentectomy for the Treatment of Hepatocellular Carcinoma: A Practical Review of Evidence

Radiation segmentectomy is a versatile, safe, and effective ablative therapy for early-stage hepatocellular carcinoma. Advances in radiation segmentectomy patient selection, procedural technique, and dosimetry have positioned this modality as a curative-intent and guideline-supported treatment for patients with solitary HCC. This review describes key radiation segmentectomy concepts and summarizes the existing literary knowledgebase.

Radiation Segmentectomy for Hepatocellular Carcinoma

The application of trans-arterial radioembolization (TARE) with Yttrium-90, historically a palliative treatment option for patients with advanced hepatocellular carcinoma (HCC), is evolving. Radiation segmentectomy (RADSEG), the segmental delivery of an ablative radiation dose, is a treatment option for patients with earlier-stage HCC. This review presents an in-depth exploration of RADSEG, emphasizing its technical considerations, dosimetry advancements, and patient selection. The integration of RADSEG into the Barcelona Clinic Liver Cancer (BCLC) paradigm will be highlighted. RADSEG outcomes concerning safety and efficacy will be explored and compared with traditional locoregional cancer treatments like trans-arterial chemoembolization (TACE), percutaneous thermal ablation, and surgical resection, with an eye on future directions and considerations.

Portal hypertension increases the risk of hepatic decompensation after 90Yttrium radioembolization in patients with hepatocellular carcinoma: a cohort study

Background

Transarterial radioembolization (TARE) is increasingly used in patients with hepatocellular carcinoma (HCC). This treatment can induce or impair portal hypertension, leading to hepatic decompensation. TARE also promotes changes in liver and spleen volumes that may modify therapeutic decisions and outcomes after therapy.

Objectives

We aimed to investigate the impact of TARE on the incidence of decompensation events and its predictive factors.

Design

In all, 63 consecutive patients treated with TARE between February 2012 and December 2018 were retrospectively included.

Methods

We assessed clinical (including Barcelona Clinic Liver Cancer stage, portal hypertension assessment, and liver decompensation), laboratory parameters, and liver and spleen volumes before and 6 and 12 weeks after treatment. A multivariate analysis was performed.

Results

In total, 18 out of 63 (28.6%) patients had liver decompensation (ascites, variceal bleeding, jaundice, or encephalopathy) within the first 3 months after therapy, not associated with tumor progression. Clinically significant portal hypertension (CSPH) and bilobar treatment independently predicted the development of liver decompensation after TARE. A significant volume increase in the non-treated hemi-liver was observed only in patients with unilobar treatment (median volume increase of 20.2% in patients with right lobe TARE; p = 0.007), especially in those without CSPH. Spleen volume also increased after TARE (median volume increase of 16.1%; p = 0.0001) and was associated with worsening liver function scores and decreased platelet count.

Conclusion

Bilobar TARE and CSPH may be associated with an increased risk of liver decompensation in patients with intermediate or advanced HCC. A careful assessment considering these variables before therapy may optimize candidate selection and improve treatment planning.

Bilobar Radioembolization Carries the Risk of Radioembolization-Induced Liver Disease in the Treatment of Advanced Hepatocellular Carcinoma: Safety and Efficacy Comparison to Systemic Therapy with Atezolizumab/Bevacizumab

Recommended treatment options for advanced-stage hepatocellular carcinoma (HCC) include systemic therapy (ST) and trans-arterial radioembolization (TARE) with Yttrium-90 (Y90). Before the approval of immune-checkpoint inhibitors, a similar safety profile was reported for TARE and ST with tyrosine kinase inhibitors (TKI). However, whole-liver treatment and underlying cirrhosis were identified as risk factors for potentially lethal radioembolization-induced liver disease (REILD). Therefore, the safety and efficacy of TARE and ST with atezolizumab/bevacizumab were compared in patients with advanced HCC involving at least both liver lobes in a retrospective real-world cohort. In total, 74 patients with new or recurrent advanced-stage HCC (BCLC stage B/C) were included if treated with either bilobar TARE (n = 33) or systemic combination therapy with atezolizumab plus bevacizumab (n = 41). Most patients had compensated liver function (90.5% were classified as Child-Pugh Score A, 73% as ALBI Grade 1) at baseline. Although not significant, patients treated with ST showed a more prolonged overall survival than those treated with Y90 TARE (7.1 months vs. 13.0 months, p = 0.07). While a similar disease control rate could be achieved with bilobar TARE and atezolizumab/bevacizumab, in the TARE group, overall survival was curtailed by the occurrence of REILD. In patients with underlying liver cirrhosis, the liver function at baseline was a predictor for REILD.

Yttrium-90 Radioembolization as the Major Treatment of Hepatocellular Carcinoma

BACKGROUND

The purpose of this study was to assess the safety and efficacy of Yttrium-90 radioembolization using in unresectable hepatocellular carcinoma.

METHODS

From 2017 to 2021, 32 patients with unresectable hepatocellular carcinoma, with mean tumor diameter about 7cm (21 males, 11 females; median age, 57.5 years of age), treated with Yttrium-90 radioembolization using resin microspheres were reviewed at pre-Yttrium-90 and post-Yttrium-90 follow-up. Tumor response was assessed according to the modified Response Evaluation Criteria in Solid Tumors. Outcomes including overall survival and progression-free survival were reported.

RESULTS

Median follow-up was 18 months. At follow-up examinations at 3-, 6-, and 12-months follow-up, the overall survival rates were 94%, 87% and 59%, and the progression-free survival rates were 78%, 64% and 60%, respectively. Complete response, partial response, stable disease, and progressive disease were noted in 7 (21.9%), 14 (43.7%), 4 (12.5%), and 7 (21.9%) patients, respectively. The disease control rate was 78.1%, the objective response rate was 65.6%, and the successful downstage rate was 34.4% (11 of 32). Nine of thirty-two patients underwent resection or transplantation after Yttrium-90 radioembolization with 2-year overall survival being 100%. No serious adverse events occurred after Yttrium-90 treatment. Worse overall survival was related to the larger tumor, higher stage, Eastern Cooperative Oncology Group performance status, and Child-Pugh score. And worse progression-free survival was related to the higher tumor burden, and pre-Yttrium-90 serum α-fetoprotein level >100.

CONCLUSION

Yttrium-90 Radioembolization can control hepatocellular carcinoma well even in advanced diseases. Patients successfully downstaging/bridging to resection or transplantation have excellent overall survival.

Clinical, dosimetric, and reporting considerations for Y-90 glass microspheres in hepatocellular carcinoma: updated 2022 recommendations from an international multidisciplinary working group

PURPOSE

In light of recently published clinical reports and trials, the TheraSphere Global Dosimetry Steering Committee (DSC) reconvened to review new data and to update previously published clinical and dosimetric recommendations for the treatment of hepatocellular carcinoma (HCC).

METHODS

The TheraSphere Global DSC is comprised of health care providers across multiple disciplines involved in the treatment of HCC with yttrium-90 (Y-90) glass microsphere-based transarterial radioembolization (TARE). Literature published between January 2019 and September 2021 was reviewed, discussed, and adjudicated by the Delphi method. Recommendations included in this updated document incorporate both the results of the literature review and the expert opinion and experience of members of the committee.

RESULTS

Committee discussion and consensus led to the expansion of recommendations to apply to five common clinical scenarios in patients with HCC to support more individualized efficacious treatment with Y-90 glass microspheres. Existing clinical scenarios were updated to reflect recent developments in dosimetry approaches and broader treatment paradigms evolving for patients presenting with HCC.

CONCLUSION

Updated consensus recommendations are provided to guide clinical and dosimetric approaches for the use of Y-90 glass microsphere TARE in HCC, accounting for disease presentation, tumor biology, and treatment intent.

Hepatocellular carcinoma radiation segmentectomy treatment intensification prior to liver transplantation increases rates of complete pathologic necrosis: an explant analysis of 75 tumors

PURPOSE

To verify the correlation between yttrium-90 glass microsphere radiation segmentectomy treatment intensification of hepatocellular carcinoma (HCC) and complete pathologic necrosis (CPN) at liver transplantation.

METHODS

A retrospective, single center, analysis of patients with HCC who received radiation segmentectomy prior to liver transplantation from 2016 to 2021 was performed. The tumor treatment intensification cohort (n = 38) was prescribed radiation segmentectomy as per response recommendations identified in a previously published baseline cohort study (n = 37). Treatment intensification and baseline cohort treatment parameters were compared for rates of CPN. Both cohorts were then combined for an overall analysis of treatment parameter correlation with CPN.

RESULTS

Sixty-three patients with a combined 75 tumors were analyzed. Specific activity, dose, and treatment activity were significantly higher in the treatment intensification cohort (all p < 0.01), while particles per cubic centimeter of treated liver were not. CPN was achieved in 76% (n = 29) of tumors in the treatment intensification cohort compared to 49% (n = 18) in the baseline cohort (p = 0.013). The combined cohort CPN rate was 63% (n = 47). ROC analysis showed that specific activity ≥ 327 Bq (AUC 0.75, p < 0.001), dose ≥ 446 Gy (AUC 0.69, p = 0.005), and treatment activity ≥ 2.55 Gbq (AUC 0.71, p = 0.002) were predictive of CPN. Multivariate logistic regression demonstrated that a specific activity ≥ 327 Bq was the sole independent predictor of CPN (p = 0.013).

CONCLUSION

Radiation segmentectomy treatment intensification for patients with HCC prior to liver transplantation increases rates of CPN. While dose strongly correlated with pathologic response, specific activity was the most significant independent radiation segmentectomy treatment parameter associated with CPN.

Radiation Segmentectomy for the Treatment of Solitary Hepatocellular Carcinoma: Can Outcomes Be Compared to Surgical Resection?

PURPOSE

To investigate outcomes of radiation segmentectomy (RS) versus standard-of-care surgical resection (SR) as a quality endeavor.

MATERIALS AND METHODS

A multisite, retrospective, analysis of treatment-naïve patients who received either RS or SR was performed. Inclusion criteria were solitary HCC ≤8 cm, Eastern Cooperative Oncology Cohort performance status 0-1, and absence of macrovascular invasion or extrahepatic disease. Target tumor and overall progression, time-to-progression (TTP), and overall survival were assessed. Outcomes were censored for liver transplantation.

RESULTS

123 patients were included (RS:57, SR:66). Tumor size, Child-Pugh class, ALBI score, platelet count, and fibrosis stage were significantly different between cohorts (p≤0.01). Grade ≥3 adverse events per Clavien-Dindo classification occurred in 0 RS vs 13(20%) SR patients. Target tumor progression occurred in 3(5%) RS and 5(8%) SR patients, and overall progression in 19(33%) RS and 21(32%) SR patients. Median overall TTP was 21.9 and 29.4 months after RS and SR, respectively (95%CI:15.5-28.2 and 95%CI:18.5-40.3, p=0.03). Overall TTP subgroup analyses showed no difference between cohorts with fibrosis stage 3-4 (p=0.26) and platelets <150x10⁹/L (p=0.29). The overall progression hazard ratio for RS vs SR was not significant per multivariate cox regression analysis (1.16, 95%CI:0.51-2.63, p=0.71). Median overall survival was not reached for either cohort. Propensity scores were calculated but were too dissimilar for matching.

CONCLUSION

Radiation segmentectomy and surgical resection are performed in different patient populations, which limits comparison. Radiation segmentectomy approaches surgical resection outcomes, with a lower incidence of major adverse events, in patients who are not eligible for hepatectomy.

Chemoembolization Plus Microwave Ablation vs Chemoembolization Alone in Unresectable Hepatocellular Carcinoma Beyond the Milan Criteria: A Propensity Scoring Matching Study

Purpose

Transarterial chemoembolization (TACE) is recommended in patients with unresectable HCC beyond the Milan criteria (MC). However, the long-term efficacy of TACE remains unsatisfactory. Percutaneous microwave ablation (MWA) is a curative therapy for early-stage HCC that provides better local tumor control than TACE; however, MWA is limited for large or multifocal lesions. We aimed to compare treatment efficacy and downstaging rate following combined TACE-MWA and TACE alone in patients with unresectable HCC beyond the MC.

Patients and Methods

Patients with unresectable HCC beyond the MC who underwent either TACE-MWA (n=91) or TACE alone (n=140) at four medical institutions were included. Potential influencing factors on overall survival (OS) and progression-free survival (PFS) were included in the Cox regression analysis. Propensity-score matching of patients treated with TACE-MWA and TACE alone was performed. Differences in OS and PFS were compared with the Log rank test. Patients who met the University of California, San Francisco criteria were eligible for assessment of the probability of downstaging within the MC. Downstaging rate was compared between the two groups.

Results

In multivariate analysis, treatment with TACE alone was an independent predictor of poor PFS (P=0.011) and OS (P<0.001). Both PFS (P=0.043) and OS (P=0.002) were significantly higher in patients treated with TACE-MWA than those treated with TACE alone. The downstaging rate was higher in patients treated with TACE-MWA than those treated with TACE alone (P=0.039).

Conclusion

Compared with TACE alone, TACE-MWA may offer a survival benefit in terms of OS and PFS in HCC patients beyond the MC. Additionally, TACE-MWA may provide higher probability of downstaging within the MC than TACE alone, thereby increasing the possibility of liver transplantation.