Institutional decision to adopt Y90 as primary treatment for hepatocellular carcinoma informed by a 1,000-patient 15-year experience

Long-term Clinical Outcomes of Yttrium-90 Transarterial Radioembolization for Hepatocellular Carcinoma: A 5-Year Institutional Experience

RATIONALE AND OBJECTIVES

To examine the clinical outcomes of yttrium-90 (Y90) transarterial radioembolization (TARE) for primary hepatocellular carcinoma (HCC) through the evaluation of a 5-year institutional experience.

MATERIALS AND METHODS

This retrospective study evaluated 88 consecutive patients with primary HCC receiving Y90 TARE treatment at an academic medical center from 2017 to 2021. Disease distribution was bilobar in 60.2% of patients with an average lesion diameter of 5.0 ± 3.4 cm and Barcelona Clinic Liver Cancer stage B or C in 77% of the participants. Clinical outcomes were elucidated by examination of complications, liver function tests, biochemical response, and radiographic response. Objective response ratio (ORR) and progression-free survival (PFS) were also calculated.

RESULTS

The mean administered Y90 radiation dose was 127.8 ± 20.2 Gy. No significant complications or LFT elevations occurred post-therapy. Of the 73.9% of patients with α-fetoprotein-producing tumors, 67.8% experienced a complete or partial biochemical response 1 month post-treatment. The ORR was 83.3% on 6-month imaging and PFS was 9.6 ± 8.5 months. Functional outcomes (Eastern Cooperative Oncology Group) were maintained or improved in 79.6% and 76.1% of patients by 6 months and 1 year post-treatment, respectively. The mean survival was 14.7 ± 12.1 months. At 6 months post-treatment, 77.3% of patients were downstaged to or maintained Milan criteria, which was sustained for 74.4% and 70.0% of patients 1 year and 2 years after treatment, respectively.

CONCLUSION

Y90-TARE is a safe and effective therapy for primary HCC. Enduring outcomes further act as a realistic bridge to liver transplantation, with a majority of patients maintaining Milan criteria and preserving their functional status long term.

Long-Term Overall Survival After Selective Internal Radiation Therapy for Locally Advanced Hepatocellular Carcinomas: Updated Analysis of DOSISPHERE-01 Trial

Interim analysis of the DOSISPHERE-01 study demonstrated a strong improvement in response and overall survival (OS) on using 90Y-loaded glass microspheres with personalized dosimetry compared with standard dosimetry in patients with nonoperable locally advanced hepatocellular carcinoma. This report sought to provide a long-term analysis of OS. Methods: In this phase II study (ClinicalTrials.gov identifier NCT02582034), treatment was randomly assigned (1:1) with the goal to deliver either at least 205 Gy (if possible >250-300 Gy) to the index lesion in the personalized dosimetry approach (PDA) or 120 ± 20 Gy to the treated volume in the standard dosimetry approach (SDA). The 3-mo response of the index lesion was the primary endpoint, with OS being one of the secondary endpoints. This report is a post hoc long-term analysis of OS. Results: Overall, 60 hepatocellular carcinoma patients with at least 1 lesion larger than 7 cm and more than 30% of hepatic reserve were randomized (intent-to-treat population: PDA, n = 31; SDA, n = 29), with 56 actually treated (modified intent-to-treat population: n = 28 in each arm). The median follow-up for long-term analysis was 65.8 mo (range, 2.1-73.1 mo). Median OS was 24.8 mo and 10.7 mo (hazard ratio [HR], 0.51; 95% CI, 0.29-0.9; P = 0.02) for PDA and SDA, respectively, in the modified intent-to-treat population. Median OS was 22.9 mo for patients with a tumor dose of at least 205 Gy, versus 10.3 mo for those with a tumor dose of less than 205 Gy (HR, 0.42; 95% CI, 0.22-0.81; P = 0.0095), and was 22.9 mo for patients with a perfused liver dose of 150 Gy or higher, versus 10.3 mo for those with a perfused liver dose of less than 150 Gy (HR, 0.42; 95% CI, 0.23-0.75; P = 0.0033). Lastly, median OS was not reached in patients who were secondarily resected (n = 11, 10 in the PDA group and 1 in the SDA group), versus 10.8 mo in those without secondary resection (n = 45) (HR, 0.17; 95% CI, 0.065-0.43; P = 0.0002). Only resected patients displayed favorable long-term OS rates, meaning an OS of more than 50% at 5 y. Conclusion: After longer follow-up, personalized dosimetry sustained a meaningful improvement in OS, which was dramatically improved for patients who were accurately downstaged toward resection, including most portal vein thrombosis patients.

Cost-effectiveness analysis of interventional liver-directed therapies for downstaging of HCC before liver transplant

Transarterial chemoembolization (TACE) and transarterial radioembolization (TARE) are the 2 most used modalities for patients with HCC while awaiting liver transplant. The purpose of this study is to perform a cost-effectiveness analysis comparing TACE and TARE for downstaging (DS) patients with HCC. A cost-effectiveness analysis was performed comparing TACE and TARE in DS HCC over a 5-year time horizon from a payer's perspective. The clinical course, including those who achieved successful DS leading to liver transplant and those who failed DS with possible disease progression, was obtained from the United Network for Organ Sharing. Costs and effectiveness were measured in US dollars and quality-adjusted life years (QALYs). Probabilistic and deterministic sensitivity analyses were performed. TARE achieved a higher effectiveness of 2.51 QALY (TACE: 2.29 QALY) at a higher cost of $172,162 (TACE: $159,706), with the incremental cost-effectiveness ratio of $55,964/QALY, making TARE the more cost-effective strategy. The difference in outcome was equivalent to 104 days (nearly 3.5 months) in compensated cirrhosis state. Probabilistic sensitivity analyses showed that TARE was more cost-effective in 91.69% of 10,000 Monte Carlo simulations. TARE was more effective if greater than 48.2% of patients who received TACE or TARE were successfully downstaged (base case: 74.6% from the pooled analysis of multiple published cohorts). TARE became more cost-effective when the cost of TACE exceeded $4,831 (base case: $12,722) or when the cost of TARE was lower than $43,542 (base case: $30,609). Subgroup analyses identified TARE to be the more cost-effective strategy if the TARE cohort required 1 fewer locoregional therapy than the TACE cohort. TARE is the more cost-effective DS strategy for patients with HCC exceeding Milan criteria compared to TACE.

Management of Intermediate-Stage Hepatocellular Carcinoma: Systemic Versus Locoregional Therapy

Intermediate-stage hepatocellular carcinoma (HCC) comprises a heterogeneous group of patients with varying levels of tumor burden. Transarterial chemoembolization was traditionally the mainstay of treatment for intermediate-stage HCC for almost 2 decades. New and emerging treatment options have revolutionized HCC therapy, allowing for broader application to patients with intermediate- and advanced-stage disease. Accordingly, new guidelines acknowledge these options, and intermediate stage HCC can now be treated with surgical, locoregional or systemic therapies, or a combination thereof. Patients will continue to benefit from the development of complex treatment strategies in a multidisciplinary setting to optimize individual outcomes.

Lineage-specific regulation of PD-1 expression in early-stage hepatocellular carcinoma following 90yttrium transarterial radioembolization - Implications in treatment outcomes

BACKGROUND

Hepatocellular carcinoma (HCC) remains one of the leading causes of cancer-related deaths in the world. Liver-directed therapies, including 90Yttrium (90Y) radioembolization, play an integral role in the management of HCC with excellent response rates. This has led to clinical trials of immunotherapy in combination with 90Y. Elevated PD-1 expression and lymphopenia were recently shown as risk factors for disease progression in early-stage HCC treated with liver-directed therapies. The aim of this study was to investigate PD-1 expression dynamics in bridge/downstage to transplant in HCC patients receiving first-cycle 90Y and evaluate the impact of these changes on response rates and time-to-progression (TTP).

METHODS

Patients with HCC receiving first-cycle 90Y as a bridge to liver transplantation (n = 99) were prospectively enrolled. Blood specimens were collected before 90Y and again during routine imagining follow-up to analyze PD-1 expression via flow cytometry. Complete and objective response rates (CR and ORR) were determined using mRECIST.

RESULTS

In 84/88 patients with available follow-up imaging, 83% had a localized ORR with 63% having localized CR. For overall response, 71% and 54% experienced ORR and CR, respectively. Post-90Y PD-1 upregulation in CD8 + associated with HCC progression and decreased TTP. Treatment with 90Y was associated with an anticipated significant post-treatment drop in lymphocytes (P < 0.001) that was independent of PD-1 expression for either CD4+ or CD8+ T cells (P = 0.751 and P = 0.375) and not associated with TTP risk. The change in lymphocytes was not correlated with PD-1 expression following treatment nor TTP.

CONCLUSIONS

Elevated PD-1 expression on peripheral T cells is associated with increased risk of HCC progression and shorter time to progression in bridging/downstaging to transplant HCC patients undergoing first-cycle 90Y. Treatment-induced lymphopenia was not associated with treatment response, or increased progression risk, suggesting this anticipated adverse event does not impact short-term HCC outcomes.

Impact of Low Skeletal Muscle Mass on Long-Term Outcomes in Hepatocellular Carcinoma Treated with Trans-Arterial Radioembolization: A Retrospective Multi-Center Study

Trans-arterial radioembolization (TARE) is a form of radiation therapy performed for hepatocellular carcinoma (HCC) via selective intra-arterial injection of Yttrium-90-loaded microspheres. This was a multi-center retrospective study of consecutive patients with HCC who underwent TARE between July 2009 and May 2019. Using pre-treatment computed tomography imaging, the total cross-sectional area (cm2) of the abdominal skeletal muscle at the third lumbar vertebra was measured. The skeletal muscle index (SMI) was calculated by normalizing the muscle area to patient height. In total, 347 patients (median age, 65 years; 284 male) were included in the study. A total of 108 (31.1%) patients had portal vein tumor thrombus (PVTT), and 126 (36.3%) were classified as LSMM. The median overall survival (OS) was 28.1 months (95% CI, 24.8-35.7), and median progression-free survival was 8.0 months (95% CI, 6.4-9.4). Multivariate Cox regression analysis revealed that LSMM (hazard ratio [HR], 1.36; 95% CI, 1.00-1.85, p = 0.05), PVTT (HR, 1.82; 95% CI, 1.33-2.49, p < 0.01), alpha-fetoprotein (AFP) (≥200 ng/mL) (HR 1.41; 95% CI, 1.04-1.92, p = 0.03), and albumin-bilirubin grade (2-3) (HR 1.74; 95% CI, 1.24-2.43, p < 0.01) were independently associated with poor OS. TARE provided favorable long-term outcomes for patients with advanced HCC. Pre-treatment LSMM independently associated with survival, suggesting its utility as a surrogate biomarker for identifying TARE candidates.

Early Prediction of Response of Hepatocellular Carcinoma to Yttrium-90 Radiation Segmentectomy Using a Machine Learning MR Imaging Radiomic Approach

PURPOSE

To assess the accuracy of a machine learning (ML) approach based on magnetic resonance (MR) imaging radiomic quantification obtained before treatment and early after treatment for prediction of early hepatocellular carcinoma (HCC) response to yttrium-90 transarterial radioembolization (TARE).

MATERIALS AND METHODS

In this retrospective single-center study of 76 patients with HCC, baseline and early (1-2 months) post-TARE MR images were collected. Semiautomated tumor segmentation facilitated extraction of shape, first-order histogram, and custom signal intensity-based radiomic features, which were then trained (n = 46) using a ML XGBoost model and validated on a separate cohort (n = 30) not used in training to predict treatment response assessed at 4-6 months (based on modified Response and Evaluation Criteria in Solid Tumors criteria). Performance of this ML radiomic model was compared with those of models comprising clinical parameters and standard imaging characteristics using area under the receiver operating curve (AUROC) analysis for prediction of complete response (CR).

RESULTS

Seventy-six tumors with a mean (±SD) diameter of 2.6 cm ± 1.6 were included. Sixty, 12, 1, and 3 patients were classified as having CR, partial response, stable disease, and progressive disease, respectively, at 4-6 months posttreatment on the basis of MR images. In the validation cohort, the radiomic model showed good performance (AUROC, 0.89) for prediction of CR, compared with models comprising clinical and standard imaging criteria (AUROC, 0.58 and 0.59, respectively). Baseline imaging features appeared to be more heavily weighted in the radiomic model.

CONCLUSIONS

The use of ML modeling of radiomic data combining baseline and early follow-up MR imaging could predict HCC response to TARE. These models need to be investigated further in an independent cohort.

Yttrium-90 transarterial radioembolization and capecitabine in hepatocellular carcinoma with portal vein involvement

Hepatocellular carcinoma (HCC) with portal vein tumor thrombus is considered an advanced stage disease. Non-surgical local and systemic therapies are the only treatment options available. To analyze the survival and toxicity outcomes of systemic treatment concurrent with yttrium-90 transarterial radioembolization in HCC with liver-limited disease and portal vein involvement with Child-Pugh B liver reserve. The medical records of 22 patients who underwent yttrium-90 transarterial radioembolization concomitant with capecitabine chemotherapy as first-line treatment between 2014 and 2019 were retrospectively reviewed. Twenty-two patients were included in the study. Grade 3 to 4 side effects were evaluated, and hepatic encephalopathy developed in 1 patient after yttrium-90 transarterial radioembolization. In the fourth month of radiological evaluation, 11 patients had a partial response (50%), 5 patients had stable disease (22.7%), and 6 patients (27.3%) developed progressive disease. The median survival time was 21 months. Combined treatment with yttrium-90 transarterial radioembolization and capecitabine may be an effective and safe treatment option. Treatment was associated with a median overall survival of 21 months and a disease control rate of 72.7% at 4 months in patients with inoperable HCC.

Surgery and radioembolization of liver tumors

Surgical resection is considered the curative treatment par excellence for patients with primary or metastatic liver tumors. However, less than 40% of them are candidates for surgery, either due to non-modifiable factors (comorbidities, age, liver dysfunction…), or to the invasion or proximity of the tumor to the main vascular requirements, the lack of a future liver remnant (FLR) adequate to maintain postoperative liver function, or criteria of tumor size and number. In these last factors, hepatic radioembolization has been shown to play a role as a presurgical tool, either by hypertrophy of the FLR or by reducing tumor size that manages to reduce tumor staging (term known as "downstaging"). To these is added a third factor, which is its ability to apply the test of time, which makes it possible to identify those patients who present progression of the disease in a short period of time (both locally and at distance), avoiding a unnecessary surgery. This paper aims to review RE as a tool to facilitate liver surgery, both through the experience of our center and the available scientific evidence.

188 Re-N-DEDC Lipiodol for Treatment of Hepatocellular Carcinoma (HCC)-A Clinical and Prospective Study to Assess In-Vivo Distribution in Patients and Clinical Feasibility of Therapy

Objective  The incidence of inoperable hepatocellular carcinoma (HCC) with/without malignant portal vein thrombosis (PVT) is increasing in India for the last decade; thus, Bhabha Atomic Research Centre (BARC), Mumbai, India, developed diethydithiocarbamate (DEDC), a new transarterial radionuclide therapy (TART) agent. ¹⁸⁸ Re-N-DEDC lipiodol is an emerging radiotherapeutic agent for inoperable HCC treatment due to its simple and onsite labeling procedure, cost-effectiveness, and least radiation-induced side effects. This study aimed to evaluate in-vivo biodistribution and clinical feasibility of ¹⁸⁸ Re-N-DEDC lipiodol TART in HCC and optimization of labeling procedure to assess post-labeling stability and radiochemical yield of labeled lipiodol with ¹⁸⁸ Re-N-DEDC complex. Materials and Methods  DEDC kits were obtained as gift from BARC, Mumbai. Therapy was given to 31 HCC patients. Post-therapy planar and single-photon emission computed tomography/computed tomography (SPECT/CT) imaging were performed to see tumor uptake and biodistribution. Clinical feasibility and toxicity were decided by Common Terminology Criteria for Adverse Events version 5.0 (CTCAE v 5.0). Statistical Analysis  Descriptive statistics was done for data using SPSS v22. Values was expressed as mean ± standard deviation or median with range. Results  Post-therapy planar and SPECT/CT imaging showed radiotracer localization in hepatic lesions. Few patients showed lungs uptake due to hepato-pulmonary shunt (lung shunt < 10%). Maximum clearance was observed through urinary tract with very less elimination through hepatobiliary route due to slow rate of leaching of tracer. No patient showed myelosuppression or any other long-term toxicity over median follow-up of 6 months. Mean overall % radiochemical yield of ¹⁸⁸ Re-N-DEDC lipiodol was 86.04 ± 2.35%. The complex ¹⁸⁸ Re-N-DEDC was found to be stable at 37°C under sterile condition over a period of 1 hour without any significant change on the % radiochemical purity (90.83 ± 3.24%, 89.78 ± 3.67%, 89.22 ± 3.77% at 0, 0.5, 1 hours, respectively). Conclusion  Human biodistribution showed very high retention of radiotracer in hepatic lesions with no long-term toxicity with this therapy. The kit preparation procedure is ideally suited for a busy hospital radio-pharmacy. By this procedure, ¹⁸⁸ Re-N-DEDC lipiodol can be prepared in high radiochemical yield within a short time (∼45 minutes). Thus, ¹⁸⁸ Re-N-DEDC lipiodol can be considered for TART in advanced and/or intermediate HCC.

Local Therapies for Hepatocellular Carcinoma and Role of MRI-Guided Adaptive Radiation Therapy

Hepatocellular carcinoma (HCC) is the most common liver tumor, with a continually rising incidence. The curative treatment for HCC is surgical resection or liver transplantation; however, only a small portion of patients are eligible due to local tumor burden or underlying liver dysfunction. Most HCC patients receive nonsurgical liver-directed therapies (LDTs), including thermal ablation, transarterial chemoembolization (TACE), transarterial radioembolization (TARE), and external beam radiation therapy (EBRT). Stereotactic ablative body radiation (SABR) is a specific type of EBRT that can precisely deliver a high dose of radiation to ablate tumor cells using a small number of treatments (or fractions, typically 5 or less). With onboard MRI imaging, MRI-guided SABR can improve therapeutic dose while minimizing normal tissue exposure. In the current review, we discuss different LDTs and compare them with EBRT, specifically SABR. The emerging MRI-guided adaptive radiation therapy has been reviewed, highlighting its advantages and potential role in HCC management.

Trends and perspectives on the commercialization of bioactive glasses

At least 25 bioactive glass (BG) medical devices have been approved for clinical use by global regulatory agencies. Diverse applications include monolithic implants, bone void fillers, dentin hypersensitivity agents, wound dressing, and cancer therapeutics. The morphology and delivery systems of bioactive glasses have evolved dramatically since the first devices based on 45S5 Bioglass®. The particle size of these devices has generally decreased with the evolution of bioactive glass technology but primarily lies in the micron size range. Morphologies have progressed from glass monoliths to granules, putties, and cements, allowing medical professionals greater flexibility and control. Compositions of these commercial materials have primarily relied on silicate-based systems with varying concentrations of sodium, calcium, and phosphorus. Furthermore, therapeutic ions have been investigated and show promise for greater control of biological stimulation of genetic processes and increased bioactivity. Some commercial products have exploited the borate and phosphate-based compositions for soft tissue repair/regeneration. Mesoporous BGs also promise anticancer therapies due to their ability to deliver drugs in combination with radiotherapy, photothermal therapy, and magnetic hyperthermia. The objective of this article is to critically discuss all clinically approved bioactive glass products. Understanding essential regulatory standards and rules for production is presented through a review of the commercialization process. The future of bioactive glasses, their promising applications, and the challenges are outlined. STATEMENT OF SIGNIFICANCE: Bioactive glasses have evolved into a wide range of products used to treat various medical conditions. They are non-equilibrium, non-crystalline materials that have been designed to induce specific biological activity. They can bond to bone and soft tissues and contribute to their regeneration. They are promising in combating pathogens and malignancies by delivering drugs, inorganic therapeutic ions, and heat for magnetic-induced hyperthermia or laser-induced phototherapy. This review addresses each bioactive glass product approved by regulatory agencies for clinical use. A review of the commercialization process is also provided with insight into critical regulatory standards and guidelines for manufacturing. Finally, a critical evaluation of the future of bioactive glass development, applications, and challenges are discussed.

Boosted-Dose Yttrium-90 Radiation Segmentectomy or Lobectomy for Hepatocellular Carcinoma Refractory to Prior Transarterial Embolization or Chemoembolization: A Single Institution Retrospective Case Series

PURPOSE

To assess the tumor response rates and liver toxicity of boosted-dose transarterial radioembolization (TARE) for treatment of hepatocellular carcinoma (HCC) refractory to previous transarterial embolization (TAE) and/or chemoembolization (TACE).

MATERIALS AND METHODS

All patients were identified who had HCC treated between 2017 and 2020 that had been refractory to prior TAE or TACE, then treated with boosted-dose segmental or lobar TARE. Tumor response was assessed by multiphasic CT or MRI using localized mRECIST imaging criteria and serological alpha-fetoprotein levels at three and six months after TARE, if available. Liver toxicity was evaluated using serial serological liver function tests, platelet counts, and clinical Child-Pugh and MELD scores.

RESULTS

Twenty-four patients met inclusion criteria. Mean age was 68.7 years (54-89); 8 were females. Three (12.5%) patients had Barcelona Clinical Liver Cancer stage A, 4 (16.7%) stage B, and 17 (70.8%) stage C disease. Three months after TARE, 52% of patients had a complete response and 33% had a partial response. Mean AFP decreased from 33.2 ng/mL at baseline to 17 ng/mL at 3 months (p = 0.782). The median MELD-Na score increased from 11 at baseline to 16 at 6 months post-TARE (p = 0.044); the mean Child-Pugh score rose from 5 at baseline to 6 at 3 months post-TARE (p < 0.01).

CONCLUSION

Boosted-dose TARE resulted in statistically significant favorable tumor responses by imaging criteria in 85% of patients previously refractory to TAE or TACE. TARE resulted in transient but acceptable deterioration of liver function and clinical scores.

Cost-Effectiveness Analysis of Interventional Liver-Directed Therapies for a Single, Small Hepatocellular Carcinoma in Liver Transplant Candidates

PURPOSE

To assess the cost effectiveness of 3 main locoregional therapies (LRTs) (transarterial chemoembolization [TACE], transarterial radioembolization [TARE], and percutaneous ablation) as bridging therapy.

MATERIALS AND METHODS

A cost-effectiveness analysis was performed comparing the 3 LRTs for patients with a single hepatocellular carcinoma (HCC) with a diameter of 3 cm or less over a 5-year time horizon from a payer's perspective. The clinical courses, including transplantation, decompensation resulting in delisting, and the need for a second LRT, were based on data from the United Network for Organ Sharing (2016-2019). Costs and effectiveness were measured in U.S. dollars and quality-adjusted life-years, respectively. Probabilistic and deterministic sensitivity analyses were performed.

RESULTS

A total of 2,594, 1,576, and 903 patients underwent TACE, ablation, and TARE, respectively. Ablation was the dominant strategy, with the lowest expected cost and highest effectiveness. The probabilistic sensitivity analysis demonstrated that ablation was the most cost-effective strategy in 93.9% of simulations. A subgroup analysis was performed for different wait times, with ablation remaining the most cost-effective strategy. The sensitivity analysis showed that ablation was most effective if the risk of waitlist dropout was less than 2.00% and the rate of transplantation was more than 15.1% quarterly. TARE was most effective if the risk of dropout was less than 1.19% and the rate of transplantation was more than 24.0%. TACE was most effective if the risk of dropout was less than 1.01% and the rate of transplantation was more than 45.7%. Ablation remained the most cost-effective modality until its procedural cost was more than $34,843.

CONCLUSIONS

Ablation is the most cost-effective bridging strategy for patients with a single, small (≤3 cm) HCC prior to liver transplantation. The conclusion remained robust in multiple sensitivity analyses.

Voxel-S-value methods adapted to heterogeneous media for quantitative Y-90 microsphere radioembolization dosimetry

PURPOSE

The absorbed dose estimation from Voxel-S-Value (VSV) method in heterogeneous media is suboptimal as VSVs are calculated in homogeneous media. The aim of this study is to develop and evaluate new VSV methods in order to enhance the accuracy of Y-90 microspheres absorbed dose estimation in liver, lungs, tumors and lung-liver interface regions.

METHODS

Ten patients with Y-90 microspheres SPECT/CT and PET/CT data, six of whom had additional Tc-99m-macroaggregated albumin SPECT/CT data, were analyzed from the Deep Blue Data Repository. Seven existing VSV methods along with three newly proposed VSV methods were evaluated: liver and lung kernel with center voxel scaling (LiLuCK), liver kernel with density correction and lung kernel with center voxel scaling (LiKDLuCK), liver kernel with center voxel scaling and lung kernel with density correction (LiCKLuKD). Monte Carlo (MC) results were regarded as the gold standard. Absolute absorbed dose errors (%AADE) of these methods for the liver, lungs, tumors, upper liver, and lower lungs were assessed.

RESULTS

Liver and tumor's median %AADE of all methods were <3% for three types of imaging data. In the lungs, however, three recently proposed VSV methods provided median %AADEs of less than 7%, whereas the differences exceeded 20% for existing methods that did not use a lung kernel. LiCKLuKD could achieve median %AADE <2% in the liver, upper liver and tumors, and median %AADE <7% in the lungs and lower lungs in three types of data.

CONCLUSION

All methods are consistent with MC in the liver and tumors. Methods with tissue-specific kernel and effective correction achieve smaller errors in lungs. LiCKLuKD has comparable results with MC in absorbed dose estimation of Y-90 radioembolization for all target regions.

Liver Resection and Transplantation Following Yttrium-90 Radioembolization for Primary Malignant Liver Tumors: A 15-Year Single-Center Experience

Radioembolization (RE) may help local control and achieve tumor reduction while hypertrophies healthy liver and provides a test of time. For liver transplant (LT) candidates, it may attain downstaging for initially non-candidates and bridging during the waitlist.

METHODS

Patients diagnosed with HCC and ICC treated by RE with further liver resection (LR) or LT between 2005-2020 were included. All patients selected were discarded for the upfront surgical approach for not accomplishing oncological or surgical safety criteria after a multidisciplinary team assessment. Data for clinicopathological details, postoperative, and survival outcomes were retrospectively reviewed from a prospectively maintained database.

RESULTS

A total of 34 patients underwent surgery following RE (21 LR and 13 LT). Clavien-Dindo grade III-IV complications and mortality rates were 19.0% and 9.5% for LR and 7.7% and 0% for LT, respectively. After RE, for HCC and ICC patients in the LR group, 10-year OS rates were 57% and 60%, and 10-year DFS rates were 43.1% and 60%, respectively. For HCC patients in the LT group, 10-year OS and DFS rates from RE were 51.3% and 43.3%, respectively.

CONCLUSION

Liver resection after RE is safe and feasible with optimal short-term outcomes. Patients diagnosed with unresectable or high biological risk HCC or ICC, treated with RE, and rescued by LR may achieve optimal global and DFS rates. On the other hand, bridging or downstaging strategies to LT with RE in HCC patients show adequate recurrence rates as well as long-term survival.

Accuracy and reproducibility of a cone beam CT-based virtual parenchymal perfusion algorithm in the prediction of SPECT/CT anatomical and volumetric results during the planification of radioembolization for HCC

OBJECTIVES

To evaluate anatomical and volumetric predictability of a cone beam computed tomography (CBCT)-based virtual parenchymal perfusion (VPP) software for the single-photon-emission computed tomography (SPECT)/CT imaging results during the work-up for transarterial radioembolization (TARE) procedure in patients with hepatocellular carcinoma (HCC).

METHODS

VPP was evaluated retrospectively on CBCT data of patients treated by TARE for HCC. ^99mTc macroaggregated albumin particles (^99mTc-MAA) uptake territories on work-up SPECT/CT was used as ground truth for the evaluation. Semi-quantitative evaluation consisted of the ranking of visual consistency of the parenchymal enhancement and portal vein tumoral involvement on VPP and ^99mTc-MAA SPECT/CT, using a three-rank scale and two-rank scale, respectively. Inter-reader agreement was evaluated using a kappa coefficient. Quantitative evaluation included absolute volume error calculation and Pearson correlation between volumes enhanced territories on VPP and ^99mTc-MAA SPECT/CT.

RESULTS

Fifty-two CBCTs were performed in 33 included patients. Semi-quantitative evaluation showed a good concordance between actual ^99mTc-MAA uptake and the virtual enhanced territories in 73% and 75% of cases; a mild concordance in 12% and 10% and a poor concordance in 15%, for the two readers. Kappa coefficient was 0.86. Portal vein involvement evaluation showed a good concordance in 58.3% and 66.7% for the two readers, respectively, with a kappa coefficient of 0.82. Quantitative evaluation showed a volume error of 0.46 ± 0.78 mL [0.01-3.55], and Pearson R² factor at 0.75 with a p value < 0.01.

CONCLUSION

CBCT-based VPP software is accurate and reliable to predict ^99mTc-MAA SPECT/CT anatomical and volumetric results in HCC patients during TARE.

KEY POINTS

• Virtual parenchymal perfusion (VPP) software is accurate and reliable in the prediction of ^99mTc-MAA SPECT volumetric and targeting results in HCC patients during transarterial radioembolization (TARE). • VPP software may be used per-operatively to optimize the microcatheter position for ⁹⁰Y infusion allowing precise tumor targeting while preserving non-tumoral parenchyma. • Post-operatively, VPP software may allow an accurate estimation of the perfused volume by each arterial branch and, thus, a precise ⁹⁰Y dosimetry for TARE procedures.

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.

Radioembolization in patients with hepatocellular carcinoma: a series of 53 cases

OBJECTIVE

To contribute our results to increase the scientific evidence about the use of radioembolization in the management of patients with hepatocellular carcinoma.

MATERIAL AND METHODS

This retrospective review included 53 patients with hepatocellular carcinoma treated with radioembolization at our center. Patients were classified according to the BCLC algorithm in detail according to their Child-Pugh functional status. We analyzed survival using the Kaplan-Meier method. We used Cox regression analysis to determine clinically significant parameters, including the doses administered in the parameters studied.

RESULTS

Patients ranged in age from 28 to 86 years (mean, 60 years). A total of 61 procedures were done. The mean activity administered was 2.8GBq (0.7-6.4GBq), with a mean dose of 229.9Gy (74-425.9Gy) administered in the tumor. Progression-free survival was 6.7 months and overall survival was 12.8 months. Differences in disease-free survival according to BCLC and Child-Pugh classification were not significant (p=0.848 and p=0.252, respectively). The clinical parameters that were significantly different with respect to overall survival were bilirubin levels (p<0.001), pretreatment transaminase levels (AST) (p=0.022), Child-Pugh subclassification (p=0.003), and dose administered in the tumor (p=0.001). Only one patient had a severe adverse reaction, developing posttreatment liver failure resulting in death.

CONCLUSIONS

Radioembolization is safe and efficacious in the treatment of patients with hepatocellular carcinoma. Liver function and the doses received by the tumor are key parameters for the efficacy of treatment. The increase in the scientific evidence supports the inclusion of this technique in treatment guidelines.

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.

Target Trial Emulation: A Design Tool for Cancer Clinical Trials

PURPOSE

To apply target trial emulation to explore the potential impact of eligibility criteria on the primary outcome of a randomized controlled trial.

METHODS

Simulations of a real-world explanatory trial of transarterial radioembolization for advanced unresectable hepatocellular carcinoma with portal vein invasion were performed to examine the effects of cohort specification on survival outcomes and patient sample size. Simulations comprised 24 different permutations of the trial varied on three disease nonspecific eligibility parameters. Treatment and control arms for these emulated trials were drawn from the National Cancer Database and matched by treatment propensity. Target trial emulation served as the causal framework for this analysis, allowing the architecture of a true controlled experiment to address forms of bias routinely encountered in comparative effectiveness studies involving real-world observational data.

RESULTS

Twenty-four propensity score-matched cohorts comprising a wider clinical spectrum of patients than specified by the original target trial were successfully generated using the National Cancer Database. The arms for each of the emulated trials demonstrated exchangeability across all eligibility criteria and other clinical covariates. Significant treatment benefits were associated with only a narrow range of eligibility criteria, indicating that the original target trial was well specified.

CONCLUSION

The impact of patient selection on treatment outcomes can be studied using target trial emulation. This analytical framework can furthermore serve to leverage existing real-world data to inform the task of cohort specification for a randomized controlled trial, facilitating a more data-driven approach for this important step in clinical trial design.

Yttrium-90 Radioembolization: Current Indications and Outcomes

BACKGROUND

Radioembolization (RE) with 90Yttrium (Y90) has generally been used to treat patients with advanced disease. Recent data suggest, however, that RE is also safe and feasible to treat patients with early or intermediate stage disease. We herein review the current evidence regarding the use of RE with Y90 for patients with HCC.

METHODS

A comprehensive review of the literature was performed using MEDLINE/PubMed and Web of Science databases with a search end date of August 1, 2022.

RESULTS

Patients with HCC are often treated according to the BCLC staging system. Among patients with early-stage HCC (BCLC A), intermediate-stage HCC (BCLC B), and advanced-stage HCC (BCLC C), RE with Y90 has demonstrated promising results with comparable overall survival, time to disease progression, and radiological response compared with other standard of care treatment modalities. Moreover, Y90 RE can be used as a downstaging treatment modality for patients with advanced HCC who have a disease burden that is initially outside LT criteria. Radiation lobectomy (RL) has been described as a treatment modality with the intent of treating the ipsilateral liver that harbors the HCC, while also causing compensatory hypertrophy of the future liver remnant (FLR).

CONCLUSION

While initially considered as a palliative option for HCC patients, Y90 RE has emerged as an important part of the multi-modality care of patients with HCC across a wide spectrum of clinical indications.

Factors impacting survival after transarterial radioembolization in patients with hepatocellular carcinoma: Results from the prospective CIRT study

Background & Aims

Transarterial radioembolization (TARE) with Yttrium-90 resin microspheres is an established treatment option for patients with hepatocellular carcinoma (HCC). However, optimising treatment application and patient selection remains challenging. We report here on the effectiveness, safety and prognostic factors, including dosing methods, associated with TARE for HCC in the prospective observational CIRT study.

Methods

We analysed 422 patients with HCC enrolled between Jan 2015 and Dec 2017, with follow-up visits every 3 months for up to 24 months after first TARE. Patient characteristics and treatment-related data were collected at baseline; adverse events and time-to-event data (overall survival [OS], progression-free survival [PFS] and hepatic PFS) were collected at every 3-month follow-up visit. We used the multivariable Cox proportional hazard model and propensity score matching to identify independent prognostic factors for effectiveness outcomes.

Results

The median OS was 16.5 months, the median PFS was 6.1 months, and the median hepatic PFS was 6.7 months. Partition model dosimetry resulted in improved OS compared to body surface area calculations on multivariable analysis (hazard ratio 0.65; 95% CI 0.46-0.92; p = 0.0144), which was confirmed in the exact matching propensity score analysis (hazard ratio 0.56; 95% CI 0.35-0.89; p = 0.0136). Other independent prognostic factors for OS were ECOG-performance status >0 (p = 0.0018), presence of ascites (p = 0.0152), right-sided tumours (p = 0.0002), the presence of portal vein thrombosis (p = 0.0378) and main portal vein thrombosis (p = 0.0028), ALBI grade 2 (p = 0.0043) and 3 (p = 0.0014). Adverse events were recorded in 36.7% of patients, with 9.7% of patients experiencing grade 3 or higher adverse events.

Conclusions

This large prospective observational dataset shows that TARE is an effective and safe treatment in patients with HCC. Using partition model dosimetry was associated with a significant improvement in survival outcomes.

Impact and implications

Transarterial radioembolization (TARE) is a form of localised radiation therapy and is a potential treatment option for primary liver cancer. We observed how TARE was used in real-life clinical practice in various European countries and if any factors predict how well the treatment performs. We found that when a more complex but personalised method to calculate the applied radiation activity was used, the patient responded better than when a more generic method was used. Furthermore, we identified that general patient health, ascites and liver function can predict outcomes after TARE.

Clinical trial number

NCT02305459.

Frantz S, Matsuoka L, Du L, Gandhi RT, Collins ZS, Matrana MR, Petroziello M, Brower JS, Sze DY, Kennedy AS, Golzarian J, Wang EA, Brown DB. Overall survival and toxicity of Y90 radioembolization for hepatocellular carcinoma patients in Barcelona Clinic Liver Cancer stage C (BCLC-C)

Introduction

National Comprehensive Cancer Network HCC guidelines recommend Y90 to treat BCLC-C patients only in select cases given the development of systemic regimens. We sought to identify ideal candidates for Y90 by assessing survival and toxicities in this patient group.

Materials and methods

The Radiation-Emitting Selective Internal radiation spheres in Non-resectable tumor registry is a prospective observational study (NCT: 02,685,631). Patients with advanced HCC were stratified into 3 groups based on tumor location, Eastern Cooperative Oncology Group (ECOG) performance status, and liver function. Group 1: liver isolated HCC, ECOG 0 and Child Pugh (CP) A (n = 12, 16%), Group 2: liver isolated HCC, ECOG ≥ 1 or CP B/C (n = 37, 49%), and Group 3: extrahepatic HCC with any ECOG or CP score (n = 26, 35%). Patients in any group could have macrovascular invasion. Overall survival (OS) and progression-free survival (PFS) with 95% confidence intervals (95% CI) were calculated. Grade 3 + toxicities were tracked using Common Terminology Criteria for Adverse Events v5. Cox proportional hazard model was performed to determine factors affecting OS.

Results

Seventy-five BCLC-C patients treated between 2015 and 2019 were reviewed. The groups were similar in age, sex, race, and ethnicity (all p > 0.05). Bilobar disease was least common in Group 1 (p < 0.001). Median OS of the entire cohort was 13.6 (95% CI 7.5–16.1) months. Median OS of Groups 1–3 were 21.8, 13.1 and 11.5 months respectively (p = 0.6). Median PFS for the cohort was 6.3 (4.8–14.7) months. Median PFS for group 1 was not reached. Mean PFS for Group 1 was 17.3 ± 4.8 months. Median PFS for Groups 2 and 3 was 6.8 and 5.9 months (X² = 1.5, p = 0.5). Twenty-four Grade 3 or greater toxicities developed, most commonly hyperbilirubinemia (8/75, 11%) and thrombocytopenia (2/75, 3%). The incidence of toxicities between groups was similar (all p > 0.05). Cox Proportional Hazard analysis predicted shorter OS with CP class B/C (X² = 6.7, p = 0.01), while macrovascular invasion (X² = 0.5, p = 0.5) and ECOG score of ≥ 1 (X² = 2.1, p = 0.3) was not associated with OS.

Conclusions

OS of CPA patients with advanced HCC and performance status of 0 was 21.8 months following Y90. CP A cirrhosis is the best predictor of prolonged OS in advanced (BCLC-C) HCC.

Prediction of Lung Shunt Fraction for Yttrium-90 Treatment of Hepatic Tumors Using Dynamic Contrast Enhanced MRI with Quantitative Perfusion Processing

There is no noninvasive method to estimate lung shunting fraction (LSF) in patients with liver tumors undergoing Yttrium-90 (Y90) therapy. We propose to predict LSF from noninvasive dynamic contrast enhanced (DCE) MRI using perfusion quantification. Two perfusion quantification methods were used to process DCE MRI in 25 liver tumor patients: Kety's tracer kinetic modeling with a delay-fitted global arterial input function (AIF) and quantitative transport mapping (QTM) based on the inversion of transport equation using spatial deconvolution without AIF. LSF was measured on SPECT following Tc-99m macroaggregated albumin (MAA) administration via hepatic arterial catheter. The patient cohort was partitioned into a low-risk group (LSF ≤&amp;nbsp;10%) and a high-risk group (LSF &gt;&amp;nbsp;10%). Results: In this patient cohort, LSF was positively correlated with QTM velocity |u| (r = 0.61, F = 14.0363, p = 0.0021), and no significant correlation was observed with Kety's parameters, tumor volume, patient age and gender. Between the low LSF and high LSF groups, there was a significant difference for QTM |u| (0.0760 ± 0.0440 vs. 0.1822 ± 0.1225 mm/s, p = 0.0011), and Kety's Ktrans (0.0401 ± 0.0360 vs 0.1198 ± 0.3048, p = 0.0471) and Ve&amp;nbsp;(0.0900 ± 0.0307 vs. 0.1495 ± 0.0485, p = 0.0114). The area under the curve (AUC) for distinguishing between low LSF and high LSF was 0.87 for |u|, 0.80 for Ve and 0.74 for Ktrans. Noninvasive prediction of LSF is feasible from DCE MRI with QTM velocity postprocessing.

ACR Appropriateness Criteria® Management of Liver Cancer: 2022 Update

The treatment and management of hepatic malignancies can be complex because it encompasses a variety of primary and metastatic malignancies and an assortment of local and systemic treatment options. When to use each of these treatments is critical to ensure the most appropriate care for patients. Interventional radiologists have a key role to play in the delivery of a variety of liver directed treatments including percutaneous ablation, transarterial embolization with bland embolic particles alone, transarterial chemoembolization (TACE) with injection of a chemotherapeutic emulsion, and transarterial radioembolization (TARE). Based on 9 clinical variants, the appropriateness of each treatment is described in this document. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances in which peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Nivolumab after selective internal radiation therapy for the treatment of hepatocellular carcinoma: a phase 2, single-arm study

PURPOSE

To evaluate the safety and efficacy of selective internal radiation therapy (SIRT) in combination with a PD-1 inhibitor in patients with unresectable hepatocellular carcinoma (uHCC) and liver-only disease ineligible for chemoembolization.

PATIENTS AND METHODS

NASIR-HCC is a single-arm, multicenter, open-label, phase 2 trial that recruited from 2017 to 2019 patients who were naïve to immunotherapy and had tumors in the BCLC B2 substage (single or multiple tumors beyond the up-to-7 rule), or unilobar tumors with segmental or lobar portal vein invasion (PVI); no extrahepatic spread; and preserved liver function. Patients received SIRT followed 3 weeks later by nivolumab (240 mg every 2 weeks) for up to 24 doses or until disease progression or unacceptable toxicity. Safety was the primary endpoint. Secondary objectives included objective response rate (ORR), time to progression (TTP), and overall survival (OS).

RESULTS

42 patients received SIRT (31 BCLC-B2, 11 with PVI) and were followed for a median of 22.2 months. 27 patients discontinued and 1 never received Nivolumab. 41 patients had any-grade adverse events (AE) and 21 had serious AEs (SAE). Treatment-related AEs and SAEs grade 3-4 occurred in 8 and 5 patients, respectively. Using RECIST 1.1 criteria, ORR reported by investigators was 41.5% (95% CI 26.3% to 57.9%). Four patients were downstaged to partial hepatectomy. Median TTP was 8.8 months (95% CI 7.0 to 10.5) and median OS was 20.9 months (95% CI 17.7 to 24.1).

CONCLUSIONS

The combination of SIRT and nivolumab has shown an acceptable safety profile and signs of antitumor activity in the treatment of patients with uHCC that were fit for SIRT.

TRIAL REGISTRATION NUMBER

NCT03380130.

Hepatocellular carcinoma

Hepatocellular carcinoma is one of the most common cancers worldwide and represents a major global health-care challenge. Although viral hepatitis and alcohol remain important risk factors, non-alcoholic fatty liver disease is rapidly becoming a dominant cause of hepatocellular carcinoma. A broad range of treatment options are available for patients with hepatocellular carcinoma, including liver transplantation, surgical resection, percutaneous ablation, and radiation, as well as transarterial and systemic therapies. As such, clinical decision making requires a multidisciplinary team that longitudinally adapts the individual treatment strategy according to the patient's tumour stage, liver function, and performance status. With the approval of new first-line agents and second-line agents, as well as the establishment of immune checkpoint inhibitor-based therapies as standard of care, the treatment landscape of advanced hepatocellular carcinoma is more diversified than ever. Consequently, the outlook for patients with hepatocellular carcinoma has improved. However, the optimal sequencing of drugs remains to be defined, and predictive biomarkers are urgently needed to inform treatment selection. In this Seminar, we present an update on the causes, diagnosis, molecular classification, and treatment of hepatocellular carcinoma.

Effect of tumour involvement on activity determination of resin Yttrium-90 in selective internal radiation therapy of metastatic liver cancer

Introduction:

The study was aimed to evaluate the effect of tumour involvement on resin Yttrium-90 (Y90) activity determination for metastatic liver cancer treatment.

Methods:

One hundred and two cases of resin Y90 microsphere treatment were retrospectively studied. Body surface area (BSA) method was used in the calculation of resin Y90 activity. The total activity (TA) was calculated as a summation of activities obtained from BSA-based calculation and tumour involvement (TI). TI and TA of each case were evaluated. The contributions of TI to TA were calculated with the ratio of TI/TA.

Results:

The average contribution of TI to TA was 4·1%. The contributions were < 5·8% in 75% of the cases, < 2·2% in 50% of the cases and < 1·0% in 25% of the cases.

Conclusions:

Overall the effect of tumour involvement on the activity determination was small. The activity calculation could be simplified by neglecting TI in 25% of the cases where the activity contribution from TI was less than 1%. Contouring tumour and liver structures for TI calculation could be avoided in these cases, and the efficiency of the workflow for resin Y90 procedures could be improved.

Indian College of Radiology and Imaging Guidelines on Interventions in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignancies and a significant cause of cancer-related death. Treatment of HCC depends on the stage of the tumor. As many patients with HCC are not deemed fit for surgical resection or liver transplantation, locoregional therapies play an essential role in the management. Image-guided locoregional treatments include percutaneous ablative therapies and endovascular therapies. The choice of an individual or a combination of therapies is guided by the tumor and patient characteristics. As the outcomes of image-guided locoregional treatments depend on the ability to achieve necrosis of the entire tumor along with a safety margin around it, it is mandatory to follow standard guidelines. In this manuscript, we discuss in detail the various aspects of image-guided locoregional therapies to guide interventional radiologists involved in the care of patients with HCC.

Hepatic decompensation after transarterial radioembolization: A retrospective analysis of risk factors and outcome in patients with hepatocellular carcinoma

Transarterial radioembolization (TARE) is a well-established therapy for intermediate and advanced tumor stages of hepatocellular carcinoma (HCC). Treatment-associated toxicities are rare. Previous studies have outlined that the prognosis after TARE is determined primarily by tumor stage and liver function. The subset of patients benefiting from TARE remains to be defined. Sixty-one patients with HCC treated with TARE between 2015 and 2020 were retrospectively included in the study. Hepatic decompensation was defined as an increase of bilirubin or newly developed ascites that was not explained by tumor progression within 3 months after TARE. Predictive factors of hepatic decompensation and prognostic factors were assessed. Hepatic decompensation was observed in 27.9% (n = 17) of TARE-treated patients during follow-up. Albumin-bilirubin (ALBI) score at baseline and radiation dose on nontumor liver proved to be independent risk factors for the development of hepatic decompensation in multivariable regression models (ALBI score: odds ratio [OR] 6.425 [1.735;23.797], p < 0.005; radiation dose: OR 1.072 [1.016;1.131], p < 0.011). The occurrence of hepatic decompensation markedly impaired the prognosis of the patients. Survival was significantly worsened. Hepatic decompensation has shown to be an independent negative prognostic factor for death, adjusted for Barcelona Clinic Liver Cancer stage, age and ALBI grade (hazard ratio 5.694 [2.713;11.952], p < 0.001). Conclusion: Hepatic decompensation after TARE for HCC treatment is a highly relevant complication with major effects on the prognosis of patients. Main risk factors are the pretreatment ALBI score and radiation dose. There is an urgent need to define safe cutoff values and exclusion criteria for TARE to limit complications and improve patient outcomes.

Summary of key guidelines for locoregional treatment of HCC in Asia, Europe, South and North America

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide accounting for over 800,000 new cases in 2018, with the highest incidence in Asia and Africa where hepatitis B is the most common risk factor. In Europe, Japan, and the United States, hepatitis C chronic alcohol abuse and non-alcoholic fatty liver disease are more common risk factors. Five-year survival is low, less than 20% worldwide. HCC is a particularly challenging disease to treat because therapeutic options and prognosis must also consider hepatitis or cirrhosis independent of the malignancy. Locoregional therapies (LRT) including ablation, arterially directed therapy and external beam radiation are the preferred treatments for patients with good performance status, unresectable disease limited to the liver and preserved liver function. In practice, patients with portal vein tumor thrombus and limited extrahepatic disease may also be considered candidates for LRT. There are several guidelines developed by expert panels provide recommendations on treating this challenging disease including the Barcelona Clinic Liver Cancer, European Association for the Study of the Liver, European Society for Medical Oncology, American Association for the Study of the Liver Diseases, and the National Comprehensive Cancer Network. The purpose of this paper is to review the guidelines as they are applied clinically in regions with high incidence of HCC.

The American Brachytherapy Society consensus statement for permanent implant brachytherapy using Yttrium-90 microsphere radioembolization for liver tumors

PURPOSE

To develop a multidisciplinary consensus for high quality multidisciplinary implementation of brachytherapy using Yttrium-90 (90Y) microspheres transarterial radioembolization (90Y TARE) for primary and metastatic cancers in the liver.

METHODS AND MATERIALS

Members of the American Brachytherapy Society (ABS) and colleagues with multidisciplinary expertise in liver tumor therapy formulated guidelines for 90Y TARE for unresectable primary liver malignancies and unresectable metastatic cancer to the liver. The consensus is provided on the most recent literature and clinical experience.

RESULTS

The ABS strongly recommends the use of 90Y microsphere brachytherapy for the definitive/palliative treatment of unresectable liver cancer when recommended by the multidisciplinary team. A quality management program must be implemented at the start of 90Y TARE program development and follow-up data should be tracked for efficacy and toxicity. Patient-specific dosimetry optimized for treatment intent is recommended when conducting 90Y TARE. Implementation in patients on systemic therapy should account for factors that may enhance treatment related toxicity without delaying treatment inappropriately. Further management and salvage therapy options including retreatment with 90Y TARE should be carefully considered.

CONCLUSIONS

ABS consensus for implementing a safe 90Y TARE program for liver cancer in the multidisciplinary setting is presented. It builds on previous guidelines to include recommendations for appropriate implementation based on current literature and practices in experienced centers. Practitioners and cooperative groups are encouraged to use this document as a guide to formulate their clinical practices and to adopt the most recent dose reporting policies that are critical for a unified outcome analysis of future effectiveness studies.

New concepts in the treatment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third most common cause of cancer-related death and occurs mainly in the context of chronic liver disease at cirrhosis stage. The Barcelona Clinic Liver Cancer classification, first established in 1999, is the most commonly used staging system for HCC in Western countries that link tumor burden, liver function and performance status with prognosis and therapeutic management. Since the first publication of this classification, it has been implemented in several clinical guidelines and recent major therapeutic advances in the management of HCC have modified the therapeutic landscape of HCC. Accordingly, an updated version was recently published in 2022, incorporating an expert clinical decision-making component and the concept of treatment stage migration. This update also introduces the positive results of recent randomized clinical trials, and introduces atezolizumab/bevacizumab (A/B) as a first-line combination regimen for patients with advanced HCC. Finally, the complexity of the management of patients with HCC highlights the need for a multidisciplinary approach including input from hepatology, surgery, radiology, medical oncology, and radiation oncology.

Embolization therapy with microspheres for the treatment of liver cancer: State-of-the-art of clinical translation

Embolization with microspheres is a therapeutic strategy based on the selective occlusion of the blood vessels feeding a tumor. This procedure is intraarterially performed in the clinical setting for the treatment of liver cancer. The practice has evolved over the last decade through the incorporation of drug loading ability, biodegradability and imageability with the subsequent added functionality for the physicians and improved clinical outcomes for the patients. This review highlights the evolution of the embolization systems developed through the analysis of the marketed embolic microspheres for the treatment of malignant hepatocellular carcinoma, namely the most predominant form of liver cancer. Embolic microspheres for the distinct modalities of embolization (i.e., bland embolization, chemoembolization and radioembolization) are here comprehensively compiled with emphasis on material characteristics and their impact on microsphere performance. Moreover, the future application of the embolics under clinical investigation is discussed along with the scientific and regulatory challenges ahead in the field. STATEMENT OF SIGNIFICANCE: Embolization therapy with microspheres is currently used in the clinical setting for the treatment of most liver cancer conditions. The progressive development of added functionalities on embolic microspheres (such as biodegradability, imageability or drug and radiopharmaceutical loading capability) provides further benefit to patients and widens the therapeutic armamentarium for physicians towards truly personalized therapies. Therefore, it is important to analyze the possibilities that advanced biomaterials offer in the field from a clinical translational perspective to outline the future trends in therapeutic embolization.

Radioembolization Dosimetry with Total-Body 90Y PET

Transarterial radioembolization (TARE) is a locoregional radiopharmaceutical therapy based on the delivery of radioactive ⁹⁰Y microspheres to liver tumors. The importance of personalized dosimetry to make TARE safer and more effective has been demonstrated in recent clinical studies, stressing the need for quantification of the dose-response relationship to ultimately optimize the administered activity before treatment and image it after treatment. ⁹⁰Y dosimetric studies are challenging because of the lack of accurate and precise methods but are best realized with PET combined with Monte Carlo simulations and other image modalities to calculate a segmental dose distribution. The aim of this study was to assess the suitability of imaging ⁹⁰Y PET patients with the total-body PET/CT uEXPLORER and to investigate possible improvements in TARE ⁹⁰Y PET-based dosimetry. The uEXPLORER is the first commercially available ultra-high-resolution (171 cps/kBq) total-body digital PET/CT device with a 194-cm axial PET field of view that enables the whole body to be scanned at a single bed position. Methods: Two PET/CT scanners were evaluated in this study: the Biograph mCT and the total-body uEXPLORER. Images of a National Electrical Manufacturers Association (NEMA) image-quality phantom and 2 patients were reconstructed using our standard clinical oncology protocol. A late portal phase contrast-enhanced CT scan was used to contour the liver segments and create corresponding volumes of interest. To calculate the absorbed dose, Monte Carlo simulations were performed using Geant4 Application for Tomographic Emission (GATE). The absorbed dose and dose-volume histograms were calculated for all 6 spheres (diameters ranging from 10 to 37 mm) of the NEMA phantom, the liver segments, and the entire liver. Differences between the phantom doses and an analytic ground truth were quantified through the root mean squared error. Results: The uEXPLORER showed a higher signal-to-noise ratio at 10- and 13-mm diameters, consistent with its high spatial resolution and system sensitivity. The total liver-absorbed dose showed excellent agreement between the uEXPLORER and the mCT for both patients, with differences lower than 0.2%. Larger differences of up to 60% were observed when comparing the liver segment doses. All dose-volume histograms were in good agreement, with narrower tails for the uEXPLORER in all segments, indicating lower image noise. Conclusion: This patient study is compelling for the use of total-body ⁹⁰Y PET for liver dosimetry. The uEXPLORER scanner showed a better signal-to-noise ratio than mCT, especially in lower-count regions of interest, which is expected to improve dose quantification and tumor dosimetry.

Conversion to resection post radioembolization in patients with HCC: recommendations from a multidisciplinary working group

BACKGROUND

Transarterial radioembolization (TARE) with yttrium-90 (⁹⁰Y) glass microspheres is an efficacious option for converting appropriately selected patients with borderline-resectable hepatocellular carcinoma (HCC) to surgical candidacy.

METHODS

In 2018 and 2019, a diverse multidisciplinary group of surgical and interventional experts with experience using ⁹⁰Y for downstaging and bridging to liver transplant convened to review peer-reviewed literature and personal experience in the use of ⁹⁰Y to convert borderline resectable liver cancer patients to surgical candidacy. The working group included surgical oncologists specializing in liver cancer, liver transplant surgeons with experience in complex hepatobiliary surgery, and interventional radiologists with experience using ⁹⁰Y.

RESULTS

This document presents expert recommendations based upon the group's experience and consensus.

CONCLUSIONS

By combining related evidence from the literature with expert experiences with TARE in surgical candidates, these recommendations aim to demonstrate the safety, efficacy, and feasibility of TARE in converting borderline-resectable patients to surgical options. The document also addresses the concerns about potential complications associated with TARE during the surgical intervention.

Clinical Outcomes of Patients With Unresectable Primary Liver Cancer Treated With Yttrium-90 Radioembolization With an Escalated Dose

Purpose

Yttrium-90 (90Y) radioembolization with an escalated dose has been shown to improve clinical outcomes compared with standard dose radioembolization, but there are few data on the local control of primary liver tumors. We reported the clinical outcomes of patients with unresectable primary liver tumors treated with 90Y radioembolization with an escalated dose.

Methods and Materials

Clinical data of patients with unresectable hepatocellular carcinoma (HCC), cholangiocarcinoma (CC), and biphenotypic tumors (cHCC-CC) treated with radioembolization with an escalated dose (≥150 Gy) between 2013 and 2020 with >3 months follow-up were retrospectively reviewed. The primary endpoint was freedom from local progression. Clinical response was defined by Modified Response Evaluation Criteria in Solid Tumours and toxic effects were assessed using Common Terminology Criteria for Adverse Events version 5.0.

Results

Fifty-three patients with HCC and 15 patients with CC/cHCC-CC were analyzed. The median dose delivered was 205 Gy (interquartile range, 183-253 Gy) and 198 Gy (interquartile range, 154-234 Gy) for patients with HCC and CC/cHCC-CC, respectively. The 1-year freedom from local progression rate was 54% (95% confidence interval [CI], 38%-78%) for patients with HCC and 66% (95% CI, 42%-100%) for patients with CC/cHCC-CC. For patients with HCC, United Network for Organ Sharing nodal stage 1 (P = .01), nonsolitary tumors (P = .02), pretreatment α-fetoprotein of >7.7 ng/mL (P = .006), and ≤268 Gy dose delivered (P = .003) were predictors for local progression on multivariate Cox analysis. No patients with HCC who received a dose >268 Gy had a local tumor progression. The 1-year overall survival for patients with HCC was 74% (95% CI, 61%-89%). After radioembolization, 5 (7%) patients had grade 3 ascites, and 4 (6%) patients had grade 3/4 hyperbilirubinemia.

Conclusions

Treatment of unresectable primary liver tumors with 90Y radioembolization with an escalated dose was safe and well tolerated. Delivery of >268 Gy may improve local tumor control of HCC. Determination of the maximum tolerated dose needs to be performed in the context of future prospective dose-escalation trials to further evaluate the safety and efficacy of such an approach.

Interventional oncology update

Interventional Oncology (IO) is a subspecialty field of Interventional Radiology bridging between diagnostic radiology and the clinical oncology team, addressing the diagnosis and treatment of cancer. There have been many exciting advancements in the field of IO in recent years; far too many to cover in a single paper. To give each topic sufficient attention, we have limited the scope of this review article to four topics which we feel have the potential to drastically change how cancer is treated managed in the immediate future.

Trial Designs for Integrating Novel Therapeutics into the Management of Intermediate-Stage Hepatocellular Carcinoma

Intermediate-stage hepatocellular carcinoma (HCC) consists of heterogeneous groups of patients in terms of tumor burden and organ function reserves. Although liver-directed therapy (LDT), including trans-catheter arterial chemoembolization, radiofrequency ablation or even surgical resection, is the recommended frontline treatment modality, intrahepatic and distant failures are common. The recent advances in systemic treatment, notably the introduction of immune checkpoint inhibitor (ICI)-based therapy, have significantly improved the objective tumor response rate, quality of response and overall survival in patients with recurrent and advanced HCC. Whether the combination of systemic treatment and LDT can further improve the outcome of patients with intermediate-stage HCC is currently being extensively evaluated. In this article, the recent clinical trials incorporating different ICI-based combinations with different LDT for intermediate-stage HCC were reviewed focusing on trial design issues, including patient selection, endpoint definition, and biomarker development. The strength and caveats of different combination strategies and novel biomarker development were discussed.

The importance of liver functional reserve in the non-surgical treatment of hepatocellular carcinoma

The aim of any oncological treatment is not just to eliminate the tumour, but to maximise patient survival and quality of life. Since the liver has a vital function, any radical treatment that severely compromises liver function will result in a shortening of life expectancy, rather than a prolongation. Furthermore, even non-severe liver damage may prevent the delivery of further effective therapies. This is particularly important in the case of hepatocellular carcinoma (HCC), as it is associated with underlying cirrhosis in most patients - cirrhosis itself is not only a potentially lethal disease and independent prognostic factor in HCC, but it also makes liver function fragile. Accordingly, some information about liver dysfunction is included in most staging systems for HCC and can be used to guide the selection of treatments that the functional liver reserve can tolerate. Unfortunately, the prediction of functional damage to the liver in the case of antitumor treatments is very challenging and still suboptimal in any given patient. Moreover, while the assessment of functional reserve can now be used to avoid postoperative liver failure in the surgical setting, its use has been less well clarified for non-surgical therapies, which is of particular relevance today, as several lines of effective non-surgical treatments, including systemic therapies, have become available. The present article will a) critically review the implications of the assessment of liver functional reserve in patients with HCC, b) illustrate the available tools to assess liver functional reserve and c) discuss the role of functional assessment for each type of non-surgical therapy for HCC.

National Trends and Waitlist Outcomes of Locoregional Therapy Among Liver Transplant Candidates With Hepatocellular Carcinoma in the United States

BACKGROUND & AIMS

Policy changes in the United States have lengthened overall waiting times for patients with hepatocellular carcinoma (HCC). We investigated temporal trends in utilization of locoregional therapy (LRT) and associated waitlist outcomes among liver transplant (LT) candidates in the United States.

METHODS

Data for primary adult LT candidates listed from 2003 to 2018 who received HCC exception were extracted from the Organ Procurement and Transplantation Network database. Explant histology was examined, and multivariable competing risk analysis was used to evaluate the association between LRT type and waitlist dropout.

RESULTS

There were 31,609 eligible patients with at least 1 approved HCC exception, and 34,610 treatments among 24,145 LT candidates. The proportion with at least 1 LRT recorded increased from 42.3% in 2003 to 92.4% in 2018. Chemoembolization remains the most frequent type, followed by thermal ablation, with a notable increase in radioembolization from 3% in 2013 to 19% in 2018. An increased incidence of LRT was observed among patients with tumor burden beyond Milan criteria, higher α-fetoprotein level, and more compensated liver disease. Receipt of any type of LRT was associated with a lower risk of waitlist dropout; there was no significant difference by number of LRTs. In inverse probability of treatment weighting-adjusted analysis, radioembolization or ablation as the first LRT was associated with a reduced risk of waitlist dropout compared with chemoembolization.

CONCLUSIONS

In a large nationwide cohort of LT candidates with HCC, LRT, and in particular radioembolization, increasingly was used to bridge to LT. Patients with greater tumor burden and those with more compensated liver disease received more treatments while awaiting LT. Bridging LRT was associated with a lower risk of waitlist dropout.

A global evaluation of advanced dosimetry in transarterial radioembolization of hepatocellular carcinoma with Yttrium-90: the TARGET study

PURPOSE

To investigate the relationships between tumor absorbed dose (TAD) or normal tissue absorbed dose (NTAD) and clinical outcomes in hepatocellular carcinoma (HCC) treated with yttrium-90 glass microspheres.

METHODS

TARGET was a retrospective investigation in 13 centers across eight countries. Key inclusion criteria: liver-dominant HCC with or without portal vein thrombosis, < 10 tumors per lobe (at least one ≥ 3 cm), Child-Pugh stage A/B7, BCLC stages A-C, and no prior intra-arterial treatment. Multi-compartment pre-treatment dosimetry was performed retrospectively. Primary endpoint was the relationship between ≥ grade 3 hyperbilirubinemia (such that > 15% of patients experienced an event) without disease progression and NTAD. Secondary endpoints included relationships between (1) objective response (OR) and TAD, (2) overall survival (OS) and TAD, and (3) alpha fetoprotein (AFP) and TAD.

RESULTS

No relationship was found between NTAD and ≥ grade 3 hyperbilirubinemia, which occurred in 4.8% of the 209 patients. The mRECIST OR rate over all lesions was 61.7%; for the target (largest) lesion, 70.8%. Responders and non-responders had geometric mean total perfused TADs of 225.5 Gy and 188.3 Gy (p = 0.048). Probability of OR was higher with increasing TAD (p = 0.044). Higher TAD was associated with longer OS (HR per 100 Gy increase = 0.83, 95% CI: 0.71-0.95; p = 0.009). Increased TAD was associated with higher probability of AFP response (p = 0.046 for baseline AFP ≥ 200 ng/mL).

CONCLUSION

Real-world data confirmed a significant association between TAD and OR, TAD and OS, and TAD and AFP response. No association was found between ≥ grade 3 hyperbilirubinemia and NTAD.

TRIAL REGISTRATION NUMBER

NCT03295006.

[Transarterial radioembolization of hepatocellular carcinoma and intrahepatic cholangiocarcinoma]

Since the first version of the S3 guideline for the diagnosis and treatment of hepatocellular carcinoma (HCC) in 2013, a large number of studies have consolidated the data on transarterial radioembolization (TARE) and created a broad evidence base. As a result, TARE was incorporated into the current 2021 S3 guideline with a number of specific recommendations, whereas it was previously only offered under study conditions. TARE is now offered with the other minimally invasive procedures for bridging and downstaging before liver transplantation, but also as an alternative to transarterial chemotherapy (TACE) in intermediate HCC and in locally limited intrahepatic cholangiocarcinoma in second-line therapy for selected patients-albeit with different levels of evidence. Based on the study situation, however, TARE is not recommended for advanced HCC; here, systemic therapy with immunotherapeutic agents is preferred based on current data.

TARE in Hepatocellular Carcinoma: From the Right to the Left of BCLC

The Barcelona Clinic Liver Cancer (BCLC) system is the most commonly used staging system for hepatocellular carcinoma (HCC) in Western countries. BCLC aims to categorize patients into five stages with different prognoses and to allocate treatment according to these stages based on the best possible contemporary evidence. Transarterial radioembolization (TARE) has recently entered at the left of the BCLC algorithm (i.e., BCLC 0-A), mainly because of negative phase III trials in BCLC C stage. TARE has shown a steady increase in nationwide studies over the past 20 years and has even been adopted in some tertiary centers as the primary HCC treatment across all BCLC stages. We aimed to review the history of TARE in HCC, starting from advanced HCC and gradually expanding to earlier stages at the left of the BCLC system.

Histotripsy for the Treatment of Cholangiocarcinoma in a Patient-Derived Xenograft Mouse Model

Histotripsy is a focused ultrasound ablation therapy being developed for the treatment of liver tumors. A recent study investigating the feasibility of using histotripsy for the ablation of cholangiocarcinoma (CC), bile duct cancer that is difficult to treat with current therapies because of its location near critical structures and fibrous tissue, reported the feasibility of treating CC in an acute mouse model. Here, we investigate histotripsy for the in vivo ablation of CC in a chronic study using a 1-MHz transducer at an applied dose of 500 pulses/point. A pilot study determined that treating the CC tumors plus a 1- to 2-mm margin induced significant injuries to intestinal tissues, thus precluding the use of this strategy. Next, histotripsy was applied to CCs (n = 6) with the treatment contained to the tumor. Post-treatment, the ablation was visualized using ultrasound, and subjects were monitored over time. Histotripsy achieved an average of 73% reduction of tumor diameter 26 d after treatment, with no significant adverse events. Notably, three of six treated tumors were undetectable after 2.5 wk. The treated animals were found to have significantly increased tumor progression-free and overall survival. Overall, results indicate that histotripsy can be used as a safe and effective method for treating CC.

Evaluating the Effectiveness of Yttrium-90 Glass Microspheres in the Treatment of Hepatocellular Carcinoma, Intrahepatic Cholangiocarcinoma, and Metastatic Colorectal Cancer in Practice: Protocol for the Prospective PROACTIF Phase IV Registry Study in France

PRIMARY OBJECTIVE

Recently, selective internal radiation therapy using yttrium-90 (Y90) glass microspheres (TheraSphere™) was approved for reimbursement by health authorities in France. The PROACTIF study aims to gather data on effectiveness, patient quality of life, and safety with use of Y90 glass microspheres in real-world clinical settings in France.

INCLUSION CRITERIA

Patient with a diagnosis of hepatocellular carcinoma (HCC), intrahepatic cholangiocarcinoma (iCC), and/or metastatic colorectal cancer (mCRC) who was treated with a dose of Y90 glass microspheres that has been reimbursed in France and who do not oppose use of their personal medical data.

EXCLUSION CRITERIA

If data collection is opposed, treatment is reimbursed but not administered, or treatment is administered but not reimbursed.

OUTCOME MEASURES

Primary outcome measures include overall survival from time of Y90 glass microsphere treatment and quality of life, as assessed using the Functional Assessment of Cancer Therapy- Hepatobiliary questionnaire.

ESTIMATED NUMBER OF PATIENTS TO BE INCLUDED

This is an open study and there is no set number of patients; 115 have already been enrolled.

PLANNED SUBGROUP ANALYSES

Analyses will be stratified by disease state (HCC, iCC, or mCRC). Subgroups to be analyzed include age group, unilobar/bilobar disease at baseline, Eastern Cooperative Oncology Group (ECOG) status at baseline, liver tumor burden at baseline, target lesion size, and standard versus multi-compartment personalized dosimetry treatment.

PLANNED RECRUITMENT AND OBSERVATION PERIOD

Recruitment includes patients who are prescribed and treated with a commercial vial of Y90 glass microspheres between 01 January 2019 and 31 December 2024.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04069468.