Angiosomal radiopathologic analysis of transarterial radioembolization for the treatment of hepatocellular carcinoma

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 Major Hepatectomy Using Ablative Dose Yttrium-90 Radioembolization in Patients with Hepatocellular Carcinoma 5 cm or Larger

PURPOSE

To evaluate the safety and effectiveness of ablative radioembolization for large hepatocellular carcinoma (HCC) while preserving a small future liver remnant (FLR).

MATERIALS AND METHODS

Twenty-five patients with large HCC of ≥5 cm requiring treatment for >60% of the total liver volume and having well-preserved liver function were treated with ablative glass microsphere radioembolization at a single institution from January 2017 to December 2021. Radioembolization was performed with a mean absorbed dose of >150 Gy, and the FLR per nontumor liver volume (NTLV) was set at >30%. Changes in liver function, adverse events, duration of response (DoR) in a treated area, time-to-progression (TTP), and overall survival (OS) were retrospectively investigated.

RESULTS

The largest tumor diameter and planned dose per treated volume were 11.4 cm ± 3.9 and 242.3 Gy ± 63.6 (169.4 Gy ± 45.9 per whole liver volume), respectively. All patients remained at Child-Pugh Class A for 90 days. No patient experienced Grade 3‒4 hyperbilirubinemia or new ascites. One patient (lung dose, 27.8 Gy) developed radiation pneumonitis requiring transient steroid treatment. According to the posttreatment dosimetry, the tumorous and nontumorous liver absorbed doses were 418.8 Gy ± 227.4 and 69.0 Gy ± 32.1, respectively. The median DoR in a treated area and TTP were 22.0 and 17.1 months, respectively. The 5-year OS rate was 83.2%.

CONCLUSIONS

Ablative radioembolization of large HCC of ≥5 cm can be performed safely and effectively in patients with preserved liver function when FLR/NTLV exceeds 30%.

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.

Assessment of HCC response to Yttrium-90 radioembolization with gadoxetate disodium MRI: correlation with histopathology

BACKGROUND AND AIMS

Transarterial ⁹⁰Y radioembolization (TARE) is increasingly being used for hepatocellular carcinoma (HCC) treatment. However, tumor response assessment after TARE may be challenging. We aimed to assess the diagnostic performance of gadoxetate disodium MRI for predicting complete pathologic necrosis (CPN) of HCC treated with TARE, using histopathology as the reference standard.

METHODS

This retrospective study included 48 patients (M/F: 36/12, mean age: 62 years) with HCC treated by TARE followed by surgery with gadoxetate disodium MRI within 90 days of surgery. Two radiologists evaluated tumor response using RECIST1.1, mRECIST, EASL, and LI-RADS-TR criteria and evaluated the percentage of necrosis on subtraction during late arterial, portal venous, and hepatobiliary phases (AP/PVP/HBP). Statistical analysis included inter-reader agreement, correlation between radiologic and pathologic percentage of necrosis, and prediction of CPN using logistic regression and ROC analyses.

RESULTS

Histopathology demonstrated 71 HCCs (2.8 ± 1.7 cm, range: 0.5-7.5 cm) including 42 with CPN, 22 with partial necrosis, and 7 without necrosis. EASL and percentage of tumor necrosis on subtraction at the AP/PVP were independent predictors of CPN (p = 0.02-0.03). Percentage of necrosis, mRECIST, EASL, and LI-RADS-TR had fair to good performance for diagnosing CPN (AUCs: 0.78 - 0.83), with a significant difference between subtraction and LI-RADS-TR for reader 2, and in specificity between subtraction and other criteria for both readers (p-range: 0.01-0.04). Radiologic percentage of necrosis was significantly correlated to histopathologic degree of tumor necrosis (r = 0.66 - 0.8, p < 0.001).

CONCLUSIONS

Percentage of tumor necrosis on subtraction and EASL criteria were significant independent predictors of CPN in HCC treated with TARE. Image subtraction should be considered for assessing HCC response to TARE when using MRI.

KEY POINTS

• Percentage of tumor necrosis on image subtraction and EASL criteria are significant independent predictors of complete pathologic necrosis in hepatocellular carcinoma treated with⁹⁰Y radioembolization. • Subtraction, mRECIST, EASL, and LI-RADS-TR have fair to good performance for diagnosing complete pathologic necrosis in hepatocellular carcinoma treated with⁹⁰Y radioembolization.

The use of neoadjuvant lobar radioembolization prior to major hepatic resection for malignancy results in a low rate of post hepatectomy liver failure

Background

Neoadjuvant yttrium-90 transarterial radioembolization (TARE) is increasingly being used as a strategy to facilitate resection of otherwise unresectable tumors due to its ability to generate both tumor response and remnant liver hypertrophy. Perioperative outcomes after the use of neoadjuvant lobar TARE remain underinvestigated.

Methods

A single center retrospective review of patients who underwent lobar TARE prior to major hepatectomy for primary or metastatic liver cancer between 2007 and 2018 was conducted. Baseline demographics, radioembolization parameters, pre- and post-radioembolization volumetrics, intra-operative surgical data, adverse events, and post-operative outcomes were analyzed.

Results

Twenty-six patients underwent major hepatectomy after neoadjuvant lobar TARE. The mean age was 58.3 years (17-88 years). 62% of patients (n=16) had primary liver malignancies while the remainder had metastatic disease. Liver resection included right hepatectomy or trisegmentectomy, left or extended left hepatectomy, and sectorectomy/segmentectomy in 77% (n=20), 8% (n=2), and 15% (n=4) of patients, respectively. The mean length of stay was 8.3 days (range, 3-33 days) and there were no grade IV morbidities or 90-day mortalities. The incidence of post hepatectomy liver failure (PHLF) was 3.8% (n=1). The median time to progression after resection was 4.5 months (range, 3.3-10 months). Twenty-three percent (n=6) of patients had no recurrence. The median survival was 28.9 months (range, 16.9-46.8 months) from major hepatectomy and 37.6 months (range, 25.2-53.1 months) from TARE.

Conclusions

Major hepatectomy after neoadjuvant lobar radioembolization is safe with a low incidence of PHLF.

Pathologic Response of Hepatocellular Carcinoma Treated with Yttrium-90 Glass Microsphere Radiation Segmentectomy Prior to Liver Transplantation: A Validation Study

PURPOSE

To evaluate the pathologic outcomes of hepatocellular carcinoma (HCC) treated with Yttrium-90 radiation segmentectomy using glass microspheres prior to liver transplantation and explore parameters associated with pathologic necrosis.

MATERIALS AND METHODS

A single-institution retrospective analysis of HCC patients who received radiation segmentectomy prior to liver transplantation from November 2016 to May 2020 was performed. Patients were included if the treatment angiosome encompassed the entire tumor and could be correlated with available gross pathology. Archived histology slides were reviewed for percentage of pathologic necrosis. Thirty-three patients with 37 tumors were evaluated. The median tumor size was 2.3 cm (range, 1-6.7 cm).

RESULTS

All tumors received a single treatment. The median time from radiation segmentectomy to transplantation was 206 days (range, 58-550 days). Objective response per Modified Response Evaluation Criteria in Solid Tumors (mRECIST) was 92% (complete response, 76%; partial response, 16%). A total of 68% (n = 25) of tumors demonstrated ≥99% pathologic necrosis. Complete pathologic necrosis was present in 53% and 75% of tumors treated with >190 Gy (n = 18) and >500 Gy (n = 8) single-compartment Medical Internal Radiation Dose, respectively. Complete response per mRECIST, posttreatment angiosome T1 hypointensity, dose >190 Gy, microsphere specific activity >297 Bq, and a longer time between treatment and transplant were associated with ≥99% tumor necrosis (P < .05). No posttransplant tumor recurrences occurred within a median follow-up of 604 days (range, 138-1,223 days).

CONCLUSIONS

Radiation segmentectomy can serve as an ablative modality for the treatment of HCC prior to liver transplant.

Mapping angiography and transarterial technetium macroaggregated albumin particle simulation of recurrent atypical intracranial meningioma: feasibility for potential vascular brachytherapy

Atypical meningioma (AM) (WHO-II) has a recurrence rate of 28% after gross total resection (GTR) with limited salvage options. Transarterial therapies may provide treatment opportunities in AM patients who exhausted standard-of-care therapy. In cases where favorable tumor vasculature and particle simulation demonstrate acceptable target dose, Yttrium-90 trans-arterial radioemobilization (TARE) could theoretically provide salvage therapy. A 67-year-old man presented with recurrent AM post gross total resection with adjuvant radiotherapy in 2012, 2014, and 2016. The patient was deemed a poor candidate for additional therapies. Tumor vasculature mapping was performed to determine TARE candidacy. Super-selective angiography and contrast-enhanced cone-beam computed tomography angiosomes demonstrated predominant pial collaterals and minor supply from a middle meningeal artery branch. Particle simulation was performed by infusing 0.3 mCi of 99mTc-macroaggregated albumin (99mTc-MAA). SPECT/CT-MRI fusion demonstrated conformal activity solely within the tumor volume perfused by the middle meningeal artery branch with a lung shunt fraction of 54.7%. The patient subsequently received off-label Nivolumab (PD-1 inhibitor). Mapping angiography for AM using 99mTc-MAA is feasible. It may identify candidates for TARE and potential AM patients with favorable blood supply. The potential for conformal intracranial vascular brachytherapy is intriguing, however, altered arterial supply in recurrent tumors is challenging.

Individualized Ablation of Hepatocellular Carcinoma: Tailored Approaches across the Phenotype Spectrum

Ablation is now recommended by international guidelines for the definitive treatment of hepatocellular carcinoma (HCC). Extensive clinical studies have demonstrated outcomes comparable to surgical resection with shorter hospital stays, decreased costs, and improved quality of life. Successful ablation requires complete treatment of both tumor and margin while preserving critical adjacent structures. HCC exhibits highly variable presentations in both anatomic involvement and biology which have significant implications on choice of ablative therapy. There are now abundant ablation modalities and adjunctive techniques which can be used to individualize ablation and maximize curative results. This article provides a patient-centered summary of approaches to HCC ablation in the context of patient performance, hepatic reserve, tumor phenotype and biology, intra- and extrahepatic anatomy, and ablation technology.

Y90 Radioembolization Dosimetry: Concepts for the Interventional Radiologist

Transarterial radioembolization (TARE) with beta particle emitting microspheres via Yttrium-90 decay has become a fundamental component of the contemporary Interventional Oncology practice. TARE continues to advance as a result of increased utilization, clinical study, technological improvements, and evolving applications. To maximize TARE safety and efficacy, a core understanding of dosimetry is essential. The intent of this overview is to provide the reader with a general survey of radiation physics and biology, device differentiation, patient selection, anatomic assessment, activity administration models, and procedural techniques involved with TARE dosimetry.

Radioembolization Super Survivors: Extended Survival in Non-operative Hepatocellular Carcinoma

PURPOSE

To identify baseline characteristics and long-term prognostic factors in non-transplant patients with unresectable hepatocellular carcinoma (HCC) who had prolonged survival after treatment with yttrium-90 radioembolization (Y90).

MATERIALS AND METHODS

Sixty-seven "Super Survivors" (defined as ≥ 3-year survival after Y90) were identified within our 1000-patient Y90 database (2003-2017). Baseline imaging and follow-up occurred at 1 month and every 3 months thereafter. Overall survival (OS) was calculated with Kaplan-Meier estimates with log-rank test in subgroups: Child-Pugh (CP) score, distribution of disease, portal vein thrombus (PVT), and technique (segmental vs lobar Y90).

RESULTS

Median age 69.5 years (range 45-94 years); 69% male; 60% solitary HCC; 79% unilobar disease; 12% PVT; 10% ascites; Barcelona Clinic Liver Cancer Stage A-54%/B-28%/C-16%/D-2%; CP A-70%/B-28%/C-2%. Longest baseline tumor diameter was 5.4 ± 4.0 cm (mean ± SD). All patients had an imaging response (either partial or complete response). Median OS was 67.5 months (95% CI 55.2-82.5). CP score and main PVT stratified median OS (p = 0.0007 and p = 0.0187, respectively). Beyond 3 years, segmental versus lobar Y90 was associated with improved OS with a median OS of 80.2 versus 46.7 months, respectively (p = 0.0024). Dosing > 200 Gy was not a significant predictor of improved OS.

CONCLUSIONS

Super Survivors spanning the BCLC staging system maintained durable OS after radioembolization that was stratified by the extent of underlying liver disease. The common variable among all patients was an imaging response. Segmental versus lobar Y90 may have a long-term associated OS benefit.