The role of interventional radiology in the management of hepatocellular carcinoma

Ethiodized oil as an imaging biomarker after conventional transarterial chemoembolization

Conventional transarterial chemoembolization (cTACE) utilizing ethiodized oil as a chemotherapy carrier has become a standard treatment for intermediate-stage hepatocellular carcinoma (HCC) and has been adopted as a bridging and downstaging therapy for liver transplantation. Water-in-oil emulsion made up of ethiodized oil and chemotherapy solution is retained in tumor vasculature resulting in high tissue drug concentration and low systemic chemotherapy doses. The density and distribution pattern of ethiodized oil within the tumor on post-treatment imaging are predictive of the extent of tumor necrosis and duration of response to treatment. This review describes the multiple roles of ethiodized oil, particularly in its role as a biomarker of tumor response to cTACE. CLINICAL RELEVANCE: With the increasing complexity of locoregional therapy options, including the use of combination therapies, treatment response assessment has become challenging; Ethiodized oil deposition patterns can serve as an imaging biomarker for the prediction of treatment response, and perhaps predict post-treatment prognosis. KEY POINTS: • Treatment response assessment after locoregional therapy to hepatocellular carcinoma is fraught with multiple challenges given the varied post-treatment imaging appearance. • Ethiodized oil is unique in that its' radiopacity can serve as an imaging biomarker to help predict treatment response. • The pattern of deposition of ethiodozed oil has served as a mechanism to detect portions of tumor that are undertreated and can serve as an adjunct to enhancement in order to improve management in patients treated with intraarterial embolization with ethiodized oil.

[177Lu]Lu-PSMA-617 theranostic probe for hepatocellular carcinoma imaging and therapy

PURPOSE

This study aimed to explore the feasibility of using [177Lu]Lu-prostate-specific membrane antigen (PSMA)-617 and [177Lu]Lu-Evans blue (EB)-PSMA-617 for in vivo radioligand therapy by single-dose administration in a PSMA-positive hepatocellular carcinoma (HCC) xenograft mouse model.

METHODS

[177Lu]Lu-PSMA-617 and [177Lu]Lu-EB-PSMA-617 were prepared, and labelling efficiency and radiochemical purity were determined. A HepG2 human HCC subcutaneous xenograft mouse model was established. After intravenous injection of [177Lu]Lu-PSMA-617 or [177Lu]Lu-EB-PSMA-617 (37 MBq) into the mouse model, single-photon emission computed tomography/computed tomography (SPECT/CT) was performed. Biodistribution studies were conducted to verify targeting specificity and pharmacokinetics. In the radioligand therapy study, mice were randomized into 4 groups: 37 MBq [177Lu]Lu-PSMA-617, 18.5 MBq [177Lu]Lu-PSMA-617, 7.4 MBq [177Lu]Lu-EB-PSMA-617, and saline (control). A single-dose administration was applied at the beginning of therapy studies. Tumor volume, body weight, and survival were monitored every 2 days. After the end of therapy, mice were euthanized. Tumors were then weighed, and systemic toxicity was evaluated via blood testing and histological examination of healthy organs.

RESULTS

[177Lu]Lu-PSMA-617 and [177Lu]Lu-EB-PSMA-617 were successfully prepared with high purity and stability. SPECT/CT and biodistribution showed that tumor uptake was higher and persisted longer for [177Lu]Lu-EB-PSMA-617 compared with [177Lu]Lu-PSMA-617. [177Lu]Lu-PSMA-617 was rapidly cleared from the blood, while [177Lu]Lu-EB-PSMA-617 persisted for significantly longer. In radioligand therapy studies, tumor growth was significantly suppressed in the 37 MBq [177Lu]Lu-PSMA-617, 18.5 MBq [177Lu]Lu-PSMA-617, and 7.4 MBq [177Lu]Lu-EB-PSMA-617 groups compared to the saline group. Median survival was 40, 44, 43, and 30 days, respectively. No healthy organ toxicity was observed in safety and tolerability evaluation.

CONCLUSIONS

Radioligand therapy using [177Lu]Lu-PSMA-617 and [177Lu]Lu-EB-PSMA-617 significantly suppressed tumor growth and prolonged survival time in PSMA-positive HCC xenograft mice without obvious toxicity. These radioligands appear promising for clinical use in humans, and future studies are warranted.

LI-RADS Treatment Response Algorithm: Performance and Diagnostic Accuracy With Radiologic-Pathologic Explant Correlation in Patients With SBRT-Treated Hepatocellular Carcinoma

PURPOSE

Our purpose was to evaluate the accuracy of LI-RADS Treatment Response Algorithm (LR-TRA) for assessing the viability of hepatocellular carcinoma (HCC) treated with stereotactic body radiation therapy (SBRT), using explant pathology as the gold standard.

METHODS AND MATERIALS

This retrospective study included patients who underwent SBRT for locoregional treatment of HCC between 2008 and 2019 with subsequent liver transplantation. Five radiologists independently assessed all treated lesions by using the LR-TRA. Imaging and posttransplant histopathology were compared. Lesions were categorized as either completely (100%) or incompletely (<100%) necrotic, and performance characteristics and predictive values for the LR-TR viable and nonviable categories were calculated for each reader. Interreader reliability was calculated using the Fleiss kappa test.

RESULTS

A total of 40 treated lesions in 26 patients (median age, 63 years [interquartile range, 59.4-65.5]; 23 men) were included. For lesions treated with SBRT, sensitivity for incomplete tumor necrosis across readers ranged between 71% and 86%, specificity between 85% and 96%, and positive predictive value between 86% and 92%, when the LR-TR equivocal category was treated as nonviable, accounting for subject clustering. When the LR-TR equivocal category was treated as viable, sensitivity of complete tumor necrosis for lesions treated with SBRT ranged from 88% to 96%, specificity from 71% to 93%, and negative predictive value from 85% to 96%. Interreader reliability was fair (k = 0.22; 95% confidence interval, 0.13-0.33). Although a loss of arterial phase hyperenhancement (APHE) was highly correlated with pathologically nonviable tumor on explant, almost half of the patients with APHE had pathologically nonviable tumor on explant.

CONCLUSIONS

LR-TRA v2018 performs well for predicting complete and incomplete necrosis in HCC treated with SBRT. In contrast to other locoregional therapies, the presence of APHE after SBRT does not always indicate viable tumor and suggests that observation may be an appropriate strategy for these patients.

Assessing locoregional treatment response to Hepatocellular Carcinoma: comparison of hepatobiliary contrast agents to extracellular contrast agents

Cross-sectional imaging with contrast-enhanced magnetic resonance imaging (MRI) is routinely performed in patients with hepatocellular carcinoma (HCC) to assess tumor response to locoregional therapy (LRT). Current response assessment algorithms, such as the Liver Imaging Reporting and Data System (LI-RADS) treatment response algorithm (TRA), allow assessment using conventional gadolinium-based extracellular contrast agents (ECA) for accurate tumor response assessment following LRT. MRI with hepatobiliary agents (HBA) allows an acquisition of hepatobiliary phase (HBP), which is proven to increase sensitivity for detection of observations in at-risk patients, particularly for findings < 2 cm. The use of HBA is not yet incorporated into the TRA; however, it is increasingly used in clinical practice. Few published studies have evaluated the performance of LI-RADS TRA by applying ancillary features related to HBP that has resulted in category adjustment, enabling more sensitive and unequivocal diagnosis. This may help timely management of viable cases, without a significant loss of specificity in comparison with the ECA-based LI-RADS TRA assessment. In this review, we will describe and compare the imaging appearance of treated HCC on MRI using extracellular and hepatobiliary contrast agents and discuss emerging evidence and pitfalls in the assessment of tumor response following LRT with HBA.

Hepatic Hilar Nerve Block for Hepatic Interventions: Anatomy, Technique, and Initial Clinical Experience in Thermal Ablation of Liver Tumors

Background Image-guided procedures for treatment of liver diseases can be painful and require heavy sedation of the patient. Local-regional nerve blocks improve pain control and reduce oversedation risks, but there are no documented liver-specific nerve blocks. Purpose To develop a safe and technically simple liver-specific nerve block. Materials and Methods Between March 2017 and October 2019, three cadavers were dissected to evaluate the hepatic hilar anatomy. The hepatic hilar nerves were targeted with transhepatic placement of a needle adjacent to the main portal vein, under US guidance, and evaluated with use of an injection of methylene blue. A hepatic nerve block, using similar technique and 0.25% bupivacaine, was offered to patients undergoing liver tumoral ablation. In a prospective pilot study, 12 patients who received the nerve block were compared with a control group regarding complications, safety, pain scores, and intraoperative opioid requirement. Student t tests were used to compare the groups' characteristics, and Mann-Whitney U tests were used for the measured outcomes. Results Cadaver results confirmed that the hepatic nerves coursing in the hepatic hilum can be targeted with US for injection of anesthetic agents, with adequate spread of injected methylene blue around the nerves in the hepatic hilar perivascular space. The 12 participants (mean age ± standard deviation, 66 years ± 13; eight men) who received a hepatic hilar block before liver thermal ablations demonstrated reduced pain compared with a control group of 12 participants (mean age, 63 years ± 15; eight men) who received only intravenous sedation. Participants who received the nerve block had a lower mean visual analog scale score for pain than the control group (3.9 ± 2.4 vs 7.0 ± 2.8, respectively; P = .01) and decreased need for intraprocedural fentanyl (mean dose, 152 μg ± 78.0 vs 235.4 μg ± 58.2, respectively; P = .01). No major complications occurred in the hepatic hilar nerve block group. Conclusion A dedicated hepatic hilar nerve block with 0.25% bupivacaine can be safely performed to provide anesthesia during liver tumoral ablation. © RSNA, 2021.

Hepatocellular carcinoma Liver Imaging Reporting and Data Systems treatment response assessment: Lessons learned and future directions

Hepatocellular carcinoma (HCC) is a leading cause of morbidity and mortality worldwide, with rising clinical and economic burden as incidence increases. There are a multitude of evolving treatment options, including locoregional therapies which can be used alone, in combination with each other, or in combination with systemic therapy. These treatment options have shown to be effective in achieving remission, controlling tumor progression, improving disease free and overall survival in patients who cannot undergo resection and providing a bridge to transplant by debulking tumor burden to downstage patients. Following locoregional therapy (LRT), it is crucial to provide treatment response assessment to guide management and liver transplant candidacy. Therefore, Liver Imaging Reporting and Data Systems (LI-RADS) Treatment Response Algorithm (TRA) was created to provide a standardized assessment of HCC following LRT. LI-RADS TRA provides a step by step approach to evaluate each lesion independently for accurate tumor assessment. In this review, we provide an overview of different locoregional therapies for HCC, describe the expected post treatment imaging appearance following treatment, and review the LI-RADS TRA with guidance for its application in clinical practice. Unique to other publications, we will also review emerging literature supporting the use of LI-RADS for assessment of HCC treatment response after LRT.

What family physicians should know about interventional radiology?

Interventional radiology (IR) is a rapidly evolving specialty. The minimally invasive nature of the procedures has led to a paradigm shift in treating many disease processes from conventional surgery to interventional techniques that have become the first choice and the preferred method for the treatment of peripheral vascular disease, many aortic pathologies, and venous diseases. Interventional oncology procedures have become widely available for the treatment of solid hepatic and renal tumors. This includes palliative techniques for many advanced malignancies, and fluid drainage that is exclusively performed by interventional radiologists in many hospitals all around the world. Women's health-related procedures such as uterine fibroid embolization, fallopian tube recanalization, and embolization for pelvic congestion syndrome have become attractive choices for many patients. Family physicians (FPs) are the main source of patient referral to hospitals. However, there is a notable knowledge deficiency of IR among FPs in Saudi Arabia. This may be due to poor communication between FP and IR or the lack of FP's awareness of IR procedures. This is a nonsystematic review to introduce some IR procedures to FPs pertinent to their practice to optimize patient referral and management with the use of IR services. We focused on the most commonly performed IR procedures paying special attention to their clinical indications, benefits, and alternatives.

MRI Assessment of Hepatocellular Carcinoma after Local-Regional Therapy: A Comprehensive Review

Nearly 80% of cirrhotic patients diagnosed with hepatocellular carcinoma (HCC) are not eligible for surgical resection and instead undergo local-regional treatment. After therapy for HCC, patients undergo imaging surveillance to assess treatment efficacy and identify potential sites of progressive tumor elsewhere within the liver. Accurate interpretation of posttreatment imaging is essential for guiding further management decisions, and radiologists must understand expected treatment-specific imaging findings for each of the local-regional therapies. Of interest, expected imaging findings seen after radiation-based therapies (transarterial radioembolization and stereotactic body radiation therapy) are different than those seen after thermal ablation and transarterial chemoembolization. Given differences in expected posttreatment imaging findings, the current radiologic treatment response assessment algorithms used for HCC (modified Response Evaluation Criteria in Solid Tumors classification, European Association for the Study of Liver Diseases criteria, and Liver Imaging and Reporting Data System Treatment Response Algorithm) must be applied cautiously for radiation-based therapies in which persistent arterial phase hyperenhancement in the early posttreatment period is common and expected. This article will review the concept of tumor response assessment for HCC, the forms of local-regional therapy for HCC, and the expected posttreatment findings for each form of therapy. Keywords: Abdomen/GI, Liver, MR-Imaging, Treatment Effects, Tumor Response © RSNA, 2020.

Local application of doxorubicin- loaded Iron oxid nanoparticles and the vascular disrupting agent via the hepatic artery: chemoembolization-photothermal ablation treatment of hepatocellular carcinoma in rats

Objectives

This study investigates the effectiveness of local application of doxorubicin(Dox)-loaded, polydopamine (PDA)- coated single crystal hematite (α- Fe₂O₃) nanocubes (Fe₂O₃-PDA-Dox) and combretastatin A-4 phosphate disodium(CA4P)in treating hepatocellular carcinoma (HCC) in rats.

Methods

The magnetic characteristics and photothermal effects of the nanoparticles were determined in vitro. Tumor-bearing Sprague–Dawley rats were divided into 3 groups of 8 according to treatment: controls, transarterial chemoembolization–photothermal ablation (pTACE) (Lipidol+Fe₂O₃-PDA-Dox + NIR), and CA4P + pTACE (CA4P+ Lipidol+Fe₂O₃-PDA-Dox + NIR). Drugs were administered through the hepatic artery, and the tumors exposed to 808-nm near-infrared radiation. The Fe content of tumors was assessed using neutron activation analysis. Treatment effectiveness was assessed using heating curves, magnetic resonance imaging, pathology results, and immunohistochemical analysis.

Results

The mean tumor Fe content was greater in rats treated with CA4P + pTACE (1 h, 23.72 ± 12.45 μg/g; 24 h, 14.61 ± 8.23 μg/g) than in those treated with pTACE alone (1 h, 5.66 ± 4.29 μg/g; 24 h, 2.76 ± 1.33 μg/g). The tumor T2 imaging signal was lower in rats treated with CA4P + pTACE. Following laser irradiation, the tumor temperature increased, with higher temperatures reached in the CA4P + pTACE group (62 °C vs 55 °C). Tumor cells exhibited necrosis, apoptosis, and proliferation inhibition, with greater effects in the CA4P + pTACE group. Transient liver and kidney toxicity were observed on day 3, with more severe effects after CA4P + pTACE.

Conclusions

Fe₂O₃-PDA-Dox nanoparticles are effective for TACE–PTA. Pretreatment with CA4P increases nanoparticle uptake by tumors, increasing the treatment effectiveness without increasing hepatorenal toxicity.

The Combination Strategy of Transarterial Chemoembolization and Radiofrequency Ablation or Microwave Ablation against Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common primary cancer of the liver. Hepatectomy and liver transplantation (LT) are regarded as the radical treatment, but great majority of patients are already in advanced stage on the first diagnosis and lose the surgery opportunity. Multifarious image-guided interventional therapies, termed as locoregional ablations, are recommended by various HCC guidelines for the clinical practice. Transarterial chemoembolization (TACE) is firstly recommended for intermediate-stage (Barcelona Clinic Liver Cancer (BCLC) B class) HCC but has lower necrosis rates. Radiofrequency ablation (RFA) is effective in treating HCCs smaller than 3 cm in size. Microwave ablation (MWA) can ablate larger tumor within a shorter time. Combination of TACE with RFA or MWA is effective and promising in treating larger HCC lesions but needs more clinical data to confirm its long-term outcome. The combination of TACE and RFA or MWA against hepatocellular carcinoma needs more clinical data for a better strategy. The characters and advantages of TACE, RFA, MWA, and TACE combined with RFA or MWA are reviewed to provide physician a better background on decision.

Loco-regional hepatocellular carcinoma treatment services as a bridge to liver transplantation

BACKGROUND

Liver transplantation remains the main curative treatment option for hepatocellular carcinoma (HCC) patients. In the Eurotransplant area Milan criteria are used to assign priority extra points (exceptional MELD, exMELD) for patients on the waiting list. To prevent patients from tumor progression, loco-regional (neoadjuvant) treatment (LRT) is used. For patients unlikely to timely receive an organ via primary allocation, "extended critera donor (ECD) organs" are used. The present study aimed to investigate the survival after LT with a strategy of minimizing waiting list dropouts by using LRT for bridging and transplanting ECD organs if possible and necessary.

METHODS

Between October 2010 and May 2015, 50 liver transplants for HCC were included in this retrospective study. Of those, 42 (84%) met the Milan criteria according to the preoperative radiological examination. Forty-one patients (82%) received LRT. The waiting time was analyzed according to LRT. Kaplan-Meier curves with log-rank statistics were used for survival analyses.

RESULTS

One- and five-year overall survival within Milan criteria was 94.3% and 83.7% compared with 91.7% and 67.9% beyond Milan criteria, though statistical significance was not reached (P = 0.487). LRT had no impact on overall survival (P = 0.629). Median waiting time was shorter if no LRT was performed (4.6 months vs. 1.5 months, P = 0.006) and there were no cases of waiting list dropouts. Using ECD organs had no impact on overall survival (P = 0.663).

CONCLUSIONS

Patients with an expected waiting time to transplantation of >6 months could be successfully treated with LRT as a bridge to transplant. Overall and disease-free survival for patients within and beyond Milan criteria was comparable and the use of ECD organs in this cohort of HCC patients proved to be a safe option.

Cost-effectiveness analysis of lenvatinib treatment for patients with unresectable hepatocellular carcinoma (uHCC) compared with sorafenib in Japan

BACKGROUND

Lenvatinib demonstrated a treatment effect on overall survival by the statistical confirmation of non-inferiority to sorafenib for the first-line treatment of uHCC. The objective of this study was to evaluate the cost-effectiveness of lenvatinib compared with sorafenib for patients with uHCC in Japan.

METHODS

A partitioned-survival model was developed to estimate the cost-effectiveness of lenvatinib versus sorafenib when treating uHCC patients over a lifetime horizon and considering total public healthcare expenditure. Efficacy and safety data were extracted from the REFLECT trial. Utility values were derived from the European Quality-of-Life 5-Dimension Questionnaire, conducted with patients enrolled in the REFLECT trial. Direct medical costs, such as primary drug therapy, outpatient visits, diagnostic tests, hospitalization, post-progression therapy, and adverse-event treatments, were included. Cost parameters unavailable in the clinical trial or publications were obtained based on the consolidated clinical standards from a Delphi panel of four Japanese medical experts.

RESULTS

For lenvatinib versus sorafenib, the incremental cost was - 406,307 Japanese Yen (JPY), and the incremental life years and quality-adjusted life years (QALYs) were 0.27 and 0.23, respectively. Thus, lenvatinib dominated sorafenib, due to the mean incremental cost-effectiveness ratio falling in the fourth quadrant, conferring more benefit at lower costs compared with sorafenib. The probabilistic sensitivity analysis showed that 81.3% of the simulations were favorable to lenvatinib compared with sorafenib, with a payer's willingness-to-pay-per-QALY of 5 million JPY.

CONCLUSIONS

Lenvatinib was cost-effective compared with sorafenib for the first-line treatment of uHCC in Japan.

Designing pH-triggered drug release iron oxide nanocomposites for MRI-guided photothermal-chemoembolization therapy of liver orthotopic cancer

In an orthotopic liver cancer model, non-toxic versatile theranostic NPs consisting of an MRI contrast agent and a pH-sensitive and photothermal functional coating were delivered to improve tumor targeting efficacy.

Magnetic Resonance Imaging Evaluation of Hepatocellular Carcinoma Treated With Stereotactic Body Radiation Therapy: Long Term Imaging Follow-Up

PURPOSE

To determine the natural history of imaging findings seen on magnetic resonance imaging (MRI) of hepatocellular carcinoma (HCC) treated with stereotactic body radiation therapy (SBRT). Although arterial hyperenhancement is a key feature of untreated HCC, our clinical experience suggested that tumors that never progressed could still show hyperenhancement. Therefore, we undertook a systematic study to test the hypothesis that persistent arterial phase hyperenhancement (APHE) after SBRT is an expected finding that does not suggest failure of treatment.

METHODS AND MATERIALS

One hundred forty-six patients undergoing SBRT for HCC between January 1, 2007, and December 31, 2015, were screened retrospectively using an institutional review board-approved prospectively maintained registry. Inclusion criteria were (1) HCC treated with SBRT, (2) multiphasic MRI ≤3 months before SBRT, (3) up to 1 year of follow-up MRI post-SBRT, and (4) cirrhosis. The exclusion criterion was ≤3 months of locoregional therapy to the liver segment containing the SBRT-treated HCC. Pre- and post-SBRT MRI from up to 3 years were analyzed in consensus by independent pairs of subspecialty-trained radiologists to determine the temporal evolution of major features for HCC and imaging findings in off-target parenchyma.

RESULTS

Sixty-two patients with 67 HCCs (Organ Procurement and Transplantation Network imaging criteria [OPTN] 5a [n = 26], OPTN 5b [n = 28], OPTN 5x [n = 7]; Liver Imaging Reporting Data System [LI-RAD]-M [n = 4] and LiRADs-4 [n = 2]) were studied. Tumor size either decreased (66% [44 of 67]) or remained unchanged (34% [23 of 67]) within the first 12 months. Post-SBRT APHE was common (58% [39 of 67]). When graded using modified Response Evaluation Criteria in Solid Tumors at 3 to 6 months, 25% (17 of 67) met criteria for complete response and 75% (50 of 67) met criteria for stable disease.

CONCLUSIONS

SBRT is an effective locoregional treatment option for HCC. Persistent APHE is common and does not necessarily indicate viable neoplasm; thus, standard response assessment such as modified Response Evaluation Criteria should be used with caution, particularly in the early phases after SBRT therapy.

Liver targeted therapies for hepatocellular carcinoma prior to transplant: contemporary management strategies

Hepatocellular carcinoma (HCC) is an aggressive neoplastic disease that has been rapidly increasing in incidence. It usually occurs in the background of liver disease, and cirrhosis. Definitive therapy requires surgical resection. However, in majority of cases surgical resection is not tolerated, especially in the presence of portal hypertension and cirrhosis. Orthotopic liver transplant (OLT) in well selected candidates has been accepted as a viable option. Due to a relative scarcity of donors compared to the number of listed recipients, long waiting times are anticipated. To prevent patients with HCC from dropping out from the transplant list due to progression of their disease, most centers utilize loco-regional therapies. These loco-regional therapies(LRT) include minimally invasive treatments like percutaneous thermal ablation, trans-arterial chemoembolization, trans-arterial radio-embolization or a combination thereof. The type of therapy or combination used is determined by the size and location of the HCC and Barcelona Clinic Liver Cancer (BCLC) classification. The data regarding the efficacy of LRT in reducing post-transplant recurrence or disease-free survival is limited. This article reviews the available therapies, their strengths, limitations, and current use in the management of patients with hepatocellular carcinoma awaiting transplant.

Thermographic real-time-monitoring of surgical radiofrequency and microwave ablation in a perfused porcine liver model

Radiofrequency ablation (RFA) and microwave ablation (MWA) are currently the dominant modalities to treat unresectable liver tumors. Monitoring the ablation process with b-mode-sonography is often hampered by artefacts. Furthermore, vessels may cause cooling in the adjacent tumor target (heat-sink-effect) with risk of local recurrence. The present study evaluated infrared-thermography to monitor surgical RFA/MWA and detect heat-sink-effects in real-time. RFA and MWA of perfused porcine livers was conducted at peripheral and central-vessel-adjacent locations, and monitored by real-time thermography. Ablation was measured and evaluated by gross pathology. The mean time for ablation was significantly longer in RFA compared with MWA (8 vs. 2 min). Although mean macroscopic ablation diameter was similar (RFA, 3.17 cm; MWA, 3.38 cm), RFA showed a significant heat-sink-effect compared with MWA. The surface temperature during central RFA near vessels was 1/3 lower compared with peripheral RFA (47.11±8.35°C vs. 68.72±12.70°C; P<0.001). There was no significant difference in MWA (50.52±8.35°C vs. 50.18±10.35°C; P=0.74). In conclusion, thermography is suitable to monitor the correct ablation with MWA and RFA. The results of the current study demonstrated a significant heat-sink-effect for RFA, but not MWA near vessels. MWA reaches consistent surface temperatures much faster than RFA. With further in vivo validation, thermography may be useful to ensure appropriate ablation particularly near vulnerable or vascular structures.

Predictors of intermediate-term survival with destination locoregional therapy of hepatocellular cancer in patients either ineligible or unwilling for liver transplantation

Intra-arterial or percutaneous locoregional therapies (LRT) are often employed to maintain potential liver transplant (LT) recipients with hepatocellular carcinoma (HCC) within T2/Milan criteria. Predictors of survival when LRT is used as destination therapy in those who are either ineligible or unwilling for LT remain poorly defined. We evaluated predictors of 3-year survival with destination LRT in a population of cirrhotic patients diagnosed with HCC, presenting within T2 criteria, and either ineligible or unwilling for LT. The cohort surviving 3 years had a significantly lower model for end-stage liver disease (MELD) score at HCC diagnosis (9.7 vs. 11.4, P=0.037) and MELD following initial locoregional therapy (10.7 vs. 13.3, P=0.008) compared to those not surviving three years despite similar demographic, tumor, and treatment variables. LRT as destination therapy results in modest intermediate term survival, with liver function at presentation and immediately following initiation of LRT predicting intermediate survival with this approach.

Imaging Findings Within the First 12 Months of Hepatocellular Carcinoma Treated With Stereotactic Body Radiation Therapy

PURPOSE

To correlate the imaging findings of treated hepatocellular carcinoma (HCC) after stereotactic body radiation therapy (SBRT) with explant pathology and alpha-fetoprotein (AFP) response.

METHODS AND MATERIALS

From 2007 to 2015, of 146 patients treated with liver SBRT for Barcelona Clinic Liver Cancer stage A hepatocellular carcinoma, 10 were identified with inclusion criteria and had regular interval follow-up magnetic resonance imaging/triple phase computed tomography and explant pathology or declining AFP values for radiology-pathology response correlation. Reference standards for successful response were >90% necrosis on explant pathology or pretreatment AFP >75 ng/mL normalizing to <10 ng/mL within 1 year after SBRT without other treatment. Subjects were treated with 24 to 50 Gy in 3 to 5 fractions. Multiphasic magnetic resonance imaging or computed tomography performed at 3, 6, 9, and 12 months after SBRT was compared with pretreatment imaging by 2 expert radiologists. Descriptive statistics were calculated.

RESULTS

There were 10 subjects with 10 treated HCCs, classified as 3 Organ Procurement and Transplantation Network (OPTN) 5a, 4 OPTN 5b, and 3 OPTN 5x. All had successfully treated HCCs, according to explant pathology or declining AFP. Four of 10 HCCs had persistent central arterial hyperenhancement 3 to 12 months after SBRT; persistent wash-out was common up to 12 months (9 of 10). Of 10 treated HCCs, 9 exhibited decreased size at 12 months. Liver parenchyma adjacent to the lesion showed early (3-6 months) hyperemia followed by late (6-12 months) capsular retraction and delayed enhancement. No patient had a significant decline in liver function.

CONCLUSIONS

In the absence of increasing size, persistent central arterial hyperenhancement and wash-out can occur within the first 12 months after SBRT in successfully treated HCCs and may not represent residual viable tumor. Liver parenchyma adjacent to the treated lesion showed inflammation followed by fibrosis, without significant change in hepatic function. Until a radiologic signature of tumor control is determined, freedom from local progression seems to be the best measure of HCC control after SBRT.

Bridging to liver transplantation in HCC patients

BACKGROUND

Liver transplantation (LT) is the only cure for patients diagnosed with unresectable hepatocellular carcinoma (HCC), and HCC has become the leading indication for LT in the USA. The shortage of liver grafts results in a significant waiting time for LT with the risk of tumour progression. Treating HCCs during the waiting time prior to transplantation (bridging therapy) is an attractive strategy to reduce the risk of exceeding the tumour criteria for transplantation. Studies on bridging therapy are heterogenous and due to ethical issues, mostly of retrospective design.

PURPOSE

We summarize the main studies and methods that have been reported on bridging therapies for patients with HCC waiting for a LT.

CONCLUSION

During the waiting period for LT, patients with HCC at risk for tumour progression and therefore bridging therapy is recommended for patients with an estimated waiting time of ≥6 months. Bridging therapy for patients with HCC prior to LT mainly include locoregional therapies (LRTs), with transarterial chemoembolization (TACE) being the most common, followed by radio frequency ablation (RFA). Because of a continuous enhancement of therapy options, including a more precise adjustment of external radiotherapy, further possibilities for an individualized bridging therapy for patients with HCC have been developed. Patients with compensated liver cirrhosis and small tumour size are preferably treated with RFA, whereas patients with larger tumour size but compensated liver function are treated with TACE/TARE. Patients with uncompensated liver cirrhosis and larger tumour size can nowadays be successfully bridged to LT with external radiotherapy without increasing the risk for further deterioration of liver function.

Bridging locoregional therapy: Longitudinal trends and outcomes in patients with hepatocellular carcinoma

The purpose of this article is to analyze longitudinal trends in locoregional therapy (LRT) use and review locoregional therapy's role in the management of hepatocellular carcinoma prior to orthotropic liver transplantation Porrett et al. (2006) . LRT has a role in both bridge to transplantation and downstaging of patients not initially meeting Milan or UCSF Criteria. Due to the lack of randomized controlled trials, no specific bridging LRT modality is recommended over another for treating patients on the waiting list, however each modality has unique and patient-specific advantages. Pre-transplant LRT use in the United States has increased dramatically over the last two decades with more than 50% of the currently listed patients receiving LRT Freeman et al. (2008) . Despite these national trends, significant differences in LRT utilization, referral patterns, recurrence rates and survival have been observed among UNOS regions, socioeconomic levels and races. The use of LRT as a biologic selection tool based on response to treatment has shown promising results in its ability to predict successful post-transplant outcomes.

Microwave ablation of hepatocellular carcinoma as first-line treatment: long term outcomes and prognostic factors in 221 patients

This retrospective study aimed at evaluating the long-term outcomes and prognostic factors of microwave ablation (MWA) as a first-line treatment for hepatocellular carcinoma (HCC). 221 consecutive patients receiving MWA in our center between October 11, 2010 and December 31, 2013 were enrolled. Technique effectiveness was evaluated one month post-ablation. Initial complete ablation (CA1^st) was gained in 201 (90.95%) patients, secondary CA (CA2^nd) in 8 (3.62%) patients and the remaining 12 (5.43%) patients suffered from incomplete ablation (IA2^nd) after two sessions of MWA. Patients with tumor size >5 cm were less likely to gain CA1^st. Procedure-related complications were recorded and no procedure-related death occurred. 22 (10.4%) complications occurred with 8 (3.8%) being major ones. Tumor characteristics (size, number, location) do not significantly influence complication rates. After a median follow-up of 41.0 (ranging 25.0–63.5) months, the median RFS and OS was 14.0 months (95% CI: 9.254–18.746) and 41.0 months (95% CI: 33.741–48.259) respectively. Multivariate analysis identified two significant prognosticators (levels of alpha fetal protein [AFP] and gamma-glutamyl transpeptidase [GGT]) of RFS and five significant prognosticators (tumor number, tumor size, AFP, GGT and recurrence type) of OS. In conclusion, MWA provides high technique effectiveness rate and is well tolerated in patients with HCC as a first-line treatment.

Kruppel-like factor 6 suppresses growth and invasion of hepatocellular carcinoma cells in vitro and in vivo

Kruppel-like factor 6 (KLF6) as a novel tumor suppressive gene participates in multiple biological behaviors and plays an important role in regulating tumor cell growth and invasion. However, the functions of KLF6 in hepatocellular carcinoma (HCC) remain poorly understood. The expression level of KLF6 was examined by immunohistochemical assay in human HCC tissues, and KLF6-overexpressed HCC cells (SMCC-7721 and HepG2) were used for evaluating cell proliferation and invasion by MTT and Transwell assays. A subcutaneous HCC tumor model was established for assessing tumor growth in vivo. Our results showed that the expression of KLF6 was significantly downregulated in HCC tissues compared with the adjacent non-cancerous tissues (50.0% vs. 72.0%, P = 0.034) and negatively associated with the lymph-vascular space invasion (LVSI) in HCC patients (P = 0.003). Furthermore, overexpression of KLF6 reduced cell proliferation and weakened the cell invasive potential followed with the decreased expression of PCNA and MMP-9 in HCC cells. The in vivo experiment indicated that KLF6 overexpression suppressed the xenograft tumor growth. Therefore, our findings show that KLF6 suppresses growth and invasion of HCC cells in vitro and in vivo, suggesting a tumor suppressive function in HCC and provides the potential therapeutic target for the treatment of HCC.

Prognosis of cerebral lipiodol embolism caused by transarterial chemoembolization

OBJECTIVES

Transarterial chemoembolization (TACE) plays an essential role in the management of unresectable hepatocellular cell carcinoma and other hepatic neoplasms. Cerebral lipiodol embolism (CLE) is a rare complication of TACE and its prognostic factors have not been well studied. The aim of this paper was to elucidate the prognostic factors of CLE based on clinical data obtained from our patients and cases published since 2004.

METHODS

We present two patients with CLE, analyze the clinical data, and review all CLE cases published since 2004. A poor outcome was defined as stupor, coma, quadriplegia, or death within 45 days. Patients who had other neurological conditions within 45 days were considered as having a good outcome.

RESULTS

The rate of poor outcome was 25.7% (9/35). Compared with the patients with good outcome, those with poor outcome were older (mean age 68.3 ± 7.3 vs. 58.3 ± 10.6 years, p = 0.03), more often female (76.9% vs. male 33.3%, p = 0.02), and more likely chemoembolized via both the right hepatic and right inferior phrenic arteries (44.4 vs. 8.7%, p = 0.02).

DISCUSSION

The prognosis of CLE was related to age, gender, and the arteries selected for injection.

Percutaneous transcatheter embolisation of active haemorrhage following radiofrequency ablation of hepatocellular carcinoma

A 72-year-old woman with hepatitis C virus cirrhosis underwent a surveillance ultrasound examination which identified a new hepatic lesion. A workup triphasic CT examination demonstrated a 3.7 cm lesion at the hepatic dome with arterial enhancement and portal venous washout consistent with hepatocellular carcinoma. She subsequently proceeded for treatment with radiofrequency ablation (RFA). RFA was technically successful, but the patient became hypotensive and tachycardic postprocedure. A CT angiogram demonstrated active arterial intraperitoneal haemorrhage from the RFA site. The patient returned to the interventional suite for catheter angiography which confirmed the presence of active haemorrhage from the hepatic arterial branch supplying segment VIII. The bleeding vessel was selectively catheterised with a microcatheter, and successfully embolised with 250-355 µm polyvinyl alcohol particles.

New treatment modalities for hepatocellular cancer

Heptatocellular (HCC) is a rapidly progressive fatal malignancy often presenting at an advanced stage at the time of initial diagnosis. Loco-regional therapies for early-stage HCC including surgical options (surgical resection and liver transplant) and percutaneous ablations could be potentially curative. Recent technological advances in percutaneous image-guided ablations have provided clinicians with a range of options which have proven to be equal to or better than surgical resection. For intermediate- and advanced-stage HCC, palliative therapies are available which significantly increase overall and progression-free survival. These palliative therapies include intra-arterial chemo- or radioembolization as monotherapy or in combination with percutaneous ablation or antiangiogenic drugs. Availability of a multitude of treatment options for various stages of HCC as well as conflicting data comparing their safety and efficacy presented in the several randomized controlled trials poses a significant challenge to hepatologists, surgeons, and interventional radiologists in selecting optimal therapy for their patients. The aim of this article is to review and discuss currently available therapies at each stage of HCC along with presenting clinical data published in most recent and relevant randomized controlled trials.

Liver transplantation for hepatocellular carcinoma - factors influencing outcome and disease-free survival

Hepatocellular carcinoma is one of the leading causes of cancer-related death worldwide. Liver transplantation can be a curative treatment in selected patients. However, there are several factors that influence disease-free survival after transplantation. This review addresses the pre-, intra- and postoperative factors that influence the risk of tumor recurrence after liver transplantation.

The effects of percutaneous ethanol injection followed by 20-kHz ultrasound and microbubbles on rabbit hepatic tumors

OBJECTIVE

Low-frequency ultrasound (US) in combination with microbubbles (MBs) is able to inhibit the growth of VX2 rabbit liver tumors. In this study, we investigated the feasibility of using percutaneous ethanol injection (PEI) followed by low-frequency ultrasound and microbubbles (USMB) to inhibit VX2 tumor growth.

METHODS

Eighteen New Zealand rabbits with hepatic VX2 tumors were divided into three groups: PEI, low-frequency ultrasound and MBs followed by PEI (USMB + PEI), and PEI followed by USMB (PEI + USMB). PEI was performed by ultrasound-guided injection of 95% anhydrous alcohol into internal liver tumors in rabbits twice a week for 2 weeks. The US parameters were 20 kHz, 2 W/cm(2), 40% duty cycle, 5 min, and once every other day for 2 weeks. Magnetic resonance imaging (MRI) was used to observe tumors before and after treatment, to examine changes in the tumors, and to measure the diameters of the tumors. All animals were followed up for 180 days after tumor implantation. Autopsy was performed at the end of the scheduled follow-up or immediately after death. Anatomically observed metastatic sites included the liver, lung, abdomen, and pelvic cavity. The survival time of all rabbits was recorded.

RESULTS

After 4 weeks of treatment, on MRI, the tumor diameters in the PEI, USMB + PEI, and PEI + USMB groups were 8.33 ± 1.83, 19 ± 2.61, and 4.5 ± 1.22 mm, respectively. There was a significant difference in tumor size indicated by MRI in the three groups. Tumor size was smaller in the PEI + USMB group than in the PEI and USMB + PEI groups, with t = 4.54, p = 0.0062, and t = 16.38, p < .0001, respectively. The PEI + USMB group showed the fewest metastasis sites (χ(2) = 11.7333, p = 0.0194) and the longest survival period (χ(2) = 7.448, p = 0.0241).

CONCLUSION

Percutaneous ethanol injection followed by low-frequency ultrasound and microbubbles can be effective in inhibiting rabbit liver tumors and prolonging survival time.

Percutaneous microwave ablation vs radiofrequency ablation in the treatment of hepatocellular carcinoma

Hepatocellular cancer ranks fifth among cancers and is related to chronic viral hepatitis, alcohol abuse, steatohepatitis and liver autoimmunity. Surgical resection and orthotopic liver transplantation have curative potential, but fewer than 20% of patients are suitable candidates. Interventional treatments are offered to the vast majority of patients. Radiofrequency (RFA) and microwave ablation (MWA) are among the therapeutic modalities, with similar indications which include the presence of up to three lesions, smaller than 3 cm in size, and the absence of extrahepatic disease. The therapeutic effect of both methods relies on thermal injury, but MWA uses an electromagnetic field as opposed to electrical current used in RFA. Unlike MWA, the effect of RFA is partially limited by the heat-sink effect and increased impedance of the ablated tissue. Compared with RFA, MWA attains a more predictable ablation zone, permits simultaneous treatment of multiple lesions, and achieves larger coagulation volumes in a shorter procedural time. Major complications of both methods are comparable and infrequent (approximately 2%-3%), and they include haemorrhage, infection/abscess, visceral organ injury, liver failure, and pneumothorax. RFA may incur the additional complication of skin burns. Nevertheless, there is no compelling evidence for differences in clinical outcomes, including local recurrence rates and survival.

(90)Y-glass microspheres for hepatic neoplasia

Unresectable liver cancer presents a major problem in the treatment of solid tumors. Transarterial radioembolization is a modern approach toward primary and secondary liver malignancies. The mechanism of action is independent from other therapies that are based on ischemia or chemotoxicity. (90)Y-resin and (90)Y-glass microspheres are commercially available for transarterial radioembolization. Available data on the use of (90)Y-glass microspheres in hepatocellular carcinoma and metastatic disease indicate that this treatment is safe and effective. In hepatocellular carcinoma the results compare well with chemoembolization and might be considered more often. Current data in metastatic disease are promising, but there is a strong need for prospective randomized trials to identify the role of transarterial radioembolization with (90)Y-glass microspheres in metastatic liver disease.

Image-guided therapies in the treatment of hepatocellular carcinoma: A multidisciplinary perspective

A multidisciplinary approach to the treatment of patients with unresectable hepatocellular carcinoma (HCC) has led to improvements in screening, detection, and treatments. Interventional techniques include thermal ablation, transarterial chemoembolization, and radioembolization whilst stereotactic body radiation therapy also uses imaging to target the radiation. Both survival rates and cure rates have improved markedly since the introduction of these techniques. This review article describes the image guided techniques used for the treatment of HCC.

Impact of 3D Rotational Angiography on Liver Embolization Procedures: Review of Technique and Applications

In the last years, the interest into interventional applications of C-arm cone-beam CT (CBCT) progressively raised, widening its clinical application from the original field of interventional neuroradiology to the field of peripheral procedures. Liver embolization procedures, due to their complexity and potential treatment-related life-threatening complications, represent one of the main clinical applications of this novel angiographic technique. CBCT has been demonstrated to render procedures safer and technically easier, and to predict outcome as well as to avoid major complications in different treatment scenarios (trans-arterial embolization, trans-arterial chemoembolization, selective internal radiation therapy, percutaneous portal vein embolization). This review summarizes all technical, dosimetric and procedural aspects of CBCT techniques, underlying all its potential clinical advantages in the field of liver embolization procedures. Moreover, the paper provides all the instructions to obtain the best diagnostic performance out of this novel angiographic technique.