Comparison of periprocedural and procedure room times between moderate sedation and monitored anesthesia care in interventional radiology

Objectives

In recent years, there has been increased utilization of monitored anesthesia care (MAC) in interventional radiology (IR) departments. The purpose of this study was to compare pre-procedure bed, procedure room, and post-procedure bed times for IR procedures performed with either nurse-administered moderate sedation (MOSED) or MAC.

Material and Methods

An institutional review board-approved single institution retrospective review of IR procedures between January 2010 and September 2022 was performed. Procedures performed with general anesthesia or local anesthetic only, missing time stamps, or where <50 cases were performed for both MAC and MOSED were excluded from the study. Pre-procedure bed, procedure room, post-procedure bed, and total IR encounter times were compared between MAC and MOSED using the t-test. The effect size was estimated using Cohen's d statistic.

Results

97,480 cases spanning 69 procedure codes were examined. Mean time in pre-procedure bed was 27 min longer for MAC procedures (69 vs. 42 min, P < 0.001, d = 0.95). Mean procedure room time was 11 min shorter for MAC (60 vs. 71 min, P < 0.001, d = 0.48), and mean time in post-procedure bed was 10 min longer for MAC (102 vs. 92 min, P < 0.001, d = 0.22). Total IR encounter times were on average 27 min longer for MAC cases (231 vs. 204 min, P < 0.001, d = 0.41).

Conclusion

MAC improves the utilization of IR procedure rooms, but at the cost of increased patient time in the pre- and post-procedure areas.

Immune Effects of Intra-Arterial Liver-Directed Therapies

Image-guided intra-arterial locoregional therapies (LRTs) such as transarterial embolization, transarterial chemoembolization, and transarterial radioembolization exhibit effects on the immune system. Understanding the humoral (cytokine, chemokine, and growth factor) and cellular (T cell, neutrophil, dendritic cell, and macrophage) mechanisms underlying the immune effects of LRT is crucial to designing rational and effective combinations of immunotherapy and interventional radiology procedures. This article aims to review the immune effects of intra-arterial LRTs and provide insight into strategies to combine LRTs with systemic immunotherapy.

Management of Pericardial Effusion in Patients With Solid Tumor: An Algorithmic, Multidisciplinary Approach Results in Reduced Mortality After Paradoxical Hemodynamic Instability

OBJECTIVE

This study compared outcomes in patients with solid tumor treated for pericardial effusion with surgical drainage versus interventional radiology (IR) percutaneous drainage and compared incidence of paradoxical hemodynamic instability (PHI) between cohorts.

BACKGROUND

Patients with advanced-stage solid malignancies may develop large pericardial effusions requiring intervention. PHI is a fatal and underreported complication that occurs following pericardial effusion drainage.

METHODS

Clinical characteristics and outcomes were compared between patients with solid tumors who underwent s urgical drainage or IR percutaneous drainage for pericardial effusion from 2010 to 2020.

RESULTS

Among 447 patients, 243 were treated with surgical drainage, of which 27 (11%) developed PHI, compared with 7 of 204 patients (3%) who were treated with IR percutaneous drainage ( P =0.002); overall incidence of PHI decreased during the study period. Rates of reintervention (30-day: 1% vs 4%; 90-day: 4% vs 6%, P =0.7) and mortality (30-day: 21% vs 17%, P =0.3; 90-day: 39% vs 37%, P =0.7) were not different between patients treated with surgical drainage and IR percutaneous drainage. For both interventions, OS was shorter among patients with PHI than among patients without PHI (surgical drainage, median [95% confidence interval] OS, 0.89 mo [0.33-2.1] vs 6.5 mo [5.0-8.9], P <0.001; IR percutaneous drainage, 3.7 mo [0.23-6.8] vs 5.0 mo [4.0-8.1], P =0.044).

CONCLUSIONS

With a coordinated multidisciplinary approach focusing on prompt clinical and echocardiographic evaluation, triage with bias toward IR percutaneous drainage than surgical drainage and postintervention intensive care resulted in lower incidence of PHI and improved outcomes.

Efficacy and safety of regorafenib in combination with immune checkpoint inhibitor therapy as second-line and third-line regimen for patients with advanced hepatocellular carcinoma: a retrospective study

Background

Despite the emergence of immune checkpoint inhibitors (ICIs) as first-line treatment for advanced hepatocellular carcinoma (HCC), there is an unmet need regarding subsequent treatments in patients that fail ICI. Regorafenib is a vascular endothelial growth factor receptor (VEGFR) inhibitor, which could increase programmed death-ligand 1 (PD-L1) expression in tumors and increase intra-tumoral CD8+ T-cell infiltration by normalizing the cancer vasculature and improving the efficacy of the programmed cell death protein 1 (PD-1) antibody. Thus, we evaluated the combination of regorafenib and a PD-1 inhibitor for advanced HCC patients that had failed combined tyrosine kinase inhibitors (TKIs) plus ICI.

Methods

Data of patients with advanced HCC who had failed combined TKIs plus ICI treatment and were afterwards treated with combined regorafenib plus a PD-1 inhibitor were reviewed. All patients had received PD-1 inhibitors as part of the first-line treatment and regorafenib every 4 weeks until disease progression, intolerable toxicities, or physician/patient withdrawal. The clinical data, previous treatment strategies, follow-up imaging results, and adverse events (AEs) during follow-ups were recorded. Common Terminology Criteria for Adverse Events (CTCAE) v. 5.0 was used to evaluate AEs and Response Evaluation Criteria in Solid Tumors (RECIST) v. 1.1 was used to evaluate response. The primary endpoint was safety, and the secondary endpoints were the objective response rate (ORR), progression-free survival (PFS), disease control rate (DCR), overall survival (OS), and duration of response (DOR).

Results

From November 15, 2020, to January 31, 2022, data of 17 patients with advanced HCC that met the criteria were reviewed. The cohort included 16 men and 1 woman with a median age of 54 years (interquartile range, 46 to 63 years). Sixteen patients had Child-Pugh class A (n=16, 94.12%) and one with class B (n=1, 15.9%) liver disease. Thirteen patients received second-line treatment, and the remaining patients received third-line treatment. All patients received at least 1 dose of PD-1 inhibitors. The median follow-up duration was 7.62 months. Twelve recipients experienced treatment-related AEs. The most frequent AE (≥5%) included fatigue (17.64%), diarrhea (17.65%), proteinuria (5.88%), bleeding gums (11.76%), and hypertension (11.76%). No grade-4 AE or new safety signals were identified. The ORR and DCR were 41.2% and 64.7%, respectively, and the median PFS was 5.09 months.

Conclusions

Regorafenib combined with PD-1 inhibitor is a promising regimen in treating patients with advanced HCC owing to its safety and effectiveness as well as low incidence of serious AEs with its use.

Safety and Efficacy of Hepatic Artery Embolization in Heavily Treated Patients with Intrahepatic Cholangiocarcinoma: Analysis of Clinicopathological and Radiographic Parameters Associated with Better Overall Survival

The safety and efficacy of hepatic artery embolization (HAE) in treating intrahepatic cholangiocarcinoma (IHC) was evaluated. Initial treatment response, local tumor progression-free survival (L-PFS), and overall survival (OS) were evaluated in 34 IHC patients treated with HAE. A univariate survival analysis and a multivariate Cox proportional hazard analysis to identify independent factors were carried out. Objective response (OR) at 1-month was 79.4%. Median OS and L-PFS from the time of HAE was 13 (CI = 95%, 7.4-18.5) and 4 months (CI = 95%, 2.09-5.9), respectively. Tumor burden < 25% and increased tumor vascularity on preprocedure imaging and surgical resection prior to embolization were associated with longer OS (p < 0.05). Multivariate logistic regression analysis demonstrated that tumor burden < 25% and hypervascular tumors were independent risk factors. Mean post-HAE hospital stay was 4 days. Grade 3 complication rate was 8.5%. In heavily treated patients with IHC, after exhausting all chemotherapy and other locoregional options, HAE as a rescue treatment option appeared to be safe with a mean OS of 13 months. Tumor burden < 25%, increased target tumor vascularity on pre-procedure imaging, and OR on 1 month follow-up images were associated with better OS. Further studies with a control group are required to confirm the effectiveness of HAE in IHC.

Targeted Molecular Profiling of Circulating Cell-Free DNA in Patients With Advanced Hepatocellular Carcinoma

PURPOSE

Next-generation sequencing (NGS) of tumor-derived, circulating cell-free DNA (cfDNA) may aid in diagnosis, prognostication, and treatment of patients with hepatocellular carcinoma (HCC). The operating characteristics of cfDNA mutational profiling must be determined before routine clinical implementation.

METHODS

This was a single-center, retrospective study with the primary objective of defining genomic alterations in circulating cfDNA along with plasma-tissue genotype agreement between NGS of matched tumor samples in patients with advanced HCC. cfDNA was analyzed using a clinically validated 129-gene NGS assay; matched tissue-based NGS was analyzed with a US Food and Drug Administration-authorized NGS tumor assay.

RESULTS

Fifty-three plasma samples from 51 patients with histologically confirmed HCC underwent NGS-based cfDNA analysis. Genomic alterations were detected in 92.2% of patients, with the most commonly mutated genes including TERT promoter (57%), TP53 (47%), CTNNB1 (37%), ARID1A (18%), and TSC2 (14%). In total, 37 (73%) patients underwent paired tumor NGS, and concordance was high for mutations observed in patient-matched plasma samples: TERT (83%), TP53 (94%), CTNNB1 (92%), ARID1A (100%), and TSC2 (71%). In 10 (27%) of 37 tumor-plasma samples, alterations were detected by cfDNA analysis that were not detected in the patient-matched tumors. Potentially actionable mutations were identified in 37% of all cases including oncogenic/likely oncogenic alterations in TSC1/2 (18%), BRCA1/2 (8%), and PIK3CA (8%). Higher average variant allele fraction was associated with elevated alpha-fetoprotein, increased tumor volume, and no previous systemic therapy, but did not correlate with overall survival in treatment-naïve patients.

CONCLUSION

Tumor mutation profiling of cfDNA in HCC represents an alternative to tissue-based genomic profiling, given the high degree of tumor-plasma NGS concordance; however, genotyping of both blood and tumor may be required to detect all clinically actionable genomic alterations.

Anti-Glycolytic Drugs in the Treatment of Hepatocellular Carcinoma: Systemic and Locoregional Options

Hepatocellular cancer (HCC) is the most common primary liver cancer and the third leading cause of cancer-related death. Locoregional therapies, including transarterial embolization (TAE: bland embolization), chemoembolization (TACE), and radioembolization, have demonstrated survival benefits when treating patients with unresectable HCC. TAE and TACE occlude the tumor's arterial supply, causing hypoxia and nutritional deprivation and ultimately resulting in tumor necrosis. Embolization blocks the aerobic metabolic pathway. However, tumors, including HCC, use the "Warburg effect" and survive hypoxia from embolization. An adaptation to hypoxia through the Warburg effect, which was first described in 1956, is when the cancer cells switch to glycolysis even in the presence of oxygen. Hence, this is also known as aerobic glycolysis. In this article, the adaptation mechanisms of HCC, including glycolysis, are discussed, and anti-glycolytic treatments, including systemic and locoregional options that have been previously reported or have the potential to be utilized in the treatment of HCC, are reviewed.

Factors affecting outcomes of Yttrium-90 radioembolization in heavily pretreated patients with intrahepatic cholangiocarcinoma

PURPOSE

Transarterial radioembolization (TARE) is a liver-directed treatment for unresectable intrahepatic cholangiocarcinoma (ICC). The aim of this study is to evaluate factors affecting outcomes of TARE in heavily pretreated ICC patients.

METHODS

We evaluated pretreated ICC patients who received TARE from January 2013 to December 2021. Prior treatments included systemic therapy, hepatic resection, and liver-directed therapies, including hepatic arterial infusion chemotherapy, external beam radiation, transarterial embolization, and thermal ablation. Patients were classified based on history of hepatic resection and genomic status based on next-generation sequencing (NGS). The primary endpoint was overall survival (OS) after TARE.

RESULTS

Fourteen patients with median age 66.1 years (range, 52.4-87.5), 11 females and 3 males, were included. Prior therapies included systemic in 13/14 patients (93%), liver resection in 6/14 (43%), and liver-directed therapy in 6/14 (43%). Median OS was 11.9 months (range, 2.8-81.0). Resected patients had significantly longer median OS compared to unresected patients (16.6 versus 7.9 months; p = 0.038). Prior liver-directed therapy (p = 0.043), largest tumor diameter > 4 cm (p = 0.014), and > 2 hepatic segments involvement (p = 0.001) were associated with worse OS. Nine patients underwent NGS; 3/9 (33.3%) and had a high-risk gene signature (HRGS), defined as alterations in TP53, KRAS, or CDKN2A. Patients with a HRGS had worse median OS (10.0 versus 17.8 months; p = 0.024).

CONCLUSIONS

TARE may be used as salvage therapy in heavily treated ICC patients. Presence of a HRGS may predict worse OS after TARE. Further investigation with more patients is recommended to validate these results.

Image-guided percutaneous locoregional therapies for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver cancer and the 3rd leading cause of cancer death worldwide. Treatment options include surgical resection, liver transplantation, imageguided percutaneous locoregional options, external beam radiation therapy (EBRT) and systemic therapies. Treatment choice depends on the stage of the disease and patient's characteristics including performance status and liver function. Barcelona Clinic Liver Cancer (BCLC) staging system, with its recent 2022 update, is one of the most widely endorsed staging system. Locoregional therapies (LRT) are recommended for very early stage (BCLC-0), early stage (BCLC-A), and the two first subgroups of intermediate stage (BCLC-B). Image-guided percutaneous locoregional therapies include ablation, mainly thermal ablation with radiofrequency (RFA), microwave ablations (MWA) and cryoablation, transarterial embolization (TAE, also known as bland embolization), transarterial chemoembolization (TACE), drug-eluding beadstransarterial chemoembolization (DEB-TACE), combination of ablation with embolization, transarterial radioembolization (TARE) also known as selective internal radioembolization therapy, and hepatic artery infusion (HAI). While ablation is recognized as a curative therapy, all intra-arterial therapies are considered non-curative options. There is growing evidence that TARE, through radiation segmentectomy, can be considered a curative intent treatment in appropriate selective patients. In this article, we will review indications, complications, and outcomes of locoregional therapies for HCC.

Induction and preliminary characterization of neoplastic pulmonary nodules in a transgenic pig model

OBJECTIVES

Lung cancer models in large animals are lacking. Oncopigs are transgenic pigs that carry both KRASG12D and TP53R167H Cre-inducible mutations. This study aimed to develop and histologically characterize a swine model of lung cancer that could serve for preclinical studies evaluating locoregional therapies.

MATERIALS AND METHODS

In two Oncopigs, an adenoviral vector encoding the Cre-recombinase gene (AdCre) was injected endovascularly through the pulmonary arteries or inferior vena cava. In two other Oncopigs, a lung biopsy was performed and incubated with AdCre, before reinjecting the mixture into the lungs percutaneously. Animals were clinically and biologically (complete blood count, liver enzymes and lipasemia) monitored. Obtained tumors were characterized on computed tomography (CT) and on pathology and immunohistochemistry (IHC).

RESULTS

Neoplastic lung nodules developed following 1 (1/10, 10%) endovascular inoculation, and 2 (2/6, 33%) percutaneous inoculations. All lung tumors were visible at the 1-week CT, and appeared as well-circumscribed solid nodules, with a median longest diameter of 14 mm (range: 5-27 mm). Only one complication occurred: an extravasation of the mixture into the thoracic wall during a percutaneous injection that resulted in a thoracic wall tumor. Pigs remained clinically healthy during the entire follow-up (14-21 days). On histology, tumors consisted of inflammatory undifferentiated neoplasms composed of atypical spindle and epithelioid cells and/or a fibrovascular stroma and abundant mixed leukocytic infiltrate. On IHC, atypical cells diffusely displayed expression of vimentin and some showed expression of CK WSS and CK 8/18. The tumor microenvironment contained abundant IBA1 + macrophages and giant cells, CD3 + T cells, and CD31 + blood vessels.

CONCLUSION

Tumors induced in the lungs of Oncopigs are fast growing poorly differentiated neoplasms associated with a marked inflammatory reaction that can be easily and safely induced at site specific locations. This large animal model might be suitable for interventional and surgical therapies of lung cancer.

Reducing Wait Times for Radiology Exams Around Holiday Periods: A Monte Carlo Simulation

Reducing patient wait times is a key operational goal and impacts patient outcomes. The purpose of this study is to explore the effects of different radiology scheduling strategies on exam wait times before and after holiday periods at an outpatient imaging facility using computer simulation. An idealized Monte Carlo simulation of exam scheduling at an outpatient imaging facility was developed based on the actual distribution of scheduled exams at outpatient radiology sites at a tertiary care medical center. Using this simulation, we examined three scheduling strategies: (1) no scheduling modifications, (2) increase imaging capacity before or after the holiday (i.e. increase facility hours), and (3) use a novel rolling release scheduling paradigm. In the third scenario, a fraction of exam slots are blocked to long-term follow-up exams and made available only closer to the exam date, thereby preventing long-term follow-up exams from filling the schedule and ensuring slots are available for non-follow-up exams. We examined the effect of these three scenarios on utilization and wait times, which we defined as the time from order placement to exam completion, during and after the holiday period. The baseline mean wait time for non-follow-up exams was 5.4 days in our simulation. When no scheduling modifications were made, there was a significant increase in wait times in the week preceding the holiday when compared to baseline (10.0 days vs 5.4 days, p < 0.01). Wait times remained elevated for 4 weeks following the holiday. Increasing imaging capacity during the holiday and post-holiday period by 20% reduced wait times by only 6.2% (9.38 days vs 10.0 days, p < 0.01). Increasing capacity by 50% resulted in a 7.1% reduction in wait times (9.28 days, p < 0.01), and increasing capacity by 100% resulted in a 13% reduction in wait times (8.75 days, p < 0.01). In comparison, using a rolling release model produced a reduction in peak wait times equivalent to doubling capacity (8.76 days, p < 0.01) when 45% of slots were reserved. Improvements in wait times persisted even when rolling release was limited to the 3 weeks preceding or 1 week following the holiday period. Releasing slots on a rolling basis did not significantly decrease utilization or increase wait times for long-term follow-up exams except in extreme scenarios where 80% or more of slots were reserved for non-follow-up exams. A rolling release scheduling paradigm can significantly reduce wait time fluctuations around holiday periods without requiring additional capacity or impacting utilization.

Stent Graft Placement for the Treatment of Hepatic Artery Injury in Patients with Cancer: Primary Patency and Clinical Outcomes

PURPOSE

To evaluate the safety, primary patency, and clinical outcomes of hepatic artery stent graft (SG) placement for vascular injuries.

MATERIALS AND METHODS

Patients treated with hepatic arterial SG placement for vascular injuries between September 2018 and September 2021 were reviewed. Data on demographic characteristics, indication, stent graft characteristics, antiplatelet/anticoagulant use, clinical success rate, complications, and type of follow-up imaging were collected. Follow-up images were reviewed by 2 independent reviewers to assess primary patency. A time-to-event analysis was performed. The median duration of stent graft patency was estimated using Kaplan-Meier curves. A Cox proportional hazard model was used to evaluate factors related to stent graft patency.

RESULTS

Thirty-five patients were treated with hepatic arterial SG placement, 11 for postoperative bleeds and 24 for hepatic artery infusion pump catheter-related complications. Clinical success was achieved in 32 (91%) patients (95% CI, 77-98). The median primary patency was 87 days (95% CI, 73-293). Stent grafts of ≥6-mm diameter retained patency for a longer duration than that with stent grafts of smaller diameters (6 mm vs 5 mm; hazard ratio, 0.35; 95% CI, 0.14-0.88; P = .026; and 7+ mm vs 5 mm; hazard ratio, 0.27; 95% CI, 0.09-0.83; P = .023). Anticoagulation/antiplatelet regimen was not associated with increased stent graft patency duration (P > .05). Only minor complications were reported in 2 (5.7%) patients.

CONCLUSIONS

Stent grafts can be used safely and effectively to treat injuries of the hepatic artery. Stent graft diameters of ≥6 mm seem to provide more durable patency.

Abstract C016: New treatment modality for pancreatic cancer-Vascular Targeted Photodynamic therapy with WST11 (Padeliporfin) combined with endovascular light delivery

Background: Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal human malignancies. Early detection and surgical removal of PDAC, when the cancer is localized with no clinical evidence for systemic spread, may be curative but tumor spread into the vicinity of major blood vessels, e.g. superior mesenteric artery (SMA), can be lethal and therefore avoid surgery. Here we show that Vascular Targeted Photodynamic therapy (VTP) with WST11 in combination with immune modulating chemotherapeutic agents allows PDAC tumors ablation while preserving large normal vessels and tissues in animal models. New endovascular illumination system recently developed by our group (1) provides the light needed for such ablation with no damage to the SMA and complete remodeling of the surrounding normal tissue. Methods: Two orthotopic models of pancreatic cancer (KPC-Luc-mcherry and non-labeled KPC tumors (NL-KPC)) in C57B mice were subjected to VTP, alongside intraperitoneal gemzar (GEM) or cyclophosphamide (CTX) treatment. multiplex immunohistochemistry (mIHC) and single analyses using 10X Genomics platform of tumor were performed for resolving the key factors in the therapeutic process. Results: Comparing the KPC-Luc-mcherry with the NL-KPC tumor, we found that non labeled KPC has the typical morphology of human PDAC, immunologically cold and is highly aggressive compared with KPC-Luc-mcherry. WST11-VTP results in high cure rate (~50%) of animals bearing small KPC-Luc-mcherry tumors, larger tumors required combinations with metronomic administration of GEM. High rate of complete necrosis (95-100%) was achieved also with the non-labled PDAC tumors but prolonged disease- free survival required combination with CTX. The mechanism of action for both tumor models involves co-generation of oxygen and NO radicals through local photoexcitation of WST11, followed by iNOS consumption and vascular break down. Infiltration of immune cells alarmed by HMGB1 and other DAMPs leads to annihilation of residual cancer cells and prolonged anticancer immunity. The administration of CTX amplifies and prolonged the VTP oxidative stress. Conclusion: WST11-VTP combination with immune modulating chemotherapeutic agents administrations, activated by endovascular illumination through the SMA, may provide solution to the unmet need of early stage diagnosed PDAC patients. (1) Franz E. Boas et al, “Downstaging Locally Advanced Pancreatic Cancer To Resectability: Perivascular Ablation Using An Intra-arterial Balloon Laser Catheter In Pigs”, Abstract Archives of the RSNA, RSNA 2021,SDR-IR-13- “Redefining radiology” 11/29-12/4, 2021

Citation Format: Lilach Agemy, Keren Sasson, Tamar Yechezkel, Dina Priese, Yaniv Cohen, Zachary Zacks, Gil Stelzer, David P. Kelsen, Hooman Yarmohammadi, Alice C. Wei, Stephen B. Solomon, Avidgor Scherz. New treatment modality for pancreatic cancer-Vascular Targeted Photodynamic therapy with WST11 (Padeliporfin) combined with endovascular light delivery [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr C016.

Optimizing 90Y Particle Density Improves Outcomes After Radioembolization

PURPOSE

To determine how particle density affects dose distribution and outcomes after lobar radioembolization.

METHODS

Matched pairs of patients, treated with glass versus resin microspheres, were selected by propensity score matching (114 patients), in this single-institution retrospective study. For each patient, tumor and liver particle density (particles/cm³) and dose (Gy) were determined. Tumor-to-normal ratio was measured on both ^99mTc-MAA SPECT/CT and post-⁹⁰Y bremsstrahlung SPECT/CT. Microdosimetry simulations were used to calculate first percentile dose, which is the dose in the cold spots between microspheres. Local progression-free survival (LPFS) and overall survival were analyzed.

RESULTS

As more particles were delivered, doses on ⁹⁰Y SPECT/CT became more uniform throughout the treatment volume: tumor and liver doses became more similar (p = 0.04), and microscopic cold spots between particles disappeared. For hypervascular tumors (tumor-to-normal ratio ≥ 2.6 on MAA scan), delivering fewer particles (< 6000 particles/cm³ treatment volume) was associated with better LPFS (p = 0.03). For less vascular tumors (tumor-to-normal ratio < 2.6), delivering more particles (≥ 6000 particles/cm³) was associated with better LPFS (p = 0.02). In matched pairs of patients, using the optimal particle density resulted in improved overall survival (11.5 vs. 6.8 months, p = 0.047), compared to using suboptimal particle density. Microdosimetry resulted in better predictions of LPFS (p = 0.03), and overall survival (p = 0.02), compared to conventional dosimetry.

CONCLUSION

The number of particles delivered can be chosen to maximize the tumor dose and minimize the liver dose, based on tumor vascularity. Optimizing the particle density resulted in improved LPFS and overall survival.

Next-generation sequencing (NGS) of circulating cell-free DNA (cfDNA) in patients (pts) with advanced hepatocellular carcinoma (HCC)

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Background: HCC is often diagnosed based on high-quality cross-sectional imaging, and when a biopsy is pursued, acquisition of tissue may be of limited quantity and quality or complicated by underlying medical comorbidities. NGS of tumor derived circulating cfDNA represents an investigational tool for non-invasive molecular profiling, that has the potential to aid in diagnosis, prognosis, and in monitoring disease status. Although prior reports have evaluated such technologies, few studies have included tumor tissues to confirm histology and to explore plasma-tissue gene concordance. Methods: The primary objective of this retrospective cohort study was to define genomic alterations in circulating cfDNA and to explore plasma-tissue genotype concordance in HCC pts. HCC pts underwent collection of cfDNA for NGS using the MSK-ACCESS 129-gene assay between August 2019 and February 2021. Matched tissue-based NGS with the FDA authorized MSK-IMPACT gene assay was completed when tumor tissue was available. Clinical actionability of sequence variants was annotated by OncoKB, an FDA recognized knowledge base. Clinicopathologic characteristics were extracted, and all data were reported with descriptive statistics. Results: 51 unique patients with 53 plasma samples had an HCC histological diagnosis. Pts were male (39, 76%), median age 69 (42-87), viral hepatitis-related (24, 47%), and advanced stage (Stage III:9, 18%; Stage IV:38, 74.5%). Extrahepatic disease and macrovascular involvement were observed in 28 (55%) and 19 (38%) pts, respectively. 22 (43%) pts had AFP ≥400 ng/mL. 49 (92.5%) of 53 plasma samples had detectable genomic alterations. Median cfDNA yield after extraction was 39.43 ng (range: 7.93-287.68). The most frequently mutated genes occurring in > 10% of patients were TERT (57%), TP53 (47%), CTNNB1 (37%), ARID1A (18%) and TSC2 (14%). The most common oncogenic pathways that contained alterations were WNT-β-Catenin (45%) and PIK3-AKT-TOR (25%). 37 (73%) pts underwent tissue sequencing with MSK-IMPACT with a median time of 9.0 months to the time cfDNA testing. MSK-ACCESS identified mutations observed in tumor in most cases: TERT (20/22; 91%), TP53 (16/17; 94%), CTNNB1 (11/12; 92%), ARID1A (6/6; 100%) and TSC2 (6/7; 86%). In 18 (49%) of 37 paired samples, additional mutations in cfDNA not seen in tumor were detected and included KRAS, EGFR, and TP53 alterations. Potentially actionable mutations were identified through cfDNA in 37% of cases including TSC1/2 (18%), BRCA1/ 2 (8%) and PIK3CA (8%). Conclusions: Circulating cfDNA genotyping with MSK-ACCESS identifies previously reported HCC tumor genomic profiles and revealed tumor-associated mutations in 92.5% of plasma samples. Ongoing efforts will explore predictive and prognostic implications of NGS at different HCC stages as well as kinetics of treatment response.

Accuracy of a CBCT-based virtual injection software for vessel detection during hepatic arterial embolization

PURPOSE

To assess the accuracy, sensitivity, positive predictive value (PPV) and interobserver agreement of a virtual injection (VI) software that simulates selective arterial injection from nonselective cone-beam CT (CBCT) arteriography.

METHODS

From March 2019 to May 2020, 20 consecutive patients in whom a nonselective injected CBCT and a selective CT angiography (CTA) were completed in the same procedure, were retrospectively included. The position of the microcatheter tip used for selective CTA injection was identified. The VI was simulated from the exact same point on the nonselective CBCT and the two volumes were merged. VI was compared to the real injection on the selective CTA. Three interventional radiologists evaluated the accuracy using a 6-point scale (Perfect; Good; Fair; Incorrect Origin; False Negative; Non existing). Sensitivity, PPV, and Fleiss' kappa were calculated. Numerical variables were presented as means ± standard deviations.

RESULTS

Twenty procedures and 195 vessel segments were analyzed. Most vessels were 4th order (57/195; 29%) and 5th order (96/195; 49%). VI was classified as perfect to good in 96.8% ± 1.4 of 1st-3rd order arteries and in 83.4% ± 0.4 of 4th-5th order arteries. Interobserver agreement was substantial (Fleiss' kappa = 0.79; 95% confidence interval = 0.73-0.84, P < 0.01). False negatives were reported with a mean of 9.4% ± 0.3. Average sensitivity was 90.6% ± 0.3 and average PPV was 92.7% ± 0.02. Fourteen false positives were noted.

CONCLUSION

CBCT-based VI software accurately simulated distal injections in the liver with high sensitivity and a substantial interobserver agreement.

Percutaneous liver venous deprivation: outcomes in heavily pretreated metastatic colorectal cancer patients

BACKGROUND

To evaluate liver venous deprivation (LVD) outcomes in patients with colorectal liver metastasis (CRLM) heavily pretreated with systemic and hepatic arterial infusion pump (HAIP) chemotherapies that had an anticipated insufficient future liver remnant (FLR) hypertrophy after portal vein embolization (PVE).

METHODS

PVE was performed with liquid embolics using a transsplenic or ipsilateral transhepatic approach. Simultaneously and via a trans-jugular approach, the right hepatic vein was embolized with vascular plugs. Liver volumetry was assessed on computed tomography before and 3-6 weeks after LVD.

RESULTS

Twelve consecutive CRLM patients that underwent LVD before right hepatectomy or trisectionectomy were included, all previously treated with systemic chemotherapy for a mean of 11.9 months. Six patients had additional HAIP. After embolization, FLR ratio increased from 28.7% ± 5.9 to 42.2% ± 9.0 (P < 0.01). Mean kinetic growth rate (KGR) was 3.56%/week ± 2.3, with a degree of hypertrophy (DH) of 13.8% ± 7.1. In the HAIP subgroup, mean KGR and DH were respectively 3.58%/week ± 2.8 and 14.3% ± 8.7. No severe complications occurred. Ten patients reached surgery after 39 days ± 7.5.

CONCLUSION

In heavily pretreated patients, LVD safely stimulated a rapid and effective FLR hypertrophy, with a resultant high rate of resection.

Nivolumab (NIVO) and drug eluting bead transarterial chemoembolization (deb-TACE): Updated results from an ongoing phase 1 study of patients (pts) with liver limited hepatocellular carcinoma (HCC)

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Background: TACE is a standard of care for liver limited HCC and impacts the immune microenvironment, potentially augmenting the effects of immune checkpoint inhibitors. Methods: This is a multicenter phase 1 study of NIVO and deb-TACE in unresectable HCC pts and Child Pugh A cirrhosis (NCT03143270). The primary objective is to assess safety. Secondary objectives include response rate by RECIST v1.1, progression-free and overall survival by Kaplan-Meier methodology, and blood/tumor immune correlates. A 3 + 3 design with expansion cohort sequentially evaluates 3 cohorts of differing schedules of NIVO relative to deb-TACE. Deb-TACE (75mg of doxorubicin) is administered on Day 0. NIVO is dosed at 240mg IV every 14 days for 1 year (Cohort 1: NIVO begins day +14 after deb-TACE; Cohort 2, interrupted NIVO dosing begins at Day -28 but is held on the Day 0 then restarted on Day +14; Cohort 3, continuous NIVO dosing begins on Day -28 without interruption). Results: As of September 2021, 19 pts were treated [median 67 years (range: 54-78), male (80%), ECOG PS 0 (47%), Child Pugh A (100%), 3 pts in each cohort 1 and 2, 13 pts in cohort 3]. No cases of treatment related liver failure or Grade 5 adverse events (AEs) were observed. 1 DLT of Grade 3 transaminitis was observed in cohort 3 and resolved without intervention and did not recur with drug rechallenge. Median ALT at baseline, day 28, day 56, and end of treatment (EOT) were 27, 43.5, 36.5, and 29 U/L. Median bilirubin at baseline, day 28, day 56, and EOT were 0.6, 0.6, 0.5, and 0.6 mg/dL. Mean ALBI score at baseline (N=19) and EOT (N=14) were -2.75 ± 0.48 vs. -2.55 ± 0.50. The most common treatment-related AEs of any grade were fatigue (53%), ALT/AST increase (42%), fever (37%), and pruritis (32%). The objective response rate by RECIST v 1.1 was 21% (Table). 5/19 pts remained on study with SD or better for ≥12 (range 12-43) months. Updated survival analysis will be presented at the meeting; correlatives at a separate venue. Conclusions: Nivolumab administered with deb-TACE is safe with antitumor activity. This study provides a needed benchmark for the safety of embolization along with anti-PD1 therapy in liver limited HCC. The clinical question of combining immunotherapy with embolization to improve outcome over embolization alone remains investigational and several, pivotal, phase 3 studies are ongoing. Clinical trial information: NCT03143270. [Table: see text]

Percutaneous Cryoablation Provides Disease Control for Extra-Abdominal Desmoid-Type Fibromatosis Comparable with Surgical Resection

PURPOSE

The aim of this study was to determine outcomes and prognostic factors for patients with primary and locally recurrent extra-abdominal desmoid tumors who underwent percutaneous cryoablation, and to compare with patients treated with surgery.

METHODS

Group characteristics were compared using Fisher's exact test, and propensity score matching was performed using the nearest-neighbor approach. Kaplan-Meier and log-rank analyses were used to evaluate the variation in first local recurrence and disease control, while multivariate Cox regression was used to identify factors associated with first local recurrence. All statistical tests were two-sided and a p-value of 0.05 was considered statistically significant.

RESULTS

Twenty-two cryoablation patients were matched with 33 surgical patients (n = 55). Median follow-up after cryoablation was 16.3 months versus 14.9 months after surgery. Two-year local recurrence-free survival (LRFS) was 59% after cryoablation and 71% after surgery, and median LRFS was 26.6 months after cryoablation but was not reached after surgery. Two-year disease control for all patients was 85%, however median disease control was not reached in either the cryoablation or surgery groups. There was no significant difference in LRFS or disease control between matched cryoablation and surgical patients. No local recurrences occurred after the first cryoablation in patients with zero or one of the following risk factors: tumor size > 5 cm, age ≤ 25 years, or locally recurrent disease. All patients with two or more of these risk factors recurred locally after the first cryoablation.

CONCLUSION

Percutaneous cryoablation of primary and locally recurrent extra-abdominal desmoid tumors provides freedom from first local recurrence and long-term disease control comparable with surgery.

Bronchial or Pulmonary Artery Chemoembolization for Unresectable and Unablatable Lung Metastases: A Phase I Clinical Trial

Background Lung chemoembolization is an emerging treatment option for lung tumors, but the optimal embolic, drug, and technique are unknown. Purpose To determine the technical success rate and safety of bronchial or pulmonary artery chemoembolization of lung metastases using ethiodized oil, mitomycin, and microspheres. Materials and Methods Patients with unresectable and unablatable lung, endobronchial, or mediastinal metastases, who failed systemic chemotherapy, were enrolled in this prospective, single-center, single-arm, phase I clinical trial (December 2019-September 2020). Pulmonary and bronchial angiography was performed to determine the blood supply to the lung metastases. Based on the angiographic findings, bronchial or pulmonary artery chemoembolization was performed using an ethiodized oil and mitomycin emulsion, followed by microspheres. The primary objectives were technical success rate and safety, according to the National Cancer Institute Common Terminology Criteria for Adverse Events. CIs of proportions were estimated with the equal-tailed Jeffreys prior interval, and correlations were evaluated with the Spearman test. Results Ten participants (median age, 60 years; interquartile range, 52-70 years; six women) were evaluated. Nine of the 10 participants (90%) had lung metastases supplied by the bronchial artery, and one of the 10 participants (10%) had lung metastases supplied by the pulmonary artery. The technical success rate of intratumoral drug delivery was 10 of 10 (100%) (95% CI: 78, 100). There were no severe adverse events (95% CI: 0, 22). The response rate of treated tumors was one of 10 (10%) according to the Response Evaluation Criteria in Solid Tumors and four of 10 (40%) according to the PET Response Criteria in Solid Tumors. Ethiodized oil retention at 4-6 weeks was correlated with reduced tumor size (ρ = -0.83, P = .003) and metabolic activity (ρ = -0.71, P = .03). Pharmacokinetics showed that 45% of the mitomycin dose underwent burst release in 2 minutes, and 55% of the dose was retained intratumorally with a half-life of more than 5 hours. The initial tumor-to-plasma ratio of mitomycin concentration was 380. Conclusion Lung chemoembolization was technically successful for the treatment of lung, mediastinal, and endobronchial metastases, with no severe adverse events. Clinical trial registration no. NCT04200417 © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Georgiades et al in this issue.

FDG PET/CT imaging features and clinical utility in COVID-19

Purpose

To determine the imaging findings and potential clinical utility of FDG PET/CT in patients with laboratory-confirmed COVID-19.

Methods

We performed a single institution retrospective review of patients diagnosed with COVID-19 using real time reverse transcription–polymerase chain reaction (RT-PCR) who underwent FDG PET/CT for routine cancer care between March 1, 2020 to April 30, 2020, during the height of the pandemic in New York City, New York, United States. PET/CT scans were retrospectively reviewed for imaging findings suspicious for COVID-19. For positive scans, PET and CT findings were recorded, including location, FDG avidity (SUV_max) and CT morphology. Patient demographics and COVID-19 specific clinical data were collected and analyzed with respect to PET/CT scan positivity, lung SUV_max, and time interval between PET/CT and RT-PCR.

Results

Thirty-one patients (21 males and 10 females, mean age 57 years ± 16) were evaluated. Thirteen of 31 patients had positive PET/CT scans, yielding a detection rate of 41.9%. Patients with positive scans had significantly higher rates of symptomatic COVID-19 infection (77% vs 28%, p = 0.01) and hospitalizations (46% vs. 0%, p = 0.002) compared to patients with negative scans. Eleven of 13 patients (84.6%) with positive scans had FDG-avid lung findings, with mean lung SUV_max of 5.36. Six of 13 patients (46.2%) had extrapulmonary findings of FDG-avid thoracic lymph nodes. The detection rate was significantly lower when the scan was performed before RT-PCR versus after RT-PCR (18.8% (n = 3/16) vs. 66.7% (n = 10/15), p = 0.009). Lung SUV_max was not associated with COVID-19 symptoms, severity, or disease course.

Conclusion

FDG PET/CT has limited sensitivity for detecting COVID-19 infection. However, a positive PET scan is associated with higher risk of symptomatic infection and hospitalizations, which may be helpful in predicting disease severity.

Post-treatment CT LI-RADS categories: predictors of overall survival in hepatocellular carcinoma post bland transarterial embolization

PURPOSE

The LI-RADS Treatment Response (LR-TR) algorithm was introduced in 2017 to assist radiologists in assessing hepatocellular carcinoma (HCC) response following locoregional therapy. The objective of this study was to evaluate the associations between pre-treatment LI-RADS diagnostic categories, post-treatment LR-TR categories, and mRECIST response categories with overall survival (OS) of patients with HCC.

METHODS

This retrospective study included untreated patients with one or two lesions who underwent transarterial embolization with or without concomitant ablation from December 2003 to December 2017. Two radiologists (R1 and R2) reviewed pre- and post-treatment CT imaging. Associations between pre- and post-treatment variables, including post-treatment LR-TR categories (Viable, Equivocal, Nonviable), with OS were assessed using the Kaplan-Meier method and Cox proportional hazards regression.

RESULTS

Eighty-five patients were included (median age = 71 years, range 50-87; 17 women). The median OS from first embolization was 43.92 months. Pre- and post-treatment tumor size, pre-treatment LR-TIV (compared with LR-5), and post-treatment LR-TR Viable (compared with LR-TR Nonviable) were associated with OS (p < 0.05 for all). Median OS was shorter for LR-TR Viable patients (R1, 25.64 months, 95% CI 18.58-35.70; R2, 26.43 months 95% CI 20.68-43.92) than for LR-TR Nonviable patients (64.21 months R1 and R2, 95% CI 42.71-92.45 and 36.30-94.09, respectively). mRECIST categories showed similar associations with OS. Inter-reader agreement was moderate for LI-RADS categories (κ = 0.57, 95% CI 0.35-0.78) and substantial for LR-TR categories (κ = 0.68, 95% CI 0.55-0.81).

CONCLUSIONS

LR-TR categories show a strong association with OS in HCC patients treated with transarterial embolization.

Ventricular repolarization homogeneity in transthyretin cardiac amyloidosis

Funding Acknowledgements

Type of funding sources: None.

Background

Non-sustained ventricular tachycardia is frequently observed in patients with transthyretin cardiac amyloidosis (TTR-CA); however, the incidence of sudden tachyarrhythmic death is low. Homogeneity of amyloid fibril deposition within the myocardium and conduction system may mitigate against sustained ventricular tachyarrhythmias. In contrast, myocardial scar heterogeneity is an established predictor of sudden cardiac death in conditions such as hypertrophic cardiomyopathy (HCM), as evidenced by increased myocardial dispersion of repolarization. Whether such indices of arrhythmogenesis are evident in TTR-CA has not been established.

Purpose

To compare ventricular repolarization indices in TTR-CA to HCM and controls without known cardiovascular disease.

Methods

We identified TTR-CA and HCM patients from our single center respective registries, and control patients from our clinical ECG database. Only patients in normal sinus rhythm without bundle branch block, cardiac pacing or artifact were included for analysis. Demographic and clinical data were abstracted. ECGs were analyzed at 25 mm/s paper speed and 10 mm/mV amplitude. ECG parameters included QT interval, QT dispersion, and T peak to T end (TpTe) using the tangent method. All measurements were performed by two blinded independent cardiologists.

Results

A total of 112 patients (45 TTR-CA, 32 HCM, and 35 controls) were studied. Despite a longer QTc in TTR-CA (468.4 ms in TTR-CA vs. 424.6 in controls; p &lt; 0.001), patients with TTR-CA demonstrated similar repolarization indices as controls, including TpTE (93.0 ± 13.5 ms in TTR-CA vs 86.4 ± 12.2 ms in controls, p = 0.24), and TpTe/QTc (0.20 ± 0.03 in TTR-CA vs 0.2 ± 0.03 in controls, p = 0.99). In contrast, HCM patients demonstrated greater TpTe and TpTe/QTc compared with controls (Figure). and a trend toward increased QT dispersion in HCM vs. TTR-CA (p = 0.06).

Conclusion

Unlike HCM, patients with TTR-CA demonstrate a relative lack of myocardial repolarization heterogeneity compared with controls. This finding correlates with  homogeneous distribution of myocardial amyloid fibrils and may explain the low observed incidence of sudden cardiac death in this population. Abstract Figure

Phase I study of transarterial chemoembolization of lung metastases

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Background: Lung chemoembolization (via the bronchial or pulmonary artery) is a new treatment option for unresectable and unablatable lung metastases. Methods: 10 patients with unresectable and unablatable lung, endobronchial, or mediastinal metastases, who failed systemic chemotherapy, were enrolled in this single center, single arm, phase I trial. Pulmonary and bronchial angiography was performed in all patients, to determine the blood supply to the lung metastases. Based on the angiographic findings, bronchial or pulmonary artery chemoembolization was performed, using a lipiodol / mitomycin emulsion, followed by spherical particles. Technical success, safety, efficacy, and pharmacokinetics were evaluated. Wilcoxon signed-rank test was used to compare change in size of treated versus untreated tumors. Results: On angiography, all patients had lung metastases that were hypervascular compared to normal lung. 90% of patients had lung metastases supplied by the bronchial artery, and 10% were supplied by the pulmonary artery. Technical success rate of intra-tumoral drug delivery was 100% (95% CI: 76-100%). There were no severe adverse events, and all patients met criteria for discharge 4 hours post procedure. Response rate of treated lesions was 10% by RECIST and 40% by PERCIST. Treated tumors were mostly stable to decreased in size after chemoembolization (median change in size: 0%; IQR: -11% to 2%; mean: -4%), and untreated tumors were mostly increased in size (median change in size: 10%; IQR: 0% to 17%; mean 9%; p= 0.02). Intra-tumoral lipiodol retention at 4-6 weeks was correlated with decreased tumor size and metabolic activity. Pharmacokinetics showed that 45% of the mitomycin dose underwent burst release in 2 minutes, and 55% of the dose was retained intratumorally with a half-life > 5 hours. Initial tumor-to-plasma ratio of mitomycin concentration was 380. Half-life of intratumoral lipiodol retention was 16 days. In vitro experiments showed 50% emulsion separation in 6.2 days, and 50% drug release in 7.1 hours. Conclusions: Lung chemoembolization can safely treat lung, mediastinal, and endobronchial metastases, with minimal systemic toxicity. High intratumoral drug concentrations after chemoembolization can overcome chemoresistance. Clinical trial information: NCT04200417.

Management of Refractory Ascites Due to Portal Hypertension: Current Status

Refractory ascites is a costly and debilitating condition that occurs most frequently in the setting of substantial cirrhotic portal hypertension, where it portends a poor prognosis. Many treatment options are available, among them medical management, serial large volume paracenteses, transjugular intrahepatic portosystemic shunts, and implanted drainage devices. Although the availability of multiple therapies ensures that most patients will achieve satisfactory results, it can be challenging for the provider to select the appropriate treatment for each specific patient. This article reviews the available therapeutic options for refractory ascites and incorporates available data and clinical experience to suggest a linear stepwise management approach to enhance patient outcomes.

Retrospective Use of Breathing Motion Compensation Technology (MCT) Enhances Vessel Detection Software Performance

PURPOSE

Cone beam CT (CBCT) with planning software is used in intra-arterial liver-directed therapies. Software accuracy relies on high CBCT image quality, which can be impaired by breathing motion. We assessed the impact of a specific MCT on software performance for procedure planning and navigation.

MATERIALS AND METHODS

Institutional Review Board (IRB)-approved retrospective evaluation of liver-directed therapies from July 2015 to April 2018 was performed. CBCTs with at least one well-defined tumor and noticeable breathing motion were included. Each CBCT was reconstructed with and without breathing MCT (Motion Freeze, GE Healthcare). Automatic tumor-supplying vessel detection was performed on up to 4 tumors in each CBCT reconstruction (Liver ASSIST V.I., GE Healthcare). Vessel detection sensitivity and positive predictive value (PPV) were measured with and without MCT using Digital Subtracted Angiography (DSA) as reference. Preprocedural contrast-enhanced CT was also utilized in some cases to rule out the possibility of extrahepatic supplying vessels.

RESULTS

MCT was applied retrospectively to 18 CBCTs with a total of 30 tumors. At least one supplying vessel was detected for 28/30 (93%) tumors with MCT versus 20/30 (66%) without. On the subgroup of 10 CBCTs (22 tumors, 76 feeders) in which the automatic vessel detection initially worked in both reconstructions, the average sensitivity and PPV increased from 63% (48/76) and 57% (48/84) before MCT to 83% (63/76) and 79% (63/80) after (p = 0.002 and p < 0.001).

CONCLUSION

Breathing MCT improves planning software performance in CBCT impaired by breathing motion.

Phase Ib Study of Enzalutamide with or Without Sorafenib in Patients with Advanced Hepatocellular Carcinoma

LESSONS LEARNED

Androgen receptor as assessed by immunohistochemistry is expressed in a high proportion of patients with hepatocellular carcinoma (HCC). Enzalutamide at 160 mg orally daily is safe and tolerable in patients with advanced HCC but has no single-agent antitumor activity. Enzalutamide, a CYP3A4 inducer, at a standard dose of 160 mg reduces the exposure of sorafenib, a CYP3A4 substrate. Enzalutamide and sorafenib is safe and tolerable in patients with advanced HCC, but the addition of enzalutamide to sorafenib did not enhance the antitumor activity of sorafenib.

BACKGROUND

Androgen receptor (AR) interference is deleterious to hepatocellular carcinoma (HCC) in preclinical models.

METHODS

This is a multicenter, phase Ib study of enzalutamide ± sorafenib in patients with advanced HCC. In part 1, a 3 + 3 dose de-escalation design with expansion established the recommended phase II dose (RP2D) of enzalutamide in patients in whom sorafenib treatment had failed. In part 2, a 3 + 3 dose escalation with expansion established the safety of enzalutamide with sorafenib in treatment-naive patients with HCC. Secondary objectives included objective response rate (ORR), progression-free survival (PFS), overall survival (OS), pharmacokinetics (PK), and determination of AR expression by immunohistochemistry. A 7-day run-in with sorafenib alone in part 2 allowed assessment of the impact of enzalutamide on sorafenib pharmacokinetics.

RESULTS

In part 1, 16 patients received enzalutamide 160 mg daily. No dose-limiting toxicity (DLT) occurred; 1 patient required dose reduction. Responses were not observed; median PFS and OS were 1.8 (95% confidence interval [CI]: 1.6-3.6) and 7 (95% CI: 3.6 to not reached [NR]) months, respectively. In part 2, patients received sorafenib 400 mg daily (4) or twice a day (8) both with enzalutamide at the recommended phase II dose-no DLTs were observed. ORR was 10% (95% CI: 0.3-44.5), and median PFS and OS were 2.9 (95% CI: 1.6 to NR) and 6.7 (95% CI: 4.6 to NR) months, respectively. Enzalutamide reduced sorafenib exposure by 60%. Tumor AR expression did not associate with outcome.

CONCLUSION

Enzalutamide is ineffective in HCC; further development is not supported by this study.

Factors Associated With Local Tumor Control and Complications After Thermal Ablation of Colorectal Cancer Liver Metastases: A 15-year Retrospective Cohort Study

INTRODUCTION

The purpose of this study was to identify risk factors associated with local tumor progression-free survival (LTPFS) and complications after colorectal liver metastases (CLM) thermal ablation (TA).

PATIENTS AND METHODS

This retrospective analysis included 286 patients with 415 CLM undergoing TA (radiofrequency and microwave ablation) in 378 procedures from January 2003 to July 2017. Prior hepatic artery infusion (HAI), bevacizumab, pre-existing biliary dilatation, ablation modality, minimal ablation margin (MM), prior hepatectomy, CLM number, and size were analyzed as factors influencing complications and LTPFS. Statistical analysis included the Kaplan-Meier method, Cox proportional hazards model, competing risk analysis, univariate/multivariate logistic/exact logistic regressions, and the Fisher exact test. Complications were reported according to modified Society of Interventional Radiology guidelines.

RESULTS

The median follow-up was 31 months. There was no LTP for MM > 10 mm. Smaller tumor size, increased MM, and prior hepatectomy correlated with longer LTPFS. The major complications occurred following 28 (7%) of 378 procedures. There were no biliary complications in HAI-naive patients, versus 11% in HAI patients (P < .001), of which 7% were major. Biliary complications predictors in HAI patients included biliary dilatation, bevacizumab, and MM > 10 mm. In HAI patients, ablation with 6 to 10 mm and > 10 mm MM resulted in major biliary complication rates of 4% and 21% (P = .0011), with corresponding LTP rates of 24% and 0% (P = .0033). In HAI-naive patients, the LTP rates for 6 to 10 mm and > 10 mm MM were 27% and 0%, respectively.

CONCLUSIONS

No LTP was seen for MM > 10 mm. Biliary complications occurred only in HAI patients, especially in those with biliary dilatation, bevacizumab, and MM > 10 mm. In HAI patients, MM of 6 to 10 mm resulted in 76% local tumor control and 4% major biliary complications incidence.

Utilization of integrated angiography-CT interventional radiology suites at a tertiary cancer center

BACKGROUND

Integrated Angiography-Computed Tomography (ACT) suites were initially designed in the 1990's to perform complex procedures requiring high-resolution cross-sectional imaging and fluoroscopy. Since then, there have been technology developments and changes in patient management. The purpose of this study was to review the current usage patterns of a single center's integrated ACT suites.

METHODS

All procedures performed in 2017 in 3 ACT suites (InterACT Discovery RT, GE Healthcare) at a tertiary cancer center were reviewed retrospectively. Usage was classified as: Standard, in which the patient underwent a single procedure using either fluoroscopy, CT, or ultrasound (US); Combined, in which the patient underwent a single procedure utilizing both fluoroscopy and CT; or Staged, in which the patient underwent 2 separate but successive procedures using fluoroscopy and CT individually. The most frequently performed Combined and Staged procedures were further reviewed to determine how the different modalities were used. The duration of the most common Staged procedures was compared to analogous procedures' durations in single modality rooms over the period Jan 2016 to Sep 2019.

RESULTS

A total of 3591 procedures were performed on 2678 patients in the 3 ACT Suites. 80% of patients underwent a Standard procedure using fluoroscopy (38%), CT (32%) or US (10%) and accounted for 70% of the room occupation time. Fourteen and three percent of the patients underwent Combined or Staged procedures, occupying 19 and 5% of the room time, respectively. The remaining procedures were classified as both Combined and Staged, representing 3% of the patients and 6% of the room occupation time. The most common Combined procedures were drainages, hepatic arterial embolizations or radioembolizations, arterial, and biliary interventions. The most common Staged procedures were multiple drainages and hepatic arterial embolizations followed by biopsies or ablations. The room occupation time for liver tumor embolization and ablation was significantly shorter (p < 0.01) when performed in a Staged fashion versus the analogous procedures in single modality room.

CONCLUSION

An integrated ACT system provides the capability to perform complex Combined or Staged procedures as well as scheduling flexibility by allowing any type of case to be performed in the IR suite.

Induction and characterization of pancreatic cancer in a transgenic pig model

BACKGROUND

Preclinical testing of new locoregional therapies for pancreatic cancer has been challenging, due to the lack of a suitable large animal model.

PURPOSE

To develop and characterize a porcine model of pancreatic cancer. Unlike small animals, pigs have similar physiology, drug dosing, and immune response to humans. Locoregional therapy in pigs can be performed using the same size catheters and devices as in humans.

METHODS

The Oncopig is a transgenic pig with Cre-inducible TP53R167H and KRASG12D mutations. In 12 Oncopigs, CT-guided core biopsy of the pancreas was performed. The core biopsy was incubated with an adenoviral vector carrying the Cre recombinase gene. The transformed core biopsy was injected back into the pancreas (head, tail, or both). The resulting tumors (n = 19) were characterized on multi-phase contrast-enhanced CT, and on pathology, including immunohistochemistry. Angiographic characterization of the tumors was performed in 3 pigs.

RESULTS

Pancreatic tumors developed at 19 out of 22 sites (86%) that were inoculated. Average tumor size was 3.0 cm at 1 week (range: 0.5-5.1 cm). H&E and immunohistochemical stains revealed undifferentiated carcinomas, similar to those of the pancreatobiliary system in humans. Neoplastic cells were accompanied by a major inflammatory component. 1 of 12 pigs only had inflammatory nodules without evidence of neoplasia. On multiphase CT, tumors were hypovascular compared to the normal pancreas. There was no pancreatic duct dilation. In 3 pigs, angiography was performed, and in all 3 cases, the artery supplying the pancreatic tumor could be catheterized using a 2.4 F microcatheter. Selective angiography showed the pancreatic tumor, without extra-pancreatic perfusion.

CONCLUSION

Pancreatic cancer can be induced in a transgenic pig. Intra-arterial procedures using catheters designed for human interventions were technically feasible in this large animal model.

NRF2 Dysregulation in Hepatocellular Carcinoma and Ischemia: A Cohort Study and Laboratory Investigation

Background Intermediate stage hepatocellular carcinomas (HCCs) are treated by inducing ischemic cell death with transarterial embolization (TAE) or transarterial chemoembolization (TACE). A subset of HCCs harbor nuclear factor E2-related factor 2 (NRF2), a major regulator of the oxidative stress response implicated in cell survival after ischemia. NRF2-mutated HCC response to TAE and/or TACE is unknown. Purpose To test whether ischemia resistance is present in individuals with NRF2-mutated HCC and if this resistance can be overcome by means of NRF2 inhibition in HCC cell lines. Materials and Methods This was a combined retrospective review of an institutional database (from January 2011 to December 2018) and prospective study (from January 2014 to December 2018) of participants with HCC who underwent TAE and a laboratory investigation of HCC cell lines. Imaging follow-up included liver CT or MRI at 1 month after the procedure followed by 3-month interval scans. Tumor radiologic response was assessed on the basis of follow-up imaging. The time to local progression after TAE for individuals with and individuals without NRF2 pathway alterations was estimated by using competing risk analysis (Gray test). The in vitro response to ischemia in four HCC cell lines with and without NRF2 overexpression was evaluated, and the combination of ischemia with NRF2 knockdown by means of short hairpin RNA or an NRF2 inhibitor was tested. Doubling time estimates, dose response curve regression, and comparison analyses were performed. Results Sixty-five individuals (median age, 69 years [range, 19-84 years]; 53 men) were evaluated. HCCs with NRF2 pathway mutation had a shorter time to local progression after TAE compared to those without mutation (6-month cumulative incidence of local progression, 56% [range, 19%-91%] vs 22% [range, 12%-34%], respectively; P < .001) and confirmed ischemia resistance in NRF2-overexpressing HCC cell lines. However, ischemia and NRF2 knock-down worked synergistically to decrease proliferation of NRF2-overexpressing HCC cell lines. Dose response curves of ML385, an NRF2 inhibitor, showed that ischemia induces addiction to NRF2 in cells with NRF2 alterations. Conclusion Hepatocellular carcinoma with nuclear factor E2-related factor 2 (NRF2) alterations showed resistance to ischemia, but ischemia simultaneously induced sensitivity to NRF2 inhibition. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Weiss and Nezami in this issue.

Immediate post-thermal ablation biopsy of colorectal liver metastases to predict oncologic outcomes

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Background: Thermal ablation (TA) is used as a local cure for selected colorectal liver metastases (CLM) with minimal risk. A critical limitation of TA has been early local tumor progression (LTP). The goal of this study is to establish the role of ablation zone (AZ) biopsy in predicting LTP. Methods: This institutional review board-approved prospective study included patients with CLM of 5cm or less in maximum diameter, with confined liver disease or stable, limited extrahepatic disease. Both radiofrequency(RF) and microwave(MW) ablation modalities were used. A biopsy of the center and margin of the AZ was performed immediately after ablation. The applicators were also examined for the presence of viable tumor cells. All samples containing morphologically identified tumor cells were further interrogated with immunohistochemistry to determine the proliferative and viability potential of the detected tumor cells. Ablation margin size was evaluated on the first CT scan performed 4–8 weeks after ablation and was confirmed by 3D assessment with Ablation Confirmation Software (Neuwave™). Variables were evaluated as predictors of time to LTP with the competing-risks model (uni- and multivariate analyses). Results: Between November 2009 and February 2019, 102 patients with 182 CLMs were enrolled. Mean tumor size was 2.0 cm (range, 0.6–4.8 cm). MW was used in 95/182 (52%) tumors and RF in 87/182 (48%). Median follow-up was 19 months. Technical effectiveness was evident in 178/182 (97%) ablated tumors on the first contrast material–enhanced CT at 4–8-weeks post-ablation. The cumulative incidence of LTP at 12 months was 19% (95% confidence interval [CI]: 14, 27). Samples from 64 (35%) of the 178 technically successful cases contained viable tumor. At univariate analysis, tumor size, minimal margin size, and biopsy results were significant in predicting LTP. In a multivariate model, margin size of less than 5 mm (P < .001; hazard ratio [HR], 4.3), and positive biopsy results (P = .02; HR, 1.8) remained significant. LTP within 12 months after TA was noted in 3% (95% CI: 1, 6) of tumor-negative biopsy CLMs with margins of at least 5 mm. Conclusions: Biopsy and pathologic examination of the AZ predicts LTP regardless of TA modality used. This can optimize ablation as a potential local cure for patients with limited CLM.

Multicenter Study of Metastatic Lung Tumors Targeted by Interventional Cryoablation Evaluation (SOLSTICE)

OBJECTIVE

To assess the safety and local recurrence-free survival in patients after cryoablation for treatment of pulmonary metastases.

METHODS

This multicenter, prospective, single-arm, phase 2 study included 128 patients with 224 lung metastases treated with percutaneous cryoablation, with 12 and 24 months of follow-up. The patients were enrolled on the basis of the outlined key inclusion criteria, which include one to six metastases from extrapulmonary cancers with a maximal diameter of 3.5 cm. Time to progression of the index tumor(s), metastatic disease, and overall survival rates were estimated using the Kaplan-Meier method. Complications were captured for 30 days after the procedure, and changes in performance status and quality of life were also evaluated.

RESULTS

Median size of metastases was 1.0 plus or minus 0.6 cm (0.2-4.5) with a median number of tumors of 1.0 plus or minus 1.2 cm (one to six). Local recurrence-free response (local tumor efficacy) of the treated tumor was 172 of 202 (85.1%) at 12 months and 139 of 180 (77.2%) at 24 months after the initial treatment. After a second cryoablation treatment for recurrent tumor, secondary local recurrence-free response (local tumor efficacy) was 184 of 202 (91.1%) at 12 months and 152 of 180 (84.4%) at 24 months. Kaplan-Meier estimates of 12- and 24-month overall survival rates were 97.6% (95% confidence interval: 92.6-99.2) and 86.6% (95% confidence interval: 78.7-91.7), respectively. Rate of pneumothorax that required pleural catheter placement was 26% (44/169). There were eight grade 3 complication events in 169 procedures (4.7%) and one (0.6%) grade 4 event.

CONCLUSION

Percutaneous cryoablation is a safe and effective treatment for pulmonary metastases.

Nivolumab (NIVO) and drug eluting bead transarterial chemoembolization (deb-TACE): Preliminary results from a phase I study of patients (pts) with liver limited hepatocellular carcinoma (HCC)

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Background: Regional therapies in HCC impact the immune microenvironment and may augment the effects of immune checkpoint inhibitors. Methods: This is a multicenter phase 1 study of NIVO and deb-TACE in unresectable HCC pts (BCLC Stage B) and Child Pugh A cirrhosis (NCT03143270). The primary objective is to assess safety. Secondary objectives include response rate by RECIST v1.1, progression-free and overall survival by Kaplan-Meier methodology, and blood/tumor immune correlates. A 3 + 3 design sequentially evaluates 3 cohorts of differing schedules of NIVO relative to deb-TACE. Deb-TACE (75mg of doxorubicin) is administered on Day 0. NIVO is dosed at 240mg IV every 14 days for 1 year (Cohort 1: NIVO begins day +14 after deb-TACE; Cohort 2, interrupted NIVO dosing begins at Day -28 but is held on the Day 0 then restarted on Day +14; Cohort 3, continuous NIVO dosing begins on Day -28 without interruption). Results: As of July 2019, 9 pts have been treated [median 65 years (range: 54-76), male (89%), viral (44%;1 HBV, 3 HCV), non-viral (56%;2 EtOH, 1 NASH, 2 unknown), prior resection (44%), prior regional therapy (44%), 3 pts in each cohort]. No cases of treatment related liver failure, dose-limiting toxicity, or Grade 5 adverse events (AEs) were observed. Grade ≥3 AEs possibly related to nivolumab, deb-TACE, or both included: transaminase elevation (1 pt: day 1 post TACE resolved in 7 days without treatment; 2 pts: ≥30 days post TACE resolved with steroids between 20-41 days), post-embolization syndrome (1 pt: resolved in 5 days), asymptomatic lipase increase (1 pt: resolved in 14 days), post-procedural groin hematoma (1 pt: resolved in 2 days). All 9 pts were evaluable for efficacy: 2 (22%) confirmed PR and 7 (78%) SD. 4/9 pts remain on study with SD or better—2 pts continue > 18 months post embolization with durable PRs. 12 months OS rate was 71%. Ongoing correlates will be presented at a separate meeting. Conclusions: Nivolumab given at various times relative to deb-TACE appears safe and tolerable. Cohort 3 continues to accrue to provide a better estimate of safety and antitumor activity of the combination. Clinical trial information: NCT03143270.

P850 Role of echocardiography in a patient with heart failure and multiple cerebral strokes

A 78 years old male with a history of hypertension and heart failure from 10 years before presented to our hospital with dyspnea, transient loss of consciousness and fatigue. He also had a history of frequent transient ischemic attacks previously with the most recent one being one year before. He was on standard heart failure treatment without any echocardiography done during the past year. On physical examination, he had stable blood pressure and heart rate but increased respiratory rate and respiratory distress. He also had aphasia and rales in the base of his lungs. His oxygen saturation was 70% and was admitted in the intensive care unit. On baseline laboratory data he had a creatinine level of 3.6 mg/dl. After treatment with furosemide and oxygen (O2) therapy and stabilization, brain computed tomography (CT) was done for the patient which showed an old stroke in the territory of right posterior cerebral artery and a new stroke in the territory of the inferior division of the middle cerebral artery (shown in part A of the figure). Echocardiography was done for the patient which showed a large mobile apical left ventricle (LV) clot and moderate LV systolic dysfunction (Three chamber view is shown in part B of the figure) . He was put on anticoagulation and was a candidate for referral to a tertiary center for surgery but after consult due to his acute renal failure and taking in mind his own and family concerns and their refusal for surgery he stayed at our center for continuing his treatment. Unfortunately, after 2 days of treatment, his brain status deteriorated and he had more ischemic brain symptoms for which brain CT scan was done which showed a new infarct in the upper parietal lobes (shown in part C of the figure). Echocardiography was repeated (Three chamber view shown in part D of the figure) which showed a smaller LV clot which was possibly due to a partial detachment of the clot and embolization into the cerebral arteries. With heart failure treatment and proper hydration his creatinine level reduced to 1.1 mg/dl after 6 days of treatment but because of respiratory infection and distress he was intubated and put on mechanical ventilation (Lung CT scan is shown in part E of the figure). He was then put on antibiotic treatment and anticoagulation was done with heparin. His INR level increased and he had a high bleeding tendency which forced us to discontinue anticoagulation. Although his vital signs were stable all through treatment but unfortunately after 14 days of treatment he had bradycardia and asystole and did not respond to cardiopulmonary resuscitation. Conclusion: The case describes a patient with heart failure and multiple cerebral strokes because of an LV clot diagnosed by echocardiography. The case emphasizes the difficulties faced while treating a heart failure patient with co-morbid conditions and the role of echocardiography in diagnosis and guiding management.

Abstract P850 Figure

PET/CT Imaging Characteristics After Radioembolization of Hepatic Metastasis from Breast Cancer

PURPOSE

To define positron emission tomography/computed tomography (PET/CT) imaging characteristics during follow-up of patients with metastatic breast cancer (MBC) treated with yttrium-90 (Y90) radioembolization (RE).

MATERIALS AND METHODS

From January 2011 to October 2017, 30 MBC patients underwent 38 Y90 glass or resin RE treatments. Pre-RE PET/CT was performed on average 51 days before RE. There were 68 PET/CTs performed after treatment. Response was assessed using modified PERCIST criteria focusing on the hepatic territory treated with RE, normalizing SUVpeak to the mean SUV of liver uninvolved by tumor. An objective response (OR) was defined as a decrease in SUVpeak by at least 30%.

RESULTS

Of the 68 post-RE scans, 6 were performed at 0-30 days, 15 at 31-60 days, 9 at 61-90 days, 13 at 91-120 days, 14 scans at 121-180 days, and 11 scans at > 180 days after RE. Of the 30 patients, 25 (83%) achieved OR on at least one follow-up. Median survival was 15 months after the first RE administration. Highest response rates occurred at 30-90 days, with over 75% of cases demonstrating OR at that time. After 180 days, OR was seen in only 25%. There was a median TTP of 169 days among responders.

CONCLUSION

In MBC, follow-up PET/CT after RE demonstrates optimal response rates at 30-90 days, with progression noted after 180 days. These results help to guide the timing of imaging and also to inform patients of expected outcomes after RE.

Regional Chemotherapy for Biliary Tract Tumors and Hepatocellular Carcinoma

Locally advanced hepatocellular carcinoma and intrahepatic cholangiocarcinoma are associated with a grim prognosis. The development of highly effective systemic therapies for these tumors has been challenging; however, numerous locoregional treatment alternatives have emerged, including transarterial hepatic embolization (TAE), transarterial chemoembolization (TACE), drug-eluting bead TACE (DEB-TACE), hepatic arterial infusion chemotherapy (HAI), radioembolization, and stereotactic body radiation therapy. Although there is potential for long-term disease control for these therapies, the evidence to guide adequate patient selection and choose among different treatment alternatives is still limited. This review focuses on the rationale and data supporting TAE, TACE, DEB-TACE, and HAI in hepatobiliary cancers.