Liver-Directed Therapy for Neuroendocrine Tumor Metastases in the Era of Peptide Receptor Radionuclide Therapy

OPINION STATEMENT

The treatment of neuroendocrine neoplasm (NEN) liver metastases involves a multidisciplinary approach that includes liver-directed therapies (LDT) and systemic treatments, such as peptide receptor radionuclide therapy (PRRT). LDT has demonstrated efficacy in rapidly reducing tumor bulk, improving symptoms, and delaying disease progression. Interventional radiologists should be consulted prior to switching therapy for patients with progressive or symptomatic neuroendocrine tumor liver metastases. Long-term follow-up data on the safety of Yttrium-90 radioembolization before and after PRRT remain limited. Therefore, a more conservative approach may be to preferentially employ transarterial embolization (TAE) or transarterial chemoembolization (TACE) for patients' somatostatin receptor-avid disease who may be future candidates for PRRT. Notable exceptions where radioembolization may be a preferred treatment strategy may be patients with history of biliary tract instrumentation, asymmetric unilobar disease distribution, and rapidly progressive diffuse liver involvement. Selection of local treatment modality, sequencing, and combination of LDT with systemic therapy require further investigation.

Frailty as a Predictor of Complications and Transplant-Free Survival after Transarterial Chemoembolization of Hepatocellular Carcinoma

Purpose To determine the association between frailty, 30-day complications, rehospitalization, and transplant-free survival (TFS) following conventional and drug-eluting bead transarterial chemoembolization.

Materials and Methods A retrospective analysis was performed on a cohort of 125 patients with treatment-naïve hepatocellular carcinoma who underwent conventional or drug-eluting beads chemoembolization at our institution between 2014 and 2015. Liver function parameters, Barcelona clinic liver cancer tumor stage, and all components of the five-item modified frailty index (mFI-5) were used to determine the patient's frailty status. Key end points included severe (grade 3 or above) adverse events of chemoembolization, 30-day rehospitalization rates, and TFS. Logistic regression analysis was performed on conventional predictors of postoperative complications after chemoembolization. Median survival was estimated and compared using the Kaplan–Meier's estimator and log-rank test.

Results Among 125 patients who underwent first-time chemoembolization, higher frailty score was an independent predictor of both 30-day hospital readmission and severe liver toxicity (p = 0.01 and p = 0.03, respectively) on multivariate logistic regression analysis. Each point increase in mFI-5 conferred a threefold or twofold increase in the risk of experiencing 30-day rehospitalization or postoperative severe adverse events, respectively. At the data censor date, patients with mFI-5 score ≥ 2 had decreased overall TFS (28.1 vs. 39.8 months, p = 0.03).

Conclusion Increasing frailty as determined by mFI-5 is an independent predictor of 30-day complications and lower TFS following chemoembolization.

Tunneled Peritoneal Catheter vs Repeated Paracenteses for Recurrent Ascites: A Cost-Effectiveness Analysis

PURPOSE

To compare the cost-effectiveness of tunneled peritoneal catheter (TPC) versus serial large-volume paracenteses (LVP) for patients with recurrent ascites.

MATERIALS AND METHODS

Retrospective, single-institution analysis of 100 consecutive patients undergoing LVP and eventual TPC placement (2015-2018) was performed with extraction of procedural complications and hospital admissions. LVPs were associated with 17 adverse events (AEs) while only 9 AEs occurred after TPC placement. While undergoing routine LVP, the patients had 30 hospitalizations monthly (177 days in total) and 10 hospitalizations monthly (51 days) after TPC placement. A cost-effectiveness analysis with Markov modeling was performed comparing TPC and LVP. Costs were based on Medicare reimbursement rates. Statistical analyses include base case calculation, Monte Carlo simulations, and deterministic sensitivity analyses.

RESULTS

TPC placement was the dominant strategy with a comparable health benefit of 0.08060 quality-adjusted life-years (QALY) (LVP: 0.08057 QALY) at a lower cost of $4151 (LVP: $8401). Probabilistic sensitivity analysis showed TPC was superior in 97.49% of simulations. Deterministic sensitivity analysis demonstrated the superiority of TPC compared to LVP if the TPC complication rate was < 9.47% per week and the complication rate for LVP was > 1.32% per procedure. TPC was more cost-effective when its procedural cost was < $5427 (base case: 1174.5), and remained as such when the cost of LVP was varied as much as $10,000 (base case: $316.48).

CONCLUSION

In this study, TPC was more cost-effective than LVP in patients with recurrent ascites due to the reduced risk of infection, emergency department visits, and length of hospitalization stays.

Percutaneous approach options for embolization of endoleak after iliac artery aneurysm repair: stick the sac or stick the gluteal artery

Internal iliac artery aneurysms (IIAAs), isolated or associated with abdominal aortic aneurysms, are at rupture risk with growth. Treatment is recommended when symptomatic or greater than 3 cm. Surgical or endovascular therapy should exclude the arterial origin and outflow branches. If all outflow branches are not completely embolized, an endoleak can develop, pressurizing the sac leading to growth and rupture. Accessing the arteries involved can be technically challenging and understanding potential targets is critical. We describe two percutaneous approaches for treatment: percutaneously accessing the sac from an anterior trans-iliopsoas approach and percutaneously accessing the gluteal artery from a posterior approach.

Perceptions of Futility in Interventional Radiology: A Multipractice Systematic Qualitative Analysis

PURPOSE

To characterize perceptions of palliative versus futile care in interventional radiology (IR) as a roadmap for quality improvement.

METHODS

Interventional radiologists (IRs) and referring physicians were recruited for anonymous interviews and/or focus groups to discuss their perceptions and experiences related to palliative verse futile care in IR. Sessions were recorded, transcribed, and systematically analyzed using dedicated software, content analysis, and grounded theory. Data collection and analysis continued simultaneously until additional interviews stopped revealing new themes: 24 IRs (21 males, 3 females, 1-39 years of experience) and 7 referring physicians (3 males, 4 females, 6-14 years of experience) were analyzed.

RESULTS

Many IRs (75%) perceived futility as an important issue. Years of experience (r = 0.60, p = 0.03) and being in academics (r = 0.62, p = 0.04) correlated with greater perceived importance. Perceptions of futility and whether a potentially inappropriate procedure was performed involved a balance between four sets of factors (patient, clinician, procedural, and cultural). These assessments tended to be qualitative in nature and are challenged by a lack of data, education, and consistent workflows. Referring clinicians were unaware of this issue and assumed IR had guidelines for differentiating between palliation and futility.

CONCLUSION

This study characterized the complexity and qualitative nature of assessments of palliative verses futile care in IR while highlighting potential means of improving current practices. This is important given the number of critically ill patients referred to IR and costs of potentially inappropriate interventions.

Role of Interventional Procedures in Obstetrics and Gynecology

Radiological guided intervention techniques are discussed in obstetric and gynecologic patients. Fallopian tube recanalization, postpartum hemorrhage control, techniques of treating uterine leiomyomas, pelvic congestion treatment, and the use of percutaneous and transvaginal ultrasonography-guided aspirations and biopsy are covered. These techniques use basic radiological interventional skills and show how they are adapted for use in the female pelvis.

Primary constrained TIPS for treating refractory ascites or variceal bleeding secondary to hepatic cirrhosis

OBJECTIVE

To report an initial experience using a primary constrained transjugular intrahepatic portosystemic shunt (TIPS) technique for treating cirrhotic patients with refractory ascites or variceal bleeding.

METHODS

All patients undergoing primary constrained (n = 9) and conventional (n = 18) TIPS between July 2014 and June 2016 were retrospectively reviewed. Preprocedure demographics, Child-Pugh, model for end-stage liver disease and technical variables were recorded. Outcomes measured included technical and clinical success, complications, 30-day mortality, as well as necessity for TIPS revision. Average (SD) and median follow-up was 237 (190) and 226 days.

RESULTS

All constrained and conventional TIPS were technically successful (100%). Clinical success as defined as a reduction or improvement in presenting symptoms was 88.9% (8/9) and 100% (18/18) in the constrained and conventional groups, respectively (p = 1). The average reduction in portosystemic gradient was lower in the constrained group, 6.1 mmHg compared with 10.6 mmHg in the conventional group (p = 0.73). The rate of hepatic encephalopathy following TIPS placement was higher in the conventional group [16.7% (3/18)] compared with 0% in the constrained group (p = 0.52). The percentage of patients requiring TIPS revision was lower in the constrained group, although the results were not significant (11.1 vs 22.2%, p = 0.63).

CONCLUSION

Primary constrained TIPS is a feasible modification to conventional TIPS with similar technical and clinical success rates. A trend towards a smaller reduction in the portosystemic gradient and need for revision was observed in the constrained group. Advances in knowledge: Primary constrained TIPS allows for greater stepwise control over shunt diameter and may represent an improved technique for patients at risk for hepatic encephalopathy.

Primary constrained TIPS for treating refractory ascites or variceal bleeding secondary to hepatic cirrhosis

OBJECTIVE

To report an initial experience using a primary constrained transjugular intrahepatic portosystemic shunt (TIPS) technique for treating cirrhotic patients with refractory ascites or variceal bleeding.

METHODS

All patients undergoing primary constrained (n = 9) and conventional (n = 18) TIPS between July 2014 and June 2016 were retrospectively reviewed. Preprocedure demographics, Child-Pugh, model for end-stage liver disease and technical variables were recorded. Outcomes measured included technical and clinical success, complications, 30-day mortality, as well as necessity for TIPS revision. Average (SD) and median follow-up was 237 (190) and 226 days.

RESULTS

All constrained and conventional TIPS were technically successful (100%). Clinical success as defined as a reduction or improvement in presenting symptoms was 88.9% (8/9) and 100% (18/18) in the constrained and conventional groups, respectively (p = 1). The average reduction in portosystemic gradient was lower in the constrained group, 6.1 mmHg compared with 10.6 mmHg in the conventional group (p = 0.73). The rate of hepatic encephalopathy following TIPS placement was higher in the conventional group [16.7% (3/18)] compared with 0% in the constrained group (p = 0.52). The percentage of patients requiring TIPS revision was lower in the constrained group, although the results were not significant (11.1 vs 22.2%, p = 0.63).

CONCLUSION

Primary constrained TIPS is a feasible modification to conventional TIPS with similar technical and clinical success rates. A trend towards a smaller reduction in the portosystemic gradient and need for revision was observed in the constrained group. Advances in knowledge: Primary constrained TIPS allows for greater stepwise control over shunt diameter and may represent an improved technique for patients at risk for hepatic encephalopathy.

AMPA Receptor Plasticity in Accumbens Core Contributes to Incubation of Methamphetamine Craving

BACKGROUND

The incubation of cue-induced drug craving in rodents provides a model of persistent vulnerability to craving and relapse in human addicts. After prolonged withdrawal, incubated cocaine craving depends on strengthening of nucleus accumbens (NAc) core synapses through incorporation of Ca²⁺-permeable alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors (CP-AMPARs). Through metabotropic glutamate receptor 1 (mGluR1)-mediated synaptic depression, mGluR1 positive allosteric modulators remove CP-AMPARs from these synapses and thereby reduce cocaine craving. This study aimed to determine if similar plasticity accompanies incubation of methamphetamine craving.

METHODS

Rats self-administered saline or methamphetamine under extended-access conditions. Cue-induced seeking tests demonstrated incubation of methamphetamine craving. After withdrawal periods ranging from 1 to >40 days, rats underwent one of the following procedures: 1) whole-cell patch clamp recordings to characterize AMPAR transmission, 2) intra-NAc core injection of the CP-AMPAR antagonist 1-naphthyl acetyl spermine followed by a seeking test, or 3) systemic administration of a mGluR1 positive allosteric modulator followed by a seeking test.

RESULTS

Incubation of methamphetamine craving was associated with CP-AMPAR accumulation in NAc core, and both effects were maximal after ~1 week of withdrawal. Expression of incubated craving was decreased by intra-NAc core 1-naphthyl acetyl spermine injection or systemic mGluR1 positive allosteric modulator administration.

CONCLUSIONS

These results are the first to demonstrate a role for the NAc in the incubation of methamphetamine craving and describe adaptations in synaptic transmission associated with this model. They establish that incubation of craving and associated CP-AMPAR plasticity occur much more rapidly during withdrawal from methamphetamine compared with cocaine. However, a common mGluR1-based therapeutic strategy may be helpful for recovering cocaine and methamphetamine addicts.

A critical role of lateral hypothalamus in context-induced relapse to alcohol seeking after punishment-imposed abstinence

In human alcoholics, abstinence is often self-imposed, despite alcohol availability, because of the negative consequences of excessive use. During abstinence, relapse is often triggered by exposure to contexts associated with alcohol use. We recently developed a rat model that captures some features of this human condition: exposure to the alcohol self-administration environment (context A), after punishment-imposed suppression of alcohol self-administration in a different environment (context B), provoked renewal of alcohol seeking in alcohol-preferring P rats. The mechanisms underlying context-induced renewal of alcohol seeking after punishment-imposed abstinence are unknown. Here, we studied the role of the lateral hypothalamus (LH) and its forebrain projections in this effect. We first determined the effect of context-induced renewal of alcohol seeking on Fos (a neuronal activity marker) expression in LH. We next determined the effect of LH reversible inactivation by GABAA + GABAB receptor agonists (muscimol + baclofen) on this effect. Finally, we determined neuronal activation in brain areas projecting to LH during context-induced renewal tests by measuring double labeling of the retrograde tracer cholera toxin subunit B (CTb; injected in LH) with Fos. Context-induced renewal of alcohol seeking after punishment-imposed abstinence was associated with increased Fos expression in LH. Additionally, renewal was blocked by muscimol + baclofen injections into LH. Finally, double-labeling analysis of CTb + Fos showed that context-induced renewal of alcohol seeking after punishment-imposed abstinence was associated with selective activation of accumbens shell neurons projecting to LH. The results demonstrate an important role of LH in renewal of alcohol seeking after punishment-imposed abstinence and suggest a role of accumbens shell projections to LH in this form of relapse.