Transradial Approach for Hepatic Radioembolization: Initial Results and Technique

Comparative Analysis of Transradial and Transfemoral Approaches in Transarterial Radioembolization for Liver Tumors: A Systematic Review and Meta-Analysis

PURPOSE

Transarterial radioembolization (TARE) is a minimally invasive therapy combining embolization and radiation for cancer treatment. This meta-analysis compares radiation exposure, quality of life, and safety of the transradial (TRA) versus transfemoral (TFA) approaches in TARE for liver tumors.

MATERIALS AND METHODS

We searched PubMed, SCOPUS, Cochrane, EMBASE, and Web of Science for studies comparing TRA versus TFA in TARE for liver tumors. Our primary outcomes focused on various measures of patient radiation exposure, including procedure time, fluoroscopy time, air kerma, and dose-area product (DAP). For secondary outcomes, we evaluated safety parameters, such as overall pain experienced during the procedure, pain in the recovery room post-procedure, the incidence of adverse events, and the impact on quality of life. Study quality was assessed using Cochrane's ROB 2 tool for RCTs and the Newcastle-Ottawa scale for observational studies. Data analysis was conducted with REVMAN 5.4.1 software.

RESULTS

Six studies, comprising one RCT and five cohort studies with 1,209 patients, underwent comprehensive analysis. The aggregated findings revealed a significant reduction in procedure duration associated with TRA (MD =- 6.30, 95% CI [- 9.88, - 2.73], P = 0.005). However, no statistically significant differences were found between TRA and TFA groups concerning fluoroscopy time, recovery time, air kerma, DAP, pain in the recovery room, overall pain during the procedure, quality of life measuring mental health and physical function or adverse events.

CONCLUSION

TRA and TFA showed comparable results in TARE for liver tumors, but TRA offered a shorter procedure time. Further RCTs with larger samples are needed to confirm these findings. Future studies should assess long-term efficacy for a more complete evaluation.

The RAVI registry: prospective, multicenter study of radial access in embolization procedures - 30 days follow up

BACKGROUND

There is a lack of registry studies about transradial access (TRA) outcomes. This prospective registry evaluated the TRA and procedure outcomes of visceral embolizations performed via TRA with 30-day follow-up.

MATERIAL & METHODS

Prospective, multicenter registry included uterine fibroids (UFE), prostate artery (PAE), liver tumors (LT), and other hypervascular tumors (OHT) embolization performed in six US hospitals. Between February 2020 and January 2022, 99 patients underwent one radial artery visceral intervention (RAVI); 70 had UFE (70.7%), 16 PAE (16.2%), 7 LT (7.1%), and 6 OHT (6.1%). The mean age was 50.1 (±11.1) years, and 74/99 (74.7%) were females. The primary safety endpoints included hand ischemia, stroke, and death. Procedural success was defined as completing the intended procedure via radial artery (RA) access. Technical success was defined as the successful delivery of HydroPearl™ microspheres and complete embolization of the target vessel.

RESULTS

Procedural and technical successes were 100% and 97%, respectively. There was no stroke, hand ischemia, radial-to-femoral conversion, access-related serious adverse events, or clinically evident radial artery occlusion at 30 days. There were two deaths: one respiratory failure and one progression of liver disease. Minor RA-related adverse event included arterial spasm, hematoma, and post-procedure discomfort.

CONCLUSION

This prospective, multicenter, open-label registry confirmed the high safety profile and effectiveness of radial access in UFE, PAE, LT, and OHT embolization procedures without stroke, hand ischemia, or access-related serious adverse events at 30-day follow-up.

Distal radial artery access is a safe and feasible technique in the anatomical snuffbox for visceral intervention

Regarding the site of arterial access during the intervention, transracial intervention can reduce the risk of bleeding and vessel-related complications as well as improve patient comfort. Importantly, the distal radial artery (DRA) approach may reduce the incidence of radial artery occlusion and digital ischemia, but the feasibility and safety of DRA in performing subdiaphragmatic vascular interventions remain unclear. From January 2018 to December 2019, 106 patients were admitted to our department for visceral angiography and intervention by left distal radial artery accessing in an anatomical snuffbox. In total, 152 times of vascular interventions were performed during this period. Patients demographics, procedure details, technical success, and access site-related complications were recorded and evaluated. The mean age was 58.9 (range 22-86) years. Males accounted for 80.2%. Thirty-five patients (33%) had 2 or more procedures via the DRA approach. Technical success was achieved for 96.1% of procedures (146 cases) and 3.9% of cases failed to perform the intended procedure via the DRA approach (6 cases). The 4-Fr sheath was used in 86.8% of cases, and the 5 Fr sheath was used in the rest of the 13.2% of procedures. The rate of asymptomatic radial artery occlusion was 5.7% (6 of 106 patients). No patient suffered from distal limb ischemia after a long-time follow-up. Eight patients suffered postoperative local pain, transient numbness, or local bruised in the anatomical snuffbox without major complications. Patients with postoperative complications recovered quickly by using nonsteroidal anti-inflammatory drugs or without further treatment. Left distal radial artery access is safe and feasible as a new technique for visceral angiography and intervention.

Advances in Delivery of Selective Internal Radiation Therapy (SIRT): Economic and Logistical Effects of Same-Stay Work-Up and Procedure in the Treatment of Unresectable Liver Tumors in England

INTRODUCTION

Selective internal radiation therapy (SIRT) is a targeted method of treatment for unresectable liver tumors in which radiation therapy is directly delivered to the tumor(s) via the hepatic vasculature. Successful outcomes with SIRT are dependent on the specific vasculature of the liver and tumor, and the patient therefore needs to attend a "work-up" to map the hepatic vasculature prior to the SIRT procedure. Recent advances in SIRT delivery have enabled same-day or same-stay work-up and procedure, requiring only one hospital visit rather than two. We aimed to evaluate the economic, travel time, and transport-related environmental impact of a new brachytherapy device delivery program, the order-map-treat (OMT) program, in patients with unresectable hepatocellular carcinoma (HCC) in England.

METHODS

A healthcare resource group (HRG)-based analysis of costs from a national payer (Department of Health and Social Care, DHSC) perspective was conducted assuming that, with OMT, patients would have to attend hospital only once for both the SIRT work-up and procedure versus twice without OMT. Patient travel time and CO₂ emissions were then estimated by identifying the SIRT center closest to the centroid of each clinical commissioning group (CCG) and calculating straight-line distances with a "detour index" to capture the effect of indirect routes via road or rail.

RESULTS

It was estimated that 856 patients per annum would be eligible for SIRT treatment for unresectable HCC in England. OMT would be anticipated to save GBP 2842 per patient versus performing SIRT without OMT. Furthermore, across all patients with HCC eligible for SIRT in England, OMT would avoid 74,500 km of travel, 2299 h of travel time, and 13.9 metric tons of patient transport-related CO₂ emissions annually.

CONCLUSION

OMT reduces the number of hospital visits required for SIRT by 50%, resulting in financial savings from the DHSC perspective, time savings from the patient perspective, and reduced CO₂ emissions arising from patient transport.

Retrospective Comparative Study to Assess the Safety and Efficacy of Transradial Arterial Access for Hepatic Tumor Embolizations: A Single Operator Experience

Objectives To assess the efficacy and safety of transradial arterial access (TRA) for hepatic tumor embolizations and compare the outcomes between the TRA and transfemoral arterial access (TFA)

Materials and Methods A retrospective analysis of all consecutive hepatic tumor embolization procedures done through TFA or TRA by a single operator from November 2017 to April 2019 was performed. The procedural variables, including fluoroscopy time, radiation dose (reference air kerma [RAK]), conversion and complication rates, and patient preferences were recorded. The primary endpoint was technical success, which was defined as the successful completion of the embolization procedure. Procedural variables including radiation exposure and patient preferences, and complications were analyzed as secondary endpoints.

Results Out of 102 procedures in 90 patients, 44 were performed through TFA and the rest by TRA. A technical success rate of 98.2% and a crossover rate of 1.7% were recorded for TRA. There were no major vascular complications and similar rates of minor complications (8.6% for TRA, 2.3% for TFA; P = 0.055), without any clinical sequelae. After the initial learning curve, no significant differences for other procedural variables were noted between the two access sites. Faster ambulation were achieved following TRA (P < 0.055). All 12 patients who underwent repeat TACE after initial TRA chose this again over TFA.

Conclusions TRA is safe and effective for hepatic tumor embolization. Its safety and efficacy profile is comparable to that of TFA, with added improved patient comfort and faster ambulation.

Advances in Knowledge New catheter options and modifications of the existing techniques as explained in this article proved radial arterial access as a safe and effective alternative in hepatic arterial embolization.

Integrating machine learning to construct aberrant alternative splicing event related classifiers to predict prognosis and immunotherapy response in patients with hepatocellular carcinoma

Introduction: In hepatocellular carcinoma (HCC), alternative splicing (AS) is related to tumor invasion and progression. Methods: We used HCC data from a public database to identify AS subtypes by unsupervised clustering. Through feature analysis of different splicing subtypes and acquisition of the differential alternative splicing events (DASEs) combined with enrichment analysis, the differences in several subtypes were explored, cell function studies have also demonstrated that it plays an important role in HCC. Results: Finally, in keeping with the differences between these subtypes, DASEs identified survival-related AS times, and were used to construct risk proportional regression models. AS was found to be useful for the classification of HCC subtypes, which changed the activity of tumor-related pathways through differential splicing effects, affected the tumor microenvironment, and participated in immune reprogramming. Conclusion: In this study, we described the clinical and molecular characteristics providing a new approach for the personalized treatment of HCC patients.

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

PURPOSE

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

METHODS AND MATERIALS

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

RESULTS

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

CONCLUSIONS

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

Unusual Radiotracer Deposition to the Forearm After Intrahepatic Injection of 99mTc-Macroaggregated Albumin Using a Transradial Approach

ABSTRACT

Arterial mapping and 99mTc-macroaggregated albumin (99mTc-MAA) hepatic perfusion imaging are routinely performed before 90Y radioembolization of hepatic tumors. These procedures serve multiple purposes, including an anatomical survey of hepatic arterial anatomy, interrogating expected microsphere distribution to avoid nontargeted embolization during therapy, and evaluating for possible hepatopulmonary shunting. We present a case where 99mTc-MAA planar images revealed unexpected soft tissue uptake within the left forearm, an unexpected complication that may result from residual 99mTc-MAA in the catheter being expelled as the catheter is removed, which is particularly important to avoid during the 90Y radioembolization procedure given the risk for associated radionecrosis.

Prospective Study of Radial Artery Occlusion Following Transradial Arterial Access during IR Procedures

PURPOSE

To prospectively determine the rate of radial artery occlusion (RAO) in patients undergoing transradial access for intra-arterial interventions.

MATERIALS AND METHODS

Seventy-seven patients undergoing transradial access from August 2019 to March 2021 for 120 intra-arterial procedures (yttrium-90 mapping [n = 39] and radioembolization [n = 38], uterine artery embolization [n = 19], transarterial chemoembolization [n = 10], active bleed embolization [n = 8], angiomyolipoma embolization [n = 4], and other [n = 2]) were enrolled. The average patient age was 59 years ± 13.1 (range, 30-90 years), and 43 (55.8%) of the 77 patients were men. The patients underwent radial artery (RA) palpation, ultrasound evaluation, the Barbeau test, and the reverse Barbeau test prior to and following the intervention. Verapamil, nitroglycerin, and heparin were administered in a total of 114 (95%) of the 120 procedures prior to starting the procedure. The incidence of RAO and radial artery spasm (RAS) was calculated, and univariate logistic regression was performed to analyze the predictors of RAS.

RESULTS

The preprocedural RA diameter (3.0 mm ± 0.67) was not significantly different from the postprocedural RA diameter (3.0 mm ± 0.65, P = .904). The RAO rate was determined to be 0.8% (1/120), and this artery recanalized within 1 week. Due to the small number of occlusions, statistical analysis of predictors of RAO was not performed. The rate of RAS was 22.7% (27/119). None of the variables tested-including age, sex, RA diameter, initial versus repeat access, operator experience, and artery puncture technique-showed significant prediction for RAS. Patients were seen for follow-up after 111 (92.5%) of the 120 procedures.

CONCLUSIONS

Transradial access resulted in a <1% rate of RAO.

CIRSE Clinical Practice Manual

Background

Interventional radiology (IR) has come a long way to a nowadays UEMS-CESMA endorsed clinical specialty. Over the last decades IR became an essential part of modern medicine, delivering minimally invasive patient-focused care.

Purpose

To provide principles for delivering high quality of care in IR.

Methods

Systematic description of clinical skills, principles of practice, organizational standards and infrastructure needed for the provision of professional IR services.

Results

There are IR procedures for almost all body parts and organs, covering a broad range of medical conditions. In many cases IR procedures are the mainstay of therapy, e.g. in the treatment of hepatocellular carcinoma. In parallel the specialty moved from the delivery of a procedure towards taking care for a patient’s condition with the interventional radiologists taking ultimate responsibility for the patient’s outcomes.

Conclusions

The evolution from a technical specialty to a clinical specialty goes along with changing demands on how clinical care in IR is provided. The CIRSE Clinical Practice Manual provides interventional radiologist with a starting point for developing his or her IR practice as a clinician.

Transradial Embolization, an Underused Type of Uterine Artery Embolization Approach: A Systematic Review

Background and Objectives: The most utilized approach for the embolization of uterine arteries is the transfemoral path. However, the transradial approach (TRA) has been gaining popularity among cardiologic interventions in the last years but only few studies have shown its applicability in uterine myoma treatment. The objective of this paper is to assess the feasibility, safety and efficacy of TRA when compared with the transbrachial, transulnar or transfemoral approach (TFA) for uterine arteries embolization (UAE). Materials and methods: A systematic review of the literature that analyzes the TRA for UAE it was carried out, in order to assess its safety and effectiveness. It was systematically searched the literature (Google Scholar, PubMed/MEDLINE, Cochrane Library and Embase) using the words ''uterine artery embolization''/''uterine embolization'' and ''transradial''/''radial''. All the relevant papers published until March 2020 were retrieved and analyzed. Results: Ten studies were considered eligible for this topic. TRA is a comparable method with TFA for uterine artery embolization. Conclusions: These studies allowed us to conclude that TRA is as safe and efficient as TFA. Its advantages include few complications, shorter hospitalization period, and rapid mobilization but a steeper learning curve has the disadvantage of a longer learning curve compared to TFA. Yet, these findings are built on few reports and more research is needed.

A cost-utility analysis of SIR-Spheres Y-90 resin microspheres versus best supportive care in the treatment of unresectable metastatic colorectal cancer refractory to chemotherapy in the UK

BACKGROUND

Limited treatment options are available in chemotherapy-refractory or -intolerant metastatic colorectal cancer (mCRC). The objective of the present analysis was to evaluate the cost-utility of SIR-Spheres Y-90 resin microspheres relative to best supportive care (BSC) in the treatment of chemotherapy refractory mCRC from the perspective of the UK national healthcare payer.

METHODS

A cost-utility model was developed in Microsoft Excel to simulate transitions from progression-free survival to post-progression survival and death in patients with mCRC. Unit costs were captured in 2019 pounds sterling (GBP) based on the literature, formulary listings, and National Health Service (NHS) England reference costs. Future costs and effects were discounted at 3.5% per annum. A series of one-way sensitivity analyses, and probabilistic sensitivity analysis (PSA) were conducted.

RESULTS

The base case analysis showed that SIR-Spheres Y-90 resin microspheres would result in an increase in discounted quality-adjusted life years gained from 0.69 quality-adjusted life years (QALYs) to 1.50 QALYs, with an associated increase in cost from GBP 15,268 to GBP 34,168 yielding an incremental cost-utility ratio of GBP 23,435 per QALY. PSA showed that there would be a 56% likelihood that SIR-Spheres Y-90 resin microspheres would be cost-effective relative to BSC at a willingness-to-pay threshold of GBP 30,000 per QALY gained.

CONCLUSIONS

This cost-utility analysis showed that, relative to BSC, SIR-Spheres Y-90 resin microspheres would be a cost-effective treatment option for patients with mCRC in the UK setting from the national healthcare payer perspective.

Clinical experience with distal transradial access for endovascular treatment of various noncoronary interventions in a multicenter study

Background

Transradial access is a well-known alternative to conventional transfemoral access for interventional procedures. Recently, transradial access through the “snuffbox”, which lies in the radial dorsal aspect of the hand, has been introduced as a new technique with positional versatility. In this study, we aimed to evaluate the clinical feasibility and safety of distal transradial access for interventional procedures in a retrospective, multicenter study.

Material & methods

Distal transradial access was attempted in 46 patients (36 men and 10 women; mean age, 64 years) who underwent 47 consecutive procedures from January 2018 to December 2019. Procedures included chemoembolization (19/47, 40.4%), bronchial artery embolization (7/47, 14.9%), renal intervention (3/47, 6.4%), arteriovenous fistula angioplasty (7/47, 14.9%), subclavian artery stenting (5/47, 10.6%), other embolization (5/47, 10.6%), and uterine artery embolization (1/47, 2.1%). We recorded the success rate of the procedures, complications, and postprocedural hemostasis time during the follow-up period.

Results

The technical success of distal transradial access without major complications was 97.9% (46/47). Of the 46 patients, one patient (2.2%) had a minor complication, which was a thrombotic segmental occlusion of the distal radial artery. Of the enrolled patients, only one patient did not complete the transradial access procedure via the snuffbox because the left proximal subclavian artery was occluded and a crossover to conventional transfemoral access was performed. The mean postprocedural hemostasis time was 131.7 minutes (range, 120–360 minutes).

Conclusion

Distal transradial access can be a valid option for the endovascular treatment of various noncoronary interventions with technical feasibility and safety.

Pre-operative endovascular occlusion for unresectable metastatic carcinoid tumor: technique and initial results

PURPOSE

Surgery is the only curative therapy for carcinoid patients; however, many are unresectable due to direct involvement of the superior mesenteric artery (SMA) branches. In these patients, we sought to improve surgical outcomes via arterial skeletonization of the SMA prior to surgical resection.

MATERIALS AND METHODS

After left radial access, the SMA was catheterized, angiography was performed, and balloon occlusion was achieved in the tumor vessel. Following balloon occlusion of the affected artery, patients were assessed for symptoms of ischemia and angiographic evidence of distal perfusion via collaterals. If patients tolerated occlusion, an endovascular plug was deployed in the affected artery; if not, the procedure was terminated. The next day, all patients underwent exploratory laparotomy and surgical resection of tumor and bowel.

RESULTS

The procedure was performed 15 times on 14 patients. 13 out of 15 procedures went to embolization, while the other 2 proceeded to surgery without plug deployment. One of the embolized patients had serious post-surgical complications, while both non-embolized patients developed complications including short bowel syndrome and ischemic colitis. Length of stay between embolized and non-embolized patients was equal, but re-admittance within 30 days was 7.7% in the embolized group and 100% in the non-embolized group.

DISCUSSION

Our initial experience demonstrates feasibility and safety of deploying plugs within branches of the SMA prior to surgical resection and improved surgical outcomes. Palpation of the plug assisted in surgical resection. We have demonstrated that pre-operative endovascular occlusion is a safe, practical procedure, which aids surgical resection of mesenteric carcinoid disease.

Safety and Feasibility of Transradial Access in Patients Presenting With Traumatic Injuries: A Single Urban Center Experience

PURPOSE

To evaluate the efficacy, safety, and feasibility of transradial approach (TRA) for endovascular management of traumatic bleeding.

MATERIALS AND METHODS

A retrospective review was performed at a single level 1 trauma institution from August 2018 to July 2019. Patients presented to the interventional radiology department who were intended to be treating using TRA for the management of trauma-induced bleeding were selected. Demographics, indication for embolization, embolization site, preprocedural labs, hemodynamic stability, technical success, and complications were recorded.

RESULTS

Transradial approach was attempted in 29 (74.4%) of the 39 patients identified by operators who prefer TRA. Four patients received treatment using TRA on 2 separate occasions, for a total of 33 procedures completed with a technical success of 97% (32/33). Transradial approach was safely completed in 9 patients (27.3%) with preprocedural hemodynamically unstable status. For the 10 patients who received treatment via a transfemoral approach (TFA), traumatic disfiguration of the left upper extremity, preexisting arterial lines placed by the trauma team, and external iliac artery injuries requiring covered stent placement were the most common indications for TFA over TRA. There were no procedural or access site-related complications.

CONCLUSION

Transradial approach for the endovascular management of bleeding in a trauma setting is safe and effective with a high technical success rate and no complications.

Operator learning curve for transradial liver cancer embolization: implications for the initiation of a transradial access program

PURPOSE

We aimed to analyze transradial access (TRA) learning curve on patients undergoing hepatic chemoembolization, investigating the relationship between procedural volumes and various benchmarks of procedural success.

METHODS

We enrolled 60 consecutive patients who received two unilobar hepatic chemoembolizations within a 4-week interval performed by a single interventional radiologist, highly-trained in conventional transfemoral access (TFA) procedures, but without any previous practical experience in TRA procedures and with a preliminary 2-day theoretical training only. Consecutive patients were prospectively enrolled and analyzed in 3 groups: A (cases 1 to 20), B (cases 21 to 40), and C (cases 41 to 60). All patients underwent one hepatic chemoembolization using TRA and the other one using TFA in random order. All TFA procedures performed by the same operator in the same series of patients were considered as the control group. Primary endpoint was to analyze the relationship between TRA procedure operator experience and benchmarks of procedural success, to define the optimal procedural learning curve.

RESULTS

Technical success was obtained in all patients, with a crossover rate (radial to femoral access) of 0%. An association between incremental TRA operator experience (in terms of performed procedures) and decrease of preparation, puncture, fluoroscopy, and total examination times was observed. Similarly, inverse associations between incremental TRA operator experience and contrast medium (CM) volumes (P < 0.001) and radiation dose (RD) values (in terms of RAK - Reference Air Kerma) (P < 0.001) were also observed. Compared with TFA, CM volumes and RD values were significantly higher only in group A (cases 1-20). Procedure success remained high in all TRA groups and no significant association between TRA incremental experience and postprocedural outcomes was found. Higher postprocedural complaints at the access route and more limitations in performing basic activities were recorded after TFA vs. TRA (P < 0.001).

CONCLUSION

TRA catheterizations can be safely performed in patients treated for liver cancer embolization after a relatively short training in controlled conditions and with a better performance in comparison with TFA. Operator proficiency improves with greater TRA experience, with a threshold needed to overcome the learning curve represented by about 20 procedures.

Radioembolization for the Treatment of Primary and Metastatic Liver Cancers

Radioembolization using ⁹⁰Y microspheres (glass or resin) has been introduced as an effective intraarterial therapy for unresectable primary and metastatic liver cancers. Although the basic therapeutic effect of chemoembolization results from ischemia, the therapeutic efficacy of radioembolization comes from radiation. Furthermore, compared with surgical resection and local ablation therapy, radioembolization is available with less limitation on the sites or number of liver cancers. The radioisotope ⁹⁰Y is a β-radiation emitter without γ-radiation, with the emission of secondary bremsstrahlung photons and small numbers of positrons. Administration of ⁹⁰Y microspheres into the hepatic artery can deliver a high dose of radiation selectively to the target tumor with limited radiation exposure to the surrounding normal parenchyma, and has low systemic toxicity. In general, radioembolization has been considered for patients with unresectable primary or metastatic liver-only or liver-dominant cancers with no ascites or other clinical signs of liver failure, life expectancy of > 12 weeks, and good performance status. Here, we review the current radioactive compounds, pretreatment assessment, and indications for radioembolization in patients with hepatocellular carcinoma, intrahepatic cholangiocarcinoma, and liver metastases from colorectal cancer.

Current perspectives on the immunosuppressive tumor microenvironment in hepatocellular carcinoma: challenges and opportunities

Incidence of hepatocellular carcinoma (HCC) is on the rise due to the prevalence of chronic hepatitis and cirrhosis. Although there are surgical and chemotherapy treatment avenues the mortality rate of HCC remains high. Immunotherapy is currently the new frontier of cancer treatment and the immunobiology of HCC is emerging as an area for further exploration. The tumor microenvironment coexists and interacts with various immune cells to sustain the growth of HCC. Thus, immunosuppressive cells play an important role in the anti-tumor immune response. This review will discuss the current concepts of immunosuppressive cells, including tumor-associated macrophages, marrow-derived suppressor cells, tumor-associated neutrophils, cancer-associated fibroblasts, and regulatory T cell interactions to actively promote tumorigenesis. It further elaborates on current treatment modalities and future areas of exploration.

Radical Radial: Pearls and Pitfalls in Transradial Yttrium-90 Liver-Directed Therapy

The frequency of transradial access in interventional radiology has been steadily increasing, including for yttrium-90 (Y-90) selective internal radiation therapy to treat hepatic malignancies. The aim of this article is to detail an optimized approach to transradial Y-90 (TRY-90), showing it to be a safe and feasible first-line approach to hepatic selective internal radiation therapy. Salient preprocedural considerations to enable appropriate patient selection for TRY-90 are discussed and a detailed equipment list is provided. The article will describe our approach to TRY-90 in addition to a discussion around technical pearls and pitfalls.

Patient Experience and Preference in Transradial versus Transfemoral Access during Transarterial Radioembolization: A Randomized Single-Center Trial

PURPOSE

To determine patient preference for transradial access (TRA) or transfemoral access (TFA) after experiencing both.

MATERIALS AND METHODS

A randomized controlled crossover trial was conducted at a single institution. Thirty patients with hepatocellular carcinoma undergoing mapping and transarterial radioembolization (TARE) were enrolled to experience 1 TRA and 1 TFA procedure each, with randomization of which access approach was experienced first. Surveys assessing pain and quality of life (QOL) were administered after each procedure. Access site preference was collected after completion of both procedures.

RESULTS

Twenty-two subjects (73.3%) preferred TRA, 4 (13.3%) preferred TFA, and 4 (13.3%) had no preference; 14 (46.7%) reported bruising after TRA, and 17 (53.3%) reported bruising after TFA. TRA was associated with significantly lower pain scores overall during the procedure, at the access site during the procedure, and in the recovery room compared with TFA (2.0 vs 2.9, P = .0046; 2.0 vs 3.0, P = .0004; 2.1 vs 2.9, P = .0357). Pain score after discharge was not significantly different (1.4 vs 1.5, P = .4235). QOL scores were not significantly different between TRA and TFA. No significant differences were found for fluoroscopy time, air kerma, dose-area product, or procedure time between TRA and TFA for either mapping (P = .1442, P = .5871, P = .6667, P = .6131) or radioembolization (P = .8574, P = .2344, P = .1119, P =.8474). For radioembolizations, TRA had significantly shorter recovery times compared with TFA (108 min vs 153 min, P = .0193).

CONCLUSIONS

Patients exhibited a strong preference for TRA. With TRA, patients experienced less periprocedural pain and shorter recovery times without significant differences in radiation exposure or procedure length.

Prone transradial catheterization for combined single-session endovascular and percutaneous interventions: approach, technical success, safety, and outcomes in 15 patients

PURPOSE

We aimed to report approach, safety, technical success, and clinical outcomes of prone trans- radial access (PTRA) and demonstrate feasibility for procedures requiring simultaneous arterial intervention and prone percutaneous access.

METHODS

Fifteen patients underwent PTRA, seven females (47%) and eight males (53%), mean age of 55 years (range, 19-78 years). All patients underwent PTRA for combined transarterial and posterior-approach percutaneous interventions. Variables included sheath size (French, F), type of anesthesia, arterial intervention technical success, posterior-approach percutaneous intervention technical success, estimated blood loss (mL), fluoroscopy and procedure time, complications, and follow-up.

RESULTS

Mean sheath size was 4 F (range, 4-6 F; SD = 0.5). Arterial interventions included transarterial embolization of renal (n=6), hepatic (n=2), and pelvic vessels (n=2), diagnostic arteriography (n=4), and embolization of an arteriovenous malformation (n=1). Posterior-approach intervention technical success was 100% (15/15). PTRA technical success was 100% (15/15). Posterior-approach percutaneous interventions included retroperitoneal (n=5) and pelvic (n=1) mass biopsies, nephrostomy tube placement (n=2), cryoablation of pelvic (n=2) and renal (n=1) masses, sclerotherapy of arteriovenous malformations (n=2), foreign body removal from the renal collecting system (n=2), ablation of a renal tumor (n=1), intracavitary injection of pulmonary mycetoma (n=1), and ablation and cementoplasty of a vertebral body tumor (n=1). The biopsies were diagnostic (6/6). There were no minor or major access-site complications.

CONCLUSION

PTRA is a safe and feasible method for performing combined arterial and posterior approach percutaneous interventions without the need for repositioning.

Treatment of Primary Liver Tumors and Liver Metastases, Part 1: Nuclear Medicine Techniques

⁹⁰Y radioembolization is an increasingly used treatment for both primary and metastatic malignancy in the liver. Understanding the biophysical properties, dosing concerns, and imaging appearance of this treatment is important for interventional radiologists and nuclear medicine physicians to provide important therapy. ⁹⁰Y radioembolization is efficacious and safe, although the possibility of complications does exist. This article provides a comprehensive in-depth discussion about the indications for ⁹⁰Y radioembolization, reviews the role of preprocedural angiography and ^99mTc-macroaggregated albumin scans, illustrates different dosing techniques, compares and contrasts resin and glass microspheres, and describes potential complications.

Patient Radiation Exposure in Transradial versus Transfemoral Yttrium-90 Radioembolization: A Retrospective Propensity Score-Matched Analysis

PURPOSE

To compare differences in patient radiation exposure (PRE) during transarterial yttrium-90 (⁹⁰Y) radioembolization (TARE) between transradial access (TRA) and transfemoral access (TFA).

MATERIALS AND METHODS

A total of 810 consecutive first-time TARE procedures in patients from 2013 to 2017 were retrospectively reviewed. A propensity score-matching (PSM) analysis matched TRA and TFA groups on the basis of patient age, sex, weight, height, cancer type, ⁹⁰Y microsphere type, and number of previous procedures from the same and opposite approaches. Matched groups were then compared by PRE measures fluoroscopy time (FT), dose-area product (DAP), and cumulative air kerma (AK). Effect size for each PRE measure was calculated.

RESULTS

Before PSM, TRA and TFA groups differed significantly in mean age, weight, and number of previous procedures from the same and opposite approach (all P < .05). After PSM, each group consisted of 302 procedures (overall, n = 604) and no longer differed in any procedure performed before surgery measure. TRA did not differ from the matched TFA group regarding median FT (9.50 vs 9.40 minutes, P = .095), median DAP (67,066 vs 67,219 mGy·cm²; P = .19), or median AK (323.63 vs 248.46 mGy; P = .16). Effect sizes were 0.068, 0.054, and 0.110 for FT, DAP, and AK, respectively.

CONCLUSIONS

No statistical differences were found for PRE measures between the matched TRA and TFA approach groups. Furthermore, practical effect sizes were considered to be small for AK and less than small for FT and DAP, and therefore, any differences in PRE between the radial and femoral approaches for TARE are minor and unlikely to be noticeable in everyday clinical practice.

Prone Transradial Catheterization for Combined Single-Session Transarterial Embolization and Percutaneous Posterior Approach Cryoablation of Solid Neoplasms

Transradial access (TRA) has been associated with improved post-procedure hemostasis and patient satisfaction, and decreased hemorrhagic complications, sedation requirements, recovery times, and procedure-related costs when compared with traditional transfemoral catheterization. Supine TRA has been described for the treatment of myocardial infarctions, aortoiliac and femoropopliteal stenoses, and a variety of neoplasms. This original research describes prone transradial catheterization to facilitate combined single-session transarterial embolization and percutaneous cryoablation of solid neoplasms from a posterior approach without repositioning. Prone TRA access, transarterial embolization, and percutaneous cryoablation were successful in all cases described. Mean procedure time was 210 min (range: 140-250 min). One minor complication, transient bacteremia which responded to antibiotics, was reported. No major complications occurred.