Safety and feasibility of establishing an adjuvant hepatic artery infusion program

BACKGROUND

Hepatic artery infusion (HAI) is less frequently used in the adjuvant setting for resectable colorectal liver metastasis (CRLM) due to concerns regarding toxicity. Our objective was to evaluate the safety and feasibility of establishing an adjuvant HAI program.

METHODS

Patients who underwent HAI pump placement between January 2019 and February 2023 for CRLM were identified. Complications and HAI delivery were compared between patients who received HAI in the unresectable and adjuvant settings.

RESULTS

Of 51 patients, 23 received HAI for unresectable CRLM and 28 in the adjuvant setting. Patients with unresectable CRLM more commonly had bilobar disease (n = 23/23 vs n = 18/28, p < 0.01) and more preoperative liver metastases (median 10 [IQR 6-15] vs 4 [IQR 3-7], p < 0.01). Biliary sclerosis was the most common complication (n = 2/23 vs n = 4/28); however, there were no differences in postoperative or HAI-specific complications. In the most recent two years, 0 patients in the unresectable group vs 2 patients in the adjuvant group developed biliary sclerosis. All patients were initiated on HAI with no difference in treatment times or dose reductions.

CONCLUSION

Adjuvant HAI is safe and feasible for patients with resectable CRLM. HAI programs can carefully consider including patients with resectable CRLM if managed by an experienced multidisciplinary team with quality assurance controls in place.

Integration of Ethanol and the Immune Modulator Curcumin for Immunoablation of Hepatocellular Carcinoma

PURPOSE

To investigate immuno-ethanol ablation using an ethanol and immune adjuvant formulation as a potent immunoablation approach that can achieve an enhanced anticancer effect in the treatment of hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Ethanol concentration- and exposure time-dependent cellular responses were investigated. Curcumin was combined with ethanol as an immunoablation agent. Cellular uptake of curcumin, cancer cell killing, and inflammatory markers of ethanol-curcumin treatment were characterized. To evaluate the potential in vivo anticancer immunity of ethanol-curcumin treatment, each right and left lobe of rat liver was concurrently inoculated with N1S1 HCC cells and a mixture of treated N1S1 cells (ethanol only or ethanol-curcumin) in Sprague Dawley rats (each group: 5 rats; control: nontreated N1S1 cells). Tumor growth and immune response were characterized with 7T magnetic resonance (MR) imaging, flow cytometry analysis, and immunohistology.

RESULTS

An optimized ethanol-curcumin (10% ethanol and 0.5% weight/volume (w/v) curcumin solution) treatment contributed to an enhanced cellular uptake of curcumin, increased cancer cell killing, and decreased inflammatory reaction. Ethanol-curcumin-treated N1S1 cell implantation in the rat liver demonstrated N1S1 HCC tumor rejection. The secondary tumor growth by nontreated N1S1 cell inoculation was significantly suppressed at the same time. Activated anticancer immunity was evidenced by significantly increased CD8+ T cell infiltration (3.5-fold) and CD8+-to-regulatory T cell ratio (4.5-fold) in the experimental group compared with those in the control group.

CONCLUSIONS

Enhanced anticancer effect of immuno-ethanol ablation could be achieved with ethanol-curcumin agent. The results underscore the importance of optimized immunoablation therapeutic procedures for enhanced therapeutic outcomes.

Radiology in the immune checkpoint inhibitor era

The field of oncology has undergone rapid changes following the introduction of immunotherapies and biologics. However, these changes have also created new roles for radiology in both diagnosis and treatment. Our article addresses the evolving role of radiology in the immune checkpoint inhibitor era of oncology. With the progression of new immunotherapies for cancer, imaging paradigms and image guided therapy options have changed. Multidisciplinary oncology teams should be aware of these opportunities for collaboration.

Safety and Diagnostic Efficacy of Image-Guided Biopsy of Small Renal Masses

INTRODUCTION

Image-guided renal mass biopsy is gaining increased diagnostic acceptance, but there are limited data concerning the safety and diagnostic yield of biopsy for small renal masses (≤4 cm). This study evaluated the safety, diagnostic yield, and management after image-guided percutaneous biopsy for small renal masses.

METHODS

A retrospective IRB-approved study was conducted on patients who underwent renal mass biopsy for histopathologic diagnosis at a single center from 2015 to 2021. Patients with a prior history of malignancy or a renal mass >4 cm were excluded. Descriptive statistics were used to summarize patient demographics, tumor size, the imaging modality used for biopsy, procedure details, complications, pathological diagnosis, and post-biopsy management. A biopsy was considered successful when the specimen was sufficient for diagnosis without need for a repeat biopsy. Complications were graded according to the SIR classification of adverse events. A chi-squared test (significance level set at p ≤ 0.05) was used to compare the success rate of biopsies in different lesion size groups.

RESULTS

A total of 167 patients met the inclusion criteria. The median age was 65 years (range: 26-87) and 51% were male. The median renal mass size was 2.6 cm (range: one-four). Ultrasound was solely employed in 60% of procedures, CT in 33%, a combination of US/CT in 6%, and MRI in one case. With on-site cytopathology, the median number of specimens obtained per procedure was four (range: one-nine). The overall complication rate was 5%. Grade A complications were seen in 4% (n = 7), consisting of perinephric hematoma (n = 6) and retroperitoneal hematoma (n = 1). There was one grade B complication (0.5%; pain) and one grade D complication (0.5%; pyelonephritis). There was no patient mortality within 30 days post-biopsy. Biopsy was successful in 88% of cases. A sub-group analysis showed a success rate of 85% in tumors <3 cm and 93% in tumors ≥3 cm (p = 0.01). Pathological diagnoses included renal cell carcinoma (65%), oncocytoma (18%), clear cell papillary renal cell tumors (9%), angiomyolipoma (4%), xanthogranulomatous pyelonephritis (1%), lymphoma (1%), high-grade papillary urothelial carcinoma (1%), and metanephric adenoma (1%), revealing benign diagnosis in 30% of cases. The most common treatment was surgery (40%), followed by percutaneous cryoablation (22%). In total, 37% of patients were managed conservatively, and one patient received chemotherapy.

CONCLUSION

This study demonstrates the safety and diagnostic efficacy of image-guided biopsy of small renal masses. The diagnostic yield was significantly higher for masses 3-4 cm in size compared to those <3 cm. The biopsy results showed a high percentage of benign diagnoses and informed treatment decisions in most patients.

Radiation Segmentectomy for Hepatocellular Carcinoma

The application of trans-arterial radioembolization (TARE) with Yttrium-90, historically a palliative treatment option for patients with advanced hepatocellular carcinoma (HCC), is evolving. Radiation segmentectomy (RADSEG), the segmental delivery of an ablative radiation dose, is a treatment option for patients with earlier-stage HCC. This review presents an in-depth exploration of RADSEG, emphasizing its technical considerations, dosimetry advancements, and patient selection. The integration of RADSEG into the Barcelona Clinic Liver Cancer (BCLC) paradigm will be highlighted. RADSEG outcomes concerning safety and efficacy will be explored and compared with traditional locoregional cancer treatments like trans-arterial chemoembolization (TACE), percutaneous thermal ablation, and surgical resection, with an eye on future directions and considerations.

Preclinical Development and Validation of Translational Temperature Sensitive Iodized Oil Emulsion Mediated Transcatheter Arterial Chemo-Immuno-Embolization for the Treatment of Hepatocellular Carcinoma

Herein a practical strategy for augmenting immune activation in transcatheter arterial chemoembolization (TACE) of hepatocellular carcinoma (HCC) is presented. Pluronic F127 (PF127) is incorporated with Lipiodol (LPD) to achieve safe and effective delivery of therapeutic agents during transcatheter intra-arterial (IA) local delivery. Enhanced emulsion stability, IA infusion, embolic effect, safety, pharmacokinetics, and tumor response of Doxorubicin loaded PF127-LPD (Dox-PF127-LPD) for TACE in both in vitro and in vivo preclinical VX2 liver cancer rabbit model and N1S1 HCC rat model are demonstrated. Then, transcatheter arterial chemo-immuno-embolization (TACIE) combining TACE and local delivery of immune adjuvant (TLR9 agonist CpG oligodeoxynucleotide) is successfully performed using CpG-loaded Dox-PF127-LPD. Concurrent and safe local delivery of CpG and TACE during TACIE demonstrate leveraged TACE-induced immunogenic tumor microenvironment and augment systemic anti-tumor immunity in syngeneic N1S1 HCC rat model. Finally, the broad utility and enhanced therapeutic efficacy of TACIE are validated in the diethylnitrosamine-induced rat HCC model. TACIE using clinically established protocols and materials shall be a convenient and powerful therapeutic approach that can be translated to patients with HCC. The robust anti-cancer immunity and tumor regression of TACIE, along with its favorable safety profile, indicate its potential as a novel localized combination immunotherapy for HCC treatment.

Chemical Shift MRI Monitoring of Chemoembolization Delivery for Hepatocellular Carcinoma: Multicenter Feasibility of Initial Clinical Translation

Purpose To demonstrate the feasibility of using chemical shift fat-water MRI methods to visualize and measure intrahepatic delivery of ethiodized oil to liver tumors following conventional transarterial chemoembolization (cTACE). Materials and Methods Twenty-eight participants (mean age, 66 years ± 8 [SD]; 22 men) with hepatocellular carcinoma (HCC) treated with cTACE were evaluated with follow-up chemical shift MRI in this Health Insurance Portability and Accountability Act-compliant prospective, institutional review board-approved study. Uptake of ethiodized oil was evaluated at 1-month follow-up chemical shift MRI. Measurements of tumor size (MRI and CT), attenuation and enhancement (CT), fat content percentage, and tumor:normal ratio (MRI) were compared by lesion for responders versus nonresponders, as assessed with modified Response Evaluation Criteria in Solid Tumors and European Association for the Study of the Liver (EASL) criteria. Adverse events and overall survival by the Kaplan-Meier method were secondary end points. Results Focal tumor ethiodized oil retention was 46% (12 of 26 tumors) at 24 hours and 47% (18 of 38 tumors) at 1 month after cTACE. Tumor volume at CT did not differ between EASL-defined responders and nonresponders (P = .06). Tumor ethiodized oil volume measured with chemical shift MRI was statistically significantly higher for EASL-defined nonresponders (P = .02). Doxorubicin dosing (P = .53), presence of focal fat (P = .83), and a combined end point of focal fat and low doxorubicin dosing (P = .97) did not stratify overall survival after cTACE. Conclusion Chemical shift MRI allowed for assessment of tumor delivery of ethiodized oil out to 1 month after cTACE in participants with HCC and demonstrated tumor ethiodized oil volume as a potential tool for stratification of tumor response by EASL criteria. Keywords: MRI, Chemical Shift Imaging, CT, Hepatic Chemoembolization, Ethiodized Oil Clinicaltrials.gov registration no.: NCT02173119 Supplemental material is available for this article. © RSNA, 2023.

Yttrium-90 Radiation Segmentectomy in Oligometastatic Secondary Hepatic Malignancies

PURPOSE

To evaluate the safety and efficacy of yttrium-90 (⁹⁰Y) radiation segmentectomy (RS) in the treatment of oligometastatic secondary hepatic malignancies.

MATERIALS AND METHODS

This institutional review board-approved retrospective study evaluated 16 patients with oligometastatic secondary hepatic malignancies who were treated with RS. The median patient age was 61.9 years (range, 38.6-85.7 years). Of the 16 patients, 11 (68.8%) presented with solitary lesions. The median index tumor size was 3.1 cm (95% CI, 2.3-3.9). Primary outcomes were evaluation of clinical and biochemical toxicities using National Cancer Institute Common Terminology Criteria for Adverse Events, version 5.0, and imaging response using Response Evaluation Criteria in Solid Tumors, version 1.1. Secondary outcomes were time to progression (TTP) and overall survival (OS) as estimated by the Kaplan-Meier method.

RESULTS

Clinical Grade 3 toxicities were limited to 1 (6.7%) patient who experienced fatigue, abdominal pain, nausea, and vomiting. Biochemical Grade 3 toxicities occurred in 1 (6.7%) patient who experienced lymphopenia. No Grade 4 clinical or biochemical toxicities were identified. Disease control was achieved in 14 (93.3%) of 15 patients. The median TTP of the treated tumor was 72.9 months (95% CI, 11.2 to no estimate). The median OS was 60.9 months (95% CI, 24.7 to no estimate).

CONCLUSIONS

⁹⁰Y RS displayed an excellent safety profile and was effective in achieving a high disease control rate in the treatment of oligometastatic secondary hepatic malignancies.

Predicting the Safety and Effectiveness of Inferior Vena Cava Filters (PRESERVE): Outcomes at 12 months

OBJECTIVE

To determine the safety and effectiveness of vena cava filters (VCFs).

METHODS

A total of 1429 participants (62.7 ± 14.7 years old; 762 [53.3% male]) consented to enroll in this prospective, nonrandomized study at 54 sites in the United States between October 10, 2015, and March 31, 2019. They were evaluated at baseline and at 3, 6, 12, 18, and 24 months following VCF implantation. Participants whose VCFs were removed were followed for 1 month after retrieval. Follow-up was performed at 3, 12, and 24 months. Predetermined composite primary safety (freedom from perioperative serious adverse events [AEs] and from clinically significant perforation, VCF embolization, caval thrombotic occlusion, and/or new deep vein thrombosis [DVT] within 12-months) and effectiveness (composite comprising procedural and technical success and freedom from new symptomatic pulmonary embolism [PE] confirmed by imaging at 12-months in situ or 1 month postretrieval) end points were assessed.

RESULTS

VCFs were implanted in 1421 patients. Of these, 1019 (71.7%) had current DVT and/or PE. Anticoagulation therapy was contraindicated or had failed in 1159 (81.6%). One hundred twenty-six (8.9%) VCFs were prophylactic. Mean and median follow-up for the entire population and for those whose VCFs were not removed was 243.5 ± 243.3 days and 138 days and 332.6 ± 290 days and 235 days, respectively. VCFs were removed from 632 (44.5%) patients at a mean of 101.5 ± 72.2 days and median 86.3 days following implantation. The primary safety end point and primary effectiveness end point were both achieved. Procedural AEs were uncommon and usually minor, but one patient died during attempted VCF removal. Excluding strut perforation greater than 5 mm, which was demonstrated on 31 of 201 (15.4%) patients' computed tomography scans available to the core laboratory, and of which only 3 (0.2%) were deemed clinically significant by the site investigators, VCF-related AEs were rare (7 of 1421, 0.5%). Postfilter, venous thromboembolic events (none fatal) occurred in 93 patients (6.5%), including DVT (80 events in 74 patients [5.2%]), PE (23 events in 23 patients [1.6%]), and/or caval thrombotic occlusions (15 events in 15 patients [1.1%]). No PE occurred in patients following prophylactic placement.

CONCLUSIONS

Implantation of VCFs in patients with venous thromboembolism was associated with few AEs and with a low incidence of clinically significant PEs.

Predicting the Safety and Effectiveness of Inferior Vena Cava Filters (PRESERVE): Outcomes at 12 months

OBJECTIVE

To determine the safety and effectiveness of vena cava filters (VCFs).

METHODS

A total of 1429 participants (62.7 ± 14.7 years old; 762 [53.3% male]) consented to enroll in this prospective, nonrandomized study at 54 sites in the United States between October 10, 2015, and March 31, 2019. They were evaluated at baseline and at 3, 6, 12, 18, and 24 months following VCF implantation. Participants whose VCFs were removed were followed for 1 month after retrieval. Follow-up was performed at 3, 12, and 24 months. Predetermined composite primary safety (freedom from perioperative serious adverse events [AEs] and from clinically significant perforation, VCF embolization, caval thrombotic occlusion, and/or new deep vein thrombosis [DVT] within 12-months) and effectiveness (composite comprising procedural and technical success and freedom from new symptomatic pulmonary embolism [PE] confirmed by imaging at 12-months in situ or 1 month postretrieval) end points were assessed.

RESULTS

VCFs were implanted in 1421 patients. Of these, 1019 (71.7%) had current DVT and/or PE. Anticoagulation therapy was contraindicated or had failed in 1159 (81.6%). One hundred twenty-six (8.9%) VCFs were prophylactic. Mean and median follow-up for the entire population and for those whose VCFs were not removed was 243.5 ± 243.3 days and 138 days and 332.6 ± 290 days and 235 days, respectively. VCFs were removed from 632 (44.5%) patients at a mean of 101.5 ± 72.2 days and median 86.3 days following implantation. The primary safety end point and primary effectiveness end point were both achieved. Procedural AEs were uncommon and usually minor, but one patient died during attempted VCF removal. Excluding strut perforation greater than 5 mm, which was demonstrated on 31 of 201 (15.4%) patients' computed tomography scans available to the core laboratory, and of which only 3 (0.2%) were deemed clinically significant by the site investigators, VCF-related AEs were rare (7 of 1421, 0.5%). Postfilter, venous thromboembolic events (none fatal) occurred in 93 patients (6.5%), including DVT (80 events in 74 patients [5.2%]), PE (23 events in 23 patients [1.6%]), and/or caval thrombotic occlusions (15 events in 15 patients [1.1%]). No PE occurred in patients following prophylactic placement.

CONCLUSIONS

Implantation of VCFs in patients with venous thromboembolism was associated with few AEs and with a low incidence of clinically significant PEs.

Radioembolization for Intermediate Stage Hepatocellular Carcinoma Maintains Liver Function and Permits Systemic Therapy at Progression

PURPOSE

To assess the liver function trends in intermediate-stage (BCLC B) patients undergoing Y90-radioembolization (TARE) in response to a growing concern that that liver-directed therapies negatively impact liver function and prevent HCC patients from systemic therapy candidacy.

METHODS

A prospectively acquired HCC/TARE database (2004-2017) was retrospectively reviewed. BCLC B/Child-Pugh (CP)-A patients with laboratory tests/imaging at baseline and for at least 1-month post-TARE were included. Follow-ups were at 3-month intervals. CP was assessed at each timepoint. Endpoints included time-to-persistent CP-B, time-to-CP-C, and median overall survival (OS). Time-to-endpoint analyses were performed using Kaplan-Meier method.

RESULTS

74 patients (80% males with mean age 63 years) with mostly (62%) bilobar disease underwent 186 TARE treatments (median 2 (range[r]: 1-8)). Median time-to-2^nd TARE was 2.3 months (r: 1.7-6.4), median time-to-3^rd and 4^th TARE was 11.7 (r: 7.5 - 15) and 17.3 (r: 11.5-23.1) months, respectively. 43 patients (58%) developed persistent CP-B at median time-to-persistent CP-B of 15.4 Months (CI: 9.2 - 25.3) months. 17 (23%) became CP-C at a median time-to-CP-C of 87.2 (CI: 39.8 - 136.1) months. Median OS censored to transplantation was 30.4 (CI: 22.7-37.4) months. On univariate and multivariate analyses baseline albumin was significant prognosticator of OS, while baseline albumin and bilirubin were significant prognosticators of time-to-persistent CP-B, and time-to-CP-C.

CONCLUSION

In CP-A patients undergoing TARE for BCLC B HCC, the median time-to persistent CP-B is 15.4 months. These findings indicate that patients would be candidates for systemic therapy at progression if indicated.

Clinical care in hepatocellular carcinoma: A mixed methods assessment of experiences and challenges of oncology professionals

INTRODUCTION

Healthcare providers (HCPs) may face numerous dilemmas in optimally screening, diagnosing, and treating patients with, and/or at risk for, hepatocellular carcinoma (HCC). This study aimed to achieve a greater understanding of the challenges in HCC care which in turn could delineate HCP educational opportunities within this oncologic sub-specialty.

METHODS

A mixed-methods approach was used to identify practice gaps and clinical barriers experienced by US-based medical oncologists, hepatologists, oncology physician assistants, oncology nurse practitioners, and interventional radiologists involved in HCC care. The qualitative (semi-structured interview) and quantitative (survey) data collection approaches were deployed sequentially with findings subsequently triangulated.

RESULTS

A total of 214 HCPs participated in this study. Analysis revealed challenges related to screening and diagnosing HCC, specifically in applying appropriate screening guidelines, and the optimal use and decisions related to diagnostic imaging and biopsy. Issues related to treatment selection included the application of existing HCC guidelines in treatment decision-making, weighing risk/benefit ratios of various antineoplastics regimens (i.e., tyrosine kinase inhibitors-TKIs, immunotherapy agents, chemotherapy), sequencing therapies, potential toxicity management, and optimally educating patients about their HCC.

CONCLUSION

These findings highlight the educational needs of those involved in HCC care and provide a starting point for clinicians to both reflect on their practice and identify opportunities to enhance communication within the HCC team and between provider and patient. There is an opportunity to optimize continuing professional development interventions that address the identified gaps in clinical practice specifically related to teamwork and interdisciplinary communication.

Safety and Success Rates of Excimer Laser Sheath-Assisted Retrieval of Embedded Inferior Vena Cava Filters

IMPORTANCE

Despite historically high rates of use, most inferior vena cava (IVC) filters are not retrieved. The US Food and Drug Administration safety communications recommended retrieval when the IVC filter is no longer indicated out of concern for filter-related complications. However, failure rates are high when using standard techniques for retrieval of long-dwelling filters, and until recently, there have been no devices approved for retrieval of embedded IVC filters.

OBJECTIVE

To evaluate the safety and success of excimer laser sheath-assisted retrieval of embedded IVC filters.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective, multicenter, clinical cohort study of excimer laser sheath-assisted IVC filter retrievals from 7 US sites was conducted between March 1, 2012, and February 28, 2021, among 265 patients who underwent IVC filter retrieval using the laser. Patients were substratified between a high-volume single center and a multicenter data set. A blinded physician committee adjudicated reported complications and their association with use of the laser.

EXPOSURES

Retrieval of IVC filters using excimer laser sheath.

MAIN OUTCOMES AND MEASURES

The primary safety end point was device-related major complication rate (Society of Interventional Radiology categories C to F, which included any adverse event associated with morbidity or disability that increases the level of care, results in hospital admission, or substantially lengthens the hospital stay). The primary success end point was technical success of IVC filter retrieval. The primary end points were compared with literature-derived, meta-analysis-suggested target performance goals.

RESULTS

The single-center experience included 139 participants (mean [SD] age, 52 [16] years; 78 female participants [56.1%]), and the multicenter experience included 126 participants (mean [SD] age, 52 [16] years; 75 female participants [59.5%]). The device-related major complication rate was 2.9% (4 of 139; 95% CI, 0.8%-7.2%; P = .001) for the single-center experience and 4.0% (5 of 126; 95% CI, 1.3%-9.0%; P = .01) for the multicenter experience, both of which were significantly lower than the primary safety performance goal (10%). No major complications were considered to be definitively associated with use of the laser. The technical success rate was 95.7% (133 of 139; 95% CI, 90.8%-98.4%; P = .007) for the single-center experience and 95.2% (120 of 126; 95% CI, 89.9%-98.2%; P = .02) for the multicenter experience, both of which were significantly higher than the primary performance goal (89.4%).

CONCLUSIONS AND RELEVANCE

This cohort study demonstrated high technical success and low complication rates of excimer laser sheath-assisted retrieval of embedded IVC filters in centers with variable case volume and experience, which suggests a wide applicability of the technique with proper training. The excimer laser sheath offers physicians a valuable tool for retrieval of challenging embedded IVC filters.

Impact of Portal Hypertension on Adverse Events after Splenic Arterial Aneurysm Embolization

PURPOSE

To evaluate the outcomes of splenic artery aneurysm (SAA) embolization and compare adverse event (AE) rates after embolization in patients with and without portal hypertension (PHTN).

MATERIALS AND METHODS

A retrospective review of all patients who underwent embolization of SAAs at 2 institutions was performed (34 patients from institution 1 and 7 patients from institution 2). Baseline demographic characteristics, preprocedural imaging, procedural techniques, and postprocedural outcomes were evaluated. Thirty-day postprocedural severe and life-threatening AEs were evaluated using the Society of Interventional Radiology guidelines. Thirty-day mortality and readmission rates were also evaluated. t test, χ² test, and/or Fisher exact test were used for the statistical analysis.

RESULTS

There was no statistically significant difference between patients with and without PHTN in the location, number, and size of SAA(s). All procedures were technically successful. There were 13 (32%) patients with and 28 (68%) patients without PHTN. The 30-day mortality rate (31% vs 0%; P = .007), readmission rates (61% vs 7%; P < .001), and severe/life-threatening AE rates (69% vs 0%; P < .001) were significantly higher in patients with PHTN than in those without PHTN.

CONCLUSIONS

There was a significantly higher mortality and severe/life-threatening AE rate in patients with PHTN than in those without PHTN. SAAs in patients with PHTN need to be managed very cautiously, given the risk of severe/life-threatening AEs after embolization.

Promoting Surgical Resection through Future Liver Remnant Hypertrophy

An inadequate future liver remnant (FLR) can preclude curative-intent surgical resection for patients with primary or secondary hepatic malignancies. For patients with normal baseline liver function and without risk factors, an FLR of 20% is needed to maintain postsurgical hepatic function. However, the FLR requirement is higher for patients who are exposed to systemic chemotherapy (FLR, >30%) or have cirrhosis (FLR, >40%). Interventional radiologic and surgical methods to achieve FLR hypertrophy are evolving, including portal vein ligation, portal vein embolization, radiation lobectomy, hepatic venous deprivation, and associating liver partition and portal vein ligation for staged hepatectomy. Each technique offers particular advantages and disadvantages. Knowledge of these procedures can help clinicians to choose the suitable technique for each patient. The authors review the techniques used to develop FLR hypertrophy, focusing on technical considerations, outcomes, and the advantages and disadvantages of each approach. Online supplemental material is available for this article. ^©RSNA, 2022.

Role of Radioembolization in Metastatic Neuroendocrine Tumors

The liver is the most common site of metastasis for neuroendocrine tumors originating from the gastrointestinal tract. Neuroendocrine liver metastases (NELMs) portend a worsening clinical course, making local management important. Local treatment options include surgery, thermal ablation, and trans-catheter intra-arterial therapies, such as radioembolization. Radioembolization is generally preferred over other embolotherapies in patients with colonized biliary systems. Current best practice involves personalized treatment planning, optimizing tumor radiation absorbed dose and minimizing radiation to the normal hepatic parenchyma. As part of a multidisciplinary approach, radioembolization is a versatile embolotherapy offering neoadjuvant, palliative, and ablative treatment options for patients with NELMs.

Primary retrograde urinary drainage using image and endoscopy guidance via urostomies

AIM

To report the technical success of image and endoscopy-guided retrograde trans-urostomy urinary drainage as a primary catheter placement method performed by interventional radiology (IR).

MATERIALS AND METHODS

Nine patients (15 attempted drain placements) with ureteric obstruction following radical cystectomy and urostomy creation were included. The patients were referred to IR for urinary drainage. All patients underwent primary image and endoscopy-guided retrograde trans-urostomy urinary drainage.

RESULTS

Primary image and endoscopy-guided retrograde trans-urostomy urinary drainage was successful in 13/15 (86.6%) attempts. The proposed technique had a limited complication rate omitting the percutaneous nephrostomy access step.

CONCLUSION

Primary image and endoscopy guided retrograde trans-urostomy urinary drainage should be considered before percutaneous nephrostomy in all patients with a urostomy.

Recent progress in cryoablation cancer therapy and nanoparticles mediated cryoablation

With rapid advances in modern imaging, minimally invasive ablative procedures have emerged as popular alternatives to surgical removal of tumors. Tumor ablation modalities currently offered in clinical practice include microwave ablation, radiofrequency ablation, cryoablation, high-intensity focused ultrasound, and irreversible electroporation. Cryoablation, a non-heat-based method of ablation, is increasingly being used for treating various solid tumors. Accumulated comparative data of cryoablation versus heat-based ablation techniques (e.g., radiofrequency and microwave ablation) shows superior tumor response and quicker recovery time. Evolving research has demonstrated that nanocarriers may serves as excellent catalysts for the cryoablation therapy, imaging guidance, and the co-delivery of therapeutics for minimally invasive, precise, and complete treatment of cancer with immune modulation. This review article focuses on the current status of cryoablation in clinical practice, considers opportunities for enhancing therapeutic outcomes from cryoablation, and discusses new research in the field, including theranostic nanoparticles-mediated cryotherapy and combinational cryo-based immunotherapies.

Radioembolization With Chemotherapy for Colorectal Liver Metastases: A Randomized, Open-Label, International, Multicenter, Phase III Trial

PURPOSE

To study the impact of transarterial Yttrium-90 radioembolization (TARE) in combination with second-line systemic chemotherapy for colorectal liver metastases (CLM).

METHODS

In this international, multicenter, open-label phase III trial, patients with CLM who progressed on oxaliplatin- or irinotecan-based first-line therapy were randomly assigned 1:1 to receive second-line chemotherapy with or without TARE. The two primary end points were progression-free survival (PFS) and hepatic PFS (hPFS), assessed by blinded independent central review. Random assignment was performed using a web- or voice-based system stratified by unilobar or bilobar disease, oxaliplatin- or irinotecan-based first-line chemotherapy, and KRAS mutation status.

RESULTS

Four hundred twenty-eight patients from 95 centers in North America, Europe, and Asia were randomly assigned to chemotherapy with or without TARE; this represents the intention-to-treat population and included 215 patients in the TARE plus chemotherapy group and 213 patients in the chemotherapy alone group. The hazard ratio (HR) for PFS was 0.69 (95% CI, 0.54 to 0.88; 1-sided P = .0013), with a median PFS of 8.0 (95% CI, 7.2 to 9.2) and 7.2 (95% CI, 5.7 to 7.6) months, respectively. The HR for hPFS was 0.59 (95% CI, 0.46 to 0.77; 1-sided P < .0001), with a median hPFS of 9.1 (95% CI, 7.8 to 9.7) and 7.2 (95% CI, 5.7 to 7.6) months, respectively. Objective response rates were 34.0% (95% CI, 28.0 to 40.5) and 21.1% (95% CI, 16.2 to 27.1; 1-sided P = .0019) for the TARE and chemotherapy groups, respectively. Median overall survival was 14.0 (95% CI, 11.8 to 15.5) and 14.4 months (95% CI, 12.8 to 16.4; 1-sided P = .7229) with a HR of 1.07 (95% CI, 0.86 to 1.32) for TARE and chemotherapy groups, respectively. Grade 3 adverse events were reported more frequently with TARE (68.4% v 49.3%). Both groups received full chemotherapy dose intensity.

CONCLUSION

The addition of TARE to systemic therapy for second-line CLM led to longer PFS and hPFS. Further subset analyses are needed to better define the ideal patient population that would benefit from TARE.

Yttrium-90 Radioembolization in the VX2 Rabbit Model: Radiation Safety and Factors Influencing Delivery Efficiency

The purpose of this study was to define the optimal infusion parameters and operator radiation exposure for yttrium-90 (⁹⁰Y) radioembolization in the VX2 rabbit model of liver cancer. Forty-one rabbits with VX2 were treated with glass microspheres with vial sizes of 1, 3, and 5 GBq. The mean administered activity was 51.5 MBq (95% CI, 39.1-63.9). Delivery efficiency improved with 1 GBq versus with 3 GBq (residual 11.0% vs 46.4%, respectively; P = .0013) and improved with 1 GBq versus with 5 GBq (residual 11.0% vs 33.8%, respectively; P = .0060). The mean operator extremity exposure was 41.7 μSv/infusion. The optimal minimum infusion volume and rate was 49 mL and 21 mL/min, respectively. Fecal elimination occurred with microsphere uptake in the gallbladder at 1 and 2 weeks. ⁹⁰Y radioembolization can be safely and efficiently performed in the VX2 rabbit model. Methodological considerations as a "how-to" for the setup of a preclinical ⁹⁰Y laboratory are included to support future translational research.

Contemporary Algorithm for the Management of Hepatocellular Carcinoma in 2021: The Northwestern Approach

Hepatocellular carcinoma (HCC) is the most common primary liver cancer and a major cause of cancer-related morbidity and mortality around the world. Frequently, concurrent liver dysfunction and variations in tumor burden make it difficult to design effective and standardized treatment pathways. Contemporary treatment guidelines designed for an era of personalized medicine should consider these features in a more clinically meaningful way to improve outcomes for patients across the HCC spectrum. Given the heterogeneity of HCC, we propose a detailed clinical algorithm for selecting optimal treatment using an evidence-based and practical approach, incorporating liver function, tumor burden, the extent of disease, and ultimate treatment intent, with the goal of individualizing clinical decision making.

Radiation Lobectomy: An Overview of Concept and Applications, Technical Considerations, Outcomes

Surgical resection has long been considered curative for patients with early-stage hepatocellular carcinoma (HCC). However, inadequate future liver remnant (FLR) renders many patients not amenable to surgery. Recently, lobar administration of yttrium-90 (Y90) radioembolization has been utilized to induce FLR hypertrophy while providing disease control, eventually facilitating resection in patients with hepatic malignancy. This has been termed "radiation lobectomy (RL)." The concept is evolving, with modified approaches combining RL and high-dose curative-intent radioembolization (radiation segmentectomy) to achieve tumor ablation. This article provides an overview of the concept and applications of RL, including technical considerations and outcomes in patients with hepatic malignancies.

Extrahepatic Applications of Yttrium-90 Radioembolization

While initially described and now accepted as treatment for primary and secondary malignancies in the liver, radioembolization therapy has expanded to include treatment for other disease pathologies and other organ systems. Advantages and limitations for these treatments exist and must be compared against more traditional treatments for these processes. This article provides an overview of the current applications for radioembolization outside of the liver, for both malignant and nonmalignant disease.

Evolution of Radioembolization in Treatment of Hepatocellular Carcinoma: A Pictorial Review

Transarterial radioembolization (TARE) with yttrium 90 has increasingly been performed to treat hepatocellular carcinoma (HCC). TARE was historically used as a palliative lobar therapy for patients with advanced HCC beyond surgical options, ablation, or transarterial chemoembolization, but recent advancements have led to its application across the Barcelona Clinic Liver Cancer staging paradigm. Newer techniques, termed radiation lobectomy and radiation segmentectomy, are being performed before liver resection to facilitate hypertrophy of the future liver remnant, before liver transplant to bridge or downstage to transplant, or as a definite curative treatment. Imaging assessment of therapeutic response to TARE is challenging as the intent of TARE is to deliver local high-dose radiation to tumors through microembolic microspheres, preserving blood flow to promote radiation injury to the tumor. Because of the microembolic nature, early imaging assessment after TARE cannot rely solely on changes in size. Knowledge of the evolving methods of TARE along with the tools to assess posttreatment imaging and response is essential to optimize TARE as a therapeutic option for patients with HCC. ^©RSNA, 2021.

Complications of Percutaneous Biliary Procedures

Percutaneous biliary and gallbladder drainage is routinely performed by interventional radiology. These pathologies and techniques are well described in the literature and in this issue. The purpose of this review is to focus on the recognition and management of complications. Percutaneous biliary drains can have a variety of complications which can range from minor skin issues to more serious and complex bleeding issues. Advancements in imaging and techniques improve the safety profile of percutaneous biliary and gallbladder interventions.

Yttrium-90 Radioembolization and Tumor Hypoxia: Gas-challenge BOLD Imaging in the VX2 Rabbit Model of Hepatocellular Carcinoma

RATIONALE AND OBJECTIVES

To use a rapid gas-challenge blood oxygen-level dependent magnetic resonance imaging exam to evaluate changes in tumor hypoxia after ⁹⁰Y radioembolization (Y90) in the VX2 rabbit model.

MATERIALS AND METHODS

White New Zealand rabbits (n = 11) provided a Y90 group (n = 6 rabbits) and untreated control group (n = 5 rabbits). R2* maps were generated with gas-challenges (O₂/room air) at baseline, 1 week, and 2 weeks post-Y90. Laboratory toxicity was evaluated at baseline, 24 hours, 72 hours, 1 hours, and 2 weeks. Histology was used to evaluate tumor necrosis on hematoxylin and eosin and immunofluorescence imaging was used to assess microvessel density (CD31) and proliferative index (Ki67).

RESULTS

At baseline, median tumor volumes and time to imaging were similar between groups (p = 1.000 and p = 0.4512, respectively). The median administered dose was 50.4 Gy (95% confidence interval:44.8-55.9). At week 2, mean tumor volumes were 5769.8 versus 643.7 mm³ for control versus Y90 rabbits, respectively (p = 0.0246). At two weeks, ΔR2* increased for control tumors to 12.37 ± 12.36sec^-1 and decreased to 4.48 ± 9.00sec^-1 after Y90. The Pearson correlation coefficient for ΔR2* at baseline and percent increase in tumor size by two weeks was 0.798 for the Y90 group (p = 0.002). There was no difference in mean microvessel density for control versus Y90 treated tumors (p = 0.6682). The mean proliferative index was reduced in Y90 treated tumors at 30.5% versus 47.5% for controls (p = 0.0071).

CONCLUSION

The baseline ΔR2* of tumors prior to Y90 may be a predictive imaging biomarker of tumor response and treatment of these tumors with Y90 may influence tumor oxygenation over time.

Yttrium-90 Radioembolization to the Prostate Gland: Proof of Concept in a Canine Model and Clinical Translation

PURPOSE

To investigate the feasibility, safety, and absorbed-dose distribution of prostatic artery radioembolization (RE) in a canine model.

MATERIALS AND METHODS

Fourteen male castrated beagles received dihydroandrosterone/estradiol to induce prostatic hyperplasia for the duration of the study. Each dog underwent fluoroscopic prostatic artery catheterization. Yttrium-90 (⁹⁰Y) microspheres (TheraSphere; Boston Scientific, Marlborough, Massachusetts) were delivered to 1 prostatic hemigland (dose escalation from 60 to 200 Gy), with the contralateral side serving as a control. Assessments for adverse events were performed throughout the follow-up (Common Terminology Criteria for Adverse Events v5.0). Positron emission tomography/magnetic resonance (MR) imaging provided a confirmation after the delivery of absorbed-dose distribution. MR imaging was performed before and 3, 20, and 40 days after RE. Tissue harvest of the prostate, rectum, bladder, urethra, penis, and neurovascular bundles was performed 60 days after RE.

RESULTS

All the animals successfully underwent RE. Positron emission tomography/MR imaging demonstrated localization to and good coverage of only the treated hemigland. No adverse events occurred. The MR imaging showed a significant dose-dependent decrease in the treated hemigland size at 40 days (25%-60%, P < .001). No extraprostatic radiographic changes were observed. Necropsy demonstrated no gross rectal, urethral, penile, or bladder changes. Histology revealed RE-induced changes in the treated prostatic tissues of the highest dose group, with gland atrophy and focal necrosis. No extraprostatic RE-related histologic findings were observed.

CONCLUSIONS

Prostate ⁹⁰Y RE is safe and feasible in a canine model and leads to focal dose-dependent changes in the gland without inducing unwanted extraprostatic effects. These results suggest that an investigation of nonoperative prostate cancer is warranted.

Comparing Real World, Personalized, Multidisciplinary Tumor Board Recommendations with BCLC Algorithm: 321-Patient Analysis

PURPOSE

To evaluate hepatocellular carcinoma (HCC) treatment allocation, deviation from BCLC first-treatment recommendation, and outcomes following multidisciplinary, individualized approach.

METHODS

Treatment-naïve HCC discussed at multidisciplinary tumor board (MDT) between 2010 and 2013 were included to allow minimum 5 years of follow-up. MDT first-treatment recommendation (resection, transplant, ablation, transarterial radioembolization (Y90), transarterial chemoembolization, sorafenib, palliation) was documented, as were subsequent treatments. Overall survival (OS) analyses were performed on an intention-to-treat (ITT) basis, stratified by BCLC stage.

RESULTS

Three hundred and twenty-one patients were treated in the 4-year period. Median age was 62 years, predominantly male (73%), hepatitis C (41%), and Y90 initial treatment (52%). There was a 76% rate of BCLC-discordant first-treatment. Median OS was not reached (57% alive at 10 years), 51.0 months, 25.4 months and 13.4 months for BCLC stages A, B, C and D, respectively.

CONCLUSION

Deviation from BCLC guidelines was very common when individualized, MDT treatment recommendations were made. This approach yielded expected OS in BCLC A, and exceeded general guideline expectations for BCLC B, C and D. These results suggest that while guidelines are helpful, implementing a more personalized approach that incorporates center expertise, patient-specific characteristics, and the known multi-directional treatment allocation process, improves patient outcomes.

Liver Transplantation Following Yttrium-90 Radioembolization: 15-Year Experience in 207-Patient Cohort

BACKGROUND AND AIMS

Radioembolization (yttrium-90 [Y90]) is used in hepatocellular carcinoma (HCC) as a bridging as well as downstaging liver-directed therapy to curative liver transplantation (LT). In this study, we report long-term outcomes of LT for patients with HCC who were bridged/downstaged by Y90.

APPROACH AND RESULTS

Patients undergoing LT following Y90 between 2004 and 2018 were included, with staging by United Network for Organ Sharing (UNOS) tumor-node-metastasis criteria at baseline pre-Y90 and pre-LT. Post-Y90 toxicities were recorded. Histopathological data of HCC at explant were recorded. Long-term outcomes, including overall survival (OS), recurrence-free survival (RFS), disease-specific mortality (DSM), and time-to-recurrence, were reported. Time-to-endpoint analyses were estimated using Kaplan-Meier. Univariate and multivariate analyses were performed using a log-rank test and Cox proportional-hazards model, respectively. During the 15-year period, 207 patients underwent LT after Y90. OS from LT was 12.5 years, with a median time to LT of 7.5 months [interquartile range, 4.4-10.3]. A total of 169 patients were bridged, whereas 38 were downstaged to LT. Respectively, 94 (45%), 60 (29%), and 53 (26%) patients showed complete, extensive, and partial tumor necrosis on histopathology. Three-year, 5-year, and 10-year OS rates were 84%, 77%, and 60%, respectively. Twenty-four patients developed recurrence, with a median RFS of 120 (95% confidence interval, 69-150) months. DSM at 3, 5, and 10 years was 6%, 11%, and 16%, respectively. There were no differences in OS/RFS for patients who were bridged or downstaged. RFS was higher in patients with complete/extensive versus partial tumor necrosis (P < 0.0001). For patients with UNOS T2 treated during the study period, 5.2% dropped out because of disease progression.

CONCLUSIONS

Y90 is an effective treatment for HCC in the setting of bridging/downstaging to LT. Patients who achieved extensive or complete necrosis had better RFS, supporting the practice of neoadjuvant treatment before LT.

Safety and Efficacy of Segmental Yttrium-90 Radioembolization for Hepatocellular Carcinoma after Transjugular Intrahepatic Portosystemic Shunt Creation

PURPOSE

To evaluate safety and efficacy of segmental yttrium-90 (Y90) radioembolization for hepatocellular carcinoma (HCC) after transjugular intrahepatic portosystemic shunt (TIPS) placement. The hypothesis was liver sparing segmental Y90 for HCC after TIPS would provide high antitumor response with a tolerable safety profile.

MATERIALS AND METHODS

This single-arm retrospective study included 39 patients (16 women, 23 men) with ages 49-81 years old who were treated with Y90. Child-Pugh A/B liver dysfunction was present in 72% (28/39) with a median Model for End-stage Liver Disease score of 18 (95% confidence interval, 16.4-19.4). Primary outcomes were clinical and biochemical toxicities and antitumor imaging response by World Health Organization (WHO) and European Association for the Study of the Liver (EASL) criteria. Secondary outcomes were orthotopic liver transplantation (OLT), time to progression (TTP), and overall survival (OS) estimates by the Kaplan-Meier method.

RESULTS

The 30-day mortality was 0%. Grade 3+ clinical adverse events and grade 3+ hyperbilirubinemia occurred in 5% (2/39) and 0% (0/39), respectively. Imaging response was achieved in 58% (22/38, WHO criteria) and 74% (28/38, EASL criteria), respectively. Median TTP was 16.1 months for any cause and 27.5 months for primary index lesions. OLT was completed in 88% (21/24) of listed patients at a median time of 6.1 months (range, 0.9-11.7 months). Median OS was 31.6 months and 62.9 months censored and uncensored to OLT, respectively.

CONCLUSIONS

Segmental Y90 for HCC appears safe and efficacious in patients after TIPS. Preserved transplant eligibility suggests that Y90 is a useful tool for bridging these patients to liver transplantation.

Development and Validation of Sorafenib-eluting Microspheres to Enhance Therapeutic Efficacy of Transcatheter Arterial Chemoembolization in a Rat Model of Hepatocellular Carcinoma

Purpose

To validate the therapeutic efficacy of sorafenib-eluting embolic microspheres (SOR-EMs) used in combination with transarterial chemoembolization (TACE) for treatment of hepatocellular carcinoma (HCC) in a preclinical animal model.

Materials and Methods

SOR-EMs were prepared with poly(d,l-lactide-co-glycolide), iron oxide nanoparticles, and sorafenib. The morphology of the prepared SOR-EMs was confirmed by using optical microscopy. Drug release from the SOR-EMs was quantified in vitro by using high-performance liquid chromatography. In an orthotopic rat model of HCC, embolic doxorubicin-Lipiodol (ethiodized oil) emulsion (DLE) and SOR-EMs were sequentially injected into the hepatic artery of the rats: The rats in group 1 were injected with DLE; group 2 was injected with DLE plus unloaded embolic microspheres (DLE + EM); group 3, with DLE plus SOR-EMs (DLE + SOR-EM); and group 4, with saline solution. The SOR-EM and tumor size changes in each group (of six rats each) over time were measured by using MRI. Tissues were assessed by using immunohistochemistry, with hematoxylin-eosin and terminal deoxynucleotidyl transferase-mediated dUTP (2'-deoxyuridine 5'-triphosphate) nick-end labeling staining used for dead cells and CD34 staining used for new microvessel formation.

Results

The SOR-EMs were a mean size of 6.6 μm ± 2.3 (standard deviation) and showed 53.7% ± 8.3 sorafenib loading efficiency with T2-weighted MRI capability. In the HCC rat model, the intra-arterially injected SOR-EMs were successfully monitored by using MRI. The DLE + SOR-EM-treated rats showed a superior tumor growth-inhibitory effect compared with the rats treated with DLE only (P < .05). Immunohistochemical assessment of tissue specimens showed that compared with the other treatment groups, the DLE + SOR-EM treatment group had the lowest number of microvessels, as quantified by using the percentage of CD34-positive stained area (P < .01 for all comparisons).

Conclusion

In a preclinical rat HCC model, SOR-EMs used in combination with DLE TACE were effective in treating HCC.Keywords: Chemoembolization, Experimental Investigations, Laboratory Tests, Liver, Technology Assessment Supplemental material is available for this article. © RSNA, 2021See also the commentary by Yamada and Gayed in this issue.

Duramycin radiosensitization of MCA-RH 7777 hepatoma cells through the elevation of reactive oxygen species

Objective

The objective of this study is to explore the radiosensitization effects of duramycin against the liver cancer hepatoma cells and relationship to reactive oxygen species (ROS) generation.

Materials and Methods

MCA-RH 7777 cells were treated with various combinations of duramycin concentrations and radiation doses. After the treatment, cell viabilities were determined by a cell proliferation assay; intracellular ROS levels were detected with the flow cytometric method.

Results

MCA-RH 7777 cell viability was found significantly reduced after combining duramycin and radiation exposure (comparing to that of either treatment alone). Increased intracellular ROS levels were observed in cells treated with combinations of duramycin and radiation.

Conclusion

Duramycin increased the intracellular ROS generation and also increased the radiosensitivity of MCA-RH 7777 cells.

Transarterial Yttrium-90 Radioembolization of Hepatocellular Carcinoma Perfused by the Cystic Artery: Multi-institutional Feasibility Study

PURPOSE

To assess the safety and efficacy of transarterial yttrium-90 radioembolization via the cystic artery for patients with hepatocellular carcinoma (HCC) adjacent to the gallbladder with cystic artery supply.

MATERIALS AND METHODS

This retrospective study included 17 patients treated at 4 institutions. Patients with HCC perfused by the cystic artery who received ablative-dose radioembolization were included. Median tumor size was 3.8 cm (range, 2.0-8.8 cm). Fourteen patients (82%) had Child-Pugh class A cirrhosis and 3 (18%) had class B cirrhosis. Adverse events, tumor response, and time to progression were analyzed.

RESULTS

Median dose to the tissue perfused by the cystic artery was 340 Gy (range, 200-720 Gy). There were no occurrences of acute cholecystitis warranting invasive intervention. Four patients (24%) experienced transient right upper quadrant pain, with symptom resolution within 3 mo. Six patients (35%) exhibited gallbladder wall edema on follow-up imaging. Two (12%) and 0 grade 3/4 increases in alkaline phosphatase and bilirubin were observed, respectively. Follow-up imaging demonstrated complete response in 13 target tumors (76%) and partial response in 4 (24%). There were no cases of target tumor progression during a median follow-up of 9 mo (range, 3-72 mo).

CONCLUSIONS

Direct infusion of 90Y microspheres via the cystic artery appears to have an acceptable safety profile, without resulting in acute cholecystitis warranting invasive intervention. In selected patients with HCC in whom other treatments may be contraindicated and the tumor is supplied via the cystic artery, treatment with selective ablative radioembolization can be considered.

Feasibility of Combination Intra-arterial Yttrium-90 and Irinotecan Microspheres in the VX2 Rabbit Model

PURPOSE

To evaluate the combination of 90Y radioembolization (Y90) and drug-eluting bead irinotecan (DEBIRI) microspheres in the VX2 rabbit model.

MATERIALS AND METHODS

An initial dose finding study was performed in 6 White New Zealand rabbits to identify a therapeutic but subcurative dose of Y90. In total, 29 rabbits were used in four groups: Y90 treatment (n = 8), DEBIRI treatment (n = 6), Y90 + DEBIRI treatment (n = 7), and an untreated control group (n = 8). Hepatic toxicity was evaluated at baseline, 24 h, 72 h, 1 week, and 2 weeks. MRI tumor volume (TV) and enhancing tumor volume were assessed baseline and 2 weeks. Tumor area and necrosis were evaluated on H&E for pathology.

RESULTS

Infused activities of 84.0-94.4 MBq (corresponding to 55.1-72.7 Gy) were selected based on the initial dose finding study. Infusion of DEBIRI after Y90 was technically feasible in all cases (7/7). Overall, 21/29 animals survived to 2 weeks, and the remaining animals had extrahepatic disease on necropsy. Liver transaminases were elevated with Y90, DEBIRI, and Y90 + DEBIRI compared to control at 24 h, 72 h, and 1 week post-treatment and returned to baseline by 2 weeks. By TV, Y90 + DEBIRI was the only treatment to show statistically significant reduction at 2 weeks compared to the control group (p = 0.012). The change in tumor volume (week 2-baseline) for both Y90 + DEBIRI versus control (p = 0.002) and Y90 versus control (p = 0.014) was significantly decreased. There were no statistically significant differences among groups on pathology.

CONCLUSION

Intra-arterial Y90 + DEBIRI was safe and demonstrated enhanced antitumor activity in rabbit VX2 tumors. This combined approach warrants further investigation.

On-demand degradable embolic microspheres for immediate restoration of blood flow during image-guided embolization procedures

Degradable embolic agents that provide transient arterial occlusion during embolization procedures have been of interest for many years. Ideally, embolic agents are visible with standard imaging modalities and offer on-demand degradability, permitting physicians to achieve desired arterial occlusion tailored to patient and procedure indication. Subsequent arterial recanalization potentially enhances the overall safety and efficacy of embolization procedures. Here, we report on-demand degradable and MRI-visible microspheres for embolotherapy. Embolic microspheres composed of calcium alginate and USPIO nanoclusters were synthesized with an air spray atomization and coagulation reservoir equipped with a vacuum suction. An optimized distance between spray nozzle and reservoir allowed uniform size and narrow size distribution of microspheres. The fabricated alginate embolic microspheres crosslinked with Ca²⁺ demonstrated highly responsive on-demand degradation properties in vitro and in vivo. Finally, the feasibility of using the microspheres for clinical embolization and recanalization procedures was evaluated with interventional radiologists in rabbits. Digital subtraction angiography (DSA) guided embolization of hepatic arteries with these embolic microspheres was successfully performed and the occlusion of artery was confirmed with DSA images and contrast enhanced MRI. T2 MRI visibility of the microspheres allowed to monitor the distribution of intra-arterial (IA) infused embolic microspheres. Subsequent on-demand image-guided recanalization procedures were also successfully performed with rapid degradation of microspheres upon intra-arterial infusion of an ion chelating agent. These instant degradable embolic microspheres will permit effective on-demand embolization/recanalization procedures offering great promise to overcome limitations of currently available permanent and biodegradable embolic agents.

Percutaneous Access of the Modified Hutson Loop for Retrograde Cholangiography, Endoscopy, and Biliary Interventions

PURPOSE

The purpose of this study was to present the institutional experience of performing endoscopy, cholangiography, and biliary interventions through the modified Hutson loop by interventional radiology.

MATERIALS AND METHODS

A total of 61 of 64 modified Hutson loop access procedures were successful. This single-center retrospective study included 61 successful procedures of biliary interventions using existing modified Hutson loops (surgically affixed subcutaneous jejunal limb adjacent to biliary anastomosis or anastomoses) for diagnostic or therapeutic purposes in 21 patients. Seventeen of 21 patients (81%) had undergone liver transplantation. Indications included biliary strictures (n = 18) and biliary leaks (n = 3). The clinical success and complications were evaluated.

RESULTS

There were 3 of 26 modified Hutson loop retrograde biliary intervention failures (12%) before introduction of endoscopy and no failures (0 of 38 [0%]) subsequently (P = .06). Endoscopy or cholangioscopy was performed in 19 procedures by interventional radiologists. Retrograde biliary interventions included diagnostic cholangiography (n = 26), cholangioplasty (n = 25), stent placement (n = 29), stent retrieval (n = 25), and biliary drainage catheter placement (n = 5). No procedure-related mortality occurred. There was 1 major complication (duodenal perforation) (1.6%) and 12 minor complications (19%). In the 9 patients undergoing therapeutic interventions for biliary strictures, there was a significant decrease in median alkaline phosphatase (288.5 to 174.5 U/L; P = .03). There was a trend toward decrease in median bilirubin levels (1.7 to 1 mg/dL; P = .06) at 1 month post-intervention.

CONCLUSIONS

The modified Hutson loop provided interventional radiologists a safe and effective alternative access to manage biliary complications in patients with biliary-enteric anastomoses. Introduction of the endoscope in interventional radiology has improved the success rate of these procedures.

Excimer Laser Sheath-Assisted Retrieval of "Closed-Cell" Design Inferior Vena Cava Filters

Background Numerous reports have shown that inferior vena cava filters are associated with clinically significant adverse events. Complicating factors, such as caval incorporation, may lead to technical challenges at retrieval. The use of advanced techniques including the laser sheath have increased technical success rates; however, the data are limited on which filter types necessitate and benefit from its use. Methods and Results From October 2011 to September 2019, patients with inferior vena cava filter dwell times >6 months or with prior failed retrievals were considered for laser sheath-assisted retrieval. Standard and nonlaser advanced retrieval techniques were attempted first; if the filter could not be safely or successfully detached from the caval wall using these techniques, the laser sheath was used. Technical success, filter type, necessity for laser sheath application based on "open" versus "closed-cell" filter design, dwell times, and adverse events were evaluated. A total of 441 patients (216 men; mean age, 54 years) were encountered. Mean dwell times for all filters was 56.6 months, 54.4 among closed-cell filters and 58.5 among open-cell filters (P=0.63). Technical success of retrieval was 98%, with the laser sheath required in 143 cases (40%). Successful retrieval of closed-cell filters required laser sheath assistance in 60% of cases as compared with 7% of open-cell filters (odds ratio, 20.1; P<0.01). In closed-cell inferior vena cava filters, dwell time was significantly associated with need for laser, requiring it in 64% of retrievals with dwell times >6 months (P=0.01). One major adverse event occurred among laser sheath retrievals when a patient required a 2-day inpatient admission for a femoral access site hemorrhage. Conclusions Closed-cell filters may necessitate the use of the laser sheath for higher rates of successful and safe retrieval.

Yttrium-90 Portal Vein Radioembolization in Sprague-Dawley Rats: Dose-Dependent Imaging and Pathological Changes in Normal Liver

PURPOSE

Portal vein embolization (PVE) is an established neoadjuvant method to induce future liver remnant hypertrophy prior to surgical resection of hepatic tumors. The purpose of our study was to examine the feasibility of PVE with glass ⁹⁰Y microspheres (Y90 PVE) in Sprague-Dawley rats. We tested the hypothesis that increased doses of Y90 PVE would increase target lobe fibrosis and atrophy.

METHODS

Twenty-two rats were assigned to four groups for Y90 PVE to the right median lobe: very high- (273.8 MBq; n = 2), high- (99.9 MBq; n = 10), medium- (48.1 MBq; n = 5), and low-dose (14.8 MBq; n = 5). An untreated control group included seven rats. ⁹⁰Y PET/CT of ⁹⁰Y distributions confirmed lobar targeting. MRI volumes were measured at baseline, 2-, 4-, 8- and 12-weeks. Explanted hepatic lobes were weighed, sectioned, and stained for H&E and immunohistochemistry. Digitized slides allowed quantitative measurements of fibrosis (20 foci/slide).

RESULTS

Ex vivo measurements confirmed 91-97% activity was localized to the target lobe (n = 4). The percent growth of the target lobe relative to baseline was - 5.0% (95% CI - 17.0-6.9%) for high-, medium dose rats compared to + 18.6% (95% CI + 7.6-29.7%) in the low-dose group at 12-weeks (p = 0.0043). Radiation fibrosis increased in a dose-dependent fashion. Fibrotic area/microsphere was 22,893.5, 14,946.2 ± 2253.3, 15,304.5 ± 4716.6, and 5268.8 ± 2297.2 μm² for very high- (n = 1), high- (n = 4), medium- (n = 3), and low-dose groups (n = 5), respectively.

CONCLUSION

Y90 PVE was feasible in the rat model, resulted in target lobe atrophy, and dose-dependent increases in hepatic fibrosis at 12 weeks. The onset of imaging-based volumetric changes was 8-12 weeks.

Streamlining radioembolization in UNOS T1/T2 hepatocellular carcinoma by eliminating lung shunt estimation

BACKGROUND & AIMS

Pre-treatment Tc-99m macroaggregated albumin (MAA) scans are routinely performed prior to transarterial radioembolization (TARE) to estimate lung shunt fraction (LSF) and lung dose. In this study, we investigate LSF observed in early hepatocellular carcinoma (HCC) and provide the scientific rationale for eliminating this step from routine practice.

METHODS

Patients with HCC who underwent Y90 from 2004 to 2018 were reviewed. Inclusion criteria were early stage HCC (UNOS T1/T2/Milan criteria: solitary ≤5 cm, 3 nodules ≤3 cm). LSF was determined using MAA in all patients. Associations between LSF and baseline characteristics were investigated. A "no-MAA" paradigm was then proposed based on a homogenous group that expressed very low LSF.

RESULTS

Of 1,175 patients with HCC treated with TARE, 448 patients met inclusion criteria. Mean age was 65.6 years and 303 (68%) were males. A total of 352 (79%) had solitary lesions and 406 (91%) unilobar disease. Two-hundred and forty-three (54%), 178 (40%) and 27 (6%) patients were Child-Pugh class A, B and C, respectively. Median LSF was 3.9% (IQR 2.4-6%). Median administered activity was 0.9 GBq (IQR 0.6-1.4), for a median segmental volume of 170 cm³ (range: 60-530). Median lung dose was 1.9 Gy (IQR: 1.0-3.3). The presence of a transjugular intrahepatic portosystemic shunt (TIPS; n = 38) was associated with LSF >10% (odds ratio 12.2; 95% CI 5.2-28.6; p <0.001). Median LSF was 3.8% (IQR: 2.4-5.7%) and 6% (IQR: 3.8-15.3%) in no-TIPS vs. TIPS patients (p <0.001).

CONCLUSION

LSF is clinically negligible in patients with UNOS T1/T2 HCC without TIPS. When segmental injections are planned, this step can be eliminated, thereby reducing time-to-treatment, number of procedures, and improving convenience for patients traveling from faraway.

LAY SUMMARY

Transarterial radioembolization is a microembolic transarterial treatment for hepatocellular carcinoma. In our study, we found that early stage patients, where segmental injections are planned, exhibited low lung shunting, effectively eliminating the risk of radiation pneumonitis. We propose that the lung shunt study be eliminated in this subgroup, thus leading to fewer procedures, a cost reduction and improved convenience for patients.