Impact of a unified CT angiography system on outcome of patients with hepatocellular carcinoma. AJR Am J Roentgenol. 2009;192:766-774. [PMID: 19234276 DOI: 10.2214/ajr.08.1368]

Efficacy of Yttrium-90 Transarterial Radioembolisation in Advanced Hepatocellular Carcinoma: An Experience With Hybrid Angio-Computed Tomography and Glass Microspheres

Background

Hepatocellular carcinoma is one of the most common malignancies worldwide. Transarterial radioembolisation (TARE) involves selective intra-arterial administration of microspheres loaded with a radioactive compound like Yttrium-90 (Y-90). Conventionally, C-arm-based cone-beam computed tomography has been extensively used during TARE. However, angio-computed tomography (CT) is a relatively new modality which combines the advantages of both fluoroscopy and fCT. There is scarce literature detailing the use of angio-CT in Y90 TARE.

Methods

This was a retrospective study of primary liver cancer cases in which the TARE procedure was done from November 2017 to December 2021. Glass-based Y-90 microspheres were used in all these cases. All the cases were performed in the hybrid angio-CT suite. A single photon emission computed tomography-computed comography (SPECT-CT) done postplanning session determined the lung shunt fraction and confirmed the accurate targeting of the lesion. Postdrug delivery, positron emission tomography-computed tomography (PET-CT) was obtained to confirm the distribution of the Y-90 particles. The technical success, median follow-up, objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) were recorded.

Results

A total of 56 hepatocellular carcinoma patients underwent TARE during this period, out of which 36 patients (30 males and 6 females) underwent Y90 TARE. The aetiology of cirrhosis included non-alcoholic steatohepatitis (NASH) (11), hepatitis C (HCV) (11), hepatitis B (HBV) (9), metabolic dysfunction and alcohol-associated liver disease (MetALD) (2), alcoholic liver disease (ALD) (1), cryptogenic (1), and autoimmune hepatitis (AIH) (1). The technical success was 100 % and the median follow-up was 7 months (range: 1-32 months). The median OS was 15 months (range 10.73-19.27 months; 95 % CI) and the median local PFS was 4 months (range 3.03-4.97 months; 95 % CI). The ORR (best response, CR + PR) was 58 %. No major complications were seen in this study.

Conclusion

TARE is a viable option for liver cancer in all stages, but more so in the advanced stages. The use of angio-CT in TARE aids in the precise delivery of the particles to the tumour and avoids non-target embolisation.

Imaging in interventional oncology, the better you see, the better you treat

Imaging and image processing is the fundamental pillar of interventional oncology in which diagnostic, procedure planning, treatment and follow-up are sustained. Knowing all the possibilities that the different image modalities can offer is capital to select the most appropriate and accurate guidance for interventional procedures. Despite there is a wide variability in physicians preferences and availability of the different image modalities to guide interventional procedures, it is important to recognize the advantages and limitations for each of them. In this review, we aim to provide an overview of the most frequently used image guidance modalities for interventional procedures and its typical and future applications including angiography, computed tomography (CT) and spectral CT, magnetic resonance imaging, Ultrasound and the use of hybrid systems. Finally, we resume the possible role of artificial intelligence related to image in patient selection, treatment and follow-up.

Interventional oncology of liver tumors: how it all started and where are we now

Liver was the very first organ for which interventional procedures were applied for the local treatment of primary and secondary malignancies. In this paper, the history of Interventional Oncology of liver, from the very beginning to the current situation, is summarized, including both percutaneous and intravascular procedures, and together with the evolution of the techniques for image guidance. The main ongoing developments, such as new techniques, combined interventional treatments and association of local interventions with new drugs are briefly described, too.

The Role of Catheter-Directed CT-Angiography in Radioembolisation

Radioembolisation is an established transarterial therapy for hepatocellular carcinoma and liver metastasis. Success of radioembolisation depends on meticulous angiography and accurate dosimetry. Intra-procedure catheter-directed CT-angiography is commonly performed to improve the efficacy and safety of radioembolisation. This review article will (1) introduce the differences between cone beam CT and hybrid angiography-CT, and (2) describe the benefits of catheter-directed CT-angiography in radioembolisation from both an interventional radiology and nuclear medicine perspective.

Implementation of a hybrid angiography-CT system: increased short-term revenue at an academic radiology department

PURPOSE

To analyze the financial impact following implementation of a hybrid Angio-CT system at a tertiary care academic medical center.

METHODS

Aggregate case types and volumes were compared 24 months before and 12 months after a hybrid Angio-CT system replaced a traditional interventional C-arm angiography suite at an academic medical center. Procedure revenues from this 36-month study period were derived from five payors mixes (Medicare, Medicaid, commercial insurance, out-of-pocket and managed care program) and Medicare-rate adjusted to each individual payor types.

RESULTS

Average case volume per month increased 12% in the hybrid Angio-CT suite when compared to the previous traditional angiography suite (P < 0.05). The variety of IR procedures in the hybrid Angio-CT suite also expanded to include more complex interventional radiology and interventional oncology procedures; the breadth of cases performed in the hybrid Angio-CT suite were associated with CPT codes of higher rates (average CPT value/case increased from $2,334.61 to $2,567.25). The estimated average annual revenue of the hybrid Angio-CT suite increased 23% as compared to previous traditional angiography suite.

CONCLUSION

A hybrid Angio-CT system is a financially feasible endeavor at a tertiary care academic medical center that facilitated higher complexity procedure codes and increased procedure-related revenue.

CIRSE Standards of Practice on Hepatic Transarterial Chemoembolisation

This CIRSE Standards of Practice document is aimed at interventional radiologists and provides best practices for performing transarterial chemoembolisation. It has been developed by an expert writing group under the guidance of the CIRSE Standards of Practice Committee. It will encompass all technical details reflecting European practice of different TACE procedures (Lp-TACE, DEM-TACE, DSM-TACE, b-TACE) as well as revising the existing literature on the various clinical indications (HCC, mCRC, ICC, NET). Finally, new frontiers of development will also be discussed.

Combined Angio-CT Systems: A Roadmap Tool for Precision Therapy in Interventional Oncology

Combined angiography-CT (angio-CT) systems, which combine traditional angiographic imaging with cross-sectional imaging, are a valuable tool for interventional radiology. Although cone-beam CT (CBCT) technology from flat-panel angiography systems has been established as an adjunct cross-sectional imaging tool during interventional procedures, the intrinsic advantages of angio-CT systems concerning superior soft-tissue imaging and contrast resolution, along with operational ease, have sparked renewed interest in their use in interventional oncology procedures. Owing to increases in affordability and usability due to an improved workflow, angio-CT systems have become a viable alternative to stand-alone flat-panel angiographic systems equipped with CBCT. This review aims to provide a comprehensive technical and clinical guide for the use of angio-CT systems in interventional oncology. The basic concepts related to the use of angio-CT systems, including concepts related to workflow setup, imaging characteristics, and acquisition parameters, will be discussed. Additionally, an overview on the clinical applications and the benefits of angio-CT systems in routine therapeutic and palliative interventional oncology procedures will be reviewed. Keywords: Ablation Techniques, CT-Angiography, Interventional-Body, Interventional-MSK, Chemoembolization, Embolization, Radiation Therapy/Oncology, Abdomen/GI, Skeletal-Axial Supplemental material is available for this article. © RSNA, 2021.

Hybrid angiography-CT for transarterial radioembolization: a pictorial essay

Although hybrid angiography-CT (Angio-CT) has a long history of use for interventional oncology procedures, its applications for transarterial radioembolization (TARE) are not as well described in the literature. This pictorial essay demonstrates a single-institution experience with the utilization of an Angio-CT system for TARE treatment of hepatocellular carcinoma. Procedural images and clinical data for twenty-four patients who underwent initial angiographic mapping with hepatopulmonary shunt fraction assessment and or administration of Yttrium-90 (Y-90) microspheres using the Angio-CT system to date were reviewed. Cases were reviewed for examples that highlight the specific utility of Angio-CT. Three representative TARE cases were selected which illustrate unique advantages and applications of the Angio-CT system when performing TARE. These include the ability to optimally delineate hepatic vascular anatomy, accurately calculate liver volumes for dosimetry, and improve the detection and characterization of equivocal lesions. Angio-CT has unique advantages which can be applied to TARE treatment of patients with HCC. The technology has potential to be an especially effective tool for those who aim to be at the cutting edge of the rapidly growing field of interventional oncology.

Radiation Dose during Transarterial Radioembolization: A Dosimetric Comparison of Cone-Beam CT and Angio-CT Technologies

PURPOSE

To evaluate the radiation dose differences for intraprocedural computed tomography (CT) imaging between cone-beam CT and angio-CT acquired during transarterial radioembolization (TARE) therapies for hepatocellular carcinoma.

MATERIALS AND METHODS

A retrospective cohort of 22 patients who underwent 23 TARE procedures were selected. Patients were imaged in both cone-beam CT and angio-CT rooms as a part of their conventional treatment plan. Effective dose contributions from individual CT acquisitions as well as the cumulative dose contributions from procedural 3D imaging were evaluated. Angiography dose contributions were omitted. Cone-beam CT images were acquired on a C-arm Philips Allura system. Effective doses were evaluated by coupling previously published conversion factors (effective dose per dose-area product) to patient's dose-area product meter readings after the procedure. Angio-CT images were acquired on a hybrid Canon Infinix-i Aquilion PRIME system. Effective doses from angio-CT scans were estimated using Radimetrics. Comparisons of a single patient's dose differential between the 2 technologies were made.

RESULTS

The mean effective dose from a single CT scan was 6.42 mSv and 5.99 mSv in the cone-beam CT room and the angio-CT room, respectively (P = .3224), despite the greater field of view and average craniocaudal scan coverage in angio-CT. The mean effective dose summed across all CTs in a procedure was 12.89 mSv and 34.35 mSv in the cone-beam CT room and the angio-CT room, respectively (P = .0018).

CONCLUSIONS

The mean effective dose per CT scan is comparable between cone-beam CT and angio-CT when considered in direct comparison for a single patient.

Therapy of Intermediate-Stage Hepatocellular Carcinoma: Current Evidence and Clinical Practice

Intermediate-stage Hepatocellular Carcinoma (HCC) represents a wide range of disease burden. Patients with different levels of liver function, tumor size, and number of lesions may all have intermediate-stage disease according to the Barcelona Clinic Liver Cancer (BCLC) staging system. Several minimally invasive image-guided locoregional therapies are available for the treatment of intermediate-stage HCC, including conventional transarterial chemoembolization (cTACE), drug-eluting bead TACE (DEB-TACE), yttrium-90 radioembolization (Y-90 RE), thermal ablation, bland embolization, and combination therapy. Available clinical evidence points to cTACE as the current gold standard for the locoregional treatment of intermediate-stage HCC. DEB-TACE is at best non-inferior to cTACE in terms of survival benefit. Y-90 RE is a maturing therapy, and some institutions have adopted it as first-line therapy for intermediate-stage HCC. Thermal ablation combined with TACE may be used in select patients, while bland embolization has only limited evidence for its use. The combination of locoregional therapy with VEGF inhibitors or immune checkpoint inhibitors has also been explored. This article will examine in detail the clinical evidence supporting available locoregional treatment options for intermediate-stage HCC.

Improved Utilization Following Conversion of a Fluoroscopy Suite to Hybrid CT/Angiography System

PURPOSE

To assess changes in operational utilization following conversion of a single IR suite to a hybrid CT/angiography (Angio-CT) system at an academic tertiary care center.

MATERIALS AND METHODS

The total number of interventional procedures and diagnostic CT examinations performed in 29 rooms (20 diagnostic radiology, 7 IR, 2 shared between divisions) was calculated in the 24 months before conversion of an IR suite to Angio-CT and 12 months after conversion. The total number of IR procedures (global IR/month) and diagnostic CT scans per month (global CT/month) in both before and after conversion periods was calculated and defined as baseline institutional growth. This was compared against the change in the number of IR procedures performed in the before and after periods in the converted room (Angio-CT/month) as well as the number of diagnostic CT scans performed in the shared rooms (shared CT/month).

RESULTS

The percent change in global CT and global IR from the before to the after periods was 39.2% and 3.1%, respectively. Shared CT per month and Angio-CT per month increased by 46.7% and 12.0% across the same time periods, respectively. The ratio of the percent increase in Angio-CT per month to percent increase in global IR per month was 3.87. The ratio of the percent increase in shared CT per month to percent increase in global CT per month was 1.19.

CONCLUSIONS

Operational utilization improved in both diagnostic radiology and IR sections following conversion of a conventional fluoroscopic IR suite to an Angio-CT room.

Hybrid CT-angiography to facilitate lower extremity sharp venous recanalization: a novel approach to a common procedure

Background

Post-thrombotic syndrome due to chronic venous occlusion is associated with high morbidity and healthcare costs. Sharp venous recanalization has been used with success when conventional techniques fail to cross the occlusion, permitting endovascular reconstruction with angioplasty and stenting. However, manipulation of a needle, especially in extra-anatomic locations, risks damage to adjacent structures, thus necessitating adequate imaging guidance.

Case presentation

This report describes the novel use of hybrid CT-angiography in a successful recanalization of a complex iliofemoral chronic venous occlusion, after multiple failed attempts with traditional recanalization techniques. The procedure was performed without complications, and stent patency was confirmed at three-month follow-up with patient-reported improvement in severe post-thrombotic syndrome.

Conclusions

This case demonstrates effective incorporation of hybrid CT-angiography to facilitate complex sharp venous recanalization for chronic lower extremity thrombosis, as an alternative to standard fluoroscopic techniques requiring multiple projections with or without cone-beam CT. Further studies are needed to understand the implications of this strategy.

Catheter-Directed Computed Tomography Hepatic Angiography for Yttrium-90 Selective Internal Radiotherapy of Hepatocellular Carcinoma Reduces Prophylactic Embolization of Extrahepatic Vessels

OBJECTIVES

To determine the rate of prophylactic embolization of extrahepatic vessels in patients undergoing yttrium-90 selective internal radiotherapy (⁹⁰Y SIRT) for hepatocellular carcinoma (HCC) with the use of catheter-directed computed tomography hepatic angiography (CD-CTHA).

MATERIALS AND METHODS

This retrospective study included 186 HCC patients who received ⁹⁰Y SIRT from May 2010 to June 2015 in a single institution. All procedures were performed in a hybrid angiography-CT suite equipped with digital subtraction angiography (DSA) and CD-CTHA capabilities. CD-CTHA was performed during pre-treatment hepatic angiography. ⁹⁰Y SIRT was administered approximately 2 weeks later. Selective prophylactic embolization of extrahepatic vessels was performed if extrahepatic enhancement was seen on CD-CTHA or if an extrahepatic vessel opacified on DSA/CD-CTHA despite the final microcatheter position for ⁹⁰Y microsphere delivery being beyond the origin of this vessel.

RESULTS

Thirty-five patients (18.8%) required selective embolization of extrahepatic vessels. Technical success of ⁹⁰Y SIRT was 99.5%. Two patients (1.1%) developed radiation-induced gastrointestinal ulceration, and one (0.54%) developed radiation-induced pneumonitis. Extrahepatic uptake of ⁹⁰Y microspheres was seen in the gallbladder of one patient without significant complications.

CONCLUSION

The use of CD-CTHA in ⁹⁰Y SIRT of HCC was associated with a low rate of prophylactic embolization of extrahepatic vessels while maintaining a high technical success rate of treatment and low rate of complications.

LEVEL OF EVIDENCE

Level 4, case series.

Radiation Exposure During Transarterial Chemoembolization: Angio-CT Versus Cone-Beam CT

INTRODUCTION

Cone-beam computed tomography (CBCT) has been developed to improve reliability of many interventional radiology (IR) procedures performed with Angio system, such as transarterial chemoembolization (TACE). Angio-CT has emerged as a new imaging technology that combines a CT scanner with an Angio system in the same IR suite. The purpose of our study was to compare Angio system with CBCT capability and Angio-CT in terms of patient radiation exposure during TACE procedures.

MATERIALS AND METHODS

Consecutive TACE procedures performed between January 2016 and September 2017 with the two imaging modalities (Artis Zeego defining the CBCT group and Infinix-i 4D-CT defining the Angio-CT group) were reviewed. TACE and patient's characteristics and patient radiation exposure parameters were collected. Dose-area products (DAP) and dose-length products (DLP) were converted into effective doses (ED) using conversion factors. Accuracy of tumor targeting and response was retrospectively assessed.

RESULTS

A total of 114 TACE procedures in 96 patients were included with 57 procedures in each group. The total ED in the Angio-CT group was 2.5 times lower than that in the CBCT group (median 15.4 vs. 39.2 mSv, p < 0.001). Both 2D ED and 3D ED were lower in the Angio-CT group than in the CBCT group (5.1 vs. 20 mSv, p < 0.001, and 7.4 vs. 17.9 mSv, p < 0.001, respectively). There was no significant difference neither in terms of classes of tumor targeting (p = 0.509) nor in terms of classes of tumor response (p = 0.070) between both groups.

CONCLUSION

Angio-CT provides significant decrease in patient effective dose during TACE procedures compared to Angio system with CBCT.

Use of Ultrasmall Superparamagnetic Iron Oxide Enhanced Susceptibility Weighted Imaging and Mean Vessel Density Imaging to Monitor Antiangiogenic Effects of Sorafenib on Experimental Hepatocellular Carcinoma

We investigated effectiveness of ultrasmall superparamagnetic iron oxide enhanced susceptibility weighted imaging (USPIO-enhanced SWI) and mean vessel density imaging (Q) in monitoring antiangiogenic effects of Sorafenib on orthotopic hepatocellular carcinoma (HCC). Thirty-five HCC xenografts were established. USPIO-enhanced SWI and Q were performed on a 1.5 T MR scanner at baseline, 7, 14, and 21 days after Sorafenib treatment. Intratumoral susceptibility signal intensity (ITSS) and Q were serially measured and compared between the treated (n = 15) and control groups (n = 15). Both ITSS and Q were significantly lower in the treated group at each time point (P < 0.05). Measurements in the treated group showed that ITSS persisted at 7 days (P = 0.669) and increased at 14 and 21 days (P < 0.05), while Q significantly declined at 7 days (P = 0.028) and gradually increased at 14 and 21 days. In the treated group, significant correlation was found between Q and histologic microvessel density (MVD) (r = 0.753, P < 0.001), and ITSS correlated well with MVD (r = 0.742, P = 0.002) after excluding the data from baseline. This study demonstrated that USPIO-enhanced SWI and Q could provide novel biomarkers for evaluating antiangiogenic effects of Sorafenib on HCC.

Prediction of Embolization Area after Conventional Transcatheter Arterial Chemoembolization for Hepatocellular Carcinoma Using SYNAPSE VINCENT

PURPOSE

Transcatheter arterial chemoembolization (TACE) is one of the most effective therapeutic options for hepatocellular carcinoma (HCC) and it is important to protect residual liver function after treatment as well as the effect. To reduce the liver function deterioration, we evaluated the automatic software to predict the embolization area of TACE in 3 dimensions.

MATERIALS AND METHODS

Automatic prediction software of embolization area was used in chemoembolization of 7 HCCs. Embolization area of chemoembolization was evaluated within 1 week CT findings after TACE and compared simulated area using automatic prediction software.

RESULTS

The maximal diameter of these tumors is in the range 12-42 mm (24.6 ± 9.5 mm). The average time for detecting tumor-feeding branches was 242 s. The total time to detect tumor-feeding branches and simulate the embolization area was 384 s. All cases could detect all tumor-feeding branches of HCC, and the expected embolization area of simulation with automatic prediction software was almost the same as the actual areas, as shown by CT after TACE.

CONCLUSION

This new technology has possibilities to reduce the amount of contrast medium used, protect kidney function, decrease radiation exposure, and improve the therapeutic effect of TACE.

Accurate and rapid identification of feeding arteries with multidetector-row angiography-assisted computed tomography for transarterial chemoembolization for hepatocellular carcinoma

BACKGROUND

Transarterial chemoembolization (TACE) is an important treatment modality for hepatocellular carcinoma (HCC). Accurate identification of feeding arteries and catheterization are necessary for achieving treatment efficacy, especially with selective TACE. However, this often requires multiple imaging studies. We evaluated the utility of a newly developed apparatus that combines multidetector-row computed tomography (MDCT) and angiography (angio-MDCT) to facilitate TACE for treatment of HCC.

METHODS

A total of 73 patients who underwent selective TACE with angio-MDCT were compared with 57 patients who had undergone selective TACE with single-row computed tomography assisted by angiography (angio-CT) in terms of the number of imaging studies needed to complete TACE.

RESULTS

The mean number of digital subtraction arteriography (DSA) and CT studies required for characterization of feeding arteries before embolization was 3.53 (range 1-8) and 5.16 (range 2-11), respectively, with single-row angio-CT, and 1.67 (range 1-5) and 2.90 (range 1-5), respectively, with angio-MDCT. Fewer studies were needed in patients who underwent TACE with angio-MDCT (p < 0.0001 for both DSA and CT). Whereas single-row angio-CT failed to identify extrahepatic feeders in three patients (37.5%), all extrahepatic feeders could be identified with angio-MDCT.

CONCLUSIONS

Angio-MDCT facilitates rapid and accurate identification of feeding arteries in patients undergoing TACE through the three-dimensional image analyses by the reconstruction with the workstation.

Cone-Beam CT Angiography for Hepatocellular Carcinoma: Current Status

Cone-beam CT (CBCT) is generated during a rotational sweep of the C-arm around the patient, and can be a valuable imaging technique, providing in situ cross-sectional imaging. It is easy to evaluate the morphologic characteristics of hepatic arteries from multiple views with the use of various reconstruction techniques, such as maximum intensity projection (MIP) and volume rendering. CBCT angiography is capable of providing more information than the standard 2-dimensional angiography in visualizing hepatocellular carcinomas (HCCs) and targeting tumors though precise microcatheter placement in close proximity to HCCs. It can also be useful in evaluating treatment success at the time of the procedure. It is anticipated that CBCT could reduce radiation exposure, the overall procedure time and contrast material use because it allows immediate feedback for an efficient angiographic procedure. Therefore, CBCT angiography is an exciting technology with the potential to significantly impact the practice of interventional radiology. The purpose of this article is to provide a review of the principles, clinical applications and technique of CBCT angiography for HCC treatment.

Treatment of Liver Tumors with Lipiodol TACE: Technical Recommendations from Experts Opinion

Transarterial chemoembolization with Lipiodol (Lipiodol TACE), also called conventional TACE, was developed in the early 1980s and widely adopted worldwide after randomized control trials and meta-analysis demonstrated superiority of Lipiodol TACE to best supportive care. Presently, there is no level one evidence that other TACE techniques are superior to Lipiodol TACE for intermediate stage hepatocellular carcinoma (HCC), which includes patients with preserved liver function and nonsurgical large or multinodular HCC without distant metastases. In addition, TACE is part of the treatment for progressive or symptomatic liver metastases from gastroenteropancreatic neuroendocrine tumors. When injected into the hepatic artery, Lipiodol has the unique property of selective uptake and retention in hyperarterialyzed liver tumors. Lipiodol/drug emulsion followed by particle embolization has been demonstrated to improve the pharmacokinetic of the drug and tumor response. Radio opacity of Lipiodol helps to monitor treatment delivery, with retention of Lipiodol serving as an imaging biomarker for tumor response. For 30 years, Lipiodol TACE has been inconsistently referenced in many publications with various levels of details for the method of preparation and administration, with reported progressive outcomes following improvements in the technique and the devices used to deliver the treatment and better patient selection. Consequently, there is no consensus on the standard method of TACE regarding the use of anticancer agents, embolic material, technical details, and the treatment schedule. In order to develop an internationally validated technical recommendation to standardize the Lipiodol TACE procedure, a worldwide panel of experts participated in a consensus meeting held on May 10, 2014 .

Transarterial chemoembolization for hepatocellular carcinoma: A review of techniques

Hepatocellular carcinoma (HCC) is one of the most common malignant diseases worldwide. While curative therapies, including resection, liver transplantation, and percutaneous ablation (percutaneous ethanol injection and radiofrequency ablation), are applicable for only a portion of the HCC population, transcatheter arterial chemoembolization (TACE) has been recognized as an effective palliative treatment option for patients with advanced HCC. TACE is also used even for single HCCs in which it is difficult to perform surgical resection or locoregional treatment due to systemic co-morbidities or anatomical problems. TACE has become widely adopted in the treatment of HCC. By using computed tomography-angiography, TACE is capable of performing diagnosis and treatment at the same time. Furthermore, TACE plays an important role in the multidisciplinary treatment for HCC when combined with other treatment. In this review, we first discuss the history of TACE, and then review the previous findings about techniques of achieving a locoregional treatment effect (liver infarction treatment, e.g., ultra-selective TACE, balloon-occluded TACE), and the use of TACE as a drug delivery system for anti-cancer agents (palliative, e.g., platinum complex agents, drug-eluting beads) for multiple lesions.

Current role of hybrid CT/angiography system compared with C-arm cone beam CT for interventional oncology

Hybrid CT/angiography (angiography) system and C-arm cone beam CT provide cross-sectional imaging as an adjunct to angiography. Current interventional oncological procedures can be conducted precisely using these two technologies. In this article, several cases using a hybrid CT/angiography system are shown first, and then the advantages and disadvantages of the hybrid CT/angiography and C-arm cone beam CT are discussed with literature reviews.

Tracking Navigation Imaging of Transcatheter Arterial Chemoembolization for Hepatocellular Carcinoma Using Three-Dimensional Cone-Beam CT Angiography

PURPOSE

New tracking navigation imaging software was used to evaluate the usefulness of three dimensional (3D) CT angiography for transcatheter arterial chemoembolization (TACE) in patients with hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Fifty-two patients with 73 HCCs were enrolled in this study retrospectively. Rotational angiography was performed from the hepatic artery for evaluation of the tumor feeding vessels. Arteries feeding the tumor were traced automatically by adjusting the region of interest around the targeted tumor on axial and coronal images using tracking navigation imaging with 3D cone-beam CT angiography.

RESULTS

Using final selective angiographic findings as the gold standard, the detection of feeding vessels was 90.4% (66/73) for tracking navigation imaging and 50.7% (37/73) for celiac trunk angiography. This difference was statistically significant (Wilcoxon rank sum test, p < 0.001). The sensitivity, specificity, positive predictive value, and negative predictive value for the detection of feeding arteries were 97.1% (66/68), 80.0% (4/5), 98.5% (66/67), and 66.7% (4/6), respectively. The kappa coefficient had a value of 0.638 (95% CI: 0.471-0.805), which is considered to indicate a good degree of agreement. With the assistance of tracking navigation imaging, the disease control rate of TACE for HCC was 67.3% (35/52) according to the modified Response Evaluation Criteria in Solid Tumors. During follow-up periods of 1-11 months, 10 patients (19.2%) remained cancer-free after TACE.

CONCLUSION

Tracking navigation imaging with 3D cone-beam CT angiography should be useful for TACE in HCC patients with complicated feeding arteries.

Superselective particle embolization enhances efficacy of radiofrequency ablation: effects of particle size and sequence of action

PURPOSE

To evaluate the effects of particle size and course of action of superselective bland transcatheter arterial embolization (TAE) on the efficacy of radiofrequency ablation (RFA).

METHODS

Twenty pigs were divided into five groups: group 1a, 40-μm bland TAE before RFA; group 1b, 40-μm bland TAE after RFA; group 2a, 250-μm bland TAE before RFA; group 2b, 250-μm bland TAE after RFA and group 3, RFA alone. A total of 40 treatments were performed with a combined CT and angiography system. The sizes of the treated zones were measured from contrast-enhanced CTs on days 1 and 28. Animals were humanely killed, and the treated zones were examined pathologically.

RESULTS

There were no complications during procedures and follow-up. The short-axis diameter of the ablation zone in group 1a (mean ± standard deviation, 3.19 ± 0.39 cm) was significantly larger than in group 1b (2.44 ± 0.52 cm; P = 0.021), group 2a (2.51 ± 0.32 cm; P = 0.048), group 2b (2.19 ± 0.44 cm; P = 0.02), and group 3 (1.91 ± 0.55 cm; P < 0.001). The greatest volume of ablation was achieved by performing embolization with 40-μm particles before RFA (group 1a; 20.97 ± 9.65 cm(3)). At histology, 40-μm microspheres were observed to occlude smaller and more distal arteries than 250-μm microspheres.

CONCLUSION

Bland TAE is more effective before RFA than postablation embolization. The use of very small 40-μm microspheres enhances the efficacy of RFA more than the use of larger particles.

Survival after C-arm CT-assisted chemoembolization of unresectable hepatocellular carcinoma

PURPOSE

To compare patient survival after transarterial chemoembolization with and without intraprocedural C-arm computed tomography (CT) in patients with unresectable hepatocellular carcinoma.

MATERIALS AND METHODS

We retrospectively reviewed the records of 130 patients with unresectable hepatocellular carcinoma who underwent lipiodol-based chemoembolization using a C-arm cone-beam system. We compared patients who underwent chemoembolization with angiography alone (69 patients; April 2005-July 2007) to those who underwent C-arm CT-assisted chemoembolization (61 patients; July 2007-April 2010). Overall and local progression-free survivals were compared using the Kaplan-Meier estimator with log-rank testing. Univariate and multivariate analyses were performed using the Cox proportional hazards model.

RESULTS

Overall survival rates of patients who underwent chemoembolization with and without C-arm CT assistance were 94% and 79%, 81% and 65%, and 71% and 44% at 1, 2, and 3 years, respectively. Local progression-free survival rates of these patients were 43% and 27%, 31% and 10%, and 26% and 5% at 1, 2, and 3 years, respectively. Patients receiving C-arm CT-assisted chemoembolization had significantly higher overall (P=0.005) and local progression-free (P=0.003) survival rates than those receiving chemoembolization with angiography alone. Multivariate analysis showed that C-arm CT assistance was an independent factor associated with longer overall survival (hazard ratio, 0.40; P=0.033) and local progression-free survival (hazard ratio, 0.25; P=0.003).

CONCLUSION

C-arm CT usage in addition to angiography during transarterial chemoembolization prolongs survival in patients with unresectable hepatocellular carcinoma.

Quantitative portal vein velocity of liver cancer patients with transcatheter arterial chemoembolization on angiography

Objective. We applied optical flow method (OFM) to quantify relative velocities of blood flow using digital subtraction angiography (DSA) in the vascular analysis of hepatocellular carcinoma (HCC) patients who underwent transarterial chemoembolization (TACE) treatment. Methods. A total of 40 HCC patients treated by TACE were analyzed in this study. DSA imaging with a 12-inch field of view, 1024 × 1024 pixels and 4 frames/second was acquired. OFM developed for motion estimation is applied for blood flow estimation. Two acrylic phantoms were built to validate the method. Results. The relationship between the OFM and Doppler measurements was found linear with R² = 0.99 for both straight and curved tube phantoms. Quantitative blood flow distribution images of the portal vein region were presented. After TACE, the minimum, maximum and mean velocities in the portal vein all decreased (P < 0.05). Additionally, the velocity in the portal vein is significantly lower with a higher Child-Pugh score (P < 0.01). Conclusions. The present technique provides add-on quantitative information of flows to DSA and the hemodynamic analysis in relative quantifications of blood flow in portal vein of hepatocellular carcinoma patients using DSA.

Clinical trials of interventional oncology

Interventional oncology has great potential to be a good treatment modality in the field of oncology, because its procedures are minimally invasive and fairly quick. However, except for a few procedures such as percutaneous radiofrequency ablation and trans-catheter arterial chemo-embolization that have been recognized as standard treatments for hepatocellular carcinoma, most procedures have not been established as the standard treatment modality due to the limited number of clinical trials with compelling evidence. There are several common problems when performing clinical trials of interventional oncology. The first is that the outcomes of clinical trials are greatly influenced by the level of technical skill of the physicians. The second is that equipment and devices vary widely in countries and regions, and they also influence the outcomes. The third is that the methodology of clinical trials for techniques such as interventional oncology has not yet been established. The fourth is the difficulty of setting appropriate endpoints; quality of life is suitable for evaluating interventional oncology in palliative care, but it is not easy to set as the endpoint. The fifth is the difficulty of employing a blinded design, because the procedure cannot be performed without the physician's awareness. Despite such difficult situations, many multi-institutional clinical trials of interventional oncology have been carried out in Japan, with some challenging results. Establishing evidence is critical to making interventional oncology the standard treatment. Interventional radiologists should know the importance of clinical trials, and should move ahead in this direction in a step-by-step manner.