Role of C-Arm CT in Identifying Caudate Arteries Supplying Hepatocellular Carcinoma

Radiological Vascular Anatomy of the Caudate Lobe of the Liver Required for Transarterial Chemoembolization of Hepatocellular Carcinoma

The caudate lobe is located between the bilateral hepatic lobes and is divided into three subsegments: the Spiegel lobe, paracaval portion, and caudate process. The caudate artery arises from various sites of the bilateral hepatic arteries as an independent branch, common trunk, or arcade. Extrahepatic arteries can enter the caudate lobe mainly by the right inferior phrenic artery. The caudate artery also supplies the main bile duct and posterior aspect of segment IV. Although catheterization into the caudate artery is occasionally difficult because of its small size and sharp angulation, selective embolization of a tumor feeder is a significant prognostic factor in patients with hepatocellular carcinoma originating there. Therefore, we should recognize the peculiarity of its vascular anatomy and should be familiar with catheterization and embolization techniques.

Advances in the interventional therapy of hepatocellular carcinoma originating from the caudate lobe

Hepatocellular carcinoma originating from the caudate lobe, also known as segment I hepatocellular carcinoma, is difficult to treat because of its special location, complex vascular supply, and the proximity of important vessels, bile ducts, and organs. This research is conducted to examine the efficacy and safety of interventional therapy for hepatocellular carcinoma in the caudate lobe.

Conclusion

Superselective chemoembolization and ablation techniques for the treatment of caudate lobe hepatocellular carcinoma still need to be improved. The combination of multiple interventional methods and the application of multiple imaging techniques can improve the effectiveness and safety of interventional therapy for hepatocellular carcinoma in the caudate lobe. Multidisciplinary treatment is also essential to improve the prognosis of patients with caudate lobe hepatocellular carcinoma.

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The anatomical characteristics of the arteries in the caudate lobe hepatocellular carcinoma remains an important factor restricting the success rate of superselective transcatheter arterial chemoembolization.

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The application of multiple imaging techniques may improve the effectiveness and safety of interventional therapy.

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The combination of multiple interventional methods has more advantages than disadvantages.

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Multidisciplinary treatment is increasingly becoming a trend in the treatment of caudate lobe hepatocellular carcinoma.

Superselective Transarterial Chemoembolization for Unresectable or "Ablation Unsuitable" Hepatocellular Carcinoma in the Caudate Lobe: A Real World, Single-Center Retrospective Study

OBJECTIVES

To analyze the clinical outcomes of Transarterial chemoembolization (TACE) for unresectable or "ablation unsuitable" hepatocellular carcinoma (HCC) in the caudate lobe (CL) found at initial presentation in clinical practice.

METHODS

Fifty-eight patients with HCC-CL undergoing conventional TACE from January 2015 to January 2020 were enrolled in our medical center. Overall survival (OS), progression-free survival (PFS), tumor response rate and major complication rates were analyzed. Multivariate analyses for potential clinical and radiologic factors were performed by using the Cox proportional hazard model.

RESULTS

The median OS was 23 months (95%CI: 18.1-27.9), and the median PFS was 11 months (95%CI: 7.4-14.6). The 1-, 3-, and 5-years OS rates were 66.5%, 31.9% and 15.7%, respectively. The 0.5, 1-, and 3-years PFS rates were 60.3%, 44.5% and 6.3%, respectively. Objective response rate was 53.4% and disease control rate was 79.3%. The most serious complication was bile duct injury, with an incidence of 3.4%. Multivariable analysis revealed that total bilirubin, Barcelona Clinic Liver Cancer stage, nonselective chemoembolization and TACE session were four significant factors associated with OS.

CONCLUSIONS

Superselective TACE treatment might be associated with better survival benefits in unresectable or "ablation unsuitable" HCC in the CL without macroscopic vascular invasion (MVI) and adequate liver function, compared with the non-selective TACE group, and should be considered as an important reliable therapy for surgeons and interventional radiologists.

Caudate Lobe Hepatocellular Carcinoma Treated with Sequential Transarterial Chemoembolization and Iodine 125 Seeds Implantation: A Single-Center Retrospective Study

Purpose

Resection of the hepatocellular carcinoma (HCC) in the caudate lobe (CL) is challenging even for accomplished surgeons. This retrospective study evaluated the safety and efficacy of transarterial chemoembolization (TACE) and iodine 125 seeds implantation (ISI) for unresectable or “ablation unsuitable” HCC-CL detected at the initial presentation in clinical practice.

Patients and Methods

A total of 20 HCC-CL patients undergoing sequential TACE and ISI from January 2014 to October 2018 were enrolled in this study. The overall survival (OS), progression-free survival (PFS), tumor response rate, and complication rates were analyzed and compared to non-caudate lobe (NCL) HCC patients. Multivariate analyses for potential clinical and radiological factors were performed using the Cox proportional hazard model.

Results

The technical success rate was 100%, as all the patients received 28 ISI treatments. The median OS was 35 months. The 1-, 3-, and 5-year OS rates were 100%, 63.2%, and 11.1%, respectively. The median PFS was 16 months. The objective response rate was 60.0%. The puncture tract bleeding (2/20) and pneumothorax (1/20) were the most common complications in operation, but no operation-related deaths occurred. One year after the surgery, biliary tract injury occurred in 1 patient, necessitating percutaneous biliary intervention. No statistical difference was observed between the CL and NCL groups. Multivariable analysis revealed that Barcelona Clinic Liver Cancer stage B and tumor size >3 cm were two significant factors associated with OS.

Conclusion

Sequential TACE and ISI were associated with the survival benefits in HCC-CL and should be considered as a reliable therapy for surgeons and interventional radiologists.

A predictive model of incomplete response after transarterial chemoembolization for early or intermediate stage of hepatocellular carcinoma: consideration of hepatic angiographic and cross-sectional imaging

OBJECTIVES

The purpose of the present study is to develop a predictive model for incomplete response (IR) after conventional transarterial chemoembolization (cTACE) for hepatocellular carcinoma (HCC) based on hepatic angiographic and cross-sectional imaging.

METHODS

Sixty patients with 139 target HCC lesions who underwent cTACE from February 2013 to March 2019 were included in this retrospective study. Hepatic angiographic features were identified: the number of feeding arteries, vascularity of the tumor, tumor staining on angiography, vascular lake phenomenon, and hepatic arterio-portal shunt. Cross-sectional imaging features were also identified: tumor extent, location, size, and enhancement pattern. Treatment response was assessed by the modified Response Evaluation Criteria in Solid Tumors (mRECIST) criteria. Logistic regression analysis was performed to determine the potential predictive factors for treatment response. To validate the predictive value of potential factors, the means of a decision tree were also calculated by Classification and Regression Tree (CART). P < 0.05 was considered statistically significant.

RESULTS

The IR rate was 43.2% (60/139) in the entire study population. Logistic regression analysis showed that a tumor size > 50 mm (P = 0.005; odds ratio, 7.25; 95% CI 1.79-29.33), central location (P = 0.007; odds ratio, 0.14; 95% CI 0.03-0.59), and nondense tumor staining (P < 0.001; odds ratio, 0.08; 95% CI 0.02-0.28) were predictors of IR after cTACE. Decision tree analysis showed a good ability to classify treatment response with an accuracy of 78.4%.

CONCLUSION

Tumor size > 50 mm, central tumor location, and nondense tumor staining were predictors of IR after cTACE. These factors should be taken into consideration when performing cTACE.

Benign Biliary Stricture after Yttrium-90 Radioembolization for Hepatocellular Carcinoma

PURPOSE

To determine the frequency and possible causative factors of benign biliary stricture after radioembolization in patients with hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

This retrospective study comprised 232 patients with HCC who underwent yttrium-90 radioembolization between October 2015 and September 2019. Benign biliary stricture was defined as biliary ductal dilatation of segmental or lobar biliary ducts on follow-up images. Clinical and radiologic characteristics were compared using χ² test or independent t test.

RESULTS

Mean target perfused tissue dose was 224.6 Gy ± 106.8 (median, 205.7 Gy; range, 47.0-694.7 Gy). Of 232 patients, 15 (6.5%) had benign biliary stricture, which was detected from 3 weeks to 10.3 months (mean, 3.9 months; median, 3.2 months). Whereas 5 patients did not have any symptoms or signs associated with benign biliary stricture, 10 patients had cholangitis and/or laboratory abnormality requiring biliary drainage procedures and intravenous antibiotic therapy. Selective radioembolization through a caudate artery was performed in 55 (23.7%) patients. The incidence of benign biliary stricture was 16.4% (9/55) and 3.4% (6/177) in patients with and without selective radioembolization through a caudate artery, respectively (P = .002).

CONCLUSIONS

Benign biliary stricture following yttrium-90 radioembolization may be common among patients receiving selective treatment via a caudate artery.

Selective Chemoembolization of Caudate Lobe Hepatocellular Carcinoma: Anatomy and Procedural Techniques

Transarterial chemoembolization is the most common treatment for unresectable hepatocellular carcinomas (HCCs). However, when an HCC is located in the caudate lobe, many interventional radiologists are reluctant to perform chemoembolization and percutaneous ablation owing to the tumor's complex vascular supply and deep location. With the advent of C-arm CT, rendering the three-dimensional display of the hepatic artery and detecting the tumor-feeding vessels are possible and can help guide interventional radiologists to the tumor. The common origins of the caudate artery include the right hepatic artery, left hepatic artery, right anterior hepatic artery, and right posterior hepatic artery. The origins of the tumor-feeding arteries of a caudate lobe HCC can vary depending on the tumor's subsegmental location. Caudate lobe HCCs are commonly fed by multiple caudate arteries that are connected. In addition, extrahepatic collateral arteries frequently supply recurrent tumors in the caudate lobe. The caudate artery can supply portal vein thrombi or biliary tumor thrombi in patients with HCC. Several techniques such as preshaping the microcatheter or using the shepherd's hook technique are needed to catheterize the caudate artery in complex cases. Although uncommon, bile duct stricture is a serious complication following selective chemoembolization through the caudate artery. Identification and catheterization of the caudate artery have become possible in most patients by using C-arm CT and a fine microcatheter system, respectively. The authors review the anatomy of the caudate artery with C-arm CT and describe basic technical considerations in selective chemoembolization for caudate lobe HCCs. Unusual circumstances that require catheterization and techniques used for catheterizing the caudate artery are also described. Online supplemental material is available for this article. ^©RSNA, 2019.

Yttrium-90 Radioembolization of the Right Inferior Phrenic Artery in 20 Patients with Hepatocellular Carcinoma

PURPOSE

To address the feasibility of infusion of yttrium-90 (⁹⁰Y) glass microspheres directly through the right inferior phrenic artery (RIPA).

MATERIALS AND METHODS

From November 2015 to May 2017, 20 patients underwent ⁹⁰Y radioembolization through the RIPA. When the systemic-to-pulmonary shunt was demonstrated on C-arm computed tomography (CT) of the RIPA, prophylactic embolization by polyvinyl alcohol (PVA) particles was performed prior to infusion of ⁹⁰Y glass microspheres. Follow-up CT scans were retrospectively reviewed for pulmonary complications. Tumor response was determined by the modified Response Evaluation Criteria in Solid Tumors.

RESULTS

Nine (45%) patients had systemic-to-pulmonary shunts on C-arm CT images of the RIPA. The feeder of the systemic-to-pulmonary shunt was the azygoesophageal branch (n = 7) and the anterior branch (n = 2). The mean activity of ⁹⁰Y glass microspheres infused into the RIPA was 0.49 GBq (range, 0.19-1.55 GBq). No patient had symptomatic radiation pneumonitis or cutaneous complications during follow-up. Seven patients had focal atelectasis (n = 5), focal ground-glass opacity (n = 2), and/or a small amount of pleural effusion (n = 2) on follow-up image. Best tumor response fed by the RIPA was complete response (n = 4), partial response (n = 9), stable disease (n = 2), progressive disease (n = 4), and unevaluable (n = 1).

CONCLUSION

The administration of ⁹⁰Y glass microspheres through the RIPA may be safe after embolization of a systemic-to-pulmonary shunt identified on C-arm CT.

Cone-beam computed tomography with automated bone subtraction in preoperative embolization for pelvic bone tumors

PURPOSE

To evaluate the usefulness of cone-beam computed tomography with automated bone subtraction (CBCT-ABS) in the preoperative embolization of hypervascular tumors located in the pelvic bone.

MATERIALS AND METHODS

This retrospective study included 26 patients with pelvic bone tumors who underwent preoperative embolization between January 2014 and October 2016. A CBCT-ABS scan was taken in a total of 17 patients (CBCT-ABS group), and only a series of digital subtraction angiographies (DSAs) was taken in the remaining 9 patients (DSA group). The percent devascularization, number of angiographic runs, total dose-area product (DAP), fluoroscopy time, interventional procedure time, operative time, and estimated blood loss were compared between the two groups using Mann-Whitney test.

RESULTS

The percent devascularization, interventional procedure time, fluoroscopy time, operative time, and estimated blood loss were not statistically different between the two groups (p > 0.05). On the other hand, the number of angiographic runs in the CBCT-ABS group was significantly lower than that in the DSA group (p = 0.029). The total DAP of the CBCT-ABS group (mean, 17700.7 μGym2) was higher than that of the DSA group (mean, 8939.4 μGym2) (p = 0.002).

CONCLUSIONS

The use of CBCT-ABS during the preoperative embolization of pelvic bone tumors significantly reduces the number of angiographic runs at the cost of an increased radiation dose.

The Role of Cone-Beam CT in Transcatheter Arterial Chemoembolization for Hepatocellular Carcinoma: A Systematic Review and Meta-analysis

PURPOSE

To review available evidence for use of cone-beam CT during transcatheter arterial chemoembolization in hepatocellular carcinoma (HCC) for detection of tumor and feeding arteries.

MATERIALS AND METHODS

Literature searches were conducted from inception to May 15, 2016, in PubMed (MEDLINE), Scopus, and Cochrane Central Register of Controlled Trials. Searches included "cone beam," "CBCT," "C-arm," "CACT," "cone-beam CT," "volumetric CT," "volume computed tomography," "volume CT," AND "liver," "hepatic*," "hepatoc*." Studies that involved adults with HCC specifically and treated with transcatheter arterial chemoembolization that used cone-beam CT were included.

RESULTS

Inclusion criteria were met by 18 studies. Pooled sensitivity of cone-beam CT for detecting tumor was 90% (95% confidence interval [CI], 82%-95%), whereas pooled sensitivity of digital subtraction angiography (DSA) for tumor detection was 67% (95% CI, 51%-80%). Pooled sensitivity of cone-beam CT for detecting tumor feeding arteries was 93% (95% CI, 91%-95%), whereas pooled sensitivity of DSA was 55% (95% CI, 36%-74%).

CONCLUSIONS

Cone-beam CT can significantly increase detection of tumors and tumor feeding arteries during transcatheter arterial chemoembolization. Cone-beam CT should be considered as an adjunct tool to DSA during transcatheter arterial chemoembolization treatments of HCC.

Diameter of main tumor feeding artery of a hepatocellular carcinoma: Measurement at the entry site into the nodule

AIM

To measure the diameter of the main tumor feeding artery (TFA) of a hepatocellular carcinoma (HCC) nodule at the entry site into the nodule.

METHODS

Fifty-seven HCC nodules in 43 patients were analyzed using a 3-D workstation and picture archiving system (PACS). TFA was defined as an artery connected to a HCC nodule on catheter-assisted multidetector computed tomography angiography (CAMDCTA). The entry site of the main TFA into the nodule was identified on CAMDCTA, and the corresponding portion was measured on digital angiography (DA) or digital subtracted angiography (DSA). The measuring scale of the PACS was calibrated using the platinum tip of microballoon catheters 0.68 mm in diameter. We investigated the relationship between diameters of the nodule and its main TFA.

RESULTS

The diameters of the nodule and its main TFA ranged 7-63 mm (20.3 ± 12.7) and 0.12-1.79 mm (0.41 ± 0.32), respectively. Simple regression analysis revealed a relationship between diameters of the nodule and its main TFA (P < 0.0001). The diameter of the main TFA was less than 1 mm in 53 of 57 nodules (93.0%), and less than 0.5 mm in 42 (73.7%).

CONCLUSION

The diameter of main TFA was thicker in the larger nodule. The size of commercially available porous gelatin particles (1 or 2 mm in diameter) seems too large for embolization of most of HCC nodules.

The Safety and Clinical Outcomes of Chemoembolization in Child-Pugh Class C Patients with Hepatocellular Carcinomas

OBJECTIVE

To evaluate the safety and clinical outcomes of chemoembolization in Child-Pugh class C patients with hepatocellular carcinomas (HCC).

MATERIALS AND METHODS

The study comprised 55 patients with HCC who were classified as Child-Pugh class C and who underwent initial chemoembolization between January 2003 and December 2012. Selective chemoembolization was performed in all technically feasible cases to minimize procedure-related complications. All adverse events within 30 days were recorded using the Common Terminology Criteria for Adverse Events (CTCAE). The tumor response to chemoembolization was evaluated using the modified Response Evaluation Criteria In Solid Tumors.

RESULTS

Thirty (54.5%) patients were within the Milan criteria, and 25 (45.5%) were beyond. The mortality of study subjects at 30 days was 5.5%. Major complications were observed in five (9.1%) patients who were all beyond the Milan criteria: two hepatic failures, one hepatic encephalopathy, and two CTCAE grade 3 increases in aspartate aminotransferase/alanine aminotransferase abnormality. The mean length of hospitalization was 6.3 ± 8.3 days (standard deviation), and 18 (32.7%) patients were discharged on the next day after chemoembolization. The tumor responses of the patients who met the Milan criteria were significantly higher (p = 0.014) than those of the patients who did not. The overall median survival was 7.1 months (95% confidence interval: 4.4-9.8 months).

CONCLUSION

Even in patients with Child-Pugh class C, chemoembolization can be performed safely with a selective technique in selected cases with a small tumor burden.

Does Establishing a Safety Margin Reduce Local Recurrence in Subsegmental Transarterial Chemoembolization for Small Nodular Hepatocellular Carcinomas?

Objective

To test the hypothesis that a safety margin may affect local tumor recurrence (LTR) in subsegmental chemoembolization.

Materials and Methods

In 101 patients with 128 hepatocellular carcinoma (HCC) nodules (1-3 cm in size and ≤ 3 in number), cone-beam CT-assisted subsegmental lipiodol chemoembolization was performed. Immediately thereafter, a non-contrast thin-section CT image was obtained to evaluate the presence or absence of intra-tumoral lipiodol uptake defect and safety margin. The effect of lipiodol uptake defect and safety margin on LTR was evaluated. Univariate and multivariate analyses were performed to indentify determinant factors of LTR.

Results

Of the 128 HCC nodules in 101 patients, 49 (38.3%) nodules in 40 patients showed LTR during follow-up period (median, 34.1 months). Cumulative 1- and 2-year LTR rates of nodules with lipiodol uptake defect (n = 27) and those without defect (n = 101) were 58.1% vs. 10.1% and 72.1% vs. 19.5%, respectively (p < 0.001). Among the 101 nodules without a defect, the 1- and 2-year cumulative LTR rates for nodules with complete safety margin (n = 52) and those with incomplete safety margin (n = 49) were 9.8% vs. 12.8% and 18.9% vs. 19.0% (p = 0.912). In multivariate analyses, ascites (p = 0.035), indistinct tumor margin on cone-beam CT (p = 0.039), heterogeneous lipiodol uptake (p = 0.023), and intra-tumoral lipiodol uptake defect (p < 0.001) were determinant factors of higher LTR.

Conclusion

In lipiodol chemoembolization, the safety margin in completely lipiodolized nodule without defect will not affect LTR in small nodular HCCs.

Role of C-arm cone-beam CT in chemoembolization for hepatocellular carcinoma

With the advent of C-arm cone-beam computed tomography (CBCT), minimally-invasive procedures in the angiography suite made a new leap beyond the limitations of 2-dimensional (D) angiography alone. C-arm CBCT can help interventional radiologists in several ways with the treatment of hepatocellular carcinoma (HCC); visualization of small tumors and tumor-feeding arteries, identification of occult lesion and 3D configuration of tortuous hepatic arteries, assurance of completeness of chemoembolization, suggestion of presence of extrahepatic collateral arteries supplying HCCs, and prevention of nontarget embolization. With more improvements in the technology, C-arm CBCT may be essential in all kinds of interventional procedures in the near future.

Chemoembolization of extrahepatic collateral arteries for treatment of hepatocellular carcinoma in the caudate lobe of the liver

PURPOSE

This study was designed to evaluate the efficacy and safety in performing chemoembolization of extrahepatic collateral arteries (EHC) for hepatocellular carcinoma (HCC) located in the caudate lobe.

METHODS

Between January 2006 and November 2013, chemoembolization via EHC was performed in 35 patients with 35 caudate HCCs. Preprocedural and follow-up CT or MR scans, angiographic images, and medical records were reviewed retrospectively in consensus. Chi-square analysis was used to evaluate the relationship between tumor characteristics and type of EHC and that between tumor response and the characteristics of the tumor and chemoembolization.

RESULTS

In 31 (88.6 %) patients, EHCs supplying the caudate HCC originated from the right inferior phrenic artery (RIPA). The remaining four HCCs were supplied by the gastroduodenal artery, dorsal pancreatic artery, and right and left gastric arteries. Superselective catheterization of tumor-feeding vessels from the EHC was achieved in 27 patients (77.1 %). There were no major complications. Individual tumor response supplied by the EHC at follow-up contrast-enhanced CT were as follows: complete response (n = 18), partial response (n = 9), stable disease (n = 3), and progressive disease (n = 3). Non-RIPA EHCs were significantly more common in patients who had previously received chemoembolization via the RIPA (50 %) than those who had not (6.5 %; P = 0.01). There was no significant predictive factor associated with tumor response.

CONCLUSIONS

HCC in the caudate lobe can be supplied by several EHCs. Chemoembolization via these arteries can be performed safely and effectively.