Interventional Radiology for Bleeding Ectopic Varices: Individualized Approach Based on Vascular Anatomy.

Ectopic varices are rare but potentially life-threatening conditions usually resulting from a combination of global portal hypertension and local occlusive components. As imaging, innovative devices, and interventional radiologic techniques evolve and are more widely adopted, interventional radiology is becoming essential in the management of ectopic varices. The interventional radiologist starts by diagnosing the underlying causes of portal hypertension and evaluating the afferent and efferent veins of ectopic varices with CT. If decompensated portal hypertension is causing ectopic varices, placement of a transjugular intrahepatic portosystemic shunt is considered the first-line treatment, although this treatment alone may not be effective in managing ectopic variceal bleeding because it may not sufficiently resolve focal mesenteric venous obstruction causing ectopic varices. Therefore, additional variceal embolization should be considered after placement of a transjugular intrahepatic portosystemic shunt. Retrograde transvenous obliteration can serve as a definitive treatment when the efferent vein connected to the systemic vein is accessible. Antegrade transvenous obliteration is a vital component of interventional radiologic management of ectopic varices because ectopic varices often exhibit complex anatomy and commonly lack catheterizable portosystemic shunts. Superficial veins of the portal venous system such as recanalized umbilical veins may provide safe access for antegrade transvenous obliteration. Given the absence of consensus and guidelines, a multidisciplinary team approach is essential for the individualized management of ectopic varices. Interventional radiologists must be knowledgeable about the anatomy and hemodynamic characteristics of ectopic varices based on CT images and be prepared to consider appropriate options for each specific situation. ©RSNA, 2024 Supplemental material is available for this article.

Ethiodized oil as an imaging biomarker after conventional transarterial chemoembolization.

Conventional transarterial chemoembolization (cTACE) utilizing ethiodized oil as a chemotherapy carrier has become a standard treatment for intermediate-stage hepatocellular carcinoma (HCC) and has been adopted as a bridging and downstaging therapy for liver transplantation. Water-in-oil emulsion made up of ethiodized oil and chemotherapy solution is retained in tumor vasculature resulting in high tissue drug concentration and low systemic chemotherapy doses. The density and distribution pattern of ethiodized oil within the tumor on post-treatment imaging are predictive of the extent of tumor necrosis and duration of response to treatment. This review describes the multiple roles of ethiodized oil, particularly in its role as a biomarker of tumor response to cTACE. CLINICAL RELEVANCE: With the increasing complexity of locoregional therapy options, including the use of combination therapies, treatment response assessment has become challenging; Ethiodized oil deposition patterns can serve as an imaging biomarker for the prediction of treatment response, and perhaps predict post-treatment prognosis. KEY POINTS: • Treatment response assessment after locoregional therapy to hepatocellular carcinoma is fraught with multiple challenges given the varied post-treatment imaging appearance. • Ethiodized oil is unique in that its' radiopacity can serve as an imaging biomarker to help predict treatment response. • The pattern of deposition of ethiodozed oil has served as a mechanism to detect portions of tumor that are undertreated and can serve as an adjunct to enhancement in order to improve management in patients treated with intraarterial embolization with ethiodized oil.

Hepatocellular Carcinoma Supplied by the Inferior Phrenic Artery or Cystic Artery: Anatomic and Technical Considerations.

Intra-arterial treatment has been identified as one of the mainstays in the management of unresectable hepatocellular carcinoma. A thorough knowledge of tumor arterial supply enables selective therapy, which improves both safety and efficacy. The inferior phrenic artery (IPA) is the most common extrahepatic collateral artery that feeds hepatocellular carcinoma. The bilateral IPAs are known to have a specific vascular anatomy. A systemic-to-pulmonary shunt and a gastric branch from the IPAs may be present and should not be confused with tumor blush. The supraceliac aorta and celiac trunk are the common origin sites of the IPAs, and their orifice may be compressed by the diaphragm. Various techniques and catheters are used for catheterization of the IPAs, depending on their origin sites. Because the IPA is normally connected with the intercostal, internal mammary, retroperitoneal, and hepatic arteries, its hemodynamics may be altered when its orifice is occluded. In general, superselective chemoembolization via the target branch of the IPA is safe and effective. When a systemic-to-pulmonary shunt from the IPA is adequately embolized with coils or particles, radioembolization through the IPA can be performed safely in most cases. The cystic artery branches into deep and superficial cystic arteries; deep cystic arteries often supply tumors near the gallbladder. Chemoembolization through the cystic artery is relatively safe, with transient embolic materials. Radioembolization through the cystic artery has been recently tried, with acceptable efficacy and toxicity results, but it requires further investigation. ©RSNA, 2022.

Response Evaluation Criteria in Cancer of the liver version 6 (Response Evaluation Criteria in Cancer of the Liver 2021 revised version).

Response Evaluation Criteria in Solid Tumors (RECIST) is inappropriate to assess the direct effects of treatment on hepatocellular carcinoma (HCC) by locoregional therapies, such as radiofrequency ablation or transarterial chemoembolization. Therefore, establishment of response evaluation criteria solely devoted to HCC is needed in clinical practice, as well as in clinical trials of HCC treatment, such as systemic therapies, which cause necrosis of the tumor. Response Evaluation Criteria in Cancer of the Liver (RECICL) was revised in 2021 by the Liver Cancer Study Group of Japan based on the 2019 version of RECICL, which was commonly used in Japan. The major revised points of the RECICL 2021 is inclusion of RECIST version 1.1 and modified RECIST as response evaluation criteria in systemic therapy for HCC. We hope this new treatment response criteria, RECICL, proposed by the Liver Cancer Study Group of Japan will benefit the HCC treatment response evaluation in the setting of daily clinical practice and clinical trials as well, not only in Japan, but also internationally.

Usefulness of virtual parenchymal perfusion software visualizing embolized areas to determine optimal catheter position in superselective conventional transarterial chemoembolization for hepatocellular carcinoma.

AIM: To determine the optimal catheter position during superselective conventional transarterial chemoembolization (cTACE) for hepatocellular carcinoma (HCC) using virtual parenchymal perfusion software. METHODS: Patients who had newly developed HCC nodules ≤6 cm and five or fewer lesions were eligible. The virtual catheter tip was placed on a tumor-feeder identified by TACE guidance software using cone-beam computed tomography during hepatic arteriography to minimize the virtual embolized area (VEA), including the tumor with a safety margin. Conventional transarterial chemoembolization was then carried out at the same position. The VEA and real embolized area where iodized oil was retained on cone-beam computed tomography after cTACE were compared using the dice similarity coefficient, linear regression analysis, and mean surface distance. Technical success of cTACE and therapeutic effects by the modified Response Evaluation Criteria in Solid Tumors were also evaluated. RESULTS: Ninety-one tumors in 56 patients were embolized. The mean dice similarity coefficient values in 80 VEAs and real embolized areas were 0.78 ± 0.01. Both volumes were well correlated (r = 0.957, p < 0.001) with a mean surface distance of 2.78 ± 2.11 mm. Eighty-four (92.3%) tumors were embolized with a safety margin. Regarding the early response of 82 tumors, complete response was achieved in 72 (87.8%), partial response in six (7.3%), and stable disease in four (4.9%). Regarding responses of 81 tumors during the follow-up (mean, 20 ± 4.9 months), complete response was maintained in 62 (76.5%), whereas 19 (23.5%), including six that were incompletely embolized, locally progressed. CONCLUSION: Virtual parenchymal perfusion software can determine the optimal catheter position in superselective cTACE.

Outcomes of Patients with Hepatocellular Carcinoma Treated with Conventional Transarterial Chemoembolization Using Guidance Software.

PURPOSE: To evaluate the outcomes of conventional transarterial chemoembolization using guidance software for hepatocellular carcinoma (HCC) patients. MATERIALS AND METHODS: One hundred two patients with treatment-naïve HCC with ≤ 7-cm and ≤ 5 lesions treated with conventional transarterial chemoembolization using guidance software were selected. Technical success was classified into 3 grades by computed tomography performed 1 week after transarterial chemoembolization: (i) A, complete embolization with a safety margin; (ii) B, entire tumor embolization without a safety margin; and (iii) C, incomplete embolization. Intrahepatic tumor recurrence was classified into 2 categories: local tumor progression (LTP) and intrahepatic distant recurrence (IDR). Overall survival (OS) and tumor recurrence rates were calculated by the Kaplan-Meier method. Additionally, the incidences of LTP between grade A and B tumors, IDR with/without LTP, and OS with/without LTP were compared by the log-rank test. RESULTS: One hundred fifty-six (82.1%) tumors were determined to be grade A, 26 (13.7%) were determined to be grade B, and 8 (4.2%) were determined to be grade C. The 1-, 3-, and 5-year LTP and IDR rates were 31.7%, 49.4%, and 59.4% and 33.9%, 58.2%, and 73.3%, respectively. LTP developed more frequently in grade B tumors than grade A tumors (P = .0016). IDR developed more frequently in patients with LTP than without LTP (P = .0004). The 1-, 3-, and 5-year OS rates were 96.1%, 71.1%, and 60%, respectively; the 1-, 3-, and 5-year OS rates in patients with/without LTP were 95.7%, 69.8%, and 59.3% and 96.2%, 71.6%, and 59.4%, respectively (P = .9984). CONCLUSIONS: Transarterial chemoembolization guidance software promotes the technical success of transarterial chemoembolization and excellent OS in HCC patients.

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.

Outcomes of conventional transarterial chemoembolization for hepatocellular carcinoma ≥10 cm.

AIM: To retrospectively evaluate the outcomes of conventional transarterial chemoembolization (cTACE) for hepatocellular carcinoma (HCC) ≥10 cm. METHODS: Twenty-five patients with naïve HCC ≥10 cm (mean maximum tumor diameter, 130 ± 27.6 mm; single [n = 12], 2-9 [n = 6], and ≥10 [n = 7]) without extrahepatic spread treated with cTACE were eligible. Five (20%) had vascular invasion. Two to three stepwise cTACE sessions using iodized oil ≤10 mL in one cTACE session were scheduled. When the tumor recurred, additional cTACE was repeated on demand, if possible. Overall survival (OS) rates were calculated using the Kaplan-Meier method. The prognostic factors were evaluated using uni- and multivariate analyses. RESULTS: Stepwise cTACE sessions were completed for 20 (80%) patients, but could not be completed for four (16%). In the remaining (4%) patient, the whole tumor was embolized in one session. Additional treatment, mainly cTACE, was undertaken for 19 (76%) patients. The OS rates at 1, 3, and 5 years were 68, 34.7, and 23.1%, respectively. A tumor number of three was a significant prognostic factor (P = 0.020) and the 1-, 3-, and 4-year OS rates in patients with ≤3 and ≥4 tumors were 81.3 and 33.3, 55.6 and 11.1, and 38.9% and 0%, respectively. Whole tumor embolization and the serum level of protein induced by vitamin K absence or antagonist-II were also significant prognostic factors (P < 0.001 and P = 0.042, respectively). Bile duct complications requiring additional interventions developed in two (8%) patients. CONCLUSION: Conventional TACE is safe and effective for huge HCCs, but has limited effects in cases with four or more tumors.

Response Evaluation Criteria in Cancer of the Liver version 5 (RECICL 2019 revised version).

Response Evaluation Criteria in Solid Tumors (RECIST) is inappropriate to assess the direct effects of treatment on hepatocellular carcinoma (HCC) by locoregional therapies, such as radiofrequency ablation and transarterial chemoembolization. Therefore, establishment of response evaluation criteria solely devoted to HCC is needed in clinical practice, as well as in clinical trials of HCC treatment, such as systemic therapies, which cause necrosis of the tumor. Response Evaluation Criteria in Cancer of the Liver (RECICL) was revised in 2019 by the Liver Cancer Study Group of Japan based on the 2015 version of RECICL, which was commonly used in Japan. The major revised points of the RECICL 2019 are as follows: (i) CEA and CA19-9 have been newly added as tumor markers that should be recorded for use as criteria in the response evaluation for intrahepatic cholangiocarcinoma; (ii) the criteria now state that the details of molecular targeted therapy should be specified; and (iii) specific methods for overall evaluation are now described. Also, as an assessment of overall TE4 requires that TE4 is achieved in all nodules (even non-target lesions), the same calculation methods described above are used. We hope this new treatment response criteria, RECICL, proposed by the Liver Cancer Study Group of Japan will benefit the HCC treatment response evaluation in the setting of daily clinical practice and clinical trials as well, not only in Japan, but also internationally.

Isolated Arteries Originating from the Intrahepatic Arteries: Anatomy, Function, and Importance in Intervention.

Isolated hepatic arteries are defined as hepatic terminal arterioles that are not accompanied by portal venules or bile ductules and penetrate the liver parenchyma and distribute to the hepatic capsule and intrahepatic hepatic veins. Abundant communications exist between intra- and extrahepatic arteries through isolated arteries and capsular arterial plexus. They play a principal role in the development of subcapsular hemorrhage and arterial collateral formation following transcatheter arterial chemoembolization for liver cancers. The anatomy, function, and clinical importance of isolated hepatic arteries in interventional radiology, especially regarding subcapsular hemorrhage and arterial collateral formation, are highlighted in this article.

Performance of novel virtual parenchymal perfusion software visualizing embolized areas of transcatheter arterial chemoembolization for hepatocellular carcinoma.

AIM: To evaluate the performance of novel virtual parenchymal perfusion (VPP) software in conventional transcatheter arterial chemoembolization (cTACE) for hepatocellular carcinoma. METHODS: VPP was retrospectively applied to 43 hepatocellular carcinomas treated with cTACE. The virtual embolized area (VEA) was estimated after positioning a virtual injection point on images of non-selective cone-beam computed tomography during hepatic arteriography, at the same position in superselective cTACE. The real embolized area (REA) was defined as the area where iodized oil was retained on 1-week computed tomography after cTACE. Three dimensions across the tumor (maximum [a] and minimum [b] in the axial and craniocaudal [c]) directions, and the volume of the VEA and REA were compared using linear regression analysis. It was also evaluated whether an adequate safety margin ≥5 mm could be predicted by VPP. RESULTS: The mean lengths of a, b, and c of the VEA and REA were 54.6 ± 15.9 mm (range 24.9-91.0 mm) and 55.0 ± 15.7 mm (range 23.9-92.8 mm; r = 0.9448, P < 0.001), 35.4 ± 11.7 mm (range 16.1-66.0 mm) and 35.4 ± 13.2 mm (range 12.2-69.2 mm; r = 0.9369, P < 0.001), and 42.1 ± 11.6 mm (range 25.0-75.7 mm) and 42.9 ± 11.7 mm (range 25.7-78.7 mm; r = 0.9092, P < 0.001), respectively. The mean volume of the VEA and REA was 71.8 ± 44.8 mL and 75.5 ± 46.9 mL, respectively (r = 0.9913, P < 0.0001). VPP showed no safety margins in seven tumors, including all three actually embolized without safety margins. CONCLUSION: The VEA estimated using VPP showed a good correlation with the REA of cTACE.

Excretion of necrotic hepatocellular carcinoma tissues into the biliary system after transcatheter arterial chemoembolization.

AIM: To evaluate the incidence and condition of necrotic tumor excretion into the biliary system in patients with hepatocellular carcinoma (HCC) >5 cm treated with conventional transcatheter arterial chemoembolization (TACE). METHODS: Eighty-three patients who underwent TACE for newly developed HCC >5 cm without an intraductal tumor thrombus and were followed-up by computed tomography for longer than 6 months were eligible. According to the location, the maximum tumors were divided into central (in contact with the left or right hepatic duct, n = 39) or peripheral (not in contact with them, n = 44). When high-density material in the biliary system that was not seen on pretreatment computed tomography was identified, it was determined as excreted necrotic tumor tissue containing iodized oil. The incidence, interval between TACE and occurrence of the necrotic tumor excretion, and clinical course were evaluated. RESULTS: Tumor excretion into the biliary system was identified in nine (10.8%) patients with a central tumor (mean diameter, 85.0 ± 29.6 mm) 28-433 days (mean, 219.3 ± 128.2) after the initial TACE. In one patient, the necrotic tumor cast caused cholangitis 1203 days after the initial TACE, and was endoscopically removed. Infection of the embolized tumor developed in two cases and percutaneous drainage was carried out 105 and 158 days later, respectively. CONCLUSIONS: Excretion of necrotic tumors into the biliary system after TACE was not rare in patients with centrally located HCC >5 cm. The detached tumor rarely caused symptoms and the communication between the tumor and bile duct caused the infection of tumors.

Superselective Conventional Transarterial Chemoembolization for Hepatocellular Carcinoma: Rationale, Technique, and Outcome.

Conventional transarterial chemoembolization with ethiodized oil and gelatin sponge (GS) particles is a standard technique for hepatocellular carcinoma. Ethiodized oil can temporarily block tumor sinusoids, portal venules, hepatic sinusoids, and arterial microcommunications. By adding GS embolization, strong ischemic effects not only on the tumor but also on the surrounding liver parenchyma can be achieved. Superselective conventional transarterial chemoembolization is mainly indicated for patients with Child-Pugh scores of 5-8, tumors ≤ 7 cm, and ≤ 5 lesions. According to a Japanese nationwide survey, the 5-year survival rate of patients with Child-Pugh class A and a single tumor was 52%.

Efficacy of automated tumor-feeder detection software using cone-beam computed tomography technology in transarterial embolization through extrahepatic collateral vessels for malignant hepatic tumors.

AIM: We evaluated the performance of automated tumor-feeder detection (AFD) software using cone-beam computed tomography technology in identifying tumor-feeders of extrahepatic collaterals. METHODS: AFD was prospectively used in superselective transarterial chemoembolization (TACE) or embolization (TAE) of extrahepatic collaterals for 29 hepatocellular carcinomas and one liver metastasis (mean tumor diameter ± standard deviation, 28 ± 15.6 mm) in 25 patients. The detectability of extrahepatic tumor-feeders with non-selective digital subtraction angiography (DSA) and AFD was evaluated and compared using a χ(2) -test. Tumor response of target lesions in each patient at 2-3 months after treatment was evaluated using the modified Response Evaluation Criteria in Solid Tumors. Complications were also evaluated. RESULTS: Of 46 tumor-feeders, non-selective DSA and AFD could identify 26 and 44, respectively (P < 0.001). Regarding the origin of tumor-feeders, both non-selective DSA and AFD could identify 14 of 15, six of seven and two of two tumor-feeders of the right inferior phrenic, omental and right renal capsular artery, respectively. In the cystic and left gastric or right colic artery, AFD could identify 13 of 13 and nine of nine tumor-feeders but non-selective DSA could identify only three of 13 and one of nine, respectively (P < 0.001). Complete response was obtained in 15 patients, partial response in six, stable disease in three and progressive disease in one. No severe complications developed except for right pleural effusion after embolization of the right inferior phrenic artery. CONCLUSION: AFD has a sufficient ability to identify extrahepatic tumor-feeders and may improve the safety and local effects of TACE/TAE of extrahepatic collaterals.

Evaluation of tumor recurrence after superselective conventional transcatheter arterial chemoembolization for hepatocellular carcinoma: Comparison of computed tomography and gadoxetate disodium-enhanced magnetic resonance imaging.

AIM: To retrospectively evaluate the detectability of tumor recurrence with computed tomography (CT) and magnetic resonance imaging (MRI) after superselective conventional transcatheter arterial chemoembolization (cTACE) for hepatocellular carcinoma (HCC). METHODS: The detectability of tumor recurrence with CT and gadoxetate disodium-enhanced MRI obtained within 30 days (mean, 16.9 ± 10.1) were compared in 38 patients with recurrent HCC after superselective cTACE. Tumor recurrence was divided into local and distant recurrence. Local recurrence was also divided into intratumoral and peritumoral recurrence. RESULTS: Tumor recurrence (maximum diameter, 19.7 ± 10.1 mm) was demonstrated by images 12.4 ± 11.7 months after cTACE. CT could depict 16 (76.2%) of 21 intratumoral recurrences in 12 patients and 14 (53.8%) of 26 peritumoral recurrences in 11, as well as 39 (55.7%) of 70 distant recurrences in 15 (75%) of 20 patients. Arterial phase MRI could depict 20 (95.2%) of 21 intratumoral recurrences in 14 patients and all 26 (100%) peritumoral recurrences in 21, as well as 60 (85.7%) distant recurrences in all 20 (100%) patients. The detectability of tumor recurrence with MRI was significantly higher than that with CT (P = 0.00549). On MRI, pseudolesions were observed in five (13.2%) patients and artifacts in the arterial phase in five (13.2%). Regarding the diagnostic performance, CT was superior to MRI in two (5.3%) patients and MRI was superior to CT in 19 (50%). They were almost equal in 17 (44.7%). CONCLUSION: The detectability of tumor recurrence after superselective cTACE with gadoxetate disodium-enhanced MRI was superior to that of CT.

Development of Conventional Transarterial Chemoembolization for Hepatocellular Carcinomas in Japan: Historical, Strategic, and Technical Review.

OBJECTIVE: This article reviews the development of transarterial chemoembolization (TACE) in Japan, particularly ethiodized oil-based conventional TACE, from historical, strategic, and technical points of view. We also present the current status of standardized conventional TACE. CONCLUSION: Conventional TACE has been developed toward a more-selective and hemodynamic-conscious method, along with technical innovation and knowledge accumulation. Standardization of this method is necessary for further scientific evaluation.

Usefulness of automated feeder-detection software for identification of access routes to small pancreaticoduodenal artery aneurysms during embolotherapy.

The mortality rate of patients with ruptured pancreaticoduodenal artery aneurysms is high; therefore, it is recommended to treat pancreaticoduodenal artery aneurysms regardless of their size. In small pancreaticoduodenal artery aneurysms, however, identification of the access route on two-dimensional arteriography is sometimes difficult because of the superimposition of many hypertrophied branches of pancreaticoduodenal arteries on the aneurysm. We report two cases of ruptured pancreaticoduodenal artery aneurysm embolized successfully with metallic coils, assisted by automated feeder-detection software using cone-beam computed tomography data. This new technology may reduce physicians' workload during the procedure.

Transarterial chemoembolization failure/refractoriness: JSH-LCSGJ criteria 2014 update.

In the 2010 version of the Japan Society of Hepatology (JSH) consensus-based treatment algorithm for the management of hepatocellular carcinoma (HCC), transarterial chemoembolization (TACE) failure/refractoriness was defined assuming the use of superselective lipiodol TACE, which has been widely used worldwide and particularly in Japan, and areas with lipiodol deposition were considered to be necrotic. However, this concept is not well accepted internationally. Furthermore, following the approval of microspheres, an embolic material that does not use lipiodol, in February 2014 in Japan, the phrase 'lipiodol deposition' needed to be changed to 'necrotic lesion or viable lesion'. Accordingly, the respective section in the JSH guidelines was revised to define TACE failure as an insufficient response after ≥2 consecutive TACE procedures that is evident on response evaluation computed tomography or magnetic resonance imaging after 1-3 months, even after chemotherapeutic agents have been changed and/or the feeding artery has been reanalyzed. In addition, the appearance of a higher number of lesions in the liver than that recorded at the previous TACE procedure (other than the nodule being treated) was added to the definition of TACE failure/refractoriness. Following the discussion of other issues concerning the continuous elevation of tumor markers, vascular invasion, and extrahepatic spread, descriptions similar to those in the previous version were approved. The revision of these TACE failure definitions was approved by over 85% of HCC experts.

Ultraselective transcatheter arterial chemoembolization for small hepatocellular carcinoma guided by automated tumor-feeders detection software: technical success and short-term tumor response.

PURPOSE: To analyze the technical success and tumor response of ultraselective transcatheter arterial chemoembolization (TACE) for small hepatocellular carcinoma (HCC) using automated tumor-feeders detection (AFD) software. METHODS: Prototype AFD software was prospectively applied to cone-beam computed tomography images acquired during TACE for 155 consecutive HCCs ≤50 mm in 81 patients. The detectability of tumor-feeding subsubsegmental arteries was analyzed. Technical success of TACE was classified into three grades according to 1-week CT; the tumor was embolized with a safety margin (5 mm wide for tumors <25 mm, and 10 mm wide for tumors ≥25 mm) (grade A), without a margin in parts (grade B), or the entire tumor was not embolized (grade C). Tumor response at 2-3 months after TACE was also evaluated in 71 patients using the modified Response Evaluation Criteria in Solid Tumors. RESULTS: One-hundred and twenty-eight (82.6%) tumors were classed as grade A, 17 (11%) as grade B, and 10 (6.5%) as grade C. AFD software could identify 211 (85.4%) of 247 tumor-feeders but not 36 (14.6%). Eighteen (7.9%) were false positive. The tumor response of target lesions in each patient was complete response (CR) in 49 (69%) patients, partial response (PR) in 19 (26.8%), and stable disease (SD) in 3 (4.2%). The overall tumor response was CR in 39 (54.9%) patients, PR in 15 (21.2%), SD in 1 (1.4%), and progressive disease in 16 (22.5%). CONCLUSIONS: AFD software has sufficient performance to identify tumor-feeders and contributes to the high technical success in ultraselective TACE.

Transarterial Therapy for Hepatocellular Carcinoma Invading the Bile Duct.

Hepatocellular carcinoma invading the bile duct (bile duct tumor thrombus) is an unfavorable condition. Although overall survival following surgical resection among patients with hepatocellular carcinoma with bile duct tumor thrombus is significantly better than that among those treated with transarterial chemoembolization or chemotherapy, surgical resection can be indicated for selected patients. Additionally, systemic therapy is indicated only for patients with Child-Pugh class A. Therefore, transarterial therapy plays an essential role in the treatment of bile duct tumor thrombus. Transarterial chemoembolization with iodized oil and gelatin sponge particles is an established first-line transarterial treatment that can necrotize most bile duct tumor thrombi. However, we should pay attention to symptoms caused by intraductal hemorrhage during transarterial chemoembolization and the sloughing of necrotized bile duct tumor thrombi.