Therapeutic effect of transcatheter oily chemoembolization therapy for encapsulated nodular hepatocellular carcinoma: CT and pathologic findings

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.

Preoperative Balloon-Occluded Transcatheter Arterial Chemoembolization Followed by Surgical Resection: Pathological Evaluation of Necrosis

This study investigates the clinical and pathological outcomes of preoperative balloon-occluded transcatheter arterial chemoembolization (B-TACE) in patients with single hepatocellular carcinoma (HCC). The data are from 25 consecutive patients who underwent sequential treatment of subsegmental B-TACE and hepatic surgery for single HCC. Radiological and pathological evaluation of oily subsegmentectomy, defined as the iodized oil-laden necrotic area that includes the entire HCC and surrounding liver parenchyma, were performed. Subsegmental B-TACE was technically successful in all patients. The major and minor complication rates were 8% and 24%, respectively. On the first follow-up computed tomography (CT), oily subsegmentectomy was observed in 18 (72%) out of 25 patients. Apart from one patient showing a partial response, the remaining 24 (96%) patients showed a complete response. Pathological complete necrosis of the HCC was observed in 18 (72%) out of 25 patients with complete or extensive necrosis of the peritumoral liver parenchyma. The remaining seven patients without peritumoral parenchymal necrosis had extensive necrosis of the HCCs. In conclusion, preoperative B-TACE can be a safe and effective method for the treatment of single HCC and a good bridge treatment for subsequent surgical resection. In addition, oily subsegmentectomy itself on the CT can be a good predictor of pathological complete necrosis of the HCC. The findings obtained from this study would provide a potential role of B-TACE in the treatment strategy for single HCC.

Local Recurrence following Radiological Complete Response in Patients Treated with Subsegmental Balloon-Occluded Transcatheter Arterial Chemoembolization for Hepatocellular Carcinoma

The aim of this study was to determine the local recurrence (LR) rate and identify factors associated with LR in patients who achieve a radiological complete response (CR) after undergoing balloon-occluded transcatheter arterial chemoembolization (B-TACE) for hepatocellular carcinoma (HCC). From November 2017 to September 2021, 60 patients (44 men, 16 women; mean age, 63.5 years; range, 39-82 years) with 72 HCCs (mean diameter, 31 mm; range, 10-50 mm) who underwent subsegmental B-TACE were included in this retrospective study. Radiological and clinical evaluation of oily subsegmentectomy, defined as radiological CR of the HCC and peritumoral parenchymal necrosis, was performed. The CR rate was 97.2% (70 of 72 HCCs) at first follow-up (mean, 41 days; range, 14-110 days). Overall, 13 HCCs (19.7%) demonstrated LR at a mean of 29.8 months (range, 3-63 months) and cumulative LR rates were 1.5% 14.2% 21%, 21%, and 21% at 6, 12, 24, 36, and 48 months, respectively. In 28 (38.9%) of 72 HCCs, oily subsegmentectomy was achieved, tumor markers were normalized, and LR did not occur. The oily subsegmentectomy-positive group had a significantly lower LR rate than the oily subsegmentectomy-negative group (p = 0.001). Age ≥65 years (adjusted hazard ration (HR), 0.124; 95% confidence interval (CI), 0.037-0.412; p < 0.001) and peripheral location (adjusted HR, 0.112; 95% CI, 0.046-0.272; p < 0.001) were independent predictive factors of LR. Subsegmental B-TACE can be an effective method with a high initial CR rate and low LR incidence. Oily subsegmentectomy can be considered as an index of successful treatment because it did not demonstrate any LR.

Double closed loop small bowel obstruction due to right diaphragmatic hernia after transcatheter arterial chemoembolization and microwave ablation for hepatocellular carcinoma

64-Year-old male patient with hepatocellular carcinoma (HCC), liver cirrhosis, chronic hepatitis C infection, and glottic cancer presented with acute progressive abdominal pain and palpable mass in right upper quadrant of the abdomen. Despite treatment with hyoscine and tramadol, the symptoms persisted. He had received three sessions of Transcatheter arterial chemoembolization (TACE) and two sessions of microwave ablation (MWA) for HCC treatment, with the last session being TACE 11 months prior. Plain film abdomen showed bowel gas pattern in the right hemithorax compatible with bowel obstruction. CT imaging revealed a right diaphragmatic hernia containing closed loop small bowel obstruction. An emergency exploratory laparotomy was performed. The patient improved and was discharged. There was no recurrence of diaphragmatic hernia or abdominal mass or pain at the 6-month follow-up visit. We herein demonstrate a catastrophic complication of TACE by using an IPA and MWA which leads to right diaphragmatic hernia.

Transarterial chemoembolisation for very early and early stage hepatocellular carcinoma: single-centre experience

AIM

To evaluate the safety and efficacy of transarterial chemoembolisation (TACE) in patients with very early and early stage hepatocellular carcinoma (VES-HCC).

MATERIALS AND METHODS

A retrospective analysis was performed for all TACE procedures done at King's College Hospital, a tertiary liver centre, for VES-HCC during a 5-year period (January 2014-December 2018). Patients with solitary tumours ≤5 cm and patients with 2-3 tumours (each ≤3 cm) were included.

RESULTS

Two hundred and thirty-seven eligible patients were included. Technical success was achieved in 233 (98.3%) procedures. TACE using drug-eluting beads (DEB-TACE) was performed in 192 (82.4%) procedures. A complete response was achieved in 109 (45.9%) patients. The recurrence rate was 44% (48 cases), during a median imaging follow-up of 31.9 months (IQR 15.9-44.7). Median overall survival was 71.1 months (95% confidence interval [CI]: 62.9-79.3). Median recurrence-free survival was 58.9 months (95% CI: 47.1-70.7). Sixty-six (27.8%) patients eventually underwent transplantation, and six (2.5%) patients underwent surgical resection. Mild, moderate, and severe adverse events were encountered in 2.9%, 5.4%, and 0.8% of cases, respectively. No 30-day mortality was encountered.

CONCLUSION

DEB-TACE is safe and effective for treating VES-HCC patients, who are unsuitable for thermal ablation or surgery, and may offer comparable survival benefit. It can also be used as a bridge to transplantation for these patients.

A novel method for predicting hepatocellular carcinoma response to chemoembolization using an intraprocedural CT hepatic arteriography-based enhancement mapping: a proof-of-concept analysis

BACKGROUND

To evaluate the feasibility of a novel approach for predicting hepatocellular carcinoma (HCC) response to drug-eluting beads transarterial chemoembolization (DEB-TACE) using computed tomography hepatic arteriography enhancement mapping (CTHA-EM) method.

METHODS

This three-institution retrospective study included 29 patients with 46 HCCs treated with DEB-TACE between 2017 and 2020. Pre- and posttreatment CTHA-EM images were generated using a prototype deformable registration and subtraction software. Relative tumor enhancement (T_Post/pre-RE) defined as the ratio of tumor enhancement to normal liver tissue was calculated to categorize tumor response as residual (T_Post-RE > 1) versus non-residual (T_Post-RE ≤ 1) enhancement, which was blinded compared to the response assessment on first follow-up imaging using modified RECIST criteria. Additionally, for tumors with residual enhancement, CTHA-EM was evaluated to identify its potential feeding arteries.

RESULTS

CTHA-EM showed residual enhancement in 18/46 (39.1%) and non-residual enhancement in 28/46 (60.9%) HCCs, with significant differences on T_Post-RE (3.05 ± 2.4 versus 0.48 ± 0.23, respectively; p < 0.001). The first follow-up imaging showed non-complete response (partial response or stable disease) in 19/46 (41.3%) and complete response in 27/46 (58.7%) HCCs. CTHA-EM had a response prediction sensitivity of 94.7% (95% CI, 74.0-99.9) and specificity of 100% (95% CI, 87.2-100). Feeding arteries to the residual enhancement areas were demonstrated in all 18 HCCs (20 arteries where DEB-TACE was delivered, 2 newly developed collaterals following DEB-TACE).

CONCLUSION

CTHA-EM method was highly accurate in predicting initial HCC response to DEB-TACE and identifying feeding arteries to the areas of residual arterial enhancement.

Correlation of tumor response on CT with pathologically proven necrosis in hepatocellular carcinoma treated by conventional transcatheter arterial chemoembolization: threshold value of intratumoral Lipiodol accumulation predicting tumor necrosis

PURPOSE

To evaluate associations between pathology and CT assessments made according to the mRECIST in HCC treated by conventional TACE (cTACE), and to identify predictors of complete tumor necrosis.

METHODS

From March 2016 to July 2018, 83 patients with a total of 100 masses were retrospectively included. Patients underwent sequential cTACE and portal vein embolization, and later hepatic surgery. Evaluation of treatment response and measurement of baseline lipiodol accumulation as mean HU was performed on CT at the time point closest to the time of operation (mean, 54.5 days after cTACE). Significant predictors associated with complete necrosis were identified by multivariate analysis. The optimal cut-off HU value of lipiodol accumulation for prediction of complete necrosis was determined using a ROC analysis.

RESULTS

According to mRECIST, complete response (CR, n = 70) and partial response (n = 30) were classified. 34.3% (24/70) masses classified as CR according to mRECIST were found to have viable lesions on pathology. On multivariate analysis, mean HU of lipiodol accumulation was the only significant predictor of complete necrosis (p = .003, odds ratio 1.746, 95% CI 1.201-2.539). On ROC analysis, 460 HU as a cut-off value was significantly associated with complete necrosis (67.4% sensitivity, 75.0% specificity).

CONCLUSIONS

A threshold value for lipiodol accumulation > 460 HU was highly sensitive and specific for complete necrosis, even in complete response according to mRECIST. Therefore, if lipiodol accumulation is insufficient in post-TACE CT, recurrence should be monitored more sensitively.

Microvascular Flow Imaging of Residual or Recurrent Hepatocellular Carcinoma after Transarterial Chemoembolization: Comparison with Color/Power Doppler Imaging

Objective

To determine the feasibility of microvascular flow imaging (MVFI) in comparison with color/power Doppler imaging (CDI/PDI) for detection of intratumoral vascularity in suspected post-transarterial chemoembolization (TACE) residual or recurrent hepatocellular carcinomas (HCCs) by using contrast-enhanced ultrasonography (CEUS) or hepatic angiography (HA) findings as the reference standard.

Materials and Methods

One hundred HCCs (mean size, 2.2 cm) in 100 patients treated with TACE were included in this prospective study. CDI, PDI, and MVFI were performed in tandem for evaluating intratumoral vascularity of the lesions by using an RS85 ultrasound scanner (Samsung Medison Co., Ltd.). Intratumoral vascularity in each technique was assessed by two radiologists in consensus by using a 5-point scale. Then, one of the two radiologists and another radiologist performed additional image review in the reverse order (MVFI-PDI-CDI) for evaluation of intra- and interobserver agreements. Results were then compared with those of either HA or CEUS as the reference. The McNemar test, logistic regression analysis, and intraclass correlation coefficient (ICC) were used.

Results

CEUS or HA revealed intratumoral vascularity in 87% (87/100) of the tumors. Sensitivity (79.3%, 69/87) and accuracy (80.0%, 80/100) of MVFI were significantly higher than those of CDI (sensitivity, 27.6% [24/87]; accuracy, 37.0% [37/100]) or PDI (sensitivity, 36.8% [32/87]; accuracy, 44.0% [44/100]) (all p < 0.05). CDI, PDI, and MVFI presented excellent intraobserver (ICCs > 0.9) and good interobserver agreements (ICCs > 0.6).

Conclusion

MVFI demonstrated significantly higher sensitivity and accuracy than did CDI and PDI for the detection of intratumoral vascularity in suspected residual or recurrent HCCs after TACE.

Occurrence of Vascular Lake Phenomenon Before Embolization for the Prediction of Lipiodol Uptake for Intermediate-Stage Hepatocellular Carcinoma Patients that Underwent cTACE

PURPOSE

To compare Lipiodol uptake and tumor response in intermediate-stage hepatocellular carcinoma (HCC) with and without pre-embolization vascular lake phenomenon (VLP) and to identify the incidence and predictive factors of this phenomenon, in patients treated by conventional transarterial chemoembolization (cTACE).

MATERIALS AND METHODS

This retrospective study included 151 consecutive patients with intermediate HCC totaling 232 nodules, who underwent cTACE from June 2015 to October 2018. Patients were divided into two groups according to the presence of VLP before embolization. Initial Lipiodol uptake was assessed using post-cTACE computed tomography (CT) within 1-1.5 months after cTACE. Enhanced CT or magnetic resonance imaging was performed at 6 months after the procedure to assess local recurrence and distant metastasis.

RESULTS

The VLP was demonstrated in 21.85% (33/151) patients and 16.81% (39/232) nodules on the super-selective angiography. On nodule-based analysis, significantly better Lipiodol uptake (p < 0.001) and higher ORR (60.61% vs. 26.49%, p < 0.001) and DCR (87.88% vs. 51.66%, p < 0.001) were observed in the VLP group compared to the non-VLP group. The multivariate logistic regression analysis showed that the presence of VLP (OR 6.431, 95% CI 2.495-16.579) might be a predictive factor for better Lipiodol uptake. Univariate and multivariate logistic regression analysis showed that poor differentiation of tumor (OR 6.397, 95% CI 2.804-19.635) remained predictive for the VLP.

CONCLUSION

The incidence of VLP before embolization is 21.19%. The presence of VLP is well correlated with tumor Lipiodol uptake after cTACE and may be a new predictive factor for evaluation of cTACE efficacy and prognosis of intermediate HCC.

Utility of Contrast-Enhanced Ultrasound for Early Therapeutic Evaluation of Hepatocellular Carcinoma After Transcatheter Arterial Chemoembolization

OBJECTIVES

We aimed to investigate whether contrast-enhanced ultrasound (CEUS) could be useful for early evaluation of the treatment response to transcatheter arterial chemoembolization (TACE) of hepatocellular carcinoma (HCC).

METHODS

This study retrospectively selected HCCs in which homogeneous retention of iodized oil was confirmed on non-contrast-enhanced computed tomography performed immediately after TACE. Therapeutic responses of HCCs were evaluated by CEUS 1 to 2 days after TACE and by contrast-enhanced computed tomography (CECT) approximately 4 weeks after TACE. We investigated the noninferiority of CEUS 1 to 2 days after TACE to CECT approximately 4 weeks after TACE in terms of the diagnostic accuracy of the therapeutic response to TACE on HCC.

RESULTS

Eighty-nine HCCs were enrolled in this study between April 2014 and June 2016. A complete response was observed in 57 of 89 nodules (64.0%), and an incomplete response was observed in the remaining 32 nodules (36.0%). The accuracy rates for CEUS 1 to 2 days after TACE and CECT approximately 4 weeks after TACE in the therapeutic effect of TACE on HCCs were 83.1% (95% confidence interval, 73.7%-90.2%) and 83.1% (95% confidence interval, 73.7%-90.2%), respectively. The difference in diagnostic accuracy between methods was 0%, which was below the predetermined noninferiority limit of 15%, and CEUS 1 to 2 days after TACE was noninferior to CECT approximately 4 weeks after TACE.

CONCLUSIONS

Our results suggest that CEUS is a useful modality for early therapeutic evaluation of TACE for HCC, and we can thus plan the next treatment strategies for HCC within a few days after TACE.

Therapeutic efficacy of TACE 125I seed implantation and its combination with intra-tumor injection of cisplatin for the treatment of hepatocellular carcinoma

Background

This study aimed to compare the therapeutic efficacy of transcatheter arterial chemoembolization (TACE) combined with either ¹²⁵I seed implantation or ¹²⁵I seed implantation and intra-tumor injection of cisplatin in treating hepatocellular carcinoma (HCC).

Methods

A total of 100 patients with HCC were analyzed. The control group (n = 50) received TACE combined with ¹²⁵I seed implantation therapy. The therapy group (n = 50) was treated with an intra-tumor injection of cisplatin along with TACE and ¹²⁵I seed implantation therapy. After treatment, routine blood, liver and kidney function, tumor volume, T lymphocyte subset count (CD3, CD4, and CD8), implanted metastases, and survival were studied.

Results

The tumor volume decreased by 27.4% on average in the control group, and by 38.6% in the therapy group. Alpha fetoprotein (AFP) level decreased in all cases, and it was significantly lower in the therapy group than in the control group. Remote metastasis was observed in both groups (7 in the control group and 3 in the therapy group). No significant difference in routine blood, liver and kidney function, and T-lymphocyte subset counts were found between the two groups. Eight patients died of metastases in the control group and 2 in the therapy group at 1-year follow-up (P < 0.05).

Conclusion

TACE combined with either ¹²⁵I seed implantation or ¹²⁵I seed implantation and intra-tumor injection of cisplatin was effective for the treatment of HCC. Of the 2 combination therapies, TACE combined with ¹²⁵I seed implantation and intra-tumor injection of cisplatin was more effective for the treatment of HCC.

[Interventional radiology of liver tumors]

Interventional radiology (IR) has considerably grown since the 90s and has currently a central position in the management of patients suffering from cancer. The aim of this paper is to describe the principle, indications, technique and results of three common hepatic oncologic IR procedures: preoperative portal vein embolization, transarterial chemoembolization and radioembolization. Portal vein embolization is performed before a right hepatectomy in order to increase the left liver volume and functional capacity to ensure adequate liver function of the future remnant liver and to prevent the post-hepatectomy liver failure. It is a proven, well-tolerated and effective technique, allowing most of patients to undergo surgery. Transarterial chemoembolization consists of an injection of a chemotherapeutic agent and an embolic agent into the hepatic artery to locally act on liver tumors. It is the standard of care for BCLC stage B hepatocellular carcinoma and is also recommended for the liver metastases treatment, mainly from neuroendocrine tumors. Radioembolization is an IR procedure on the rise that consists of the injection into the hepatic artery of Yttrium 90 loaded microparticles, which will preferentially deliver high dose on the tumors, sparing the adjacent hepatic parenchyma. Radioembolization is recommended for the palliative treatment of HCC and for colorectal cancer liver metastases resistant to treatment. It is a very well tolerated intervention which place has yet to be defined in the management of neuroendocrine tumors liver metastases and unresectable cholangiocarcinoma. IR is a constantly evolving discipline with proven techniques playing a major role in the oncological management of liver tumor patients. In oncology, IR is now the 4th patient management linchpin alongside oncology, surgery and radiotherapy.

Lipiodol deposition in portal vein tumour thrombus predicts treatment outcome in HCC patients after transarterial chemoembolisation

OBJECTIVE

To study lipiodol deposition in portal vein tumour thrombus (PVTT) in predicting the treatment outcome of hepatocellular carcinoma (HCC) patients after transarterial chemoembolisation (TACE).

METHODS

We retrospectively reviewed data from 379 HCC patients with PVTT who underwent TACE as the initial treatment at Sun Yat-Sen University Cancer Center from January 2008 to December 2015. Patients were grouped by positive and negative lipiodol deposition based on the extent of lipiodol deposition in PVTT. The overall survival (OS) and progression-free survival (PFS) were compared between negative and positive lipiodol deposition groups; furthermore, the value of the combinatorial evaluation of tumour responses and lipiodol deposition in PVTT in predicting prognosis was analysed in subgroup patients with stable disease (SD) after TACE.

RESULTS

Of the 379 patients, 264 (69.7%) had negative and 115 (30.3%) had positive lipiodol deposition in PVTT after TACE. Multivariate analysis identified positive lipiodol deposition in PVTT as an independent prognostic factor for favourable OS (p = 0.001). The median OS and PFS of negative and positive lipiodol deposition groups were 4.70 vs. 8.97 months (p = 0.001) and 3.1 months vs. 5.8 months (p < 0.001). In subgroup patients, the median OS and PFS of negative and positive lipiodol deposition groups were 4.7 months vs. 10.5 months (p < 0.001) and 3.5 months vs. 7.0 months (p < 0.001), respectively.

CONCLUSIONS

The patients with positive lipiodol deposition in PVTT had a longer OS than those with negative lipiodol deposition. Furthermore, the positive lipiodol deposition in PVTT can further differentiate HCC patients with favourable prognosis from SD patients.

KEY POINTS

• Lipiodol deposition in PVTT is a prognostic indicator for HCC patients after TACE treatment. • Positive lipiodol deposition in PVTT is associated with a better prognosis.

Volumetric analysis at abdominal CT: oncologic and non-oncologic applications

Volumetric analysis is an objective three-dimensional assessment of a lesion or organ that may more accurately depict the burden of complex objects compared to traditional linear size measurement. Small changes in linear size are amplified by corresponding changes in volume, which could have significant clinical implications. Though early methods of calculating volumes were time-consuming and laborious, multiple software platforms are now available with varying degrees of user-software interaction ranging from manual to fully automated. For the assessment of primary malignancy and metastatic disease, volumetric measurements have shown utility in the evaluation of disease burden prior to and following therapy in a variety of cancers. Additionally, volume can be useful in treatment planning prior to resection or locoregional therapies, particularly for hepatic tumours. The utility of CT volumetry in a wide spectrum of non-oncologic pathology has also been described. While clear advantages exist in certain applications, some data have shown that volume is not always the superior method of size assessment and the associated labor intensity may not be worthwhile. Further, lack of uniformity among software platforms is a challenge to widespread implementation. This review will discuss CT volumetry and its potential oncologic and non-oncologic applications in abdominal imaging, as well as advantages and limitations to this quantitative technique.

Radiation exposure during TACE procedures using additional cone-beam CT (CBCT) for guidance: safety and precautions

Background During transarterial chemoembolization (TACE), cone-beam computed tomography (CBCT) can be used for tumor and feeding vessel detection as well as postembolization CT imaging. However, there will be additional radiation exposure from CBCT. Purpose To evaluate the additional dose raised through CBCT-assisted guidance in comparison to TACE procedures guided with pulsed digital subtraction angiography (DSA) alone. Material and Methods In 70 of 140 consecutive patients undergoing TACE for liver cancer, CBCT was used to facilitate the TACE. Cumulative dose area product (DAP), cumulative kerma(air), DAP values of DSA, total and cine specific fluoroscopy times (FT) of 1375 DSA runs, and DAP of 91 CBCTs were recorded and analyzed using Spearman's correlation, Mann-Whitney U-test, and Kruskal-Wallis test. P values < 0.05 were considered significant. Results Additional CBCT increased DAP by 2% ( P = 0.737), kerma(air) by 24.6% ( P = 0.206), and FT by 0.02% ( P = 0.453). Subgroup analysis revealed that postembolization CBCT for detection of ethiodized oil deposits added more DAP to the procedure. Performing CBCT-assisted TACE, DSA until first CBCT contributed about 38% to the total DAP. Guidance CBCT acquisitions conduced to 6% of the procedure's DAP. Additional DSA for guidance after CBCT acquisition required approximately 46% of the mean DAP. The last DSA run for documentation purposes contributed about 10% of the DAP. Conclusion CBCT adds radiation exposure in TACE. However, the capability of CBCT to detect vessels and overlay in real-time during fluoroscopy facilitates TACE with resultant reduction of DAPs up to 46%.

Baseline Tumor Lipiodol Uptake after Transarterial Chemoembolization for Hepatocellular Carcinoma: Identification of a Threshold Value Predicting Tumor Recurrence

Background

The aim of the study was to evaluate the association between baseline Lipiodol uptake in hepatocellular carcinoma (HCC) after transarterial chemoembolization (TACE) with early tumor recurrence, and to identify a threshold baseline uptake value predicting tumor response.

Patients and methods

A single-institution retrospective database of HCC treated with Lipiodol-TACE was reviewed. Forty-six tumors in 30 patients treated with a Lipiodol-chemotherapy emulsion and no additional particle embolization were included. Baseline Lipiodol uptake was measured as the mean Hounsfield units (HU) on a CT within one week after TACE. Washout rate was calculated dividing the difference in HU between the baseline CT and follow-up CT by time (HU/month). Cox proportional hazard models were used to correlate baseline Lipiodol uptake and other variables with tumor response. A receiver operating characteristic (ROC) curve was used to identify the optimal threshold for baseline Lipiodol uptake predicting tumor response.

Results

During the follow-up period (mean 5.6 months), 19 (41.3%) tumors recurred (mean time to recurrence = 3.6 months). In a multivariate model, low baseline Lipiodol uptake and higher washout rate were significant predictors of early tumor recurrence (P = 0.001 and < 0.0001, respectively). On ROC analysis, a threshold Lipiodol uptake of 270.2 HU was significantly associated with tumor response (95% sensitivity, 93% specificity).

Conclusions

Baseline Lipiodol uptake and washout rate on follow-up were independent predictors of early tumor recurrence. A threshold value of baseline Lipiodol uptake > 270.2 HU was highly sensitive and specific for tumor response. These findings may prove useful for determining subsequent treatment strategies after Lipiodol TACE.

Evaluation of the relationship between hepatocellular carcinoma location and transarterial chemoembolization efficacy

AIM

To evaluate the relationship between the location of hepatocellular carcinoma (HCC) and the efficacy of transarterial chemoembolization (TACE).

METHODS

We evaluated 115 patients (127 nodules), excluding recurrent nodules, treated with TACE between January 2011 and June 2014. TACE efficacy was evaluated according to mRECIST. The HCC location coefficient was calculated as the distance from the central portal portion to the HCC center (mm)/liver diameter (mm) on multiplanar reconstruction images rendered (MPR) to visualize bifurcation of the right and left branches of the portal vein and HCC center. The HCC location coefficient was compared between complete response (CR) and non-CR groups in Child-Pugh grade A and B patients.

RESULTS

The median location coefficient of HCC among all nodules, the right lobe, and the medial segment was significantly higher in the CR group than in the non-CR group in the Child-Pugh grade A patients (0.82 vs 0.62, P < 0.001; 0.71 vs 0.59, P < 0.01; 0.81 vs 0.49, P < 0.05, respectively). However, there was no significant difference in the median location coefficient of the HCC in the lateral segment between in the CR and in the non-CR groups (0.67 vs 0.65, P > 0.05). On the other hand, in the Child-Pugh grade B patients, the HCC median location coefficient in each lobe and segment was not significantly different between in the CR and in the non-CR groups.

CONCLUSION

Improved TACE efficacy may be obtained for HCC in the peripheral zone of the right lobe and the medial segment in Child-Pugh grade A patients.

The role of scheduled second TACE in early-stage hepatocellular carcinoma with complete response to initial TACE

Background/Aims

We investigated the outcomes of early-stage hepatocellular carcinoma (HCC) patients who showed a complete response (CR) to initial transarterial chemoembolization (TACE), with a focus on the role of scheduled TACE repetition.

Methods

A total of 178 patients with early-stage HCC who were initially treated with TACE and showed a CR based on the modified Response Evaluation Criteria in Solid Tumors (mRECIST) criteria on one month follow-up computed tomography (CT) were analyzed. Among them, 90 patients underwent scheduled repetition of TACE in the absence of viable tumor on CT.

Results

During a median follow-up period of 4.6 years (range: 0.4-8.8 years), mortality was observed in 71 patients (39.9%). The overall recurrence-free and local recurrence-free survival rates at 1 year were 44.4% and 56.2%. In the multivariable model, scheduled repetition of TACE was an independent factor associated with survival (hazard ratio [95% confidence interval]: 0.56 [0.34-0.93], P=0.025). When stratified using Barcelona clinic liver cancer (BCLC) stage, scheduled repetition of TACE was associated with a favorable survival rate in BCLC stage A patients, but not in BCLC 0 patients.

Conclusions

Scheduled repetition of TACE was associated with better survival for early-stage HCC patients showing a CR after initial TACE, especially in BCLC stage A patients.

Lipiodol retention pattern assessed by cone beam computed tomography during conventional transarterial chemoembolization of hepatocellular carcinoma: accuracy and correlation with response

BACKGROUND

To investigate accuracy of intraprocedural cone beam computed tomography (CBCT) compared to fluoroscopy for detection of lipiodol retention pattern during conventional transarterial chemoembolization (cTACE) of hepatocellular carcinoma (HCC) and its correlation with short-term response.

METHODS

Between September 2013 and July 2014, 29 patients with HCC underwent chemoembolization of 51 tumors (mean diameter 28.1 mm, range 10.0-136.3 mm). Lipiodol retention pattern was assessed by CBCT at the endpoint of cTACE compared by fluoroscopy. Depending on the pattern of tumor covered by lipiodol three classes were defined: complete (more than 90 %, no peripheral defects), moderate (50-90 %, some with or without peripheral defects), and poor (less than 50 %). Tumor response was assessed by modified Response Evaluation Criteria in Solid Tumors (mRECIST) based on follow-up contrast enhanced (CE) computed tomography (CT) or magnetic resonance imaging (MRI) obtained 4-6 weeks post-cTACE. Correlations between lipiodol retention patterns on CBCT and fluoroscopy as well as tumor response were assessed using multivariate logistic regression.

RESULTS

Of 51 hepatic tumors, 40 (78.4 %) had complete response (CR); 8 (15.7 %) had partial response (PR); 1 (2.0 %) had stable disease (SD); and 2 (3.9 %) had progressive disease (PD). The degree of lipiodol retention scored excellent, moderate, and poor, in fluoroscopic images vs CBCT images were 23 (45.1 %) vs 39 (76.5 %), 19 (37.3 %) vs 11 (21.6 %), and 9 (17.6 %) vs 1 (2.0 %), respectively. Lipiodol retention assessment with CBCT (A_z = 0.75) is more accurate than fluoroscopy (A_z = 0.54) in predicting target tumor response. Other than lipiodol retention pattern assessed with CBCT (p = 0.01), tumor size (p = 0.04) is an independent predictors of CR.

CONCLUSION

CBCT is more accurate than fluoroscopy in classification of lipiodol retention pattern in HCC tumors at the time of cTACE. CBCT could be used as a reliable intra precedural monitoring modality of cTACE.

Detection of Viable Tumor Cells in Hepatocellular Carcinoma following Transcatheter Arterial Chemoembolization with Iodized Oil

To evaluate the effect of transcatheter arterial chemoembolization (TACE) with iodized oil for hepatocellular carcinoma (HCC), dynamic turbo-fast low angle shot (turbo-FLASH) (TR/TE/flip angle/TI, 8.5/4.6/10/200) MR imaging with gadopentetate dimeglumine was performed in 10 patients with HCC after TACE with iodized oil and before partial hepatectomy. Immediately after 0.05 mmol/kg b.w. of gadopentetate dimeglumine was administered intravenously, 10 images were obtained in the first 20 s (early phase). Then, one image every 30 s from 1 to 3 min (late phase), and images at 5 min and 7 min (delayed phase) were obtained serially. In the early phase, HCC showed no enhancement in 5 patients, partial hyperintense enhancement in 4, and total hyperintense enhancement in one. Viable regions of the tumor, evaluated at histopathology, showed hyperintense enhancement relative to the surrounding liver parenchyma in the early phase, while necrotic regions showed no enhancement. Both viable and necrotic regions showed lower signal intensities than the surrounding liver parenchyma in both late and delayed phases. By using dynamic turbo-FLASH MR imaging, we were able to accurately evaluate the effect of TACE with iodized oil for HCC in 8 of the 10 patients. In 2 patients, in whom small viable cells were seen in the HCC, viable regions could not be detected with our technique. It is concluded that turbo-FLASH dynamic MR imaging was useful for evaluating the effect of TACE for HCC.

Evaluation of transcatheter arterial embolization therapy on hepatocellular carcinomas using contrast-enhanced harmonic power Doppler sonography: comparison with CT, power Doppler sonography, and dynamic MRI

PURPOSE

The aim of this study was to assess and compare the sensitivity of power Doppler sonography, contrast-enhanced sonography, plain computed tomography (CT), and dynamic magnetic resonance imaging (MRI) for detecting hepatocellular carcinoma (HCC) nodules incompletely treated with transcatheter arterial embolization (TAE).

METHODS

A total of 63 unresectable HCC nodules were examined in this study. The HCCs were treated with TAE. All patients underwent plain CT, power Doppler sonography, contrast-enhanced harmonic power Doppler sonography, and dynamic MRI 1 week after TAE. The sensitivity of each modality to incompletely treated HCC nodules was compared. Detection of the residual viable HCC on angiography or tumor biopsy was regarded as the gold standard for the diagnosis of incomplete treatment.

RESULTS

Twenty-four nodules (38%) were diagnosed as incompletely treated. The sensitivities of plain CT, power Doppler sonography, contrast-enhanced harmonic power Doppler sonography, and dynamic MRI to these incompletely treated nodules were 42% (10/24), 46% (11/24), 88% (21/24), and 79% (19/24), respectively. Eighty percent (19 nodules) of the 24 incompletely treated nodules were located within a depth of less than 8 cm. The sensitivities of plain CT, power Doppler sonography, contrast-enhanced harmonic power Doppler sonography, and dynamic MRI to these superficial incompletely treated nodules were 37% (7/19), 53% (10/19), 100% (19/19), and 74% (14/19), respectively. In contrast, the sensitivities of each modality to deeply located nodules were 60% (3/5), 20% (1/5), 40% (2/5), and 100% (5/5), respectively.

CONCLUSION

Plain CT and power Doppler sonography had a low sensitivity to HCC nodules incompletely treated with TAE. Except for those that were deeply located, contrast-enhanced harmonic sonography showed the highest sensitivity in detecting incompletely treated HCC nodules.

Detection of tumor vascularity in hepatocellular carcinoma with contrast-enhanced Dynamic Flow imaging: Comparison with contrast-enhanced power Doppler imaging

OBJECTIVE

To compare the effectiveness of contrast-enhanced Dynamic Flow imaging and contrast-enhanced power Doppler imaging using Levovist(®) as a microbubble contrast agent in evaluating intratumoral vascularity in hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Twenty-nine patients with 54 hepatocellular carcinoma nodules (before treatment, 31; after treatment, 23) were studied with both Dynamic Flow and power Doppler imaging with intravenous injection of Levovist(®). Tumor vascularity was categorized as 0, no blood flow signals within the tumor; 1, dotlike blood flow signals within the tumor; 2, moderate blood flow signals within the tumor; and 3, abundant blood flow signals within the tumor. Detectability of intratumoral vascularity of hepatocellular carcinoma in three groups based on tumor depth, blooming and noise artifacts on contrast-enhanced Dynamic Flow and contrast-enhanced power Doppler imaging were also compared with results obtained using dynamic CT as a the gold standard. The effectiveness of contrast-enhanced Dynamic Flow and contrast-enhanced power Doppler imaging in assessing therapeutic effect were compared at the same time.

RESULTS

The ability of contrast-enhanced Dynamic Flow Doppler imaging to detect tumor vascularity in the superficial and intermediate hepatocellular carcinoma groups was close to that of contrast-enhanced power Doppler imaging (p>0.05). However, contrast-enhanced Dynamic Flow imaging demonstrated tumor parenchymal stain in 28 hepatocellular carcinoma nodules (61%), which was not detected by contrast-enhanced power Doppler imaging. Further, significantly fewer artifacts appeared in contrast-enhanced Dynamic Flow imaging than in contrast-enhanced power Doppler imaging (p<0.001). In assessing therapeutic response, the sensitivity of contrast-enhanced Dynamic Flow imaging was similar to that of dynamic CT. In deep areas, however, those more than 6 cm below the surface of the body, contrast-enhanced Dynamic Flow imaging was less sensitivity than contrast-enhanced power Doppler imaging (p=0.005).

CONCLUSION

Contrast-enhanced Dynamic Flow imaging provides an effective approach to assessing intratumoral vascularity and therapeutic response in HCC lesions situated less than 6 cm from the surface of the body. It is superior to contrast-enhanced power Doppler imaging in its ability to detect tumor parenchymal stain and production of fewer artifacts.

Initial Experience with Balloon-Occluded Trans-catheter Arterial Chemoembolization (B-TACE) for Hepatocellular Carcinoma

PURPOSE

This study was performed to evaluate the accumulation of lipiodol emulsion (LE) and adverse events during our initial experience of balloon-occluded trans-catheter arterial chemoembolization (B-TACE) for hepatocellular carcinoma (HCC) compared with conventional TACE (C-TACE).

METHODS

B-TACE group (50 cases) was compared with C-TACE group (50 cases). The ratio of the LE concentration in the tumor to that in the surrounding embolized liver parenchyma (LE ratio) was calculated after each treatment. Adverse events were evaluated according to the Common Terminology Criteria for Adverse Effects (CTCAE) version 4.0.

RESULTS

The LE ratio at the level of subsegmental showed a statistically significant difference between the groups (t test: P < 0.05). Only elevation of alanine aminotransferase was more frequent in the B-TACE group, showing a statistically significant difference (Mann-Whitney test: P < 0.05). While B-TACE caused severe adverse events (liver abscess and infarction) in patients with bile duct dilatation, there was no statistically significant difference in incidence between the groups. Multivariate logistic regression analysis suggested that the significant risk factor for liver abscess/infarction was bile duct dilatation (P < 0.05).

CONCLUSION

The LE ratio at the level of subsegmental showed a statistically significant difference between the groups (t test: P < 0.05). B-TACE caused severe adverse events (liver abscess and infarction) in patients with bile duct dilatation.

The usefulness of contrast-enhanced ultrasonography in the early detection of hepatocellular carcinoma viability after transarterial chemoembolization: pilot study

Background/Aims

The therapeutic effect of transarterial chemoembolization (TACE) against hepatocellular carcinoma (HCC) is usually assessed using multidetector computed tomography (MDCT). However, dense lipiodol depositions can mask the enhancement of viable HCC tissue in MDCT. Contrast-enhanced ultrasonography (CEUS) could be effective in detecting small areas of viability and patency in vessels. We investigated whether arterial enhancement in CEUS after treatment with TACE can be used to detect HCC viability earlier than when using MDCT.

Methods

Twelve patients received CEUS, MDCT, and gadoxetic-acid-enhanced dynamic magnetic resonance imaging (MRI) at baseline and 4 and 12 weeks after TACE. The definition of viable HCC was defined as MRI positivity after 4 or 12 weeks.

Results

Eight of the 12 patients showed MRI positivity at 4 or 12 weeks. All patients with positive CEUS findings at 4 weeks (n=8) showed MRI positivity and residual viable HCC at 4 or 12 weeks. Five of the eight patients with positive CEUS findings at 4 weeks had negative results on the 4-week MDCT scan. Four (50%) of these eight patients did not have MRI positivity at 4 weeks and were ultimately confirmed as having residual HCC tissue at the 12-week MRI. Kappa statistics revealed near-perfect agreement between CEUS and MRI (κ=1.00) and substantial agreement between MDCT and MRI (κ=0.67).

Conclusions

In the assessment of the response to TACE, CEUS at 4 weeks showed excellent results for detecting residual viable HCC, which suggests that CEUS can be used as an early additive diagnosis tool when deciding early additional treatment with TACE.

Parametric response mapping of dynamic CT as an imaging biomarker to distinguish viability of hepatocellular carcinoma treated with transcatheter arterial chemoembolization

PURPOSE

Accurate assessment of viability of hepatocellular carcinoma (HCC) after transcatheter arterial chemoembolization (TACE) is important for therapy planning. The purpose of this study is to determine the diagnostic value of a novel image analysis method called parametric response mapping (PRM) in predicting viability of tumor in HCC treated with TACE for dynamic CT images.

METHODS

35 patients who had 35 iodized-oil defect areas (IODAs) in HCCs treated with TACE were included in our study. These patients were divided into two groups, one group with viable tumors (n = 22) and the other group with non-viable tumors (n = 13) in the IODA. All patients were followed up using triple-phase dynamic CT after the treatment. We compared (a) manual analysis, (b) using PRM results, and (c) using PRM results with automatic classifier to distinguish between two tumor groups based on dynamic CT images from two longitudinal exams. Two radiologists performed the manual analysis. The PRM approach was implemented using prototype software. We adopted an off-the-shelf k nearest neighbor (kNN) classifier and leave-one-out cross-validation for the third approach. The area under the curve (AUC) values were compared for three approaches.

RESULTS

Manual analysis yielded AUC of 0.74, using PRM results yielded AUC of 0.84, and using PRM results with an automatic classifier yielded AUC of 0.87.

CONCLUSIONS

We improved upon the standard manual analysis approach by adopting a novel image analysis method of PRM combined with an automatic classifier.

Using intravoxel incoherent motion (IVIM) MR imaging to predict lipiodol uptake in patients with hepatocellular carcinoma following transcatheter arterial chemoembolization: a preliminary result

PURPOSE

To assess the usefulness of intravoxel incoherent motion diffusion weighted imaging (IVIM-DWI) for predicting lipiodol uptake in patients with hepatocellular carcinoma (HCC) after transcatheter arterial chemoembolization (TACE).

MATERIALS AND METHODS

The institutional review board approved this study. 44 HCC patients underwent IVIM-DWI and Gd-EOB-DTPA-enhanced MRI prior to TACE. Using post-TACE CT as a reference standard, each HCC was classified into either lipiodol good uptake (LGU) or poor uptake (LPU) group. Apparent diffusion coefficient (ADC), true diffusion coefficient (D), perfusion coefficient (D*), and perfusion fraction (f) in HCC were calculated. Arterial enhancement ratio (AER) and IVIM parameters were compared between those two groups using the Mann-Whitney U test.

RESULTS

Of the 51 HCCs, 37 (72.5%) were LGU group and 14 (27.5%) were LPU group. AER of HCC was significantly higher in LGU than LPU (0.99±0.54 and 0.67±0.45; P=.034). ADC, D, and f values were not significantly different (P=.073, .059, and .196, respectively) between these two groups. D* was significantly elevated in LGU than LPU (48.10±15.33 and 26.75±9.55; P=.001).

CONCLUSION

Both AER derived from contrast enhanced MRI and D* values derived from IVIM-DWI for HCC were significantly higher in LGU than in LPU. These parameters would be helpful for predicting the lipiodol uptake.

Quantitative assessment of lipiodol deposition after chemoembolization: comparison between cone-beam CT and multidetector CT

PURPOSE

To evaluate the ability of cone-beam computed tomography (CBCT) performed directly after transarterial chemoembolization to assess ethiodized oil (Lipiodol) deposition in hepatocellular carcinoma (HCC) and compare it with unenhanced multidetector computed tomography (CT).

MATERIALS AND METHODS

Conventional transarterial chemoembolization was used to treat 15 patients with HCC, and CBCT was performed to assess Lipiodol deposition directly after transarterial chemoembolization. Unenhanced multidetector CT was performed 24 hours after transarterial chemoembolization. Four patients were excluded because the margin of tumor or area of Lipiodol deposition was unclear. The image enhancement density of the entire tumor and liver parenchyma was measured by ImageJ software, and tumor-to-liver contrast (TLC) was calculated. In addition, volumetric measurement of tumor and Lipiodol was performed by semiautomatic three-dimensional volume segmentation and compared using linear regression to evaluate consistency between the two imaging modalities.

RESULTS

The mean value of TLC on CBCT was not significantly different from TLC on multidetector CT (337.7 HU ± 233.5 vs 283.0 HU ± 152.1, P = .103).The average volume of the whole tumor and of only the regions with Lipiodol deposition and the calculated average percentage of Lipiodol retention on CBCT were not significantly different compared with multidetector CT (tumor volume, 9.6 cm(3) ± 11.8 vs 10.8 cm(3) ± 14.2, P = .142; Lipiodol volume, 6.3 cm(3) ± 7.7 vs 7.0 cm(3) ± 8.1, P = .214; percentage of Lipiodol retention, 68.9% ± 24.0% vs 72.2% ± 23.1%, P = .578). Additionally, there was a high correlation in the volume of tumor and Lipiodol between CBCT and multidetector CT (R(2) = 0.919 and 0.903).

CONCLUSIONS

The quantitative image enhancement and volume analyses demonstrate that CBCT is similar to multidetector CT in assessing Lipiodol deposition in HCC after transarterial chemoembolization.

Radiofrequency ablation for intrahepatic recurrent hepatocellular carcinoma: long-term results and prognostic factors in 168 patients with cirrhosis

PURPOSE

To analyze the clinical outcome of radiofrequency ablation (RFA) for recurrent intrahepatic hepatocellular carcinoma (HCC) after variable first-line treatment.

MATERIALS AND METHODS

From January 2006 to December 2007, 168 consecutive patients (133 male, 35 female; mean age 66.7 ± 10.1 years) with cirrhosis (Child-Pugh class A/B [146/22]) who underwent RFA for treatment for recurrent intrahepatic HCC ≤5 cm, and in up to three nodules (214 HCCs; mean diameter 20.8 ± 7.5 mm; 38 multinodular forms), were included. Univariate and multivariate analyses for potential clinical, tumor-related, and radiologic factors affecting overall and recurrence-free patient survival were performed using the Cox proportional hazard model.

RESULTS

Major complications occurred in 5 patients (5 of 168, 3.0 %), although there were no procedure-related deaths. Complete ablation was achieved in 161 patients (161 of 168, 95.8 %). After a mean follow-up period of 4 ± 21 months, local tumor progression, distant intrahepatic recurrence, and extrahepatic metastasis occurred in 22, 132, and 41 patients, respectively. Overall 5-year survival and recurrence-free survival were 48.0 and 11.9 %, respectively. Significant predicting factors for overall patient survival were Child-Pugh class B (relative risk [RR] = 4.52, 95 % confidence interval [CI] 1.97-10.34; P < 0.001), serum alpha-fetoprotein (AFP) level (RR = 1.01, 95 % CI 1.01-1.01; P < 0.001), number of HCC nodules (RR = 1.70, 95 % CI 1.04-2.76; P = 0.033), tumor size (RR = 1.40, 95 % CI 1.07-1.83; P = 0.014), and presence of portosystemic collaterals (RR = 1.78, 95 % CI 1.09-2.92; P = 0.022).

CONCLUSION

RFA is a safe and effective treatment modality for recurrent intrahepatic HCC and has a 5-year survival rate of 48.0 %. Serum AFP level, Child-Pugh class, tumor number and size, and presence of portosystemic collaterals significantly affect overall patient survival.

Inflammatory myofibroblastic tumor mimicking hepatocellular carcinoma with dense lipiodol uptake

Inflammatory myofibroblastic tumor (IMT) of the liver is a very rare lesion that has radiologic similarity with malignant liver tumor. Differential diagnosis of IMT from a malignant lesion of the liver is very important because surgical resection is not mandatory for IMT. Lipiodol computed tomography is a very sensitive and specific diagnostic tool for hepatocellular carcinomas (HCC). Herein, we describe a case of IMT that had dense lipiodol uptake in the tumor and mimicked HCC. To our knowledge, previously, only one case of IMT with dense lipiodol retention has been reported.

Sorafenib alone versus sorafenib combined with transarterial chemoembolization for advanced-stage hepatocellular carcinoma: results of propensity score analyses

PURPOSE

To compare the time to progression (TTP) and overall survival (OS) in patients with advanced-stage hepatocellular carcinoma (HCC) who are undergoing sorafenib treatment combined with transarterial chemoembolization (TACE) versus sorafenib monotherapy.

MATERIALS AND METHODS

The retrospective analysis of the data was approved by the institutional review board, and the requirement to obtain informed consent was waived. Of 355 patients with advanced-stage HCC (Barcelona Clinic Liver Cancer stage C) who were undergoing sorafenib therapy for at least 5 weeks between April 2007 and July 2011, 164 (46.2%) underwent repeat TACE (or chemolipiodolization if indicated) along with sorafenib therapy (combined group); the remaining 191 patients (53.8%) received sorafenib alone (monotherapy group). The median patient age was 53 years (range, 22-84 years). The median age was 53 years (range, 26-84 years) for men and 56 years (range, 22-75 years) for women. Propensity score-based methods were used to minimize bias when evaluating TTP on the basis of modified Response Evaluation Criteria in Solid Tumors and OS. Statistical analysis was performed with the Kaplan-Meier method by using the log-rank test and Cox regression models.

RESULTS

In the combined and monotherapy groups, respectively, 64.6% and 49.2% of patients had vascular invasion, 87.8% and 91.1% had extrahepatic metastasis, and 54.3% and 47.1% had both. During follow-up (median duration, 5.5 months), the median TTP and OS in the combined group were longer than those in the monotherapy group (TTP: 2.5 months vs 2.1 months, respectively, P = .008; OS: 8.9 months vs 5.9 months, P = .009). At univariate and subsequent multivariate analyses, additional TACE was an independent predictor of favorable TTP and OS (adjusted hazard ratio: 0.74 and 0.57, respectively; P < .05 for both), consistent with the outcomes of inverse probability of treatment weighting. In the propensity score-matched cohort (96 pairs), the median TTP in the combined group was significantly longer than that in the monotherapy group (2.7 months vs 2.1 months, respectively; P = .011), but median OS was not (9.1 months vs 6.7 months, P = .21).

CONCLUSION

In this retrospective study, TACE plus sorafenib was superior to sorafenib alone with respect to TTP in patients with advanced-stage HCC, although it may or may not improve OS.

SUPPLEMENTAL MATERIAL

http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.13130150/-/DC1.

Comparison of positron emission tomography and bremsstrahlung imaging to detect particle distribution in patients undergoing yttrium-90 radioembolization for large hepatocellular carcinomas or associated portal vein thrombosis

PURPOSE

To compare positron emission tomography/computed tomography (PET/CT) imaging with bremsstrahlung single photon emission computed tomography (SPECT) in patients after yttrium-90 ((90)Y) microsphere radioembolization to assess particle uptake.

MATERIALS AND METHODS

This prospective study comprised patients with large (> 5 cm) hepatocellular carcinoma (HCC) or tumor-associated portal vein thrombus (PVT), or both. After radioembolization for HCC, patients underwent bremsstrahlung SPECT/CT and time-of-flight PET/CT imaging of (90)Y without additional tracer administration. Follow-up imaging and toxicity was analyzed. Imaging analyses of PET/CT and bremsstrahlung SPECT/CT were independently performed.

RESULTS

There were 13 patients enrolled in the study, including 7 with PVT. Median tumor diameter was 7 cm. PET/CT demonstrated precise localization of (90)Y particles in the liver, with specific patterns of uptake in large tumors. In cases of PVT, PET/CT showed activity within the PVT. When correlated to short-term follow-up imaging, areas of necrosis correlated with regions of uptake seen on PET/CT. Compared with bremsstrahlung imaging, PET/CT demonstrated at least comparable spatial resolution with less scatter. Quantitative uptake in nontreated regions of interest showed significantly reduced scatter with PET/CT versus SPECT/CT (1% vs 14%, P < .001).

CONCLUSIONS

Evaluation of (90)Y particle uptake with PET/CT potentially demonstrates high spatial resolution and low scatter compared with bremsstrahlung SPECT/CT. Confirmation of particles within PVT on PET/CT correlates with response on follow-up imaging and may account for the efficacy of radioembolization in patients with PVT.

Predisposing factors of hepatocellular carcinoma recurrence following complete remission in response to transarterial chemoembolization

BACKGROUND AND AIM

The aim of our study was to determine the predictors of recurrences in hepatocellular carcinoma (HCC) patients who had achieved complete remission (CR) by transarterial chemoembolization (TACE).

METHODS

A total of 220 consecutive HCC patients who had achieved CR by TACE were followed for a median 72 months. CR was defined as complete lipiodol uptake based on the results of lipiodol-computed tomography 4 weeks after TACE and no additional tumor staining on the follow-up angiography. Recurrence patterns were classified as local recurrence and secondary tumor, respectively, in relation to the location of recurrence; early and late recurrence were classified in relation to recurrence time.

RESULTS

Recurrence of HCC was observed in 169 patients (77 %), of whom 91 (54 %) had local recurrences, 61 (36 %) had secondary tumor, and 17 (10 %) had both. There were 45 (27 %) early and 124 (73 %) late recurrences. Local recurrence developed more frequently in patients with early recurrence than in those with late recurrence (62 vs. 51 %, respectively), while secondary tumor was detected more commonly in patients with late recurrence than in those with early recurrence (39 vs. 29 %, respectively; P < 0.001). In multivariate analyses, multinodularity [hazard ratio (HR) 2.351, P = 0.023] and a persistently high serum alpha-fetoprotein level following CR (HR 3.173, P < 0.001) were significant predictors of early recurrence. Older age (≥ 60 years; HR 1.531, P = 0.043), advanced Child-Pugh class (HR 1.983, P = 0.002), and the association with cirrhosis (HR 1.756, P = 0.028) were predictors of late recurrence following CR.

CONCLUSIONS

Early recurrences following CR by TACE may be due mainly to undetectable remaining tumors, whereas late recurrences may be caused by newly appearing tumors in patients with a background of advanced cirrhotic liver.

Optimal measurement modality and method for evaluation of responses to transarterial chemoembolization of hepatocellular carcinoma based on enhancement criteria

PURPOSE

To determine the usefulness of enhancement by iodized oil deposits on computed tomography (CT) following transarterial chemoembolization for hepatocellular carcinoma (HCC), and to compare the reliability of such CT imaging with that of magnetic resonance (MR) imaging.

MATERIALS AND METHODS

Fifty-one patients for whom resected or explanted livers containing chemoembolized HCC lesions of at least 1 cm were available. Imaging responses were determined based on modified Response Evaluation Criteria In Solid Tumors (mRECIST) and European Association for the Study of the Liver (EASL) criteria for 59 target tumors on CT and MR scans before surgery. CT-based evaluation was performed per mRECIST and EASL criteria, considering iodized oil retention as indicating necrosis and, alternatively, as enhancing viable tissue ("mRECIST-Lipiodol" and "EASL-Lipiodol"). Pathologic necrosis was graded as 100%, 50%-99%, or less than 50%.

RESULTS

Goodman-Kruskal γ-values for radiologic-pathologic correlation were greater than 0.95 for mRECIST and EASL criteria on CT or MR imaging. However, mRECIST-Lipiodol and EASL-Lipiodol measurements showed weaker correlation with pathologic findings, with γ-values of 0.797 and 0.846, respectively. With respect to intermethod agreement, weighted γ-values for mRECIST by CT and MR, and for EASL criteria by CT and MR, both exceeded 0.80, whereas mRECIST-Lipiodol and EASL-Lipiodol showed only moderate levels of agreement with mRECIST/EASL criteria by CT or MR imaging, with γ-values of 0.522-0.631.

CONCLUSIONS

Response estimation based on measurement of iodized oil deposits as necrosis on CT when applying enhancement criteria after chemoembolization for HCC correlated well with actual pathologic class, and agreed with MR-based evaluation.

Detection of recurrent hepatocellular carcinoma in cirrhotic liver after transcatheter arterial chemoembolization: value of quantitative color mapping of the arterial enhancement fraction of the liver

Objective

To investigate the additional diagnostic value of color mapping of the hepatic arterial enhancement fraction (AEF) for detecting recurrent or residual hepatocellular carcinoma (HCC) in patients treated with transcatheter arterial chemoembolization (TACE).

Materials and Methods

Seventy-six patients with 126 HCCs, all of whom had undergone previous TACE, and subsequently, underwent follow-up multiphasic liver CT scans, were included in this study. Quantitative color maps of the AEF of the whole liver were created, by using prototype software with non-rigid registration. The AEF was defined as the ratio of the attenuation increment during the arterial phase to the attenuation increment during the portal phase. Two radiologists independently analyzed the two image sets at a two-week interval, i.e., the multiphasic CT image set and the second image set of the AEF color maps and the CT images. The additional diagnostic value of the AEF color mapping was determined, by the use of the jackknife-alternative free-response receiver-operating-characteristic analysis. The sensitivity and positive predictive values for detecting HCCs of each image set were also evaluated and compared.

Results

The reader-averaged figures of merit were 0.699 on the initial interpretation of the MDCT image set, and 0.831 on the second interpretation of the combined image set; the difference between the two interpretations was significant (p value < 0.001). The mean sensitivity for residual or recurrent HCC detection increased from 62.7% on the initial analysis to 82.1% on the second analysis using the AEF color maps (p value < 0.001). The mean positive predictive value for HCC detection was 74.5% on the initial analysis using MDCT, and 71.6% on the second analysis using AEF color mapping.

Conclusion

Quantitative color mapping of the hepatic AEF may have the possibility to increase the diagnostic performance of MDCT for the detection of recurrent or residual HCC without the potential risk of radiation-related hazards.

Pattern of retained contrast on immediate postprocedure computed tomography (CT) after particle embolization of liver tumors predicts subsequent treatment response

PURPOSE

To determine if the pattern of retained contrast on immediate postprocedure computed tomography (CT) after particle embolization of hepatic tumors predicts modified Response Evaluation Criteria in Solid Tumors (mRECIST) response.

MATERIALS AND METHODS

This study was approved by the Institutional Review Board with a waiver of authorization. One hundred four liver tumors were embolized with spherical embolic agents (Embospheres, Bead Block, LC Bead) and polyvinyl alcohol. Noncontrast CT was performed immediately after embolization to assess contrast retention in the targeted tumors, and treatment response was assessed by mRECIST criteria on follow-up CT (average time 9.0 ± 7.7 weeks after embolization). Tumor contrast retention (TCR) was determined based on change in Hounsfield units (HUs) of the index tumors between the preprocedure and immediate postprocedure scans; vascular contrast retention (VCR) was rated; and defects in contrast retention (DCR) were also documented. The morphology of residual enhancing tumor on follow-up CT was described as partial, circumferential, or total. Association between TCR variables and tumor response were assessed using multivariate logistic regression.

RESULTS

Of 104 hepatic tumors, 51 (49%) tumors had complete response (CR) by mRECIST criteria; 23 (22.1%) had partial response (PR); 21 (20.2%) had stable disease (SD); and 9 (8.7%) had progressive disease (PD). By multivariate analysis, TCR, VCR, and tumor size are independent predictors of CR (p = 0.02, 0.05, and 0.005 respectively). In 75 tumors, DCR was found to be an independent predictor of failure to achieve complete response (p < 0.0001) by imaging criteria.

CONCLUSION

TCR, VCR, and DCR on immediate posttreatment CT are independent predictors of CR by mRECIST criteria.

Value of noncontrast CT immediately after transarterial chemoembolization of hepatocellular carcinoma with drug-eluting beads

PURPOSE

To retrospectively evaluate the presence and distribution patterns of contrast agent retention in the liver on noncontrast computed tomography (CT) immediately following chemoembolization with drug-eluting beads (DEBs).

MATERIALS AND METHODS

From 2008 to 2010, 95 patients with 224 liver lesions had chemoembolization performed with DEBs and a noncontrast CT examination of the liver performed immediately after embolization. Of these, 85 patients with 193 lesions were included. The postembolization CT scan was reviewed by a diagnostic radiologist, and the presence of contrast agent retention within the lesion was assessed. Varying patterns of contrast agent retention were defined.

RESULTS

Of the 193 lesions included, 146 (76%) retained contrast medium. Aside from some contrast medium in vessels, very little if any contrast medium was seen in the surrounding liver. Various patterns of contrast agent retention were noted within lesions. In a single case, repeat imaging was obtained 6 hours later, which demonstrated washout of contrast agent in a lesion that had retained contrast agent on the postprocedure CT scan. Of significance, 13 additional foci of contrast agent retention were identified on postchemoembolization CT scans that, on retrospective review of preprocedure imaging, represented enhancing lesions not previously identified.

CONCLUSIONS

Noncontrast CT after chemoembolization with DEBs demonstrates contrast agent retention in 76% of cases, without significant contrast medium seen in the adjacent liver parenchyma. The presence or absence of contrast agent retention may prove to be useful in evaluating accurate targeting of a lesion.

Imaging predictors of the response to transarterial chemoembolization in patients with hepatocellular carcinoma: a radiological-pathological correlation

Transarterial chemoembolization (TACE) is one of the standard therapies for bridging patients with hepatocellular carcinoma (HCC) to transplantation. This study was designed to determine which features on pre- and post-TACE imaging are associated with tumor necrosis in pathological specimens. Records of 105 patients with 132 HCC lesions who underwent liver transplantation after TACE were retrospectively reviewed. In 70% of the nodules, >90% necrosis was achieved. The development of >90% lesion necrosis upon pathological analysis was associated with avid lesion enhancement (P = 0.03) and the presence of a feeding vessel larger than 0.9 mm in diameter on the pre-TACE visceral angiogram (P = 0.01). Near-complete lesion necrosis was also associated with an extensive accumulation of ethiodized oil within a lesion during TACE administration (P = 0.04). On post-TACE computed tomography imaging, a lack of residual contrast enhancement (P < 0.0001), a decrease in the lesion size (P = 0.04), a high lesion density due to an accumulation of ethiodized oil (P = 0.03), and a diffuse distribution of ethiodized oil throughout the lesion (P = 0.0001) were also correlated with near-complete lesion necrosis upon pathological analysis. In conclusion, this study found multiple pre- and post-TACE imaging characteristics of HCC that were associated with near-complete tumor necrosis upon histopathological analysis after TACE. These findings may help to guide the selection of an optimal treatment strategy for bridging patients with HCC to liver transplantation.

Clinical utility of des-γ-carboxyprothrombin kinetics as a complement to radiologic response in patients with hepatocellular carcinoma undergoing transarterial chemoembolization

PURPOSE

Serial α-fetoprotein (AFP) measurements are useful for assessing tumor responses to numerous therapies for hepatocellular carcinoma (HCC). This study tested the predictive value of changes in des-γ-carboxy prothrombin (DCP), in parallel with AFP, as an indicator of HCC response after transarterial chemoembolization.

MATERIALS AND METHODS

The study group consisted of 327 patients with HCC initially seropositive for DCP (≥ 40 mAU/mL) and/or AFP (≥ 100 ng/mL) who underwent repeated chemoembolization as first-line therapy. Radiologic responses were measured based on modified Response Evaluation Criteria In Solid Tumors guidelines. Serologic response was defined as a decrease of at least 50% in DCP or AFP level from baseline. Radiologic-serologic correlation and disease progression and survival according to serologic responses were analyzed.

RESULTS

Before treatment, 129 patients (39%) had high DCP alone, 66 (20%) had high AFP alone, and 58 (18%) had high levels of both. Radiologic and serologic responses were achieved in 88.2% and 91.4% of patients with high DCP levels and in 89.5% and 91.1% of those with high AFP levels, respectively. Serologic response based on AFP or DCP was significantly correlated with radiologic response, and this was confirmed by landmark analysis (P < .001). DCP and AFP responders had better times to progression and overall survival than nonresponders (P < .001). Cox models revealed that both serologic responses were independent estimates of survival (hazard ratios, 0.11 for DCP and 0.14 for AFP; P < .001).

CONCLUSIONS

After transarterial chemoembolization for HCC, DCP response may be a useful surrogate endpoint of immediate and prolonged clinical outcomes, along with AFP response.

Maximum number of target lesions required to measure responses to transarterial chemoembolization using the enhancement criteria in patients with intrahepatic hepatocellular carcinoma

BACKGROUND & AIMS

The European Association for the Study of the Liver (EASL) criteria and, more recently, the modified Response Evaluation Criteria in Solid Tumors (mRECIST), have been widely adopted for evaluating responses to locoregional therapies for hepatocellular carcinoma (HCC). We wished to establish the optimum maximum number of target lesions that need to be measured in enhancement estimations.

METHODS

From a prospective registry in our institution we identified 160 consecutive patients who had at least two measurable HCCs of nodular type exceeding 10mm in diameter, and who initially underwent transarterial chemoembolization (TACE). Intra-patient and inter-method agreement on confirmed response status were evaluated based on a maximum of one, two, or three target lesions selected among the measurable lesions according to size, versus all baseline lesions.

RESULTS

Per patient analyses showed that the most consistent response distribution under both EASL and mRECIST was obtained using two or three targets versus all measurable lesions. These features were maintained even in analyses of subgroups stratified according to size, distribution, and number of tumors. The kappa values of comparisons between using a maximum of two or three targets versus using all the lesions were near 1.0, significantly higher than those obtained under both criteria using just the largest tumor. Similar conclusions were obtained when either two or three targets were measured.

CONCLUSIONS

Our data indicate that evaluating the largest two lesions is generally the most useful procedure for measuring TACE responses under both EASL and mRECIST.

Which response criteria best help predict survival of patients with hepatocellular carcinoma following chemoembolization? A validation study of old and new models

PURPOSE

To identify differences in radiologic assessment methods and determine optimal imaging criteria for response evaluation in hepatocellular carcinoma (HCC) patients treated with chemoembolization.

MATERIALS AND METHODS

Institutional review board approval was obtained, and patient informed consent was waived. The present study included 332 patients with intermediate stage HCC and Child-Pugh A cirrhosis who underwent serial chemoembolization. All measurable target lesions of 1 cm or larger in diameter were uni- and bidimensionally measured both at baseline and during follow-up. Intermodel agreement among the guidelines of the World Health Organization (WHO), Response Evaluation Criteria in Solid Tumors (RECIST), the European Association for the Study of the Liver (EASL), and modified RECIST (mRECIST) were examined. The most reliable model was selected on the basis of the correlation with survival prediction.

RESULTS

The κ values of comparisons among WHO, RECIST, and mRECIST guidelines were less than 0.20, whereas the κ value for the comparison of EASL and mRECIST guidelines was 0.94. In patients with a partial response (PR), stable disease (SD), or progressive disease (PD), compared with patients with a complete response (CR), hazard ratios (HRs) for survival were 2.99 (95% confidence interval [CI]: 2.14, 4.17), 3.49 (95% CI: 1.71, 7.10), and 15.63 (95% CI: 9.51, 25.69), respectively, for EASL criteria. In patients with a PR, SD, or PD, compared with patients with a CR, the HRs were 2.75 (95% CI: 1.96, 3.87), 6.32 (95% CI: 3.67, 10.90), and 16.06 (95% CI: 9.76, 26.43), respectively, for mRECIST guidelines (P<.001). The C index for the multivariate model was 0.76 (95% CI: 0.72, 0.79) for both EASL and mRECIST guidelines, thus exhibiting satisfactory capability to help predict survival. The Cox regression model revealed that both mRECIST and EASL guidelines were independent predictors of overall survival (P<.001 for both).

CONCLUSION

The enhancement models more accurately helped predict long-term survival in HCC patients treated with chemoembolization.

Imaging in interventional oncology

Medical imaging in interventional oncology is used differently than in diagnostic radiology and prioritizes different imaging features. Whereas diagnostic imaging prioritizes the highest-quality imaging, interventional imaging prioritizes real-time imaging with lower radiation dose in addition to high-quality imaging. In general, medical imaging plays five key roles in image-guided therapy, and interventional oncology, in particular. These roles are (a) preprocedure planning, (b) intraprocedural targeting, (c) intraprocedural monitoring, (d) intraprocedural control, and (e) postprocedure assessment. Although many of these roles are still relatively basic in interventional oncology, as research and development in medical imaging focuses on interventional needs, it is likely that the role of medical imaging in intervention will become even more integral and more widely applied. In this review, the current status of medical imaging for intervention in oncology will be described and directions for future development will be examined.

Semiautomated segmentation for volumetric analysis of intratumoral ethiodol uptake and subsequent tumor necrosis after chemoembolization

OBJECTIVE

Linear measurements, such as those described by the Response Evaluation Criteria in Solid Tumors (RECIST) criteria, may be limited for assessment of response after transarterial chemoembolization (TACE). The purpose of this pilot study was to show intra- and interobserver reproducibility of volumetric measurements of Ethiodol (ethiodized oil) seen within tumor 24 hours after TACE and of necrotic and viable tumor 1 month after treatment. Volumetric measurements are compared with linear measurements and survival outcomes.

MATERIALS AND METHODS

Between 2006 and 2009, 37 consecutive TACE procedures were performed in 27 patients with hepatic malignancies. CT images obtained 24 hours and 1 month after TACE were retrospectively analyzed. Three observers measured volumes twice. Intraoperator reproducibility was determined using Wilcoxon's signed rank test to assess whether the difference in each volumetric measurement approaches zero. The intraclass correlation coefficient (ICC) and Bland-Altman plots were used to determine interoperator reproducibility. Survival data were retrospectively obtained from the electronic medical record.

RESULTS

Good intraobserver reproducibility and interobserver reproducibility (p > 0.05, ICC > 0.9, respectively) were shown for Ethiodol, whole tumor, and necrotic tumor volumes. The volume of Ethiodol correlated with subsequent necrotic tumor volume (p = 0.009), reduction in whole tumor volume (p = 0.004), and patient survival (p = 0.029). Kaplan-Meier curves suggest that Ethiodol accumulation in more than 50% of the tumor and a 10% or greater increase in the volume of necrotic tumor correlated with survival (p = 0.028 and 0.047, respectively).

CONCLUSION

Semiautomated volumetric analysis can be performed with good intra- and interobserver reproducibility. The volume of Ethiodol accumulated in the tumor after TACE correlates with subsequent necrosis. These early measurements may predict survival outcomes.

Added value of 80 kVp images to averaged 120 kVp images in the detection of hepatocellular carcinomas in liver transplantation candidates using dual-source dual-energy MDCT: results of JAFROC analysis

BACKGROUND

To assess the added value of 80 kVp images to weighted average 120 kVp images for detecting hepatocellular carcinomas (HCCs) using dual-source, dual-energy MDCT.

MATERIALS AND METHODS

Forty-one HCCs in 42 patients who underwent liver transplantation (LT) were included. All patients underwent quadruple-phase CT using a 64-row dual-source, dual-energy MDCT with 80 kVp and 140 kVp. For 120 kVp, a linear blending ratio of 0.3 was chosen. Interval reviews for both simulated 120 kVp images without and with pure 80 kVp data were performed independently by two radiologists. They detected HCCs using a 4-point confidence scale. Tumor-to-liver contrast-to-noise ratio (CNR) was calculated and compared between the 80 kVp and simulated 120 kVp images. The additional diagnostic value of 80 kVp images was evaluated by jackknife alternative free-response receiver-operating characteristic (JAFROC) analysis.

RESULTS

There were 41 HCCs on pathology and 37 of the 41 HCCs were depicted on CT scan. The mean CNR of the 37 HCCs in late arterial and portal-phase images was significantly better in the 80 kVp images than in 120 kVp images. The average JAFROC figure of merit, however, was not significantly improved when 80 kVp was added. Furthermore, the number of false-positives was significantly increased in reader 1 when adding 80kVp data.

CONCLUSION

The addition of 80 kVp CT images to simulated 120 kVp images did not significantly improve the detection of HCCs despite of the significantly better CNR of 80 kVp images.