Evaluation of therapeutic effectiveness of transarterial chemoembolization for hepatocellular carcinoma: correlation of dynamic susceptibility contrast-enhanced echoplanar imaging and hepatic angiography

Applying arterial enhancement fraction (AEF) texture features to predict the tumor response in hepatocellular carcinoma (HCC) treated with Transarterial chemoembolization (TACE)

Background

To evaluate the application of Arterial Enhancement Fraction (AEF) texture features in predicting the tumor response in Hepatocellular Carcinoma (HCC) treated with Transarterial Chemoembolization (TACE) by means of texture analysis.

Methods

HCC patients treated with TACE in Shengjing Hospital of China Medical University from June 2018 to December 2019 were retrospectively enrolled in this study. Pre-TACE Contrast Enhanced Computed Tomography (CECT) and imaging follow-up within 6 months were both acquired. The tumor responses were categorized according to the modified RECIST (mRECIST) criteria. Based on the CECT images, Region of Interest (ROI) of HCC lesion was drawn, the AEF calculation and texture analysis upon AEF values in the ROI were performed using CT-Kinetics (C.K., GE Healthcare, China). A total of 32 AEF texture features were extracted and compared between different tumor response groups. Multi-variate logistic regression was performed using certain AEF features to build the differential models to predict the tumor response. The Receiver Operator Characteristic (ROC) analysis was implemented to assess the discriminative performance of these models.

Results

Forty-five patients were finally enrolled in the study. Eight AEF texture features showed significant distinction between Improved and Un-improved patients (p < 0.05). In multi-variate logistic regression, 9 AEF texture features were applied into modeling to predict “Improved” outcome, and 4 AEF texture features were applied into modeling to predict “Un-worsened” outcome. The Area Under Curve (AUC), diagnostic accuracy, sensitivity, and specificity of the two models were 0.941, 0.911, 1.000, 0.826, and 0.824, 0.711, 0.581, 1.000, respectively.

Conclusions

Certain AEF heterogeneous features of HCC could possibly be utilized to predict the tumor response to TACE treatment.

Dynamic Computed Tomography Perfusion Imaging: Complementary Diagnostic Tool in Hepatocellular Carcinoma Assessment From Diagnosis to Treatment Follow-up

Early diagnosis of HCC is of paramount importance in order to enable the application of curative treatments. Among these, radiofrequency ablation (RFA) is actually considered the most effective ablative therapy for early stage hepatocellular carcinoma (HCC) not suitable for surgery. On the other hand, transarterial chemoembolization (TACE) represents the standard of care for intermediate stage HCC and compensated liver function. Finally, sorafenib, an oral antiangiogenic targeted drug, is the only approved systemic therapy for advanced HCC with vascular invasion, extrahepatic spread, and well-preserved liver function. Beside traditional radiological techniques, new functional imaging tools have been introduced in order to provide not only morphological information but also quantitative functional data. In this review, we analyze perfusion-CT (pCT) from a technical point of view, describing the main different mathematical analytical models for the quantification of tissue perfusion from acquired CT raw data, the most commonly acquired perfusion parameters, and the technical parameters required to perform a standard pCT examination. Moreover, a systematic review of the literature was performed to assess the role of pCT as an emerging imaging biomarker for HCC diagnosis, response evaluation to RFA, TACE, and sorafenib, and we examine its challenges in HCC management.

Contrast-Enhanced Ultrasound in Residual Tumor of Hepatocellular Carcinoma following Transarterial Chemoembolization: Is It Helpful for Tumor Response?

Aim

To investigate the enhancement pattern of residual tumor on contrast-enhanced ultrasonography (CEUS) in patients with hepatocellular carcinoma (HCC) treated with transarterial chemoembolization (TACE).

Methods

Our study initially included 76 patients with HCC, 73 of which were finally allocated into two groups: group 1 (43 patients, post-TACE group) and group 2 (30 patients, untreated HCC group). All patients were performed with CEUS using SonoVue, and qualitative and quantitative enhancement characteristics (rise time, peak time, and washout time) were evaluated for the residual tumors. T test or χ2 test was used to estimate for differences between two groups.

Results

In group 1, the mean rise time, peak time, and washout times in group 1 were 16.1±2.7 sec, 31.3±3.1 sec, and 191.0±31.3 sec, respectively. In group 2, these were 15.1±3.5 sec, 30.9±3.2 sec, and 142.6±16.1 sec, respectively. The differences in rise time and peak time were not statistically significant (P=0.09 and 0.30, respectively), but the washout time was significantly prolonged in group 1 (P<0.01). The enhanced pattern in arterial phase was inhomogeneous (n=11), regular homogeneous (n=11), partial (n=12), peripheral (n=7), and peripheral rim-like (n=2) in group 1. The average of the longest tumor size of the whole lesion in the 5 types was 4.7±1.3cm, 2.9±1.0cm, 3.1±1.7cm, 2.5±0.6cm, and 2.1 cm.

Conclusion

It suggested that the washout time of post-TACE residual lesions was prolonged compared with untreated HCC nodules on CEUS imaging. Combined with the triple-phase enhancement pattern seen on CEUS, the washout time may provide additional information to guide further treatment for residual tumors.

Magnitude of change in alpha-fetoprotein in response to transarterial chemoembolization predicts survival in patients undergoing liver transplantation for hepatocellular carcinoma

BACKGROUND

Downsizing strategies are often attempted for patients with hepatocellular carcinoma (hcc) before liver transplantation (lt). The objective of the present study was to determine clinical predictors of favourable survival outcomes after transarterial chemoembolization (tace) before lt for hcc outside the Milan criteria, so as to better select candidates for this strategy.

METHODS

In this retrospective study, patients with hcc tumours either beyond Milan criteria (single lesion > 5 cm, 3 lesions with 1 or more > 3 cm) or at the upper limit of Milan criteria (single lesions between 4.1 cm and 5.0 cm), with a predicted waiting time of more than 3 months, received carboplatin-based tace treatments. Exclusion criteria for tace included Child-Pugh C cirrhosis or the presence of portal vein invasion or extrahepatic disease on imaging. Only patients without tumour progression after tace underwent lt.

RESULTS

Of 160 hcc patients who received liver grafts between 1997 and 2010, 35 were treated with tace preoperatively. The median of the sum of tumour diameters was 6.7 cm (range: 4.8-8.5 cm), which decreased with tace to 5.0 cm (range: 3.3-7.0 cm) at transplantation (p < 0.0004). The percentage drop in alpha-fetoprotein (αfp) was a positive predictor (p = 0.0051) and the time from last tace treatment to transplantation was a negative predictor (p < 0.0001) for overall survival.

CONCLUSIONS

The percentage drop in αfp and a shorter time from the final tace treatment to transplantation significantly predicted improved overall survival after lt for hcc downsized with tace. As a serum marker, αfp should be followed when tace is used as a strategy to stabilize or downsize hcc lesions before lt.

Functional magnetic resonance imaging of the liver: parametric assessments beyond morphology

There is growing interest in exploring and using functional imaging techniques to provide additional information on structural alterations in the liver, which often occur late in the disease process. This article presents a summary of the different functional MR imaging techniques currently in use, focusing on dynamic contrast-enhanced MR imaging, diffusion-weighted MR imaging, MR spectroscopy, in- and oppose-phase MR imaging, and T2*-weighted imaging. For each technique, the biologic underpinning for the technique is explained, the clinical applications surveyed, and the challenges for their application enumerated. Developing and less frequently used techniques such as MR elastography, blood oxygenation level dependent imaging, dynamic susceptibility contrast-enhanced MR imaging, and diffusion-tensor imaging are reviewed. The challenges widespread adoption of functional MR imaging and the translation of such techniques to high field strengths are also discussed.

Transarterial chemoembolization using docetaxel-loaded phytantriol cubic phase precursor for the treatment of hepatocellular carcinoma

The purpose of this study was to evaluate the transarterial chemoembolic agent based on docetaxel-loaded phytantriol cubic phase precursor (DTX PCPP) by in vitro cytotoxicity study and in vivo evaluation of antitumor efficacy as well as the histological examination. The methythiazolyl tereazolium bromide assay in Hep G2 cell line revealed that DTX PCPP generated high cytotoxicity by causing cell apoptosis and G2/M phase arrest. In vivo studies conducted in rabbits bearing VX2 tumors, which were treated with DTX PCPP, used as a transarterial chemoembolic agent, showed a significant antitumor efficacy and prominent higher DTX concentrations in tumor and liver than those in other organs. The histology presented typical necrosis in tumor that demonstrated excellent therapeutic effect. In conclusion, the DTX PCPP could achieve an excellent antitumor effect with low systemic toxicity for the treatment of hepatocellular carcinoma and therefore implied the prospect of DTX PCPP for clinical applications.

The usefulness of perfusion-weighted magnetic resonance imaging in advanced pancreatic cancer

OBJECTIVES

Perfusion-weighted magnetic resonance imaging (MRI) can detect the changes of signal intensity in tumors. We evaluated the prognostic value of perfusion-weighted MRI in patients with advanced pancreatic cancer (PC).

METHODS

Perfusion-weighted MRI was performed before treatment on 27 consecutive patients with advanced PC. The American Joint Committee on Cancer (AJCC) stages of patients were as follows (8, stage III; 19, stage IV). Imaging acquisition was continually repeated with echo planar sequence every 2 seconds for 2 minutes after a bolus injection of gadolinium. We made a time intensity curve of PC and calculated the signal ratio (SR) on perfusion-weighted imaging. We assessed the relation between SR and clinical factors including tumor stage, lymph node metastasis, liver metastasis, and so on. Patients were divided into low and high SR group and compared SR with the overall survival.

RESULTS

All cases showed transient decreases signal intensity (SR, 6.9-55.7%). These patients were classified into 2 groups at cutoff median SR of 22.0% The high SR group significantly correlated with the higher stage (P=0.03) and the presence of lymph node metastasis (P=0.04). The high SR group had significantly shorter overall survival (P=0.04).

CONCLUSIONS

Perfusion-weighted MRI may predict the survival in advanced PC patients.

Computed tomography perfusion in evaluating the therapeutic effect of transarterial chemoembolization for hepatocellular carcinoma

AIM: To prospectively assess the changes in parameters of computed tomography (CT) perfusion pre- and post-transarterial chemoembolization (TACE) of hepatocellular carcinoma (HCC) in different treatment response groups, and to correlate the changes with various responses of HCC to TACE.

METHODS: Thirty-nine HCC patients underwent CT perfusion examinations pre-(1 d before TACE) and post-treatment (4 wk after TACE). The response evaluation criteria for solid tumors (RECIST) were referred to when treatment responses were distributed. Wilcoxon-signed ranks test was used to compare the differences in CT perfusion parameters pre- and post-TACE for different response groups.

RESULTS: Only one case had treatment response to CR and the CT perfusion maps of post-treatment lesion displayed complete absence of signals. In the PR treatment response group, hepatic artery perfusion (HAP), hepatic arterial fracture (HAF) and hepatic blood volume (HBV) of viable tumors post-TACE were reduced compared with pre-TACE (P = 0.001, 0.030 and 0.001, respectively). In the SD group, all CT perfusion parameters were not significantly different pre- and post-TACE. In the PD group, HAP, HAF, portal vein perfusion (PVP) and hepatic blood flow (HBF) of viable tumors post-TACE were significantly increased compared with pre-TACE (P = 0.005, 0.012, 0.035 and 0.005, respectively).

CONCLUSION: Changes in CT perfusion parameters of viable tumors are correlated with different responses of HCC to TACE. Therefore, CT perfusion imaging is a feasible technique for monitoring response of HCC to TACE.

Characteristics of liver on magnetic resonance diffusion-weighted imaging: Dynamic and image pathological investigation in rabbit liver VX-2 tumor model

AIM: To investigate dynamical and image pathological characteristics of the liver on magnetic resonance (MR) diffusion-weighted imaging (DWI) in the rabbit VX-2 tumor model.

METHODS: Forty New Zealand rabbits were included in the study and VX-2 tumor piece was implanted intrahepatically. Fifteen animals received two intrahepatic implantations while 25 had one intrahepatical implantation. DWI, T1- and T2-weighted of magnetic resonance imaging (MRI) were carried out on the 7th and the 14th d after implantation and DWI was conducted, respectively on the 21th d. Ten VX-2 tumor samples were studied pathologically.

RESULTS: The rate of lump detected by DWI, T1WI and T2WI was 78.7%, 10.7% and 53.5% (χ² = 32.61, P < 0.001) on the 7th d after implantation and 95.8%, 54.3% and 82.9% (χ² = 21.50, P < 0.001) on the 14th d. The signal of most VX-2 tumors on DWI was uniform and it was equal on the map of apparent diffusion coefficient (ADC). The signal of VX tumors did not decrease on the 7th d after implantation, most of them slowly growing during the week following implantation without significant cell dying within the tumor. VX-2 tumors grew increasingly within 14 d after implantation but the signal of most VX-2 tumors on DWI or on the map of ADC was uniform or uneven and ADC of VX tumors decreased obscurely or slightly because tumor necrosis was still not obvious. On the 21th d after implantation, the signal of most VX-2 tumors on DWI or on the map of ADC was uneven because tumor necrosis was evident and ADC of VX-2 tumor necrotic areas decreased. The areas of viable cells in VX-2 tumors manifested a high signal on DWI and a low signal on the map of ADC. The areas of dead cells or necrosis in VX-2 tumors manifested low signals on DWI and low, equal or high signals on the map of ADC but they manifested high signals on DWI and on the map of ADC at the same time when the areas of necrotic tumor became liquefied or cystic. The border of tumors on DWI appeared gradually distinct and internal signals of tumor became progressively uneven.

CONCLUSION: The manifestations of viable, necrotic and liquefied or cystic areas in VX-2 tumors on DWI are typical and DWI is of significant and potential values in clinical application in both the early detection and diagnosis of liver tumors.

Progress in application of high-field-strength MR to diagnosis and treatment of hepatocellular carcinoma

Magnetic resonance imaging (MRI), a modern imaging modality, cannot only diagnose diseases, but also participate in their treatment. With the increase in static magnetic field strength, the features of high-field-strength MRI become increasingly predominant, thus MRI has been widely used in the diagnosis and treatment of diseases. MRI at high field strength can provide information on abnormal function and metabolism, monitor therapeutic procedures and reactions, and present excellent morphologic images for hepatocellular carcinoma.

Characteristics and pathological mechanism on magnetic resonance diffusion-weighted imaging after chemoembolization in rabbit liver VX-2 tumor model

AIM: To investigate dynamic characteristics and pathological mechanism of signal in rabbit VX-2 tumor model on diffusion-weighted imaging (DWI) after chemoembolization.

METHODS: Forty New Zealand rabbits were included in the study and forty-seven rabbit VX-2 tumor models were raised by implanting directly and intrahepatically after abdominal cavity opened. Forty VX-2 tumor models from them were divided into four groups. DWI was performed periodically and respectively for each group after chemoembolization. All VX-2 tumor samples of each group were studied by pathology. The distinction of VX-2 tumors on DWI was assessed by their apparent diffusion coefficient (ADC) values. The statistical significance between different time groups, different area groups or different b-value groups was calculated by using SPSS12.0 software.

RESULTS: Under b-value of 100 s/mm², ADC values were lowest at 16 h after chemoembolization in area of VX-2 tumor periphery, central, and normal liver parenchyma around tumor, but turned to increase with further elongation of chemoembolization treatment. The distinction of ADC between different time groups was significant respectively (F = 7.325, P < 0.001; F = 2.496, P < 0.048; F = 6.856, P < 0.001). Cellular edema in the area of VX-2 tumor periphery or normal liver parenchyma around tumor, increased quickly in sixteen h after chemoembolization but, from the 16th h to the 48th h, cellular edema in the area of normal liver parenchyma around tumor decreased gradually and that in the area of VX-2 tumor periphery decreased lightly at, and then increased continually. After chemoembolization, Cellular necrosis in the area of VX-2 tumor periphery was more significantly high than that before chemoembolization. The areas of dead cells in VX-2 tumors manifested low signal and high ADC value, while the areas of viable cells manifested high signal and low ADC value.

CONCLUSION: DWI is able to detect and differentiate tumor necrotic areas from viable cellular areas before and after chemoembolization. ADC of normal liver parenchyma and VX-2 tumor are influenced by intracellular edema, tissue cellular death and microcirculation disturbance after chemoembolization.

Magnetic Resonance As a Cancer Imaging Biomarker

Cancer is a diverse disease with many manifestations. Magnetic resonance (MR) has a wide range of sensitivities, and therefore has often been used to study cancer in humans in numerous different ways, most typically with MR spectroscopy and MR imaging. This article is not an exhaustive catalog of the use of MR in cancer, but will briefly highlight some of the many promising MR methods that have been developed, proposed, or used to focus on the problem of detecting and characterizing cancer, its treatments, and adverse effects.

Liver tumor model with implanted rhabdomyosarcoma in rats: MR imaging, microangiography, and histopathologic analysis

In compliance with institutional regulations for care and use of laboratory animals, the aim of this study was to establish and characterize a rodent liver tumor model to provide a platform for preclinical assessment of new diagnostic and therapeutic strategies. A rhabdomyosarcoma tumor was implanted in the right and left liver lobes of 20 rats, for a total of 40 tumors. T1- and T2-weighted magnetic resonance (MR) images, diffusion-weighted images, and dynamic susceptibility contrast agent-enhanced perfusion-weighted images were obtained up to 16 days after tumor implantation and were compared with postmortem three-dimensional computed tomographic (CT) images, digital microangiograms, and histopathologic findings. Fifteen tumors were examined with proton ((1)H) MR spectroscopy. All tumors grew, with a mean volume doubling time of 2.2 days +/- 0.9 (standard deviation) and a final size of 591 mm(3)+/- 124. The rhabdomyosarcoma tumor showed hypervascularity at MR imaging, three-dimensional CT, microangiography, and histologic analysis. On dynamic susceptibility contrast-enhanced perfusion-weighted images, the maximum signal intensity decrease differed in time and extent between the tumor and the liver, with a significantly (P < .001) higher relative blood volume, relative blood flow, and permeability value in the tumor than in the liver. With (1)H MR spectroscopy, the rhabdomyosarcoma tumor and the liver featured significant (P < .001) choline and lipid peaks, respectively. Implantation of a rhabdomyosarcoma tumor in the livers of rats is feasible and reproducible, and this animal model seems promising for future testing of new diagnostic and therapeutic strategies.

Hepatocellular carcinoma treated with interventional procedures: CT and MRI follow-up

In the past decade, a variety of interventional procedures have been employed for local control of hepatocellular carcinoma (HCC). These include transcather arterial chemoembolization (TACE) and several tumour ablation techniques, such as percutaneous ethanol injection (PEI), radio-frequency ablation (RFA), or percutaneous microwave coagulation therapy (PMC), laser-induced interstitial thermotherapy (LITT), etc. For a definite assessment of the therapeutic efficacy of interventional procedures, histological examination using percutaneous needle biopsy may be the most definite assessment of the therapeutic efficacy of interventional therapy, however, it is invasive and the specimen retrieved does not always represent the entire lesion owing to sampling errors. Therefore, computed tomography (CT) and magnetic resonance imaging (MRI) play a crucial role in follow-up of HCC treated by interventional procedures, by which the local treatment efficacy, recurrent disease and some of therapy-induced complications are evaluated. Contrast enhanced axial imaging (CT or MR imaging) may be the most sensitive test for assessing the therapeutic efficacy. The goal of the review was to describe the value of CT and MRI in the evaluation of interventional treatments.

Changes of tumor microcirculation after transcatheter arterial chemoembolization: First pass perfusion MR imaging and Chinese ink casting in a rabbit model

AIM: To observe the change of tumor microcirculation after transcatheter arterial chemoembolization (TACE) with bletilla microspheres by using first pass perfusion MR imaging (FP) and Chinese ink casting.

METHODS: VX2 carcinoma cells were surgically implanted into the left and right lobes of liver of 30 New Zealand white rabbits, which were divided into 3 groups at random. Emulsion of lipiodol mixed with mitomycin C, and 5-FU bletilla microspheres were injected into the hepatic artery respectively, and saline was used as control agent. MR imaging was performed with turbo-flash sequence 14 d after tumor implantation and 7 d after interventional therapy. The steepest slopes (SS) of the signal intensity versus time curves were created for quantitative analysis, 7.5% Chinese ink gelatin solution was injected through ascending artery (17 cases) or portal vein (2 cases) for lesion microvessel area (MVA) measurement after the last MRI examination.The correlation between perfusion imaging and MVA was studied blindly.

RESULTS: The SS values at the rim of tumor in lipiodol group (mean, 49% per second) and bletilla group (mean, 35% per second) were significantly decreased (P < 0.05) as compared with control group (mean, 124% per second), no difference was found between lipiodol and bletilla groups (P > 0.05). In lipiodol group, the MVAs (24974 ± 11836 μm²) in the center of the tumor were significantly smaller than those of the control group (35510 ± 15675 μm²) (P < 0.05), while the MVAs (80031 ± 22745 μm²) around the tumor were significantly increased because small and dense plexuses appeared around the tumor which correlated to intense reaction of granulation tissue. None of the vessels was seen in the tumor in bletilla group, the peripheral MVAs of the tumor were significantly smaller than those of the control group (P < 0.05) and lipiodol group (P < 0.05). There was a good correlation between SS and MVAs in control group (r_s, 0.985, P < 0.0001) and bletilla group (r_s, 0.743, P < 0.05), the correlation was not significant in lipiodol group (r_s, 0.527, P > 0.05).

CONCLUSION: TACE with bletilla microspheres may enhance its anti-tumor effect by inhibiting the angiogenesis, and FP-MRI provides useful information to assess the TACE effect by depicting tumor vascularization and perfusion.

Role and limitation of FMPSPGR dynamic contrast scanning in the follow-up of patients with hepatocellular carcinoma treated by TACE

AIM

To evaluate the role and limitation of fast multiplanar spoiled gradient-recalled (FMPSPGR) MR dynamic contrast scanning in the follow-up of patients with HCC treated by transarterial chemoembolization (TACE).

METHODS

Twenty-two patients with 24 HCC lesions confirmed by biopsy or surgical resection underwent MR imaging in 4-9wks after TACE with a superconducting 1.5 T MR scanner, including SE T(1)WI, T(2)WI and FMPSPGR dynamic contrast scanning. The signal intensities of all lesions on SE T(1)WI,T(2)WI and the enhancement patterns on FMPSPGR dynamic contrast scanning were observed, and the comparison was made between MRI findings and pathological results in all the cases.

RESULTS

Of the 24 lesions, the signal intensities were various on SE T(1)WI and T(2)WI. On T(1)WI, 13 lesions appeared as hyperintense, 4 lesions were isointense and the other 7 lesions were hypointensese. Histologically, hyperintense lesions showed on T(1)WI were viable tumor or hemorrhage; isointensities were coagulative necrosis or inflammatory infiltration; hypointensities were tumor, liquified necrosis, coagulative necrosis or inflammatory infiltration. On T(2)WI, 15 lesions appeared as hyperintense, 3 lesions were isointense and the other 6 lesions were hypointensese. Hyperintense lesions showed on T(2)WI were residuals of viable tumor, hemorrhage, liquefied necrosis or inflammatory infiltration; isointense lesions were residuals of viable tumor or inflammatory infiltration; hypointense lesions were coagulative necrosis. On FMPSPGR dynamic contrast scanning, 18 of the 24 lesions enhanced on early-phase dynamic scanning corresponding to residuals of viable tumor and the other 6 lesions had no enhancement at this phase because complete necrosis were seen in the histologic examination. On delayed-phase dynamic scanning, 6 lesions had permanent enhancement appeared as inhomogeneous hyperintensity and both residuals of viable tumor and inflammatory infiltration were found by histologic examination. 18 lesions were hypointense at this phase and 8 of them coexisted with peripheral ring-like enhancement of the lesions resulting from viable tumors or inflammatory infiltration.

CONCLUSION

FMPSPGR MR dynamic contrast scanning can reflect the pathologic changes of HCC treated by TACE. Especially, early-phase dynamic scanning can evaluate accurately residuals of viable tumor and necrosis in HCC lesions. FMPSPGR dynamic contrast scanning is useful in the follow-up of patients with HCC treated by TACE combined with SE T(1)WI and T(2)WI, but it is difficult to differentiate peripheral viable tumors from inflammatory infiltration.