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

Intraprocedural 3D Quantification of Lipiodol Deposition on Cone-Beam CT Predicts Tumor Response After Transarterial Chemoembolization in Patients with Hepatocellular Carcinoma

PURPOSE

To evaluate whether intraprocedural 3D quantification of Lipiodol deposition on cone-beam computed tomography (CBCT) can predict tumor response on follow-up contrast-enhanced magnetic resonance imaging (CE-MRI) in patients with hepatocellular carcinoma (HCC) treated with conventional transarterial chemoembolization (cTACE).

MATERIALS AND METHODS

This IRB approved, retrospective analysis included 36 patients with 51 HCC target lesions, who underwent cTACE with CBCT. CE-MRI was acquired at baseline and 1 month after cTACE. Overall tumor volumes as well as intratumoral Lipiodol volumes on CBCT were measured and compared with the overall and necrotic (non-enhancing) tumor volumes on CE-MRI using the paired student's t test. Tumor response on CE-MRI was assessed using modified response evaluation criteria in solid tumors (mRECIST). A linear regression model was used to correlate tumor volumes, Lipiodol volumes, and the percentage of Lipiodol deposition on CBCT with the corresponding parameters on CE-MRI. Nonparametric spearman rank-order correlation and trend test were used to correlate the percentage of Lipiodol deposition in the tumor with tumor response.

RESULT

A strong correlation between overall tumor volumes on CBCT and CE-MRI was observed (R(2) = 0.986). In addition, a strong correlation was obtained between the volume of Lipiodol deposition on CBCT and tumor necrosis (in cm(3)) on CE-MRI (R(2) = 0.960), and between the percentage of Lipiodol deposition and tumor necrosis (R(2) = 0.979). Importantly, the extent of Lipiodol deposition (in percentage of total tumor volume) correlated strongly with tumor response on CE-MRI (Spearman rho = 0.84, p < 0.001).

CONCLUSIONS

Intraprocedural 3D quantification of Lipiodol deposition on CBCT can be used to predict tumor response on follow-up CE-MRI.

A new angiographic imaging platform reduces radiation exposure for patients with liver cancer treated with transarterial chemoembolization

OBJECTIVES

To quantify the reduction of radiation liver cancer patients are exposed to during transarterial chemoembolization (TACE), while maintaining diagnostic image quality, using a new C-arm imaging platform.

METHODS

In this prospective, HIPAA-compliant, IRB-approved, two-arm trial, 78 consecutive patients with primary or secondary liver cancer were treated with TACE on a C-arm imaging platform before and after an upgrade incorporating optimized acquisition parameters and advanced real-time image processing algorithms. Dose area product (DAP) and radiation time of each digital fluoroscopy (DF), digital subtraction angiography (DSA) and cone beam CT (CBCT) were recorded. DSA image quality was assessed by two blinded and independent readers on a four-rank scale.

RESULTS

Both cohorts showed no significant differences with regard to patient characteristics and tumour burden. The new system resulted in a statistically significant reduction of cumulative DAP of 66% compared to the old platform (median 132.9 vs. 395.8 Gy cm(2)). Individually, DAP of DF, DSA and CBCT decreased by 52%, 79% and 15% (p < 0.01, p < 0.01, p = 0.51), respectively. No statistically significant differences in DSA image quality were found between the two imaging platforms.

CONCLUSIONS

The new imaging platform significantly reduced radiation exposure for TACE procedures without increased radiation time or negative impact on DSA image quality.

KEY POINTS

• The new C-arm system allowed reduction of radiation exposure by two thirds • The procedure's course was not affected by the new platform • No decrease in DSA image quality was observed after the radiation reduction.

Application value of DynaCT in patients with hepatic carcinoma undergoing transcatheter arterial chemoembolization

AIM: To evaluate the application value of Dyna computed tomography (DynaCT) technology in hepatic carcinoma patients undergoing transcatheter arterial chemoembolization (TACE) and to provide evidence for clinical utilization of DynaCT.

METHODS: Eighty-nine patients with primary liver cancer were retrospectively analyzed, and they were divided into either a DynaCT group (46 cases) or a conventional digital subtraction angiography (DSA) group (43 cases). Patients in the DynaCT group underwent two-dimensional conventional DSA combined with DynaCT, and the conventional DSA group underwent DSA only. Operative time, X-ray radiation and dosage of contrast agent were analyzed in two groups. The number of lesions detected and the ability to detect blood vessels were compared between the two groups. All patients were followed to analyze overall survival.

RESULTS: Compared with the conventional DSA group, the DynaCT group has significantly shortened operative time (P < 0.05). There was no statistical significant difference in X-ray radiation and dosage of contrast medium between the two groups. DynaCT detected a total of 92 lesions (in 46 patients). DynaCT was superior to conventional CT and MDCT in the detection of lesions with a diameter < 10 mm or between 10 and 20 mm (P < 0.001), although there was no significant difference in the detection of lesions with a diameter > 20 mm. Eleven cases in the DynaCT group manifested no clear tumor feeding artery during conventional DSA, of which 9 cases had clearly indicated blood supplying artery branches by DynaCT. Overall survival of the DynaCT group was 17.3 mo ± 1.1 mo, which was significantly longer than that of the conventional DSA group (12.6 mo ± 0.9 mo; Log-rank, P = 0.003).

CONCLUSION: Utilization of DynaCT on the basis of conventional DSA in TACE for primary liver cancer has important clinical value, providing more diagnosis and treatment information that can help improve the prognosis of patients.

Feasibility of a Modified Cone-Beam CT Rotation Trajectory to Improve Liver Periphery Visualization during Transarterial Chemoembolization

PURPOSE

To compare liver coverage and tumor detectability by using preprocedural magnetic resonance (MR) images as a reference, as well as radiation exposure of cone-beam computed tomography (CT) with different rotational trajectories.

MATERIALS AND METHODS

Fifteen patients (nine men and six women; mean age ± standard deviation, 65 years ± 5) with primary or secondary liver cancer were retrospectively included in this institutional review board-approved study. A modified cone-beam CT protocol was used in which the C-arm rotates from +55° to -185° (open arc cone-beam CT) instead of -120° to +120° (closed arc cone-beam CT). Each patient underwent two sessions of transarterial chemoembolization between February 2013 and March 2014 with closed arc and open arc cone-beam CT (during the first and second transarterial chemoembolization sessions, respectively, as part of the institutional transarterial chemoembolization protocol). For each cone-beam CT examination, liver volume and tumor detectability were assessed by using MR images as the reference. Radiation exposure was compared by means of a phantom study. For statistical analysis, paired t tests and a Wilcoxon signed rank test were performed.

RESULTS

Mean liver volume imaged was 1695 cm(3) ± 542 and 1857 cm(3) ± 571 at closed arc and open arc cone-beam CT, respectively. The coverage of open arc cone-beam CT was significantly higher compared with closed arc cone-beam CT (97% vs 86% of the MR imaging liver volume, P = .002). In eight patients (53%), tumors were partially or completely outside the closed arc cone-beam CT field of view. All tumors were within the open arc cone-beam CT field of view. The open arc cone-beam CT radiation exposure by means of weighted CT index was slightly lower compared with that of closed arc cone-beam CT (-5.1%).

CONCLUSION

Open arc cone-beam CT allowed for a significantly improved intraprocedural depiction of peripheral hepatic tumors while achieving a slight radiation exposure reduction.

How I do it: Cone-beam CT during transarterial chemoembolization for liver cancer

Cone-beam computed tomography (CBCT) is an imaging technique that provides computed tomographic (CT) images from a rotational scan acquired with a C-arm equipped with a flat panel detector. Utilizing CBCT images during interventional procedures bridges the gap between the world of diagnostic imaging (typically three-dimensional imaging but performed separately from the procedure) and that of interventional radiology (typically two-dimensional imaging). CBCT is capable of providing more information than standard two-dimensional angiography in localizing and/or visualizing liver tumors ("seeing" the tumor) and targeting tumors though precise microcatheter placement in close proximity to the tumors ("reaching" the tumor). It can also be useful in evaluating treatment success at the time of procedure ("assessing" treatment success). CBCT technology is rapidly evolving along with the development of various contrast material injection protocols and multiphasic CBCT techniques. The purpose of this article is to provide a review of the principles of CBCT imaging, including purpose and clinical evidence of the different techniques, and to introduce a decision-making algorithm as a guide for the routine utilization of CBCT during transarterial chemoembolization of liver cancer.

Preparation and evaluation of biocompatible long-term radiopaque microspheres based on polyvinyl alcohol and lipiodol for embolization

The aim of this work was to develop long-term radiopaque microspheres (LRMs) by entrapping lipiodol in biocompatible polyvinyl alcohol with multiple emulsions chemical crosslinking method. The high content of lipiodol (0.366 g/mL) was hardly released from LRMs in vitro and the radiopacity could maintain at least 3 months after subcutaneous injection in mice without weakening. A series of tests was performed to evaluate the feasibility of LRMs for embolization. LRMs were proved to be smooth, spherical, and well dispersed with diameter range of 100–1200 μm. Young's modulus of LRMs was 55.39 ± 9.10 kPa and LRMs could be easily delivered through catheter without aggregating or clogging. No toxicity of LRMs was found to mouse L929 fibroblasts cells and only moderate inflammatory in surrounding tissue of mice was found after subcutaneous injection of LRMs. After LRMs were embolized in renal artery of a rabbit, the distribution and radiopacity of LRMs in vivo were easily detectable by X-ray fluoroscopy and computed tomography (CT) imaging, respectively. More accurate distribution of LRMs in embolized kidney and vessels could be detected by high-revolution visualization of micro-CT ex vivo. In conclusion, the LRMs were proved to be biocompatible and provide long-term radiopacity with good physical and mechanical properties for embolization.

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

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

Impact of 3D Rotational Angiography on Liver Embolization Procedures: Review of Technique and Applications

In the last years, the interest into interventional applications of C-arm cone-beam CT (CBCT) progressively raised, widening its clinical application from the original field of interventional neuroradiology to the field of peripheral procedures. Liver embolization procedures, due to their complexity and potential treatment-related life-threatening complications, represent one of the main clinical applications of this novel angiographic technique. CBCT has been demonstrated to render procedures safer and technically easier, and to predict outcome as well as to avoid major complications in different treatment scenarios (trans-arterial embolization, trans-arterial chemoembolization, selective internal radiation therapy, percutaneous portal vein embolization). This review summarizes all technical, dosimetric and procedural aspects of CBCT techniques, underlying all its potential clinical advantages in the field of liver embolization procedures. Moreover, the paper provides all the instructions to obtain the best diagnostic performance out of this novel angiographic technique.

C-arm cone-beam computed tomography in interventional oncology: technical aspects and clinical applications

C-arm cone-beam computed tomography (CBCT) is a new imaging technology integrated in modern angiographic systems. Due to its ability to obtain cross-sectional imaging and the possibility to use dedicated planning and navigation software, it provides an informed platform for interventional oncology procedures. In this paper, we highlight the technical aspects and clinical applications of CBCT imaging and navigation in the most common loco-regional oncological treatments.

Three-dimensional evaluation of lipiodol retention in HCC after chemoembolization: a quantitative comparison between CBCT and MDCT

RATIONALE AND OBJECTIVES

To evaluate the capability of cone-beam computed tomography (CBCT) acquired immediately after transcatheter arterial chemoembolization (TACE) in determining lipiodol retention quantitatively and volumetrically when compared to 1-day postprocedure unenhanced multidetector computed tomography (MDCT).

MATERIALS AND METHODS

From June to December 2012, 15 patients met the inclusion criteria of unresectable hepatocellular carcinoma (HCC) that was treated with conventional TACE (cTACE) and had intraprocedural CBCT and 1-day post-TACE MDCT. Four patients were excluded because the lipiodol was diffuse throughout the entire liver or lipiodol deposition was not clear on both CBCT and MDCT. Eleven patients with a total of 31 target lesions were included in the analysis. A quantitative three-dimensional software was used to assess complete, localized, and diffuse lipiodol deposition. Tumor volume, lipiodol volume in the tumor, percent lipiodol retention, and lipiodol enhancement in Hounsfield units (HU) were calculated and compared between CBCT and MDCT using two-tailed Student's t test and Bland-Altman plots.

RESULTS

The mean value of tumor volume, lipiodol-deposited regions, calculated average percent lipiodol retention, and HU value of CBCT were not significantly different from those of MDCT (tumor volume: 9.37 ± 11.35 cm(3) vs 9.34 ± 11.44 cm(3), P = .991; lipiodol volume: 7.84 ± 9.34 cm(3) vs 7.84 ± 9.60 cm(3), P = .998; lipiodol retention: 89.3% ± 14.7% vs. 90.2% ± 14.9%, P = .811; HU value: 307.7 ± 160.1 HU vs. 257.2 ± 120.0 HU, P = .139). Bland-Altman plots showed only minimal difference and high agreement when comparing CBCT to MDCT.

CONCLUSIONS

CBCT has a similar capability, intraprocedurally, to assess lipiodol deposition in three dimensions for patients with HCC treated with cTACE when compared to MDCT.

Dual-phase cone-beam computed tomography to see, reach, and treat hepatocellular carcinoma during drug-eluting beads transarterial chemo-embolization

The advent of cone-beam computed tomography (CBCT) in the angiography suite has been revolutionary in interventional radiology. CBCT offers 3 dimensional (3D) diagnostic imaging in the interventional suite and can enhance minimally-invasive therapy beyond the limitations of 2D angiography alone. The role of CBCT has been recognized in transarterial chemo-embolization (TACE) treatment of hepatocellular carcinoma (HCC). The recent introduction of a CBCT technique: dual-phase CBCT (DP-CBCT) improves intra-arterial HCC treatment with drug-eluting beads (DEB-TACE). DP-CBCT can be used to localize liver tumors with the diagnostic accuracy of multi-phasic multidetector computed tomography (M-MDCT) and contrast enhanced magnetic resonance imaging (CE-MRI) (See the tumor), to guide intra-arterially guidewire and microcatheter to the desired location for selective therapy (Reach the tumor), and to evaluate treatment success during the procedure (Treat the tumor). The purpose of this manuscript is to illustrate how DP-CBCT is used in DEB-TACE to see, reach, and treat HCC.

Intratumoral gas in hepatocellular carcinoma following transarterial chemoembolization: associated factors and clinical impact

PURPOSE

To determine the frequency and factors associated with the presence of intratumoral gas-containing areas in hepatocellular carcinoma (HCC) on computed tomography (CT) scans obtained 4-6 weeks after transarterial chemoembolization.

MATERIALS AND METHODS

From June 2010 to December 2011, 201 patients underwent 286 chemoembolization procedures for HCC (n = 497 tumors) and were retrospectively included. The presence of intratumoral gas was assessed on CT 4-6 weeks after chemoembolization. Clinical and biologic data and tumoral and chemoembolization procedure characteristics were noted. Factors associated with the presence of intratumoral gas were evaluated. Tumor response was assessed by using European Society for the Study of the Liver criteria. Tumors containing gas or not containing gas were compared by univariate and multivariate analysis.

RESULTS

Intratumoral gas was found in 26 tumors (5%) after 26 chemoembolization procedures (9.1%) in 26 patients (13%). Gas was related to abscess formation in three patients (11.5%). On multivariate analysis, a large mean tumor diameter at baseline (72.4 mm vs 40.2 mm; P = .003), chemoembolization with drug-eluting beads (P = .033), and superselective approach (P = .024) were independently associated with the presence of gas. Tumors that exhibited gas-containing areas at 1 month had a significantly higher objective response rate than those that did not (P < .0001).

CONCLUSIONS

Intratumoral gas-containing areas after chemoembolization are rarely related to the formation of abscesses. The presence of intratumoral gas on CT 4-6 weeks after chemoembolization could be a surrogate marker for marked tumor necrosis.

Comparison of local control in transcatheter arterial chemoembolization of hepatocellular carcinoma ≤6 cm with or without intraprocedural monitoring of the embolized area using cone-beam computed tomography

PURPOSE

This study was designed to compare technical success and local recurrence rates of transcatheter arterial chemoembolization (TACE) for hepatocellular carcinoma (HCC) with/without monitoring of embolized areas using cone-beam computed tomography (CBCT).

METHODS

A total of 207 HCCs ≤6 cm were treated with superselective TACE using digital subtraction angiography (DSA) alone (DSA group, 98 tumors of 70 patients) or plus CBCT monitoring (CBCT group, 109 tumors of 79 patients). Technical success of TACE was classified into three grades according to 1-week CT; the tumor was embolized with a safety margin (5-mm wide for tumors <25 mm, and 10-mm wide for tumors 25≥ and ≤60 mm; grade A), without a margin in parts (grade B), or the entire tumor was not embolized (grade C). Technical success and local recurrence rates in the DSA and CBCT groups were compared. Local recurrence rates of grade A and B tumors were also compared.

RESULTS

The grade A/B/C tumors in the DSA and CBCT groups were 64 (65.3%)/25 (25.5%)/9 (9.2%) and 95 (87.2%)/11 (10.1%)/3 (2.8%), respectively. Local recurrence developed in 46/158 (29.1%) grade A tumors and 24/36 (66.7%) grade B. There were significant differences in technical success between the DSA and CBCT groups (p < 0.001) and local recurrence rates between grade A and B tumors (p < 0.001). The 1-, 2-, and 3-year local recurrence rates in the DSA and CBCT groups were 33.3 and 22.3%, 41.3 and 26.8%, and 48 and 30.6%, respectively (p = 0.0217).

CONCLUSION

Intraprocedural CBCT monitoring of embolized areas reduces the local tumor recurrence.

Identification of small hepatocellular carcinoma and tumor-feeding branches with cone-beam CT guidance technology during transcatheter arterial chemoembolization

PURPOSE

To evaluate the performance of transcatheter arterial chemoembolization guidance software that uses cone-beam computed tomography (CT) technology in identifying small hepatocellular carcinoma (HCC) tumors and feeding branches.

MATERIALS AND METHODS

Cone-beam CT and manual feeder vessel detection (MFD) software were used in chemoembolization of 68 HCCs 30 mm or smaller (mean ± standard deviation, 15.3 mm ± 5.2). Detectability of tumors and tumor-feeding sub-subsegmental arteries was compared versus that of nonselective digital subtraction angiography (DSA). Technical success of chemoembolization was divided into three grades according to 1-week CT findings: entire tumor embolized with at least a 5-mm-wide margin (ie, complete), tumor embolized without a margin in parts (ie, adequate), or entire tumor not embolized (ie, incomplete). All cone-beam CT data were also reanalyzed with automatic feeder vessel detection (AFD) software that was developed later.

RESULTS

Cone-beam CT could depict all tumors, including eight that were first discovered during chemoembolization. Sixty-one tumors (89.7%) were detected on CT during arterial portography and during hepatic arteriography, and seven (10.3%) were detected with one or the other. Nonselective DSA depicted 49 tumors (72.1%). Among 100 tumor-feeding vessels, 81 were identified with MFD and 38 with nonselective DSA. Detectability of tumors with CT and tumor-feeding branches with MFD was significantly better than with nonselective DSA (both P<.001). Fifty-nine tumors (86.8%) were completely embolized and nine (13.2%) were adequately embolized. AFD identified 96 feeder vessels; 88 (88%) represented true-positive findings.

CONCLUSIONS

Transcatheter arterial chemoembolization guidance software with cone-beam CT technology has a sufficient performance level to detect small HCCs and their feeding branches.