Application of Cone-beam Computed Tomography in Interventional Therapies for Liver Malignancy: A Consensus Statement by the Chinese College of Interventionalists

Despite its crucial role in interventional therapies for liver malignancy, cone-beam computed tomography (CBCT) has not yet been fully integrated into clinical practice due to several complicating factors, including nonstandardized operations and limited recognition of CBCT among interventional radiologists. In response, the Chinese College of Interventionalists has released a consensus statement aimed at standardizing and promoting the application of CBCT in the interventional therapies for liver malignancy. This statement summarizes CBCT scanning techniques, and operational standards, and highlights its potential applications in clinical practice.

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.

Impact of cone-beam computed tomography with automated feeder detection software on the survival outcome of patients with hepatocellular carcinoma during treatment with conventional transarterial chemoembolization

Background

Inoperable hepatocellular carcinoma (HCC) is treated by conventional transarterial chemoembolization (cTACE) using cone-beam computed tomography (CBCT) or digital subtraction angiography (DSA). We compared patient survival outcomes between CBCT-cTACE with automated tumor-feeder detection (AFD) software and DSA-cTACE alone in inoperable HCC patients.

Methods

We reviewed the data of 337 HCC patients treated by CBCT-cTACE or DSA-cTACE between January 2015 and December 2019. Treatment response, progression-free survival (PFS), overall survival (OS), and complications between the CBCT-cTACE and DSA-cTACE groups were compared. Univariate and multivariate logistic regression analyses examined the potential prognostic factors affecting survival after chemoembolization.

Results

Tumor response rates in complete response, partial response, and stable disease at 1 month were 67%, 28%, and 4% in the CBCT-cTACE group and 22%, 48%, and 9% in the DSA-cTACE group, respectively. OS rates of patients in the CBCT-cTACE versus DSA-cTACE groups were 87% versus 54%, 44% versus 15%, and 34% versus 7% at 1, 3, and 5 years, respectively. The CBCT-cTACE group had significantly improved PFS (p < 0.001) and OS (p < 0.001). Multivariate analysis showed that CBCT with AFD software was an independent factor associated with longer OS (hazard ratio, 0.38; p < 0.001).

Conclusions

Compared with conventional DSA, combining selective cTACE with CBCT and AFD software leads to better tumor response and prolongs OS in patients with inoperable HCC.

In the Era of Systemic Therapy for Hepatocellular Carcinoma Is Transarterial Chemoembolization Still a Card to Play?

Conventional transarterial embolization (cTACE) has been proven to be effective for intermediate stage hepatocellular carcinoma (HCC), with a recent systematic review showing an overall survival (OS) of 19.4 months. Nevertheless, due to the rapid development of the systemic therapeutic landscape, the place of TACE is becoming questionable. Is there still a niche for TACE in the era of immunotherapy and combination treatments such as atezolizumab-bevacizumab, which has shown an OS of 19.2 months with excellent tolerance? The development of drug-eluting microspheres (DEMs) has led to the standardization of the technique, and along with adequate selection, it showed an OS of 48 months in a retrospective study. In order to increase treatment selectivity, new catheters have also been added to the TACE arsenal as well as the use of cone-beam CT (CBCT), which provides three-dimensional volumetric images and guidance during procedures. Moreover, the TACE indications have also widened. It may serve as a "bridging therapy" for liver transplantation candidates while they are on the waiting list, and it represents a valuable downstaging tool to transplantation criteria. The aim of this review is to explore the current data on the advancements of TACE and its future place amongst the growing panel of treatments.

Role of Cone-Beam CT in the Intraprocedural Evaluation of Chemoembolization of Hepatocellular Carcinoma

Purpose

To assess the ability of Cone-Beam CT (CBCT), performed during the Transcatheter Arterial Chemoembolization (TACE), in predicting the response to treatment of hepatocellular carcinoma (HCC).

Materials and Methods

We evaluated fifty patients (M/F = 40/10, mean age: 66.7 years ± 8.22) with hepatocellular carcinoma (HCC), for a total of 82 nodules evaluated (mean diameter: 21.4 ± 11 mm). All patients performed a CT scan one month before and one month after TACE. After TACE is completed, a CBCT was performed to assess the degree of drug retention in the lesions. For each lesion, the major diameter, volume, and density of the vital portion were evaluated. The response to TACE was assessed using the mRECIST criteria on the CT scan carried out one month after the procedure. The receiver operating characteristic (ROC) curves were performed to assess the accuracy of the CBCT in predicting the response to treatment and to identify the cut-off points for each parameter under examination.

Results

A complete response (CR) was observed in 24/50 patients (48%), a partial response (PR) in 16/50 (32%), stable disease (SD) in 8/50 (16%), and progressive disease (PD) in 2/50 (4%). Evaluation of the area under the ROC curve showed that the diameter, volume, and density of the lesion, measured with CBTC, had an accuracy of 94%, 96%, and 98%, respectively, in discriminating a complete response from a not complete response.

Conclusion

CBCT is effective in predicting short-term response at 1-month follow-up of HCC treated by chemoembolization.

Combined Therapy with Transarterial Chemoembolization and Radiofrequency Ablation for Hepatocellular Carcinoma: Does the Degree of Ethiodized Oil Accumulation within the Tumor Affect the Therapeutic Efficacy?

PURPOSE

To evaluate the effects of the degree of ethiodized oil accumulation achieved by transarterial chemoembolization followed by radiofrequency (RF) ablation on the treatment efficacy for a single intermediate-sized hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

A total of 153 consecutive patients who underwent chemoembolization and RF ablation for a single intermediate-sized HCC (2-5 cm) were included. On the basis of the degree of ethiodized oil accumulation in HCC on cone-beam CT images, patients who underwent chemoembolization and RF ablation were classified into 2 groups: compact accumulation (≥ 75%) and noncompact accumulation (< 75%). The rates of cumulative local tumor progression (LTP), disease-free survival (DFS), and overall survival (OS) were compared between groups.

RESULTS

Of the 153 patients, 89 were classified into the compact ethiodized oil accumulation group and 64 in the noncompact ethiodized oil accumulation group. There were no significant differences in patient demographic or HCC characteristics between groups except for the incidence of liver cirrhosis (P = .038) and the tumor margin morphology (P = .008). The cumulative LTP rate was significantly lower in the compact accumulation group than in the noncompact accumulation group (P = .013). There were no significant differences in the incidences of complications, DFS rates (P = .055), or OS rates (P = .184).

CONCLUSIONS

The degree of ethiodized oil accumulation does not play a role in decreasing the OS or DFS rate after chemoembolization and RF ablation for intermediate-sized HCC; however, it may contribute to reducing the rate of LTP.

Usefulness of fusion images of unenhanced and contrast-enhanced arterial phase cone-beam CT in the detection of viable hepatocellular carcinoma during transarterial chemoembolization

PURPOSE

We aimed to evaluate the diagnostic efficacy of fusion imaging of unenhanced and arterial phase contrast-enhanced cone-beam computed tomography (CBCT) by comparing with multidetector computed tomography (MDCT) in detection of viable hepatocellular carcinoma (HCC) in patients who have been previously treated with transarterial chemoembolization (TACE).

METHODS

In this retrospective study, a total of 173 tumors in 33 known HCC patients (21 men, 12 women; mean age, 64±7.6 years; mean tumor size, 2.15±1.70 cm) who had been previously treated with TACE and underwent additional session of TACE were included. The sensitivity and positive predictive values of preprocedural MDCT and fusion CBCT for detection of viable tumor were analyzed with follow-up MDCT images performed 3-4 weeks after TACE, as reference standard.

RESULTS

A total of 141 remote and 32 marginal viable tumors were included. The sensitivities for detection of remote, marginal, and total viable tumors were 80.9%, 68.8%, and 78.6% for MDCT and 96.5%, 96.9%, and 96.5% for fusion CBCT, respectively. The positive predictive values for detection of remote, marginal, and total viable tumors were 95.0%, 78.6%, and 95.8% for MDCT, and 97.1%, 88.6%, and 97.7% for fusion CBCT, respectively. Fusion CBCT showed statistically higher sensitivity and positive predictive value for detection of viable tumors (P < 0.001).

CONCLUSION

The diagnostic performance of fusion imaging of unenhanced and contrast-enhanced arterial phase CBCT was superior to MDCT for detection of viable HCCs.

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Detectability of hepatic tumors during 3D post-processed ultrafast cone-beam computed tomography

To evaluate hepatic tumor detection using ultrafast cone-beam computed tomography (UCBCT) cross-sectional and 3D post-processed image datasets. 657 patients were examined using UCBCT during hepatic transarterial chemoembolization (TACE), and data were collected retrospectively from January 2012 to September 2014. Tumor detectability, diagnostic ability, detection accuracy and sensitivity were examined for different hepatic tumors using UCBCT cross-sectional, perfusion blood volume (PBV) and UCBCT-MRI (magnetic resonance imaging) fused image datasets. Appropriate statistical tests were used to compare collected sample data. Fused image data showed the significantly higher (all P  <  0.05) diagnostic ability for hepatic tumors compared to UCBCT or PBV image data. The detectability of small hepatic tumors (<5 mm) was significantly reduced (all P  <  0.05) using UCBCT cross-sectional images compared to MRI or fused image data; however, PBV improved tumor detectability using a color display. Fused image data produced 100% tumor sensitivity due to the simultaneous availability of MRI and UCBCT information during tumor diagnosis. Fused image data produced excellent hepatic tumor sensitivity, detectability and diagnostic ability compared to other datasets assessed. Fused image data is extremely reliable and useful compared to UCBCT cross-sectional or PBV image datasets to depict hepatic tumors during TACE. Partial anatomical visualization on cross-sectional images was compensated by fused image data during tumor diagnosis.

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.

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.

Ultrafast cone-beam computed tomography imaging and postprocessing data during image-guided therapeutic practice

OBJECTIVE

Our objective was to evaluate ultrafast cone-beam computed tomography (u-CBCT) image data using cross-sectional images, perfusion blood volume (PBV), and image fusion during tumour detection at the course of transarterial chemoembolization.

METHODS

One hundred and fifty patients (63 ± 20 years; 33-82) were examined from February to October 2013 with u-CBCT. Tumour delineation and conspicuity were determined using u-CBCT cross-sectional PBV and u-CBCT-magnetic resonance imaging (MRI) fused data sets for hyperenhanced (HYET), heterogeneously enhanced (HEET), and unenhanced (UET) tumour categories. Catheter localisation and tumour feeding vessels were assessed using all data sets. Quantitative and qualitative analyses were performed using appropriate statistical tests.

RESULT

Qualitative and quantitative tumour delineation showed significant difference (all P < 0.05) among tumour categories. Mean tumour-liver-contrast was higher in HYET than in HEET, and UET; moreover, differences between tumour categories were statistically significant (all P < 0.0001). Fused data showed higher value with statistical significance (P < 0.05) compared with other data sets during catheter localisation and feeding-vessel identification.

CONCLUSION

Tumour delineation was clearly possible using u-CBCT cross sections with contrast material. PBV uses color-coded images to increase detection and produces good tumour differentiation. Image fusion helps accurately identify tumour and feeding vessels and locate contrast material injection sites and catheter tips without additional data acquisition.

KEY POINTS

• Ultrafast CBCT cross-sectional data provide good tumour delineation with contrast material • Postprocessed PBV using u-CBCT increased detectability and tumour differentiation • u-CBCT cross-sectional PBV and u-CBCT-MRI data helps image guidance during chemoembolization • u-CBCT-MRI can identify tumours and feeding vessels and locate catheter tip accurately.

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.

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.

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.

Radiation dose and image quality of X-ray volume imaging systems: cone-beam computed tomography, digital subtraction angiography and digital fluoroscopy

OBJECTIVE

Radiation dose and image quality estimation of three X-ray volume imaging (XVI) systems.

METHODS

A total of 126 patients were examined using three XVI systems (groups 1-3) and their data were retrospectively analysed from 2007 to 2012. Each group consisted of 42 patients and each patient was examined using cone-beam computed tomography (CBCT), digital subtraction angiography (DSA) and digital fluoroscopy (DF). Dose parameters such as dose-area product (DAP), skin entry dose (SED) and image quality parameters such as Hounsfield unit (HU), noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were estimated and compared using appropriate statistical tests.

RESULTS

Mean DAP and SED were lower in recent XVI than its previous counterparts in CBCT, DSA and DF. HU of all measured locations was non-significant between the groups except the hepatic artery. Noise showed significant difference among groups (P < 0.05). Regarding CNR and SNR, the recent XVI showed a higher and significant difference compared to its previous versions. Qualitatively, CBCT showed significance between versions unlike the DSA and DF which showed non-significance.

CONCLUSION

A reduction of radiation dose was obtained for the recent-generation XVI system in CBCT, DSA and DF. Image noise was significantly lower; SNR and CNR were higher than in previous versions. The technological advancements and the reduction in the number of frames led to a significant dose reduction and improved image quality with the recent-generation XVI system.

KEY POINTS

• X-ray volume imaging (XVI) systems are increasingly used for interventional radiological procedures. • More modern XVI systems use lower radiation doses compared with earlier counterparts. • Furthermore more modern XVI systems provide higher image quality. • Technological advances reduce radiation dose and improve image quality.

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

PURPOSE

To compare patient survival after transarterial chemoembolization with and without intraprocedural C-arm computed tomography (CT) in patients with unresectable hepatocellular carcinoma.

MATERIALS AND METHODS

We retrospectively reviewed the records of 130 patients with unresectable hepatocellular carcinoma who underwent lipiodol-based chemoembolization using a C-arm cone-beam system. We compared patients who underwent chemoembolization with angiography alone (69 patients; April 2005-July 2007) to those who underwent C-arm CT-assisted chemoembolization (61 patients; July 2007-April 2010). Overall and local progression-free survivals were compared using the Kaplan-Meier estimator with log-rank testing. Univariate and multivariate analyses were performed using the Cox proportional hazards model.

RESULTS

Overall survival rates of patients who underwent chemoembolization with and without C-arm CT assistance were 94% and 79%, 81% and 65%, and 71% and 44% at 1, 2, and 3 years, respectively. Local progression-free survival rates of these patients were 43% and 27%, 31% and 10%, and 26% and 5% at 1, 2, and 3 years, respectively. Patients receiving C-arm CT-assisted chemoembolization had significantly higher overall (P=0.005) and local progression-free (P=0.003) survival rates than those receiving chemoembolization with angiography alone. Multivariate analysis showed that C-arm CT assistance was an independent factor associated with longer overall survival (hazard ratio, 0.40; P=0.033) and local progression-free survival (hazard ratio, 0.25; P=0.003).

CONCLUSION

C-arm CT usage in addition to angiography during transarterial chemoembolization prolongs survival in patients with unresectable hepatocellular carcinoma.