Percutaneous coil placement prior to radiofrequency ablation of poorly visible hepatic tumors

Thermal ablation of ultrasound and non-contrast computed tomography invisible primary and secondary liver tumors: targeting by selective intra-arterial lipiodol injection

PURPOSE

To evaluate the technical feasibility and outcomes of thermal ablation following selective intra-arterial lipiodol injection (SIALI) for targeting primary and secondary liver tumors invisible on ultrasound (US) and non-contrast computed tomography (CT).

METHODS

This retrospective study included 18 patients with 20 tumors (67% male, mean age 60.8 ± 12.1 years). The 20 tumors included 15 liver metastases and 5 hepatocellular carcinomas. All patients underwent single-session SIALI and subsequent CT-guided thermal ablation. The primary outcome was a technical success, defined as visualization of the tumor after SIALI and successful thermal ablation. Secondary outcomes were local recurrence rate and procedure-related complications.

RESULTS

The median tumor size was 1.5 (1-2.5) cm. In addition, SIALI was performed with a median volume of 3 (1-10) mL of lipiodol resulting in intra-tumoral iodized oil accumulation in 19 tumors and negative imprint with iodized oil accumulation of the surrounding liver parenchyma in 1 tumor. The technical success rate was 100%. No local occurrence was observed at a mean follow-up time of 3 ± 2.5 years.

CONCLUSION

SIALI to tag liver tumors not visible with US and non-contrast CT before percutaneous ablation is highly feasible and has a high success rate for the treatment of both primary and secondary liver tumors.

Coil-assisted RFA of poorly visible liver tumors: effectiveness and risk factors of local tumor progression

OBJECTIVES

This study was designed to determine the effectiveness of a percutaneously inserted coil as a landmark before radiofrequency ablation (RFA) of poorly visible liver tumors on unenhanced computed tomography and ultrasound.

METHODS

This was a single-center, retrospective study of 46 consecutive patients treated from January 2008 to June 2012 with RFA under CT guidance for 57 poorly visible liver tumors after percutaneous coil insertion. Effectiveness was evaluated by the rate of local tumor progression (LTP), and the risk factors of LTP were evaluated by multiple univariate analysis.

RESULTS

After a mean follow-up of 15.9 months, the overall rate of LTP was 22.8 % (13/57). An increase in the distance between the coil and the center of the tumor was a predictive factor of LTP (p = 0.005) and resulted in an increase in time to place the RFA probe. LTP was significantly reduced in case of coil placed within the tumor (10 vs. 43.5 %, p = 0.009).

CONCLUSIONS

The effectiveness of the "coil-assisted" RFA for poorly visible liver tumors is improved by centering the coil in the tumor in order to facilitate the placement of the RFA probe and equal to the results of RFA under direct image guidance.

Ultrasound-guided treatments under low acoustic power contrast harmonic imaging for hepatocellular carcinomas undetected by B-mode ultrasonography

BACKGROUND/AIMS

The aim was to examine the efficacy of contrast-enhanced ultrasound (US) with Sonazoid to demonstrate ultrasonically unrecognizable hypervascular hepatocellular carcinoma (HCC) and apply percutaneous US-guided treatments.

METHODS

The subjects of this prospective study were 44 cirrhotic patients with 55 hypervascular lesions (12.7+/-4.5 mm) found by contrast-enhanced computed tomography but unrecognized by non-contrast US. Contrast-enhanced US was performed to demonstrate these hepatic lesions after an intravenous injection of Sonazoid (0.0075 ml/kg). The sonograms in both the early phase (for 1 min after injection) and the late phase (5-10 min after) were taken in the harmonic imaging mode under a low mechanical index (0.24-0.3).

RESULTS

Fifty-three lesions were demonstrated by contrast-enhanced US, 52 with positive enhancement in the early phase and 44 with negative enhancement in the late phase. Percutaneous US-guided treatments were successfully performed for 42 lesions (ethanol injection in 20 and radiofrequency ablation in 22) in 32 patients with reference to contrast-enhanced US findings. Six patients were treated by transarterial chemoembolization alone because they had more than three lesions in the liver. In the remaining seven lesions in six patients, six were diagnosed as non-HCC lesions: five with vascular abnormalities such as arterioportal or arteriovenous communication and the other one with benign lesion in alcoholic liver disease. These six lesions and one HCC lesion with severe liver damage were followed up without any treatment.

CONCLUSIONS

As the detectability of ultrasonically unrecognizable hypervascular HCC improved by contrast-enhanced US with Sonazoid, a wider application of percutaneous US-guided treatments may be possible.

The sonographer's role in RFA therapy of liver lesions

Interventional techniques using ultrasound guidance, such as Radio Frequency Ablation (RFA) of liver lesions, are the domain of the radiologist. However, real time ultrasound imaging as performed by the sonographer, is critical in monitoring the successful insertion and placement of the RFA needle. RFA is used to create a localised and controlled application of heat in order to induce necrosis of cells within the liver lesions.

The role of the sonographer is to assist in establishing the criteria for RFA therapy. This includes assessing the liver to establish how easily the lesion can be identified; the size of the lesion; its proximity to large blood vessels and adjacent vital organs and the access route to the lesion itself. In essence, in this discussion, the focus will be on the sonographic techniques in the assessment of the liver prior to RFA and the RFA procedure itself. A brief review of the clinical role that can be provided by Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) is also included.

Percutaneous radiofrequency ablation of liver dome hepatocellular carcinoma invisible on ultrasonography: a new targeting strategy

Targeting of index tumours is prerequisite to their radiofrequency ablation. However, small hepatocellular carcinomas (HCCs) in the liver dome are often invisible on ultrasonography, thus causing difficulty in their targeting. In cases with multinodular HCCs, adjacent HCC lesions with compact iodized oil retention can be used as anatomic landmarks to guide radiofrequency (RF) ablation of such nodules under fluoroscopy. We present two cases in which nodules that were difficult to target with conventional methods were successfully treated by RF ablation using this targeting strategy.

Combined Percutaneous Radiofrequency Ablation and Ethanol Injection of Renal Tumours: Midterm Results

OBJECTIVES

To evaluate the safety and efficacy of combined percutaneous, image-guided, radiofrequency (RF) ablation and ethanol injection of renal tumours, and to present our midterm results.

METHODS

Since February 2002, 27 consecutive patients (22 men, 5 women; age range: 39-84 yr; mean: 69) with 28 renal tumours (mean diameter: 2.87cm) were treated with combined percutaneous RF and ethanol ablation, and were prospectively evaluated. Twenty-five patients were considered nonsurgical candidates because of comorbid conditions (16 patients) or had previous nephrectomy (9 patients), and 2 had refused surgery. Thirty-three ablation sessions were performed, with computed tomography (26 sessions), ultrasound (6), or combined magnetic resonance imaging/fluoroscopic guidance in 1. Absolute ethanol (0.5-3ml; mean: 1.7) was injected into the tumour immediately before treatment with radiofrequency. Mean follow-up period was 18.6 mo (range: 3-56).

RESULTS

Twenty-seven of the 28 tumours were completely ablated with either one (21 tumours) or two treatment sessions (6 tumours). One patient with residual disease refused further treatment. Only three minor complications, including a subcapsular haematoma and two patients with loin pain, occurred; all three patients were treated conservatively. None of the complications was related to the ethanol injection. During the follow-up period, no evidence of local recurrence or metastatic disease was seen. Creatinine levels have not changed significantly in any of the patients following ablation.

CONCLUSIONS

Combined use of percutaneous RF and ethanol ablation is a safe and effective alternative treatment for selective patients with renal tumours.

Application of a new combined guiding technique in RF ablation of subphrenic liver tumors

We present an unreported technique used to treat with RF ablation hepatic subphrenic hepatocellular carcinoma. It consists in the combination of fluoroscopic and computed tomography guidance for lesions already embolized with lipiodol located at the hepatic dome, approached in parallel fashion with a 22-gauge chiba "finder" needle followed by the RF electrode.

Application of percutaneous ultrasound-guided treatment for ultrasonically invisible hypervascular hepatocellular carcinoma using microbubble contrast agent

AIM

To evaluate the efficacy of contrast-enhanced ultrasound for the localization of ultrasonically invisible hypervascular lesions in the liver to facilitate percutaneous ultrasound-guided treatment.

MATERIALS AND METHODS

Forty patients with 47 ultrasonically invisible hypervascular lesions (5-20mm) diagnosed on contrast-enhanced computed tomography were enrolled in the retrospective study. Contrast-enhanced ultrasound (CEUS) with Levovist was performed to localize the lesions both in the early phase and liver-specific phase. Diagnosis of was confirmed by percutaneous needle biopsy where feasible, and on the basis of on treatment outcomes or changes in computed tomography findings in those not amenable to biopsy.

RESULTS

Thirty-two lesions were diagnosed as hepatocellular carcinoma (HCC). Contrast-enhanced ultrasound localized hepatocellular carcinoma in 24/32 (75%) lesions, the mean diameter (15.1+/-4.9mm), as measured using computed tomography, being significantly larger than that of the remaining eight lesions (10.5+/-2.1mm). Ultrasound-guided treatment was performed in 19 of the 24 lesions, and transarterial chemoembolization (TACE) was applied for the other five lesions because of difficult percutaneous access. Five of the eight non-visualised lesions were treated by transarterial chemoembolization, and the other three by surgical resection. The beneficial effect of CEUS was significantly greater when the reason for poor initial visualisation was the coarse liver architecture (17/17) than when it was due to adverse location (seven of 15, p<0.005). Fifteen of the CT-detected hypervascular lesions were considered to represent false positives for HCC, based on their behaviour during follow-up.

CONCLUSION

Contrast-enhanced ultrasound with Levovist facilitates the application of percutaneous ultrasound-guided treatment by improving localization of ultrasonically invisible hypervascular hepatocellular carcinomas in the liver.

Contrast harmonic sonography-guided radiofrequency ablation therapy versus B-mode sonography in hepatocellular carcinoma: prospective randomized controlled trial

OBJECTIVE

The purpose of this study was to evaluate the effectiveness of contrast harmonic sonographic guidance in radiofrequency ablation of locally progressive hepatocellular carcinoma poorly depicted with B-mode sonography.

SUBJECTS AND METHODS

A series of 40 patients with hepatocellular carcinoma with local tumor progression poorly depicted with B-mode sonography were randomly treated with radiofrequency ablation guided by either contrast harmonic sonography (n = 20) or conventional B-mode sonography (n = 20). Unpaired Student's t tests were performed to compare numbers of treatment sessions.

RESULTS

Treatment analysis showed that the complete ablation rate after a single treatment session was significantly higher in the contrast harmonic sonography group than in the B-mode sonography group (94.7% vs 65.0%; p = 0.043) and that the number of treatment sessions was significantly lower in the contrast harmonic sonography group (mean, 1.1 +/- 0.2 vs 1.4 +/- 0.6; p =0.037).

CONCLUSION

Contrast harmonic sonography-guided radiofrequency ablation is an efficient technique for guiding further ablation of local tumor progression not clearly demarcated with B-mode sonography.

A new technique for localization of hepatic tumors that are poorly visible with CT fluoroscopy

The purpose of this study was to report a new technique for localization of hepatic tumors that are poorly visible with CT fluoroscopy. Forty-three hepatocellular carcinomas were not visible with CT fluoroscopy. A 22-gauge Chiba end-hole needle was inserted in the approximate location of a lesion estimated on the basis of anatomical landmarks demonstrated on both previous MR and CT images. We injected 3 ml of a mixture of nonionic contrast material and saline solution. Following the first injection, contrast solution filled the hepatic lesion in 29 of 43 cases. In 8 of 43 cases, contrast solution was distributed in the normal surrounding liver. In 7 of these 8 cases, repositioning allowed us to adjust the needle in the tumor. In the other 6 of 43 cases, contrast solution spread within capsule or pseudocapsule (pattern 3). In all 6 cases, repositioning allowed to adjust the needle in the tumor. This new technique allows an accurate localization of hepatic tumors that are poorly visible with CT fluoroscopy.

Radiofrequency thermal ablation (RFA) after transarterial chemoembolization (TACE) as a combined therapy for unresectable non-early hepatocellular carcinoma (HCC)

The treatment of unresectable "non-early" (according to the BCLC classification) hepatocellular carcinoma (HCC) in cirrhotic patients with transcatheter arterial chemoembolization (TACE) followed by radiofrequency ablation (RFA) is retrospectively evaluated and possible prognostic factors of this combined therapy are investigated. Forty-six consecutive cirrhotic patients (Child-Pugh class A or B) with solitary or oligonodular HCC underwent RFA after TACE. The treated lesions were 51 overall (size 30-80 mm, mean 48.9). RFA was performed by a multitined expandable electrodes device after one TACE administration. Local efficacy was evaluated with multiphasic computed tomography (CT) performed an average of 2 months after treatment and then during follow-up. Patient survival rate was also evaluated (follow-up time 1-51 months, mean 15 months). Technical success (defined as complete devascularization during the arterial phase) was achieved in 34/51 lesions (66.7%) at the first CT check and in 29/51 (56.9%) during the succeeding follow-up. Among the considered prognostic factors, only lesion diameter (< or > = 50 mm) was statistically significant in the Fisher's exact test in terms of local control (85.2 vs. 45.8% at first CT, p=.0065; 70.4 vs. 41.7% during follow-up, p=.051). There were two major complications (6.5%): one hepatic failure and one death. A Kaplan-Meier analysis showed survival rates of 89.7% at 12 months and 67.1% at 24 months. Combined therapy for non-early HCC shows a relatively high complete local response (especially in lesions less than 5 cm in diameter) and promising mid-term clinical success. Its overall usefulness has yet to be established by a larger series and risk-benefit analysis.