Radiofrequency ablation in the management of liver tumours

Laparoscopic thermoablation for hepatocellular carcinoma in patients with liver cirrhosis: an effective procedure for tricky tumors

The optimal treatment for hepatocellular carcinoma (HCC) is surgical resection. However, only a small percentage of patients are amenable to this option. Percutaneous radiofrequency interstitial thermal ablation (TA) proved to be effective in the treatment of unresectable HCC. Recent advances in laparoscopic ultrasound have improved the accuracy in detecting small intrahepatic HCC nodules missed by pre-operative imaging techniques. Our objective was to evaluate an operative combination of laparoscopic ultrasound with laparoscopic thermoablation (LTA) in the treatment of HCC not amenable to liver resection. The aim of our review was to evaluate the advantages and limits of the laparoscopic approach according the criteria of the evidence-based medicine. LTA of HCC proved to be a safe and effective technique both in the short- and long-term follow-up period. This technique may be indicated in selected cases when the percutaneous approach to the lesion is very difficult or contraindicated.

Evaluation of Contrast-Enhanced Intraoperative Ultrasound in the Detection and Management of Liver Lesions in Patients with Hepatocellular Carcinoma

AIM

To evaluate the role of contrast-enhanced intraoperative ultrasound (CE-IOUS) during liver surgery in the detection and management of liver lesions in patients with hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

From December 2016 to December 2017, 50 patients with HCC, who were candidates for liver resection, were evaluated with intraoperative ultrasound (IOUS). For all patients, MRI and/or CT were performed before surgery. During surgery, IOUS was performed after liver mobilization, and when nodules that had not been detected in the preoperative MRI and/or CT were observed, CE-IOUS scans were carried out with the dual purpose of better characterizing the unknown lesion and discovering new lesions.

RESULTS

In 12 patients, IOUS showed 14 nodules not detected by preoperative MRI and/or CT, before surgery. Out of the 12 lesions, five presented vascular features compatible with those of malignant HCC to the evaluation with CE-IOUS and four of these were simultaneously treated with intraoperative radiofrequency ablation (RFA). The fifth lesion was resected by the surgeon. The remaining nine lesions recognized by IOUS were evaluated as benign at CE-IOUS and considered regenerative nodules. The last diagnosis was confirmed during follow-up obtained by means of CT and/or MRI after 1, 3, 6, or 12 months.

CONCLUSION

In our experience, CE-IOUS is a useful diagnostic tool in both benign pathologies, such as regenerative nodules, and malignant liver lesions. The advantage of this approach is the possibility of intraoperatively characterizing, based on vascularization patterns, lesions that could not be diagnosed by preoperative imaging, resulting in modification of the surgical therapy decision and expansion of the resection or intraoperative ablation.

Titanium wire implants with nanotube arrays: A study model for localized cancer treatment

Adverse complications associated with systemic administration of anti-cancer drugs are a major problem in cancer therapy in current clinical practice. To increase effectiveness and reduce side effects, localized drug delivery to tumour sites requiring therapy is essential. Direct delivery of potent anti-cancer drugs locally to the cancer site based on nanotechnology has been recognised as a promising alternative approach. Previously, we reported the design and fabrication of nano-engineered 3D titanium wire based implants with titania (TiO2) nanotube arrays (Ti-TNTs) for applications such as bone integration by using in-vitro culture systems. The aim of present study is to demonstrate the feasibility of using such Ti-TNTs loaded with anti-cancer agent for localized cancer therapy using pre-clinical cancer models and to test local drug delivery efficiency and anti-tumour efficacy within the tumour environment. TNF-related apoptosis-inducing ligand (TRAIL) which has proven anti-cancer properties was selected as the model drug for therapeutic delivery by Ti-TNTs. Our in-vitro 2D and 3D cell culture studies demonstrated a significant decrease in breast cancer cell viability upon incubation with TRAIL loaded Ti-TNT implants (TRAIL-TNTs). Subcutaneous tumour xenografts were established to test TRAIL-TNTs implant performance in the tumour environment by monitoring the changes in tumour burden over a selected time course. TRAIL-TNTs showed a significant regression in tumour burden within the first three days of implant insertion at the tumour site. Based on current experimental findings these Ti-TNTs wire implants have shown promising capacity to load and deliver anti-cancer agents maintaining their efficacy for cancer treatment.

Perspectives on surgical management of neuroendocrine liver metastases

Abstract: 

Neuroendocrine tumors (NETs) commonly metastasize to the liver. Different treatments are available for the management of metastatic NETs. Both primary tumor and metastases can significantly affect the patients’ quality of life and overall survival (OS). Surgical resection is the only chance for cure and should be considered for every patient. For operable patients, current evidence suggests that liver resection is a safe and effective treatment for neuroendocrine liver metastases. High rates of recurrence are reported following resection of neuroendocrine liver metastases. There is no evidence to support incomplete (R2) resection (debulking) surgery to improve OS or quality of life. When surgery is performed for NETs, other conservative adjuvant treatments should also be considered to prolong symptom-free, disease-free and OS.

Pain control in patients with hepatocellular carcinoma treated by percutaneous radiofrequency ablation: comparison of the efficacy of one-shot and continuous intravenous fentanyl delivery

BACKGROUND

Hepatic percutaneous radiofrequency ablation (RFA) is usually performed with the patient under deep intravenous (i.v.) sedation or general anesthesia. Nonetheless, many patients report pain during and/or after the procedure.

PURPOSE

To perform a prospective study of pain control obtained by the i.v. one-shot delivery and the continuous i.v. infusion of fentanyl in patients with hepatocellular carcinoma (HCC) treated by RFA.

MATERIAL AND METHODS

Between April 2007 and March 2010, 83 patients with 106 HCCs underwent percutaneous RFA. All HCCs were addressed by computed tomography (CT)-guided percutaneous RFA performed within 5 h of embolization of the tumor vessels with iodized oil and gelatin sponges. Standard anesthesia consisted of 10 mL of 1% lidocaine injected locally. For conscious sedation, group one patients (n = 41) were injected i.v. with 100 µg of fentanyl before and 100 µg of fentanyl 30 min after percutaneous RFA. In group two (n = 42) we delivered fentanyl by continuous i.v. infusion at 100 µg/h during RFA. Upon request, patients in both groups also received 5 mg of diazepam i.v. for pain during the RFA procedure. The severity of pain experienced by all patients was evaluated on a visual analogue scale (VAS) and complications elicited by the anesthesia regimens were recorded. We also assessed the effectiveness of the treatment on sequential follow-up CT and/or magnetic resonance imaging (MRI) at 3-month intervals.

RESULTS

Percutaneous RFA was technically successful in all 83 patients. Two patients in group one (4.8%) and one patient in group two (2.4%) manifested residual enhancement 3 months post RFA. There was no significant difference in the local recurrence rate between the two groups. At 4.0 ± 1.8 for group one and 3.4 ± 1.9 for group two, the VAS score was not significantly different. Major fentanyl or diazepam toxicity was recorded in 11 patients (24.4%) in group one and two patients (4.8%) in group two; the difference was statistically significant (P < 0.01).

CONCLUSION

The continuous infusion of fentanyl provided effective and safe analgesia in HCC patients undergoing percutaneous RFA.

Review of dynamic contrast-enhanced ultrasound guidance in ablation therapy for hepatocellular carcinoma

Local ablative techniques-percutaneous ethanol injection, microwave coagulation therapy and radiofrequency ablation (RFA)-have been developed to treat unresectable hepatocellular carcinoma (HCC). The success rate of percutaneous ablation therapy for HCC depends on correct targeting of the tumor via an imaging technique. However, probe insertion often is not completely accurate for small HCC nodules, which are poorly defined on conventional B-mode ultrasound (US) alone. Thus, multiple sessions of ablation therapy are frequently required in difficult cases. By means of two breakthroughs in US technology, harmonic imaging and the development of second-generation contrast agents, dynamic contrast-enhanced harmonic US imaging with an intravenous contrast agent can depict tumor vascularity sensitively and accurately, and is able to evaluate small hypervascular HCCs even when B-mode US cannot adequately characterize the tumors. Therefore, dynamic contrast-enhanced US can facilitate RFA electrode placement in hypervascular HCC, which is poorly depicted by B-mode US. The use of dynamic contrast-enhanced US guidance in ablation therapy for liver cancer is an efficient approach. Here, we present an overview of the current status of dynamic contrast-enhanced US-guided ablation therapy, and summarize the current indications and outcomes of reported clinical use in comparison with that of other modalities.

Radiofrequency ablation of hepatocellular carcinoma: a literature review

Radiofrequency ablation (RFA) of liver cancers can be performed safely using percutaneous, laparoscopic, or open surgical techniques, and much of the impetus for the use of RFA has come from cohort series that have provided an evidence base for this technique. Here, we give an overview of the current status of radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC), including its physical properties, to assess the characteristics that make this technique applicable in clinical practice. We review the technical development of probe design and summarize current indications and outcomes of reported clinical use. An accurate evaluation of treatment response is very important to secure successful RFA therapy since a sufficient safety margin (at least 0.5 cm) can prevent local tumor recurrences. We also provide a profile of side effects and information on the integration of this technique into the general management of patients with HCC. To minimize complications of RFA, physicians should be familiar with each feature of complication. Appropriate management of complications is essential for successful RFA treatment. Moreover, adjuvant therapy, such as molecular targeted therapies following curative therapy, is expected to further improve survival after RFA.

Radioablation settings affecting the size of lesions created ex vivo in porcine livers with monopolar perfusion electrodes

RATIONALE AND OBJECTIVES

To explore the morphological characteristics of ablated lesions and find which combination of duration, temperature, and power was preferable to create largest lesion size with monopolar perfusion electrodes.

MATERIALS AND METHODS

Using monopolar perfusion electrodes to create 72 lesions in 30 excised porcine livers with radiofrequency radiation at different durations (5, 10, 15, and 20 minutes), temperatures (83 degrees C, 93 degrees C, 103 degrees C, and 113 degrees C), and powers (20, 30, and 40 W). Lesion volumes were calculated from longitudinal diameters and transverse diameters. Morphological characteristics were assessed microscopically from slides stained with hematoxylin and eosin.

RESULTS

Positive correlations were found between duration and longitudinal diameter (r = 0.66; P < .001), transverse diameter (r = 0.66; P < .001), distance of ablation beyond the electrode tip (r = 0.56; P < .001), and volume of lesions (r = 0.66; P < .001). Temperature was also positively correlated with longitudinal diameter (r = 0.70; P < .001), transverse diameter (r = 0.72; P < .001), distance of ablation beyond the electrode tip (r = 0.61; P < .001), and lesion volume (r = 0.711; P < .001). Lesion size did not increase when duration was longer than 15 minutes and temperature was higher than 103 degrees C. Power was not correlated with lesion size. Lesion size did not increase with increasing power. Macroscopically, all lesions were elliptical in cross section and appeared three zones: a central zone (I), a coagulated necrotic zone (II), and a hemorrhagic and edematous zone (III) from inside to outside. Microscopically, cells morphology and the nucleus were irregular or even disappeared in zone I. In zone II and III, cells did not appear deformation.

CONCLUSION

Duration and temperature, not power, affected lesion size. The largest lesion size was about 3.5 cm x 2.5 cm x 2.5 cm as temperature and duration was 15 minutes/103 degrees C.

Laparoscopic redo surgery for recurrent hepatocellular carcinoma in cirrhotic patients: feasibility, safety, and results

BACKGROUND

Recurrence of cancer and the need for several surgical treatments are the Achilles' heel of the treatment for hepatocellular carcinoma (HCC) in cases of cirrhosis. The difficulty of reintervention is increased by the formation of adhesions after the previous hepatectomy that can make a new surgical procedure more difficult and less safe. With a minimally invasive approach, the formation of postoperative adhesions seems to be minimized, and the adhesiolysis procedure seems to be faster and safer in terms of blood loss and risk of visceral injuries.

METHODS

This report describes a series of 15 patients submitted to a laparoscopic reintervention (hepatic resection or radiofrequency ablation) for a recurrence of HCC after a previous open (group 1) or laparoscopic (group 2) procedure for a primary tumor. It aims to explain the feasibility, safety, and results of repeated laparoscopic liver surgery.

RESULTS

The rates for overall postoperative mortality and morbidity were respectively 0% and 26.6% (4/15). No patients had a severe postoperative complication. Only one patient in group 2 presented with moderate ascites postoperatively, whereas two patients in group 1 reported atelectasis requiring physiotherapy and one experienced pneumonia, which was treated with antibiotics. In this series, the findings indicated that patients submitted first to an open hepatic resection (group 1) experience more intraabdominal adhesions. Moreover, in group 1, hypervascularized adhesions typical of cirrhotic patients were several and thicker, with a major potential risk of bleeding and bowel injuries at the time of reintervention. Although for group 2 the length of the intervention was shorter, for group 1, the operating times and safety in terms of bowel injuries were acceptable, demonstrating the feasibility of iterative laparoscopic surgery also for cirrhotic patients previously treated by the open surgical approach. The operative time for the second surgical procedure was shorter and the adhesiolysis easier for the patients previously treated with the laparoscopic approach (group 2). This underscores the advantages of the minimally invasive approach for managing the long oncologic history of cirrhotic patients.

CONCLUSION

Laparoscopic redo surgery for recurrent HCC in cirrhotic patients is a safe and feasible procedure with good short-term outcomes, but further prospective studies are needed to support these results.

Laparoscopic radiofrequency ablation of hepatocellular carcinoma: A critical review from the surgeon's perspective

BACKGROUND

The treatment of choice for hepatocellular carcinoma (HCC) is surgical resection but only a small percentage of patients are operative candidates. Percutaneous radiofrequency interstitial thermal ablation (RFA) has proved to be effective in the treatment of unresectable HCC. However, there is a sub-group of patients who may benefit from a laparoscopic rather than a percutaneous approach. Laparoscopic RFA offers the combined advantages of improved tumor staging based on the intracorporeal ultrasound examination and safer access to liver lesions that are difficult or impossible to treat with a percutaneous approach. The aim of our review was to evaluate the advantages and limitations of the laparoscopic approach, according to the criteria of evidence-based medicine.

CONCLUSIONS

Laparoscopic RFA of HCC proved to be a safe and effective technique, at least in terms of the short- and mid-term results. This technique may be indicated in selected cases of HCC when percutaneous RFA is very difficult or contraindicated.

Switching Monopolar Radiofrequency Ablation Technique Using Multiple, Internally Cooled Electrodes and a Multichannel Generator

OBJECTIVE

We sought to determine the optimal switching time and interprobe distance for creating a large coagulation zone in the liver by switching monopolar radiofrequency ablation (RFA) technique using a prototype multichannel radiofrequency generator and multiple electrodes.

MATERIALS AND METHODS

Using 3, 17-gauge, internally cooled electrodes and a prototype multichannel radiofrequency (RF) generator to allow automatic switching of RF energy among 3 electrodes according to their impedance changes, RF energy was applied in a switching monopolar mode to explanted bovine livers or to the livers of 7 dogs. In the ex vivo study, we evaluated the effect of the switching time (5, 15, 30, and 60 seconds) and the interprobe distance (3 cm and 4 cm) on the mean volume of the ablation zone using the switching RFA; we then compared the ablation volume of the switching RFA group (12 minutes) with that of the overlapping RFA group (12 minutes x 3 = 36 minutes). In our preliminary in vivo experiments using 2 dogs, the electrodes were placed in a triangular array (spacing 2 cm, 3 cm, 3.5 cm, or 4 cm) and were activated for 12 minutes or 20 minutes in a monopolar mode (power output 200 W). In our primary experiments using 5 dogs, RFA in a switching mode created 10 coagulation zones at a 2- to 3-cm interprobe distance. The duration of the RFA was 12 minutes. The size and geometry of the coagulation zone also were assessed.

RESULTS

In this ex vivo study, switching monopolar RFA at a 3-cm interprobe distance and at a 30-second switching time allowed the creation of a large, confluent ablation zone. There was no significant difference in the mean ablation volume between the overlapping (72.9 +/- 12.6(3) cm) and the switching RFA groups (65.7 +/- 12.6 cm(3); P>0.05). In the preliminary in vivo experiments, RFA created spherical coagulations at interprobe distances of 2 cm and 3 cm but at larger distances than 3 cm, RFA created partially confluent coagulation zones. In our principal experiments, switching RFA created areas of well-defined coagulation, ie, at a 2-cm interprobe distance, the volume and short-axis coagulation diameter were 35.5+/- 5.7(3) cm and 4.6 +/- 0.5 cm, respectively, whereas at 3 cm, they were 40.7 +/- 12.8(3) cm and 4.8 +/- 0.8 cm, respectively. The mean values of the circularity (isometric ratio) of the coagulation at the 2- and 3-cm interprobe distances were 0.95 +/- 0.02, and 0.85+/- 0.06, respectively.

CONCLUSIONS

Our study demonstrated that switching monopolar RFA using the multichannel RF system at a 2- or 3-cm interprobe distance and at a 30-second switching time can create a large, confluent coagulation zone in the liver within a clinically acceptable time frame. We believe that this technology will provide a useful tool for the treatment of large liver tumors.

Radiofrequency ablation for hepatocellular carcinoma and metastatic liver tumors: a comparative study

BACKGROUND

This study compared the effectiveness of radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC) and liver metastases.

METHODS

We compared the outcomes of 240 patients with HCC and 44 patients with liver metastases treated with RFA. Data were prospectively collected and retrospectively analyzed. Effects of different variables on recurrences were studied.

RESULTS

A total of 406 tumor nodules were treated. The median size of the largest ablated tumor was 2.5 cm, and the median tumor number was 1. Complete tumor ablation was achieved in 91.2%. Local recurrence rate was 15.4% after a median follow-up of 24.5 months. There was no significant impact of tumor pathology on local recurrence. However, patients with liver metastasis had higher extrahepatic recurrence rate (P = 0.019) and shorter disease-free survival (P = 0.007). Patients with multiple tumors had higher local (P = 0.047) and extrahepatic (P = 0.019) recurrence rates than those with a solitary tumor. Tumor size had an impact on local recurrence rate only in patients with liver metastasis with a higher rate in those with tumor > 2.5 cm in diameter (P = 0.028).

CONCLUSIONS

Tumor pathology does not appear to have a significant impact on local recurrence rates. RFA is effective in local tumor control for both HCC and liver metastasis.

Survival and intra-hepatic recurrences after laparoscopic radiofrequency of hepatocellular carcinoma in patients with liver cirrhosis

BACKGROUND

The optimal treatment for hepatocellular carcinoma (HCC) is surgical resection. However, only a small percentage of patients are operative candidates. Percutaneous radiofrequency interstitial thermal ablation proved to be effective, too. Our objective was to assess a novel operative combination of laparoscopic ultrasound (LUS) with laparoscopic radiofrequency (LRF) in the treatment of HCC not amenable to liver resection.

METHODS

One hundred and four patients with HCC in liver cirrhosis were submitted to laparoscopic LRF. A LRF was indicated in patients not amenable to liver resection that had at least one of the following criteria: (a) severe impairment of the coagulation tests; (b) large tumors (but <5 cm) or multiple lesions requiring repeated punctures; (c) superficial lesions adjacent to visceral structures; (d) deep-sited lesions with a very difficult or impossible percutaneous approach; (e) short-term recurrence of HCC following percutaneous loco-regional therapies.

RESULTS

The LRF procedure was completed in 102 out of 104 patients (98% feasibility rate). LUS identified 26 new malignant lesions (25%) undetected by pre-operative imaging. There was no operative mortality. Seventy-six patients had no complication (73%). At 1-month computed tomography (CT) evaluation, a complete response with a 100% necrosis was achieved in 88 out of 101 patients (87%). During the follow-up (mean follow-up: 22.5 +/- 15.9 months), 55 patients (54%) developed new malignant nodules (42% of these recurrences were localized in the same segment of the HCC treated).

CONCLUSIONS

LRF of HCC proved to be a safe and effective technique at least in the short and mid-term: in fact it permits to treat lesions not treatable with the per cutaneous approach, to detect 25% of new HCC nodules and it has a low morbidity rate.

Percutaneous image-guided radiofrequency ablation in the therapeutic management of hepatocellular carcinoma

Owing to surveillance programs for detection of hepatocellular carcinoma (HCC) in patients with cirrhosis, more tumors are being detected at an early, asymptomatic stage. Percutaneous ablation is considered the best treatment option for patients with Child-Pugh class A or B cirrhosis and a single, nodular-type HCC smaller than 5 cm or as many as three HCC lesions, each smaller than 3 cm, when surgical resection or liver transplantation is not suitable. Radiofrequency ablation (RFA) has emerged as the most powerful method for percutaneous treatment of early-stage HCC. Recent studies have shown that RFA can achieve more effective local tumor control than ethanol injection and with fewer treatment sessions. In a randomized trial, local recurrence-free survival rates were significantly higher in patients who received RFA than in those treated by ethanol injection, and treatment allocation was confirmed as an independent prognostic factor by multivariate analysis. Due to advances in radiofrequency technology, RFA also has been used to treat patients with more advanced tumors. Preliminary reports have shown that RFA performed after balloon catheter occlusion of the hepatic artery, transarterial embolization, or chemoembolization results in increased volumes of coagulation necrosis, thus enabling successful destruction of large HCC lesions. This report reviews the current status of percutaneous, image-guided RFA in the therapeutic management of HCC.

Radiofrequency ablation of liver tumours: systematic review

Thermal ablation by use of radiofrequency energy can be used to achieve necrosis of liver tumours, and increased availability of this technique is leading to more widespread use. Much of the impetus for the use of radiofrequency ablation has come from cohort series that have provided an evidence base for this technique. Here, we give an overview of the current status of radiofrequency ablation for liver tumours, including its physical properties, to assess the characteristics that make this technique applicable in clinical practice. We review the technical development of probe design and summarise current indications and outcomes of reported clinical use. We also provide a profile of side-effects and information on the integration of this technique into the general management of patients with liver tumours. Current evidence suggests that radiofrequency ablation can be done with few side effects; however, although this technique seems to ablate tumours effectively, it should form part of multidisciplinary care for liver cancer. Crucially, the role of radiofrequency ablation in lengthening the survival of patients with liver tumours remains to be assessed.

Intraoperative radiofrequency ablation (RFA) for irresectable liver malignancies

AIMS

To evaluate the outcome of patients who received radiofrequency ablation (RFA) at open laparotomy in patients with irresectable liver malignancies.

METHODS

Twenty-six consecutive patients who underwent explorative laparotomy and were found to be irresectable or who had been assessed not suitable for either resection or percutaneous RFA received intraoperative RFA. An expandable electrode (RITA Medical systems) was used. Follow-up comprised CT-scans in 6-12 week intervals.

RESULTS

Patients' age ranged from 35 to 72 years (median 61). A variety of pathologies were treated. In 26 patients, 88 hepatic lesions were treated: 32 with resection and 56 with RFA. The mean diameter was 4.0+/-2.6 cm with a maximum of 10 cm. In 22 patients with hepatic metastases (18 colorectal, one leiomyosarcoma, one endometrium carcinoma, one renal cell carcinoma, one malignant phaeochromocytoma) 74 lesions (median 3.4 per patient) were treated (25 by resection, 49 by RFA). Eleven patients received simultaneous resection and RFA: resection of anatomical segments in six and atypical resection in seven patients. Procedure related complication rate was 19.2%. The mean follow-up was 14.6+/-9.2 months (2-36 months). Three patients developed recurrence at the site of previous RFA indicating incomplete ablation. The overall local control rate after one year was 92 and 90.9% for patients with colorectal liver metastases, respectively. Seventeen patients (65.4%) suffered from tumour progress. In 14 patients (53.9%) tumour occurred at new hepatic localisations and in five patients extrahepatic tumour relapse was diagnosed. Twelve patients have died so far (median survival 18 months, range 4-27). Nineteen patients had either completed a follow-up of at least 12 months or died within this period, resulting in an one year survival rate of 79% (80% for liver metastases).

CONCLUSION

Intraoperative RFA is a valuable tool in liver surgery which extends the surgical spectrum in cases of irresectable malignancies.

MR-guided radiofrequency ablation of hepatic malignancies at 1.5 T: Initial results

PURPOSE

To assess the feasibility of magnetic resonance (MR)-guided radiofrequency ablation (RFA) of hepatic malignancies using a high-field MR scanner.

MATERIALS AND METHODS

A total of 10 patients with 14 primary (N = 1) or secondary (N = 13) hepatic malignancies underwent MR-guided RFA using a closed-bore 1.5 T MR scanner. Lesion diameters ranged from 2.0 cm to 4.7 cm. RFA was performed using a 200-W generator in combination with a 3.5-cm LeVeen electrode applying a standardized energy protocol.

RESULTS

RFA was technically feasible in all patients. Necrosis diameter ranged from 2.5 cm to 6.8 cm. The mean follow-up period is 12.2 (1-18) months. In nine out of 10 patients, local tumor control was achieved. For this purpose, a second CT-guided RFA was required in two patients. In four patients, multifocal hepatic tumor progression occurred, with the treated lesion remaining tumor-free in three of these patients. Two patients showed extrahepatic tumor progression. Four patients remained tumor-free. No major complications occurred.

CONCLUSION

MR-guided RFA of hepatic malignancies in a closed-bore high-field MR scanner is technically feasible and safe. It can be advantageous in locations considered unfavorable for CT-guided puncture or in patients in which iodinated contrast material is contraindicated.