Radiofrequency ablation of hepatic tumors

This article aims to review the state of the art in ablation techniques for hepatic lesions. In addition to discussing the indications, outcomes, and potential complications of the technique, we illustrate the spectrum of imaging findings after treatment. Recent years have seen the development of a wide variety of minimally invasive techniques to treat liver cancer. These include ethanol injection, and thermal ablation using radiofrequency, laser, microwaves, or cryosurgery. Percutaneous radiofrequency ablation is one of the most promising non-surgical treatments for hepatic neoplasms. The results of several studies show that radiofrequency ablation enables adequate local control of tumors with few complications, achieving acceptable survival rates. Radiofrequency ablation can be performed using any imaging technique, although it is most commonly performed under ultrasound guidance. CT and MRI show the degree of tumor necrosis better and are more frequently employed in follow up. This article reviews the indications and contraindications for the procedure, potential complications, long-term outcome, and imaging findings for percutaneous radiofrequency ablation of hepatic tumors.     

Percutaneous radiofrequency and other liver ablation techniques: 2011 update

Percutaneous ablation of liver tumors was initially limited to patients that were not surgical candidates and with a limited number of relatively small liver lesions. Because of the diversification of techniques and technologies, percutaneous liver ablation has progressively been integrating to more and more complex therapeutic strategies available to a wider group of patients. Local knowledge and expertise with these techniques, largely dominated by radiofrequency ablation, often dictate the role of these techniques in the management of patients with liver tumors. We will review the clinical indications of percutaneous ablation techniques for liver tumors based on clinical considerations as well as ablation techniques.     

Pain management in oncology

Several interventional radiology procedures are available for the management of cancer pain. In this article, we will briefly review the different procedures and their value in the setting of cancer pain management under two main categories: indirect action (regional anesthesia from neurolysis) and direct action on the tumor. Percutaneous ablation of bone tumors: alcohol, laser, radiofrequency, microwaves, ultrasound, and cryoablation. Several indications have previously been validated, including thermal ablation of bone metastases with results superior to conventional therapies. Additional applications should be validated over the next few years.     

Percutaneous minimally invasive therapies in the treatment of bone tumors: thermal ablation

Many percutaneous image-guided ablative techniques have been utilized in the treatment of bone cancers. These techniques are fast becoming a focus in the treatment of patients with both benign and malignant forms of bone cancer. This article will review the principles of radiofrequency ablation including its use in combination with other therapies, cryoablation, and microwave ablation in the treatment of osteoid osteomas and bone metastases.     

Percutaneous bone lesion ablation

Benign tumors and metastatic bone lesions can be treated by ablation techniques performed either alone or in combination with other percutaneous techniques. Ablation techniques include ethanol or acetic acid injection and thermal ablation by means of energy deposition [including laser, radiofrequency, microwave, cryoablation, radiofrequency ionization and magnetic resonance (MR)-guided high-intensity focused ultrasound (HIFU)]. Goal definition of the therapy is crucial: ablation techniques can be proposed as curative treatments in benign bone tumors or oligometastatic disease (<3 lesions). Alternatively, these techniques can be proposed as palliative treatments aiming at reduction of pain, local control of the disease and tumor decompression. Depending on the lesion’s location ablation can be combined with cementation with or without further metallic augmentation; local tumor control can be enhanced by combining ablation with transarterial bland embolization or chemoembolization. Thermal ablation of bone and soft tissues is characterized by high success and relatively low rates of potential complications, mainly iatrogenic thermal damage of surrounding sensitive structures. Successful thermal ablation requires a sufficient ablation volume and thermal protection of the surrounding vulnerable structures. This article will describe the general principles governing ablation and the mechanism of action for each technique and in addition will review the literature about safety and effectiveness of percutaneous imaging-guided ablation for benign and malignant (primary and metastatic) lesions.     

经皮射频消融治疗的几个新适应证

本文回顾分析近年来国内外采用经皮射频消融术在肝癌门静脉癌栓、胆管癌、肝血管瘤、子宫平滑肌瘤、甲状腺结节、早期乳腺癌结节6种疾病中的应用经验和体会,并阐述随着设备改进和消融技术的提高,经皮射频消融术在临床上的适应范围日趋扩大。     

Radiofrequency ablation of osseous metastases for the palliation of pain

A number of different methods have been proposed for pain relief in cancer patients with bone metastases, each with different indications, contraindications and complications (systemic analgesics, bisphosphonates, antitumor chemotherapy, radiotherapy, systemic radio-isotopes, local surgery and vertebroplasty). The ideal treatment has to be fast, safe, effective and tolerable for the patient. CT-guided radiofrequency (RF) ablation may fulfill these criteria. Our experience in the treatment of 30 patients (34 lesions) with painful bone metastases using RF ablation was assessed. There was a significant decrease in the mean past-24-h Brief Pain Inventory (BPI) score for worst pain, for average pain and for pain interference during daily life (4.7, 4.8 and 5.3 units respectively) 4 and 8 weeks after treatment. There was a marked decrease (3 out of 30 patients 4 and 8 weeks after treatment) in the use of analgesics. CT-guided RF ablation appears to be effective for treatment of painful bone metastases.     

Radiofrequency ablation of liver cancer

The development of image-guided percutaneous techniques for local tumor ablation has been one of the major advances in the treatment of liver malignancies. Over the past two decades, several methods for chemical or thermal tumor destruction have been clinically tested. Among these methods, radiofrequency (RF) ablation is currently established as the primary ablative modality at most institutions. RF ablation is accepted as the best therapeutic choice for patients with early stage hepatocellular carcinoma (HCC) when liver transplantation or surgical resection is not suitable options. In addition, RF ablation is emerging as a viable alternative to surgery for inoperable patients with limited hepatic metastatic disease, especially from colorectal cancer. Several series have shown that RF ablation can result in complete tumor eradication in properly selected candidates, and have provided indirect evidence that the treatment improves survival. In this article, we review technique, indications, and clinical results of percutaneous RF ablation in the treatment of HCC and colorectal hepatic metastases.     

Radiofrequency Thermal Ablation of Hepatocellular Carcinomas

Although surgical resection remains the best option as potentially curative therapy for hepatocellular carcinoma, radiofrequency thermal ablation has begun to receive much attention as an effective minimally invasive technique for the local control of unresectable malignant hepatic tumors. Most recent radiofrequency devices equipped with a powerful generator and larger needle electrode permit larger thermal lesions, up to 5 cm in diameter, with a single ablation. In this article, the author reviews the technical developments and early clinical results obtained with radiofrequency ablation techniques.     

Mikrowellenablation

CLINICAL ISSUE: The majority of patients with hepatic malignancies are not amenable to surgical resection. In some of these cases minimally invasive ablative therapies are a treatment option. STANDARD TREATMENT: Besides radiofrequency ablation, the most common ablative therapies are cryoablation, laser ablation and microwave ablation. TREATMENT INNOVATIONS: The classic fields of application of microwave ablation are the treatment of malignancies of the liver, kidneys and lungs. Furthermore, cases of treatment of bone tumors and tumors of the adrenal gland have been reported as well as treatment of secondary hypersplenism. PERFORMANCE: The manufacturers of microwave systems pursue different strategies to reach an optimal ablation zone, such as water or gas cooling of the antenna, the simultaneous use of different antennas or an automatic modulation of the microwave energy and frequency. ACHIEVEMENTS: In contrast to other tumor ablation methods microwave ablation causes a direct heating of a tissue volume, thus this method is less vulnerable to the cooling effect of vessels in the ablation zone. Moreover the electric conductivity of the treated tissue does not influence microwave radiation so that microwave ablation has advantages for the treatment of high-resistance organs, such as the lungs or bone. Some publications have shown that microwave ablation causes larger ablation zones in less time in comparison to radiofrequency ablation. PRACTICAL RECOMMENDATIONS: Classic indications for microwave ablation are the treatment of malignancies of the liver, lungs and kidneys. Initial technical problems have been solved, so that an increasing significance of the microwave ablation among the ablative therapies is to be expected.     

Ablación por radiofrecuencia en la enfermedad tiroidea y paratiroidea

Radiofrequency ablation is a well-known, safe, and effective method for treating benign thyroid nodules and recurring thyroid cancer as well as parathyroid adenomas that has yielded promising results in recent years. Since the Korean Society of Thyroid Radiology introduced the devices and the basic techniques for radiofrequency ablation in 2012, radiofrequency ablation has been approved all over the world and both the devices and techniques have improved.This review aims to instruct interventional radiologists who are doing or intend to start doing radiofrequency ablation of thyroid and parathyroid lesions, as well as thyroid and parathyroid specialists who provide pre- and post-operative care, in the training, execution, and quality control for radiofrequency ablation of thyroid nodules and parathyroid adenomas to optimize the efficacy and safety of the treatment.     

99Tc^m-MDP骨显像评估脊柱骨样骨瘤及成骨细胞瘤射频消融效果

目的探讨99Tcm-亚甲基二磷酸盐骨显像对脊柱骨样骨瘤和成骨细胞瘤射频消融疗效评估的价值。资料与方法回顾性收集行射频消融的7例脊柱骨样骨瘤及成骨细胞瘤患者的影像学及临床资料,分析骨显像、CT表现与患者症状、随访结果的关系。结果7例患者(其中骨样骨瘤4例,成骨细胞瘤3例)接受8次射频消融。治疗后2例无疼痛复发,第3、6个月骨显像呈轻度浓聚,其中1例第3个月CT示病变缩小,第12个月消失。3例第4~5个月疼痛复发,骨显像呈轻度浓聚1例,显著浓聚2例,同期CT示病变较治疗前均无变化,继续随访患者疼痛消失。2例射频消融后仍有间断轻度疼痛,第9、12个月骨显像均呈显著浓聚,同期CT示病变缩小1例,增大1例,患者后续分别行手术和再次射频消融。结论骨显像能够早期判断骨样骨瘤和成骨细胞瘤射频消融后病变的活性。骨显像轻度浓聚预示病变治愈,显著浓聚提示病变尚存活性,需继续随访。     

Radiofrequenzablation von Lebermetastasen – Technik und erste Ergebnisse

Primary and secondary malignant hepatic tumors are the most common tumors with a much more higher incidence of hepatic metastases. Chemotherapy and radiation therapy are in general ineffective. Therefore, surgical resection is considered the method of choice in the treatment of malignant hepatic lesions. Due to systemic disease, general medical or procedure-related reasons hindering surgery, only 25 to 45% of the patients with metastatic disease of the liver are suitable for a curative surgical therapy. In resectable lesions thermoablative methods can offer an alternative to the surgical therapy. The most experience exists in radiofrequency ablation techniques. Technique, indications, contraindications, and limitations of the radiofrequency ablation will be discussed together with a presentation of own cases and a review of the literature. In 37 patients the primary technical success rate of the ablation was 97.3% (72 of 74 lesions). In 4 cases a hematoma of the liver capsule occurred. One of these had to be treated interventionally. During the limited follow-up period of 9 months no local recurrency was seen, however 4 patients developed new hepatic metastases. Beside differences in practicability it is not yet clarified if there are differences in the therapeutic efficacy of the different thermoablation methods. Nevertheless, the results of the ablation therapy may parallel the results of the surgical resection. Interstitial thermotherapy can provide a valuable contribution to local tumor control. However, the final significance of the thermoablation techniques within oncological therapy regimens has to be evaluated in further multidisciplinary studies.     

Image-Guided Spinal Ablation: A Review

The image-guided thermal ablation procedures can be used to treat a variety of benign and malignant spinal tumours. Small size osteoid osteoma can be treated with laser or radiofrequency. Larger tumours (osteoblastoma, aneurysmal bone cyst and metastasis) can be addressed with radiofrequency or cryoablation. Results on the literature of spinal microwave ablation are scarce, and thus it should be used with caution. A distinct advantage of cryoablation is the ability to monitor the ice-ball by intermittent CT or MRI. The different thermal insulation, temperature and electrophysiological monitoring techniques should be applied. Cautious pre-procedural planning and intermittent intra-procedural monitoring of the ablation zone can help reduce neural complications. Tumour histology, patient clinical-functional status and life-expectancy should define the most efficient and least disabling treatment option.     

Fire and ice: percutaneous ablative therapies and cement injection in management of metastatic disease of the spine

Oncology intervention is actively moving beyond simple bone cement injection. Archimedes taught us that a volume displaces its volume. Where does the tumor we displace with our cement injection go? It is no longer acceptable that we displace tumor into the venous system with our cement injections. We must kill the tumor first. Different image-guided percutaneous techniques can be used for treatment in patients with primary or secondary bone tumors. Curative ablation can be applied for the treatment of specific benign or in selected cases of malignant localized spinal tumors. Pain palliation therapy of primary and secondary bone tumors can be achieved with safe, fast, effective, and tolerable percutaneous methods. Ablation (chemical, thermal, mechanical), cavitation (radiofrequency ionization), and consolidation (cementoplasty) techniques can be used separately or in combination. Each technique has its indications, with both advantages and drawbacks. To prevent pathological fractures, a consolidation is necessary. In spinal or acetabular tumors, a percutaneous cementoplasty should be associated with cryoablation to avoid a compression fracture. The cement is injected after complete thawing of the ice ball or the day after the cryotherapy. A syndrome of multiorgan failure, severe coagulopathy, and disseminated intravascular coagulation following hepatic cryoablation has been described and is referred to as the cryoshock phenomenon.     

Percutaneous radiofrequency ablation of pulmonary malignancies: combined treatment with brachytherapy

OBJECTIVE: The purpose of this article is to report the clinical experience and technical feasibility of percutaneous radiofrequency ablation in conjunction with brachytherapy, a novel approach in the treatment of lung neoplasms. Data from three patients with lung malignancies illustrate the expanding therapeutic indications of this minimally invasive intervention. CONCLUSION: Percutaneous radiofrequency ablation in conjunction with brachytherapy is a promising minimally invasive combination modality. It may be a treatment option for patients with primary, recurrent, or metastatic malignancies of the lung that are not amenable to surgery or further external beam radiation therapy.     

Radiofrequency ablation of renal cell carcinoma

Small renal cell carcinomas of less than 4 cm diameter have been detected increasingly in asymptomatic patients because of the widespread use of cross-sectional imaging. Radical or partial nephrectomy is generally considered the reference for the treatment of a solitary renal cell carcinoma. However, for those patients who are not candidates for surgery, minimally invasive procedures may be desirable. Although percutaneous radiofrequency ablation for the treatment of renal cell carcinoma is a recent innovation, the results of preliminary clinical series and animal studies are encouraging, and show it to be technically feasible with minimal morbidity. In this article, we review the technique, indications, imaging findings, as well as the results of clinical and animal studies of radiofrequency ablation for the treatment of renal cell carcinoma.     

Radiofrequency, microwave and laser ablation of pulmonary neoplasms: Clinical studies and technical considerations—Review article

Image-guided thermal ablation therapy has received significant attention for the treatment of many focal primary and metastatic pulmonary neoplasms. This interest has been associated with progressive advances in energy development, approach, technical application and adjuvant therapeutic combinations to improve the outcome results concerning local tumor control, survival rate and symptoms relief. This review provides clinical outline of percutaneous thermal ablation of lung neoplasms using radiofrequency, microwave and laser techniques regarding their principles, theoretical background, devices and techniques, technical problems and recent protocols. Advantages, limitations and technical considerations of each method will be illustrated to provide a practical guideline.