Percutaneous Radiofrequency Thermal Ablation Research Articles

The diagnosis and percutaneous treatment of osteoid osteomas

<h2>Summary</h2> Osteoid osteomas are the commonest benign bone tumours. There is frequently a delay in diagnosis, in some cases of many months or years. The plain film appearances are not always immediately recognised and the characteristic bone sclerosis may be absent in sub-periosteal intra-articular lesions. Computed tomography (CT) is the most specific investigation, and in most cases pathological confirmation is not required. Open surgical removal of the lesion has now been replaced by CT guided percutaneous radiofrequency thermal ablation.

Das hepatozelluläre Karzinom: alternative Therapiestrategien

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors in some areas of the world. The prognosis of HCC patients is generally very poor with a 5-year survival rate of less than 5%. Therapeutic strategies include surgery (resection or liver transplantation) and non-surgical interventions, such as percutaneous ethanol injection or radiofrequency thermal ablation as well as transarterial embolization or chemoembolization. Therefore, the development and evaluation of novel HCC treatment strategies such as the use of antiangiogenic, antiproliferative or antiinflammatoric drugs, immune therapeuticals, gene therapy and internal or external radiation are of utmost importance. This review should give an overview of possible alternative therapies in HCC treatment.

A case of biliary gastric fistula following percutaneous radiofrequency thermal ablation of hepatocellular carcinoma

Percutaneous radiofrequency thermal ablation (RFA) is an effective and safe therapeutic modality in the management of liver malignancies, performed with ultrasound guidance. Potential complications of RFA include liver abscess, ascites, pleural effusion, skin burn, hypoxemia, pneumothorax, subcapsular hematoma, hemoperitoneum, liver failure, tumour seeding, biliary lesions. Here we describe for the first time a case of biliary gastric fistula occurred in a 66-year old man with a Child's class A alcoholic liver cirrhosis as a complication of RFA of a large hepatocellular carcinoma lesion in the III segment. In the light of this case, RFA with injection of saline between the liver and adjacent gastrointestinal tract, as well as laparoscopic RFA, ethanol injection (PEI), or other techniques such as chemoembolization, appear to be more indicated than percutaneous RFA for large lesions close to the gastrointestinal tract.

Percutaneous Image-guided Radiofrequency Thermal Ablation for Large Symptomatic Uterine Leiomyomata after Uterine Artery Embolization: A Feasibility and Safety Study

To evaluate the feasibility and safety of percutaneous image-guided radiofrequency ablation (RFA) performed with moderate sedation for large symptomatic uterine leiomyomata. Women with large (>5 cm in diameter) symptomatic subserosal and/or intramural uterine leiomyoma were recruited for a prospective study. Patients underwent percutaneous RFA following UAE. RFA using 5 cm treatment diameter expandable needle electrodes connected to a 460 kHz monopolar RF generator, which was performed with a target temperature and power set at 85 degrees C and 150 watts respectively, with a target temperature ablation time of 10 minutes. Patients were assessed for complications in perioperative and post-procedure periods at 24 hours and 1 month, and for symptom improvements at 6 months. Thirty-five patients (mean 43.8 years +/- 6.2) were recruited. RFA targeting ablation size and temperature was achieved in 97% of the patients (34/35). There were no immediate percutaneous RFA-related complications. There was a self-limiting delayed drainage via the transabdominal RFA access track in one patient (2.9%), a urinary tract infection in one patient (2.9%) and post-embolization/post-ablation symptoms in three patients (8.6%). The mean transformed symptom severity score (SSS) as a part of the uterine fibroid symptom and quality of life (UFS-QOL) assessment shows that the improvements at 1 month were 24.3 points ( P < 0.001) and at 6 months were 40.4 points ( P < 0.001). Mean volume reduction of leiomyomata was 286.8 cm(3) or 56.5% ( P = 0.0015). Percutaneous image-guided RFA as adjunctive to UAE under moderate sedation is feasible, and appears safe without significant morbidity in the treatment of large uterine leiomyomata.

CT guided percutaneous radiofrequency thermal ablation of peripheral lung carcinoma

目的 探讨CT导向下射频消融(RFA)治疗周围型肺癌的价值.方法 43例周围型肺癌进行了CT导向下射频消融治疗.术前常规CT导向下经皮穿刺活检获取病理学诊断,鳞癌15例,腺癌19例,腺鳞癌4例,大细胞癌3例,未分化癌2例.全部瘤体直径均﹤8 cm,其中32个病灶直径﹤5 cm.结果 全部病例手术顺利,术中并发少量气胸者3例,液气胸1例,大量气胸行闭式引流者1例.术后分别在3和6个月CT复查,显示43个病灶中40个体积均有不同程度的进行性缩小,肿瘤内部均出现大片不规则低密度区;3例患者病灶体积无变化,边缘有环状强化,提示肿瘤复发.结论 CT导向下经皮穿刺RFA治疗周围型肺癌是安全有效的微创技术,值得推广应用。

Experiences in US-Guided Percutaneous Radiofrequency Ablation of 44 Renal Tumors in 31 Patients: Analysis of Predictors for Complications and Technical Success

Preliminary clinical studies have shown the feasibility, safety, and efficacy of radiofrequency thermal ablation (RFA) of renal tumors, but only a few have analyzed the prognostic factors for technical success and there are no long-term results. Our objective was to statistically evaluate our mid-term results of percutaneous US-guided RFA in order to define predictors for complications and technical success. We selected for treatment 44 tumors in 31 patients (24 with renal cell carcinoma, 7 with hereditary tumors, 15 with a solitary kidney), up to 5 cm in diameter. Eight adverse events occurred; 3 (6.8%) were major complications, successfully treated with interventional radiology procedures in 2 cases. Exophytic extension of the tumor was protective against complications (p = 0.040). Technical success was obtained in 38 lesions after one RFA session and in 39 (89%) after one more session, when possible. At the end of treatment, central extension was the only negative predictor for technical success (p = 0.007), while neither size >3 cm (p = 0.091) nor other prognostic factors were statistically significant. US-guided percutaneous RFA can be proposed for non-central renal tumors up to 5 cm, also in patients without surgical contraindications, thanks to a low incidence of complications and a high success rate. Randomized controlled trials versus surgery are now needed to investigate long-term comparative results.

Percutaneous radiofrequency thermal ablation of primary and metastatic lung tumors

Primary lung cancer is the leading cause of death from cancer. For patients with inoperable lung cancer, percutaneous radiofrequency thermal ablation (RFA) under CT-guidance represents a minimally invasive treatment. It can also be applied in combination with radiation therapy and chemotherapy. In a period of 18 months, RFA under CT-guidance 27 ablations were applied on 22 patients, 14 patients with primary lung cancer and 8 patients with metastatic lung tumor. There were 15 men and 7 women ranging in age between 48 and 79 years. All patients were not surgical candidates either due to the advanced stage or due to comorbid diseases, while five denied surgery. The lesions' size was no bigger than 6 cm (range 1-6 cm) with an average of 3.8 cm. The diagnosis of all treated lesions was obtained with percutaneous biopsy under CT guidance. The procedure was performed under local anesthesia. There were no major complications observed, but a small pneumothorax and a minor hemoptysis in four cases, all conservatively treated. All patients were hospitalized for 24h. Follow-up was initially done in 1, 3, 6 and 12 months after RFA and it was accomplished by personal interview or by telephone call up to December 2005. Median progression free intervals were 26.4 months for primary lung cancer and 29.2 months for metastatic tumor. RFA is a minimally invasive technique that can be used as a palliative treatment in nonsurgical candidates with primary or metastatic lung tumor with a low morbidity and mortality.

Percutaneous radiofrequency ablation of lung tumors with expandable needle electrodes: current status

Percutaneous radiofrequency thermal ablation (RFA) has been used to treat primary and secondary liver tumors under ultrasound, computed tomography (CT), or magnetic resonance imaging (MRI) guidance for the past decade [Park et al., Radiol Clin North Am 38:545-561, 2000; Siperstein and Gotomirski, Cancer J 6:S293-S301, 2000; Kelekis et al., Eur Radiol 13:1100-1105, 2003]. RFA is a low-cost, minimally invasive treatment that has recently attracted attention for treating tumors in different solid organs with promising results [Dupuy and Goldberg, J Vasc Interv Radiol 12:1135-1148, 2001; Friedman et al., Cardiovasc Intervent Radiol 27:427-434, 2004]. It can be provided with minimal hospitalization, and experienced practitioners have reported low complication rates [Dupuy and Goldberg, J Vasc Interv Radiol 12:1135-1148, 2001; Livraghi et al., Radiology 226:441-451, 2003]. Patients with lung malignancies (primary lung cancer or pulmonary metastases), who cannot be operated, might be candidates for RFA treatment. It can also be used in association with other treatments (i.e., chemotherapy, radiotherapy) for better disease control. Combination of the above with RFA may help reduce morbidity and mortality. Many ways to apply energy to the tumor exist (monopolar and bipolar RFA, microwave, laser, brachytherapy). In this review we will focus on expandable monopolar systems, which despite their deficiencies are the most popular in the interventional radiology sector.

Combined Ethanol Injection Therapy and Radiofrequency Ablation Therapy in Percutaneous Treatment of Hepatocellular Carcinoma Larger than 4 cm

Optimal treatment of large-sized hepatocellular carcinoma (HCC) is still debated, because percutaneous ablation therapies alone do not always achieve complete necrosis. To report our experience in the treatment of patients with HCC larger than 4 cm in diameter by combined percutaneous ethanol injection and radiofrequency thermal ablation. In a 5-year period there were 40 consecutive patients meeting the inclusion criteria (24 men and 16 women; age range 41-72 years, mean 58 years). These subjects had a single HCC larger than 4 cm. Twelve subjects also had one or two additional nodules smaller than 4 cm (mean 1.2 nodules per patient). Patients were submitted to one to three sessions consisting of ethanol injection at two opposite tumor poles (mean 12 ml) and then of radiofrequency application through one or two electrodes placed at the tumor center (mean treatment duration 30 min). Complete necrosis was obtained in all cases with one to three sessions (mean 1.3 sessions per patient). All patients experienced pain and fever but one only subject had a major complication requiring treatment (abscess development and fistulization). Overall follow-up was 7-69 months. Two patients showed local recurrence and 9 developed new etherotopic HCC nodules. Seven subjects died during follow-up while 33 were free from recurrence 8-69 months after treatment. A combination of ethanol injection and radiofrequency ablation is effective in the treatment of large HCC.

Percutaneous Radiofrequency Thermal Ablation of Primary and Metastatic Hepatic Tumors: Current Concepts and Review of the Literature

The liver is a common site for primary malignancy and hematogenous metastasis. Although surgical resection of primary or metastatic hepatic tumors is generally regarded as first-line therapy, the majority of patients with hepatic malignancy have disease that is not amenable to surgical resection because of tumor location, poor hepatic reserve, or medical comorbidities. This has led to significant interest in the development of nonsurgical image-guided therapies, including radiofrequency ablation (RFA). RFA is appealing as a minimally invasive therapy that may be performed on an outpatient basis. It enables ablation of an area 3 to 5 cm in diameter, with relatively low morbidity and mortality rates. The results concerning the use of percutaneous RFA in the treatment of hepatocellular carcinoma, colorectal metastases, and other hepatic metastases are reviewed in this article. Clinical and technical considerations and complications are also discussed.

The management of osteoid osteoma: updates and controversies

Osteoid osteoma is a benign painful bone tumor usually found in the lower extremities of children and young adults. It has been traditionally treated by surgical excision. Despite the small size of the lesion, the operative procedure for its removal can be extensive, but still sometimes remains incomplete. The purpose of this review is to highlight and discuss current developments in the management of osteoid osteoma. During the past decade, efforts were deployed to minimize bone removal, lessen the risk of pathologic fracture and the need for bone grafting, and thereby shorten the period of convalescence. Improved methods for the precise localization of an osteoid osteoma with use of radioisotope scanning or computed tomography scan have made it possible to treat this lesion with more limited and effective operations, mainly in deep and non-easily accessible osteoid osteomas. Although they bear the criticism of lacking histological proof for diagnosis of osteoid osteoma, minimally invasive techniques, such as computed tomography-guided percutaneous radiofrequency thermal ablation and laser photocoagulation have become the methods of choice for the treatment of all localizations except those in contact with neural structures (awaiting further research and experience), provided that the diagnosis is based on a typical clinical, scintigraphic and computed tomography presentation.

Quantitation of alpha-fetoprotein messenger RNA for early detection of recurrent hepatocellular carcinoma: A prospective pilot study

Background: Alpha-fetoprotein (AFP) messenger RNA (mRNA) may be a potential marker of the dissemination of hepatocellular carcinoma (HCC) cells into the circulation. The aim of this prospective pilot study was to assess the prognostic value of quantitative levels of AFP mRNA in patients undergoing ablative treatment for HCC. Methods: Peripheral blood samples were taken from seven patients before and after treatment for measurement of AFP mRNA levels by reverse-transcriptase polymerase chain reaction (RT-PCR). Patients were treated with percutaneous radiofrequency thermal ablation ( n = 3) or transarterial chemoembolization ( n = 4). The level of AFP mRNA in blood was serially determined, and the time course was related to the clinical course and disease outcome. The median duration of follow-up was 14 months (range, 9–16 months). Results: HCC recurred locally in four patients, and lung metastases developed in two of them. Patients were divided into three groups on the basis of the pre- and post-treatment AFP mRNA status. Group 1 included four patients with consistently high serum AFP and AFP mRNA levels (pre- and post-treatment). These patients developed distant and local recurrence. Group 2 included a patient with serum-negative AFP mRNA and normal AFP levels at entry. Although serum AFP remained within normal range, mean AFP mRNA increased from 10 to 95 copies/μg RNA. This patient had no distant metastases, but his tumor markedly increased in size. In Group 3, AFP mRNA and serum AFP remained within normal range before and after treatment. These two patients did not develop either local or distant metastases during the follow-up period. Conclusions: Although this is a small sample size pilot study these findings imply that quantitative measurement of AFP-expressing cells in peripheral blood may serve as a marker of HCC recurrence.

909Renal cell carcinoma: Percutaneous radio frequency thermal ablation for malignant renal tumours: Intermediate results in 15 patients

909Renal cell carcinoma: Percutaneous radio frequency thermal ablation for malignant renal tumours: Intermediate results in 15 patients

Massive hepatic infarction complicating ultrasound‐guided percutaneous radiofrequency thermal ablation

Massive hepatic infarction complicating ultrasound‐guided percutaneous radiofrequency thermal ablation

Percutaneous Radio-Frequency Ablation of Liver Malignancies

To describe the safety and efficacy of percutaneous radiofrequency ablation (PRFA) to treat liver cancer. One hundred patients with histologically or clinically confirmed primary or metastatic malignancies were treated percutaneously under ultrasound guidance using LeVeen multipolar array needle electrode and RF 2000 generator between October, 1999 and October, 2000. All patients were followed up to assess complication, treatment response, recurrence and curative effect. PRFA was performed in 76 patients with primary liver cancer and 24 patients with metastatic liver cancer. AFP positive of small hepatic cancer (inoperative) became AFP negative in 75.0% patient (21/28). The rate of completely concrete necrosis of small hepatic malignancies shown by MRI was 85.9%(61/71). PRFA as a local thermal therapy is a kind of new palliative treatment for hepatic malignancies. It is minimally invasive, safe and effective especially for small hepatic tumors and can also be used in conjunction with TACE for larger ones.

234 Percutaneous radiofrequency thermal ablation (RFTA) of small hepatocellular carcinoma: A prospective study

234 Percutaneous radiofrequency thermal ablation (RFTA) of small hepatocellular carcinoma: A prospective study

Percutaneous Radiofrequency Thermal Ablation of Lung VX2 Tumors in a Rabbit Model: Evaluation with Helical CT Findings for the Complete and Partal Ablation

Purpose: To evaluate the radiologic findings for complete and partial ablation after percutaneous CT-guided transthoracic radiofrequency ablation (RFA) of lung VX2 tumor implanted in rabbits. Materials and Methods: Thirteen rabbits with successfully implanted lung VX2 were used. Three rabbits as controls did not receive RFA while the other ten rabbits underwent RFA; 5 complete and 5 partial. RFA was performed using an internally cooled, 17-gauge electrode (Radionics, Burlington, MA) with a 1-cm active tip under CT guidance. Postprocedural CT was performed within 3 days, and we analyzed the ablated size, enhancement pattern, shape, margin, and complications of the complete and partial ablation groups. Rabbits were sacrificed after postprocedural CT with an overdose of ketamine, and pathologic findings of the ablated groups were compared with those of the control group. Results: The size of the ablated lesions and the enhancement pattern differed between the completely and partially ablated groups on chest CT. The size of the ablated lesions was increased by 47.1% in the completely ablated group and by 2.1% in the partially ablated group. In the completely ablated group, VX2 tumor showed absolutely no enhancement, whereas only ablated pulmonary parenchyma outside VX2 showed mild enhancement on enhanced CT. In the partial ablated group, a part of VX2 became strongly enhanced on enhanced CT. On microscopic examination, the completely ablated group demonstrated that a viable tumor cell was not visible. In the partially ablated group, however, a viable tumor cell within the surrounding fibrous capsule on the peripheral area of the VX2 was observed. Conclusion: The important CT findings for evaluation of complete and partial RFA are the ablated size and enhancement pattern of the ablated lesion.

Percutaneous Radiofrequency Thermal Ablation of Lung VX2 Tumors in a Rabbit Model Using a Cooled Tip-Electrode

To evaluate the feasibility, safety, and effectiveness of percutaneous CT-guided transthoracic radiofrequency ablation (RFA) of lung VX2 tumors implanted in rabbits. Thirty-five rabbits with implanted lung VX2 tumors were divided into two groups, an RFA group (n = 28) and a control group (n = 7). In the RFA group, RFA was performed on VX2 tumors using a 17-gauge internally cooled-tip electrode. Contrast-enhanced CT was performed before the RFA and on the same day, day 3, weeks 1, 2, 3, and months 1, 2, 6, and 9, after the RFA. The therapeutic efficacy was evaluated by CT and pathologic findings. RFA of lung tumors was technically successful in each instance. Complete tumor ablation was achieved in 19 of the 28 rabbits (67.9%) in the RFA group. Nine rabbits (32.1%) showed local tumor relapse and mediastinal lymph nodal or pleural metastasis. The animals in the control group died of end-stage malignancies with diffuse tumor spread and malignant pleural effusion (mean 26 +/- 2.7 days). There were 17 (60.7%) complications related to the procedure, ie, pneumothorax (n = 12), obstructive pneumonia (n = 3), hemothorax (n = 1), and burn (n = 1). RFA of centrally located VX2 tumors (in inner 2/3 of the lung) was more frequently associated with complications than RFA of peripherally located VX2 tumors ( P= 0.02). This experimental study demonstrates the feasibility of RFA therapy for treating lung VX2 tumors in rabbits, although RFA for central tumors carries the potential for major complications, including large pneumothorax or obstructive pneumonia.

Percutaneous radiofrequency thermal ablation with hypertonic saline injection: in vivo study in a rabbit liver model.

ObjectiveTo determine whether hypertonic saline (HS, 36% NaCl) injection prior to or during radiofrequency ablation (RFA) can increase the extent of thermally mediated coagulation in in-vivo rabbit liver tissue, and also to establish the ideal injection time in relation to RFA in order to maximize its effect on the extent of radiofrequency (RF)-induced coagulation.Materials and MethodsIn 26 rabbits, 43 RFA lesions were produced using a 17-gauge internally cooled electrode with a 1-cm active tip under ultrasound (US) guidance. Rabbits were assigned to one of three groups: Group A: RFA alone (n=8); Group B: RFA after the instillation of 1 mL HS (n=8); Group C: RFA after and during the instillation of 0.5 mL HS (n=10). RF energy (30 W) was applied for 3 minutes, and changes occurring in tissue impedance, current, power output, and the temperature of the electrode tip were automatically measured. After RFA, contrast-enhanced spiral CT was performed, and in each group the maximum diameters of the thermal lesions in gross specimens were compared. Technical success and the complications arising were evaluated by CT and on the basis of autopsy findings.ResultsAll procedures were technically successful. There were six procedure-related complications (6/26; 23%), including five localized perihepatic hematomas and one thermal injury to the stomach. With instillation of HS in group B rabbits, markedly decreased tissue impedance (73Ω ± 5) and increased current (704 mA ± 41) were noted, compared to RF ablation without saline infusion (116.3Ω ± 13, 308 mA ± 80). With instillation of the solution before RFA (group B), coagulation necrosis was greater (14.9 mm ± 3.8) than in rabbits not injected (group A: 11.5 mm ± 2.4; Group A vs. B: p < .05) and in those injected before and during RFA (group C: 12.5 mm ± 3.1; Group B vs. C: p > .05).ConclusionRFA using HS instillation can increase the volume of RFA-induced necrosis of the liver with a single application, thereby simplifying and accelerating the treatment of larger lesions. In addition, HS instillation before RFA more effectively achieves coagulation necrosis than HS instillation before and during RFA.

Percutaneous radiofrequency thermal ablation of hepatocellular carcinoma: a safe and effective bridge to liver transplantation.

The incidence of hepatocellular carcinoma (HCC) is increasing in the United States. Although liver transplantation is an effective means of treating selected patients, pretransplantation tumor progression may preclude some patients from undergoing transplantation. The aim of this study is to determine the safety and efficacy of percutaneous radiofrequency thermal ablation (RFA) in 33 consecutive patients with nonresectable HCC and advanced cirrhosis. Mean subject age was 57.2 +/- 10.6 years, mean Child-Turcotte-Pugh score was 7.0 +/- 1.4, and mean maximal tumor diameter was 3.6 +/- 1.1 cm. Using contrast-enhanced computed tomography and magnetic resonance imaging, 22 patients (66%) had a complete radiological response at 3 months post-RFA, whereas 11 patients (33%) had an incomplete radiological response. During follow-up, 18 patients (54%) experienced tumor progression and 9 subjects underwent repeated ablation for either residual disease or tumor progression. The overall actuarial patient survival rate of the 33 patients was 58% at 2 years, whereas the transplantation-free patient survival rate was 34% at 2 years. Fifteen of 23 transplant candidates were successfully bridged to liver transplantation after a mean post-RFA follow-up of 7.9 +/- 6.7 months. The extent of tumor necrosis in the explant varied, but no subjects had evidence of tumor seeding on post-RFA imaging, at liver transplantation, or in the explant. The 3-year actuarial posttransplantation patient survival rate was 85%. Two patients have developed posttransplantation recurrence, and both had microscopic vascular invasion in their explants. In summary, our data show that RFA is a safe and effective treatment modality for patients with advanced cirrhosis and nonresectable HCC. Although the ability of RFA to prevent or delay tumor progression requires further prospective study, its favorable safety profile and promising efficacy make it an attractive treatment option for liver transplant candidates with nonresectable HCC.