Radiofrequency Ablation of Malignant Liver Tumors

Background: Radiofrequency ablation (RFA) is being used to treat primary and metastatic liver tumors. The indications, treatment planning, and limitations of hepatic RFA must be defined and refined by surgeons treating hepatic malignancies.Methods: A review of the experience using RFA to treat unresectable primary and secondary hepatic malignancies at the University of Texas M. D. Anderson Cancer Center in Houston, Texas, and the G. Pascale National Cancer Institute in Naples, Italy, is provided. Patient selection, treatment approach, local recurrence rates, and overall cancer recurrence rates following RFA are described. The current literature on RFA of hepatic malignancies is reviewed.Results: RFA of hepatic tumors can be performed percutaneously, laparoscopically, or during an open surgical procedure. Incomplete treatment manifest as local recurrence is more common with a percutaneous approach. The morbidity and mortality rates associated with hepatic RFA are low. Local recurrence rates are low if meticulous treatment planning is performed. RFA can be combined safely with partial hepatic resection of large lesions. The long-term survival rates following RFA of primary and metastatic liver tumors have not yet been established.Conclusions: RFA of hepatic malignancies is a safe and promising technique to produce coagulative necrosis of unresectable hepatic malignancies. Experience with this treatment modality is not yet mature enough to establish long-term outcomes.     

Local Recurrence After Laparoscopic Radiofrequency Ablation of Liver Tumors: An Analysis of 1032 Tumors

Background  The best measure of the technical success of radiofrequency ablation (RFA) is local recurrence (LR). The aim of this prospective study is to identify factors that predict LR. Methods  Three hundred thirty-five patients with 1032 unresectable liver tumors underwent laparoscopic RFA between November 1999 and August 2005. All lesions were assessed prospectively regarding tumor type, size, liver segment, blood vessel proximity, and central or peripheral location in the operating room and size of ablation zone at 1-week computed tomographic (CT) scans. Lesions that recurred in follow-up CT scans were identified prospectively. LR was categorized as contiguous or adjacent. Univariate Kaplan-Meier and Cox proportional hazard models were used for statistical analysis. Results  LR was identified 21.7% of tumors on CT scans with a mean follow-up of 17 months (median, 12 months; range, 3–68 months). This was contiguous in 70% and adjacent in 30%. LR rate per tumor was highest for colorectal metastasis (34%), followed by noncolorectal, nonneuroendocrine metastasis (22%), hepatocellular carcinoma (18%), and neuroendocrine metastasis (6%). By univariate analysis, tumor type and size, ablation margin, liver segmental location, blood vessel proximity, and type of ablation (first time vs. repeat) were found to affect LR. The Cox proportional hazard model identified tumor type, tumor size, ablation margin, and blood vessel proximity to be independent predictors of LR. Conclusion  LR after RFA is predicted by certain tumor characteristics and technical factors. This information can be used intraoperatively to identify those tumors at a higher risk for failure.     

A Systematic Review of Radiofrequency Ablation for Lung Tumors

Background Radiofrequency ablation (RFA) has been increasingly utilized as a non-surgical treatment option for patients with primary and metastatic lung tumors. We performed the present systematic review to assess the safety and efficacy of RFA. Methods Searches for all relevant studies prior to November 2006 were performed on six databases. Two reviewers independently appraised each study using predetermined criteria. Clinical effectiveness was synthesized through a narrative review, with full tabulation of results of all included studies. Results A total of 17 of the most recent updates from each institution were included for appraisal and data extraction. All were case series and were classified as level-4 evidence. The mean number of lesions treated ranged from 1 to 2.8, and the mean size ranged from 1.7 cm to 5.2 cm. The overall procedure-related morbidity rate ranged from 15.2% to 55.6% and mortality from 0% to 5.6%. The most commonly reported complication was pneumothorax (4.5–61.1%). Most pneumothoraces were self-limiting and only 3.3–38.9% (median = 11%) required chest drain insertion. The local recurrence of tumors at the site of RFA ranged from 3% to 38.1% (median = 11.2%). The median progression-free interval ranged from 15 months to 26.7 months (median = 21 months), and 1-, 2- and 3-year survival rates were 63–85%, 55–65% and 15–46%, respectively. Conclusions Only observational studies were available for evaluation, which demonstrated some promising safety profiles of RFA. There were no conflicts of interest.     

Rates and Patterns of Recurrence for Percutaneous Radiofrequency Ablation and Open Wedge Resection for Solitary Colorectal Liver Metastasis

Introduction The purpose of this study was to compare rates and patterns of disease progression following percutaneous, image-guided radiofrequency ablation (RFA) and nonanatomic wedge resection for solitary colorectal liver metastases. Methods We identified 30 patients who underwent nonanatomic wedge resection for solitary liver metastases and 22 patients who underwent percutaneous RFA because of prior major hepatectomy (50%), major medical comorbidities (41%), or relative unresectability (9%). Serial imaging studies were retrospectively reviewed for evidence of local tumor progression. Results Patients in the RFA group were more likely to have undergone prior liver resection, to have a disease-free interval greater than 1 year, and to have had an abnormal carcinoembryonic antigen (CEA) level before treatment. Two-year local tumor progression-free survival (PFS) was 88% in the Wedge group and 41% in the RFA group. Two patients in the RFA group underwent re-ablation, and two patients underwent resection to improve the 2-year local tumor disease-free survival to 55%. Approximately 30% of patients in each group presented with distant metastasis as a component of their first recurrence. Median overall survival from the time of resection was 80 months in the Wedge group vs 31 months in the RFA group. However, overall survival from the time of treatment of the colorectal primary was not significantly different between the two groups. Conclusions Local tumor progression is common after percutaneous RFA. Surgical resection remains the gold standard treatment for patients who are candidates for resection. For patients who are poor candidates for resection, RFA may help to manage local disease, but close follow-up and retreatment are necessary to achieve optimal results. Presented at the Society for Surgery of the Alimentary Tract 47th Annual Meeting, May 22, 2006, Los Angeles, California. White and Avital contributed equally.     

Percutaneous Radiofrequency Ablation of Pulmonary Metastases from Colorectal Carcinoma: Prognostic Determinants for Survival

Background Preliminary results have shown that percutaneous radiofrequency ablation (RFA) may play a useful role in patients with inoperable lung tumors. This series evaluated the prognostic features for survival in nonsurgical candidates who underwent percutaneous RFA of pulmonary metastases from colorectal carcinoma.Methods Fifty-five patients not suitable for surgery underwent percutaneous RFA for colorectal pulmonary metastases. All clinical and treatment-related data were collected prospectively. The primary end point of the study was overall survival, defined from the time of RFA intervention. Univariate and multivariate analyses were performed to identify statistically significant prognostic parameters for overall survival.Results The overall median survival was 33 months (range, 4–40 months), with actuarial 1-, 2-, and 3-year survival of 85%, 64%, and 46%, respectively. Univariate analysis demonstrated that largest size of lung metastasis (P < .001), location of lung metastases (P = .032), and repeat percutaneous RFA for pulmonary recurrence (P = .024) were statistically significant for overall survival. Multivariate analysis demonstrated that largest size of lung metastasis >3 cm was independently associated with a reduced overall survival (P = .003).Conclusions Percutaneous lung RFA may play a useful role in nonsurgical candidates with colorectal pulmonary metastases. However, the survival benefit of this interventional procedure for patients with a pulmonary metastasis >3 cm was limited.     

The Efficacy of Radiofrequency Ablation for Bone Tumors Unsuitable for Radical Excision

BackgroundBone tumors can cause severe pain and poor quality of life due to recurrence and non-achievement of complete remission after surgery, chemotherapy, or radiotherapy. Radiofrequency ablation (RFA) can be considered for minimally invasive treatment of bone tumors that are difficult to radically excise. In this study, RFA was performed for bone tumors that were difficult to radically excise and did not respond to surgery, chemotherapy, or radiotherapy due to their large sizes and/or locations. The purpose of this study was to retrospectively analyze the clinical characteristics and survival rates of bone tumors after RFA and provide one more treatment option for the future.MethodsThere were 43 patients with bone tumors who underwent percutaneous RFA at our hospital from April 2007 to October 2017. The median age of the patients was 59 years (range, 31–75 years), and the median follow-up duration was 67.2 months (range, 10.2–130.5 months). Of the 43 patients, 26 were male and 17 were female. Thirty-four cases were metastatic bone tumors, 5 were chordomas, 3 were osteosarcomas, and 1 was a giant cell tumor. Pain and functional ability of the patients were evaluated using a visual analog scale (VAS) and the Musculoskeletal Tumor Society (MSTS) functional scoring system, respectively. Scores were recorded preoperatively, 1 week postoperatively, and 4 weeks postoperatively. The 1-year, 2-year, and 5-year survival rates were evaluated using the Kaplan-Meier method.ResultsThe mean VAS score was 8.21 preoperatively. The mean VAS score at 1 week, 4 weeks, 12 weeks, and 24 weeks postoperatively were 3.91, 3.67, 3.31, and 3.12, respectively. The mean preoperative MSTS score was 64.0% (range, 32%–87%). The mean postoperative MSTS score was 71.0% (range, 40%–90%). The 1-year, 2-year, and 5-year survival rates were 95.3%, 69.8%, and 30.2%, respectively.ConclusionsAs per our study findings, RFA was effective in reducing pain and improving functional ability of patients with bone tumors that were difficult to radically excise.     

Local Recurrences After Intraoperative Radiofrequency Ablation of Liver Metastases: A Comparative Study with Anatomic and Wedge Resections

Background The indications and results of intraoperative radiofrequency ablation (RFA) of liver metastases (LMs) are not well defined in the literature and have never been compared with those of hepatectomy. The aim of the study was to appreciate the local recurrence rate of RFA in comparison with anatomic and wedge resection.Methods Eighty-eight patients with technically unresectable LMs were treated with curative intent. The LMs were treated by anatomic resection (40 patients, 213 LMs) when large, by wedge resection (64 patients, 99 LMs) when peripheral and small, and by RFA (88 patients, 227 LMs) when central and small. The median follow-up was 27.6 months (range, 15–74 months), and a total of 539 LMs were treated (median of 5 per patient).Results The local recurrence rates were 5.7% for the 227 RFAs, 7.1% for the 99 wedge resections, and 12.5% for the 40 anatomic resections (P = .216). Local recurrence rates after RFA were correlated with LMs larger than 30 mm (P < .001) and with LMs in direct contact with large vessels (P < .001).Conclusions RFA is as efficient and safe as wedge or anatomic resections in terms of local control.     

Combined Resection and Radiofrequency Ablation for Advanced Hepatic Malignancies: Results in 172 Patients

Background: Resection combined with radiofrequency ablation (RFA) is a novel approach in patients who are otherwise unresectable. The objective of this study was to investigate the safety and efficacy of hepatic resection combined with RFA.Methods: Patients with multifocal hepatic malignancies were treated with surgical resection combined with RFA. All patients were followed prospectively to assess complications, treatment response, and recurrence.Results: Seven hundred thirty seven tumors in 172 patients were treated (124 with colorectal metastases; 48 with noncolorectal metastases). RFA was used to treat 350 tumors. Combined modality treatment was well tolerated with low operative times and minimal blood loss. The postoperative complication rate was 19.8% with a mortality rate of 2.3%. At a median follow-up of 21.3 months, tumors had recurred in 98 patients (56.9%). Failure at the RFA site was uncommon (2.3%). A combined total number of tumors treated with resection and RFA >10 was associated with a faster time to recurrence (P = .02). The median actuarial survival time was 45.5 months. Patients with noncolorectal metastases and those with less operative blood loss had an improved survival (P = .03 and P = .04, respectively), whereas radiofrequency ablating a lesion >3 cm adversely impacted survival (HR = 1.85, P = .04).Conclusions: Resection combined with RFA provides a surgical option to a group of patients with liver metastases who traditionally are unresectable, and may increase long-term survival.     

Local Recurrence After Laparoscopic Radiofrequency Thermal Ablation of Hepatic Tumors

Background: Since we first described laparoscopic radiofrequency ablation (LRFA) of liver tumors, several reports have documented technical and safety aspects of this procedure. Little is known, however, about the long-term follow-up of such patients.Methods: From January 1996 to February 1999, we performed LRFA on 250 liver tumors in 66 patients. Triphasic spiral computed tomographic scanning was obtained preoperatively and at 1 week, and every 3 months postoperatively. Lesion diameter was measured in the x- and y-axes and the volume estimated; 181 lesions in 43 patients for whom computed tomographic scans available were included in the study. The tumor types were as follows: 64 metastatic adenocarcinomas, 79 neuroendocrine metastases, 27 other metastases, and 11 primary liver tumors.Results: One week postoperatively, the ablated zone was larger than the original tumor in 178 of 181 lesions, which suggests ablation of the tumor and a margin of normal liver tissue. A progressive decline in lesion size was seen in 156 (88%) of 178 lesions, followed for at least 3 months (mean, 13.9 months; range, 4.9–37.8 months), which suggests resorption of the ablated tissue. Fourteen definite local treatment failures were apparent by increase in size and change in computed tomographic scan appearance, and eight lesions were scored as failures because of multifocal recurrence that encroached on ablated foci (22 total recurrences). Predictors of failure include lack of increased lesion size at 1 week (2 of 3 such lesions failed), adenocarcinoma or sarcoma (18 of 22 failures; P < .05), larger tumors (failures, M < 18cm³ vs. successes, M < 7cm³; P < .005) and vascular invasion on laparoscopic ultrasonography. By size criteria, 17 of 22 failures were apparent by 6 months. Energy delivered per gram of tissue was not significantly different (P < .45).Conclusions: LRFA has a 12% local failure rate, with larger adenocarcinomas and sarcomas at greatest risk. Failures occur early in follow-up, with most occurring by 6 months. LRFA seems to be a safe and effective treatment technique for patients with primary and metastatic liver malignancies.Presented at the 52nd Annual Meeting of the Society of Surgical Oncology, Orlando, Florida, March 4–7, 1999     

Significant Long-Term Survival After Radiofrequency Ablation of Unresectable Hepatocellular Carcinoma in Patients with Cirrhosis

Background Radiofrequency ablation (RFA) offers an alternative treatment in some unresectable hepatocellular carcinoma (HCC) patients with disease confined to the liver. We prospectively evaluated survival rates in patients with early-stage, unresectable HCC treated with RFA.Methods All patients with HCC treated with RFA between September 1, 1997, and July 31, 2002, were prospectively evaluated. Patients were treated with RFA by using a percutaneous or open intraoperative approach with ultrasound guidance and were evaluated at regular intervals to determine disease recurrence and survival.Results A total of 194 patients (153 men [79%] and 41 women [21%]) with a median age of 66 years (range, 39–86 years) underwent RFA of 289 sonographically detectable HCC tumors. All patients were followed up for at least 12 months (median follow-up, 34.8 months). Percutaneous and open intraoperative RFA was performed in 140 (72%) and 54 (28%) patients, respectively. The median diameter of tumors treated with RFA was 3.3 cm. Disease recurred in 103 (53%) of 194 patients, including 69 (49%) of 140 patients treated percutaneously and 34 (63%) of 54 treated with open RFA (not significant). Local recurrence developed in nine patients (4.6%). Most recurrence was intrahepatic. The overall complication rate was 12%. Overall survival rates at 1, 3, and 5 years for all 194 patients were 84.5%, 68.1%, and 55.4%, respectively.Conclusions Treatment with RFA can produce significant long-term survival rates for cirrhotic patients with early-stage, unresectable HCC. RFA can be performed in these patients with relatively low complication rates. Confirmation of these results in randomized trials should be considered.Presented at the 57th Annual Cancer Symposium of the Society of Surgical Oncology, New York, New York, March 18–21, 2004.Published by Springer Science+Business Media, Inc. © 2005 The Society of Surgical Oncology, Inc.     

Treatment Failure After Percutaneous Radiofrequency Ablation for Nonsurgical Candidates With Pulmonary Metastases From Colorectal Carcinoma

Background This study critically evaluated the local and overall treatment failure rates after percutaneous radiofrequency ablation (RFA) of pulmonary metastases from colorectal carcinoma. Methods Fifty-five nonsurgical candidates underwent RFA of colorectal pulmonary metastases. The primary end points of this study were local progression-free survival (PFS) and overall PFS. Univariate and multivariate analyses were performed to identify significant prognostic parameters for local and overall PFS. Results The local recurrence rate was 38%. For local PFS, univariate analysis demonstrated that the largest size of lung metastasis, the location of lung metastases, the post-RFA carcinoembryonic antigen level at 1 month, and the post-RFA carcinoembryonic antigen level at 3 months were significant prognostic indicators. In multivariate analysis, a largest size of lung metastasis of >3 cm and a post-RFA carcinoembryonic antigen level of >5 ng/mL at 1 month were independently associated with a reduced local PFS. The overall recurrence rate was 66%. For overall PFS, univariate analysis demonstrated that sex and the largest size of lung metastasis were significant prognostic indicators. In multivariate analysis, a largest size of lung metastasis of >3 cm was independently associated with a reduced overall PFS. Conclusions RFA of colorectal pulmonary metastases may have a useful role in local disease control for nonsurgical candidates, but its efficacy in patients with a lung metastasis of >3 cm is limited.     

Resection Versus Laparoscopic Radiofrequency Thermal Ablation Of Solitary Colorectal Liver Metastasis

Purpose  There is scant data in the literature regarding radiofrequency thermal ablation (RFA) versus resection of colorectal liver metastases. The aim of this study is to compare the clinical profile and survival of patients with solitary colorectal liver metastasis undergoing resection versus laparoscopic RFA. Methods  Between 1996 and 2007, 158 patients underwent RFA (n = 68) and open liver resection (n = 90) of solitary liver metastasis from colorectal cancer. Patients were evaluated in a multidisciplinary fashion and allocated to a treatment type. Data were collected prospectively for the RFA patients and retrospectively for the resection patients. Results  Although the groups were matched for age, gender, chemotherapy exposure and tumor size, RFA patients tended to have a higher ASA score and presence of extra-hepatic disease (EHD) at the time of treatment. The main indication for referral to RFA included technical reasons (n = 25), patient comorbidities (n = 24), extra-hepatic disease (n = 10) and patient decision (n = 9). There were no peri-operative mortalities in either group. The complication rate was 2.9% (n = 2) for RFA and 31.1% (n = 28) for resection. The overall Kaplan–Meier median actuarial survival from the date of surgery was 24 months for RFA patients with EHD, 34 months for RFA patients without EHD and 57 months for resection patients (p < 0.0001). The 5-year actual survival was 30% for RFA patients and 40% for resection patients (p = 0.35). Conclusions  This study shows that, although patients in both groups had a solitary liver metastasis, other factors including medical comorbidities, technically challenging tumor locations and extra-hepatic disease were different, prompting selection of therapy. With a simultaneous ablation program, higher risk patients have been channeled to RFA, leaving a highly selected group of patients for resection with a very favorable survival. RFA still achieved long-term survival in patients who were otherwise not candidates for resection.     

应用射频迷宫术治疗心房纤颤

１９９４年１０月于１９９５年８月采用射频迷宫术先天性继发孔房缺合并心房纤颤１例，瓣膜替换术的治疗风湿性二尖瓣病变合并心房纤颤９例。术后房颤全部消失，呈窦性心律６例，结性心律３例，心房扩动１例。作者认为，此方法操作简单易行，效果确实，手术时间短，避免了心脏多处切口，渗血少，术后平顺，无近期并发症。     

Treatment of Renal Tumors by Percutaneous Ultrasound-Guided Radiofrequency Ablation Using a Multitined Electrode: Effectiveness and Complications

Background

Radiofrequency ablation (RFA) is a minimally aggressive, therapeutic alternative for renal tumors. It can be an alternative to nephrectomy in patients with previous nephrectomy, bilateral tumors, von Hippel-Lindau disease, or small renal carcinomas and in those with contraindications for surgery.

Objective

To assess the effectiveness of the treatment of renal tumors by RFA in the short and medium term and to identify the possible complications and the factors that determine therapeutic success.

Design, setting, and participants

A retrospective review of patients with renal tumors treated with RFA between May 2005 and December 2008 was performed in a tertiary academic hospital. Patients were selected among those with previous nephrectomy, bilateral neoplasms, von Hippel-Lindau disease, surgical risk, comorbidity, advanced age, or patient's refusal to surgery. Tumors with evidence of extrarenal extension were excluded. Patients were followed up for 10–50 mo using computed tomography and magnetic resonance imaging.

Intervention

Ultrasound-guided RFA was performed on 65 tumors (range: 1.2–5.3 cm) of 58 patients using multitined electrodes.

Measurements

Incomplete ablation rate, therapeutic success rate, and complications rate.

Results and limitations

Therapeutic success was achieved in 59 of 65 tumors (91%): 53 in a single session, 5 in two sessions, and 1 in three sessions. A significant relationship was observed between size and growth pattern of the tumor and both therapeutic success and incomplete ablation rates. Therapeutic success in tumors >5 cm was 60%. Complications were detected in 10 patients (13%); 5% were considered major complications.Limitations include the lack of pathologic studies to confirm a complete ablation and the lack of a control group to compare with the results of those who underwent nephrectomy.

Conclusions

RFA is safe and effective in renal tumors. Corticomedullary lesions and tumors >3 cm have greater possibility of incomplete ablation. In tumors >5 cm, RFA has a significant failure rate.     

Radiofrequency ablation of 231 unresectable hepatic tumors: Indications, limitations, and complications

Background: Radiofrequency ablation (RFA) is increasingly used for the local destruction of unresectable hepatic malignancies. There is little information on its optimal approach or potential complications. Methods: Since late 1997, we have undertaken 91 RFA procedures to ablate 231 unresectable primary or metastatic liver tumors in 84 patients. RFA was performed via celiotomy (n=39), laparoscopy (n=27), or a percutaneous approach (n=25). Patients were followed with spiral computed tomographic (CT) scans at 1 to 2 weeks postprocedure and then every 3 months for 2 years. Results: Intraoperative ultrasound (IOUS) detected intrahepatic disease not evident on the preoperative scans of 25 of 66 patients (38%) undergoing RFA via celiotomy or laparoscopy. In 38 of 84 patients (45%), RFA was combined with resection or cryosurgical ablation (CSA), or both. RFA was used to treat an average of 2.8 lesions per patient, and the median size of treated lesions was 2 cm (range, 0.3–9 cm). The average hospital stay was 3.6 days overall (1.8 days for percutaneous and laparoscopic cases). Ten patients underwent a second RFA procedure (sequential ablations) and, in one case, a third RFA procedure for large (one patient), progressive (seven patients), and/or recurrent (three patients) lesions. Seven (8%) patients had complications: one skin burn; one postoperative hemorrhage; two simple hepatic abscesses; one hepatic abscess associated with diaphragmatic heat necrosis following sequential percutaneous ablations of a large lesion; one postoperative myocardial infarction; and one liver failure. There were three deaths, one (1%) of which was directly related to the RFA procedure. Three of the complications, including one RFA-related death, occurred after percutaneous RFA. At a median follow-up of 9 months (range, 1–27 months), 15 patients (18%) had recurrences at an RFA site, and 36 patients (43%) remained clinically free of disease. Conclusions: Celiotomy or laparoscopic approaches are preferred for RFA because they allow IOUS, which may demonstrate occult hepatic disease. Operative RFA also allows concomitant resection, CSA, or placement of a hepatic artery infusion pump, and isolation of the liver from adjacent organs. Percutaneous RFA should be reserved for patients at high risk for anesthesia, those with recurrent or progressive lesions, and those with smaller lesions sufficiently isolated from adjacent organs. Complications may be minimized when these approaches are applied selectively. Presented at the 53rd Annual Meeting of the Society of Surgical Oncology, March 16–19, 2000, New Orleans, Louisiana.     

Learning Curve for Percutaneous Radiofrequency Ablation of Pulmonary Metastases From Colorectal Carcinoma: A Prospective Study of 70 Consecutive Cases

Background Percutaneous radiofrequency ablation (RFA) for inoperable colorectal pulmonary metastases is associated with a morbidity rate of 30% to 40%. A learning curve in this treatment approach has not been documented before.Methods The clinical and treatment-related data regarding 70 consecutive percutaneous RFA procedures for inoperable colorectal pulmonary metastases were collected prospectively. A comparison between the initial 35 cases (group 1) and the subsequent 35 cases (group 2) was performed. Univariate and multivariate analyses were conducted to identify the significant risk factors for overall morbidity, pneumothorax, and chest drain requirement.Results There was no hospital mortality. The overall morbidity rate was 37%. The rate of pneumothorax was 27%. Twelve patients (17%) required chest drain insertion for pneumothorax. There was a significant decline in the incidence of overall morbidity, pneumothorax, and chest drain requirement in group 2 as compared with group 1. Both the number of lung metastases ablated and the RFA treatment period (group 1 vs. group 2) were independent risk factors for overall morbidity, pneumothorax, and chest drain requirement. Distribution of lung metastases (unilateral vs. bilateral) was an independent risk factor for overall morbidity and pneumothorax, but not for chest drain requirement.Conclusions There is a learning curve for percutaneous lung RFA. With accumulated experience in this procedure, a low morbidity rate can be achieved.     

Radiofrequency ablation of primary and metastatic liver tumors: a critical review of the literature

BACKGROUND: Surgical resection is the treatment of choice for hepatic tumors; however, for various reasons, the vast majority of patients are not operative candidates. As a result, several local ablative therapies have emerged as alternatives to resection or as adjuncts in total oncologic care. Presently, the most widely employed liver-directed treatment is radiofrequency thermal ablation. METHODS: To define the current status of radiofrequency ablation (RFA), the authors reviewed available safety and efficacy data from select studies on RFA. A MEDLINE search was performed using the keywords "tumor type" + "radiofrequency ablation" + "survival." Only those studies containing long-term survival data on greater than 50 patients were included in this analysis. CONCLUSIONS: Although RFA has been readily adopted into treatment paradigms, more rigorous trials are needed to solidify its place in the armamentarium of therapeutic strategies for hepatic malignancy.     

Histological,CT, and Intraoperative Ultrasound Appearance of Hepatic Tumors Previously Treated by Laparoscopic Radiofrequency Ablation

Purpose The purpose of this paper is to compare intraoperative biopsy results of previously ablated liver tumors with their preoperative computed tomography (CT) and intraoperative laparoscopic ultrasound (LUS) appearances in patients undergoing repeat radiofrequency ablation (RFA). Methods Seventy repeat RFA procedures were performed in 59 (13%) patients. Laparoscopically, suspected recurrent and stable appearing foci were biopsied using an 18 G biopsy gun. Preoperative CT and LUS appearances of the previously ablated lesions were compared with core biopsy results. Results There were 33 patients with colorectal cancer, 11 with hepatocellular cancer, 8 with neuroendocrine tumors, and 7 with other tumor types. Two hundred lesions were treated by RFA in these 70 repeat ablations. Suspected recurrent tumor foci were enhanced on CT and produced a more finely stippled echo pattern on LUS. Biopsy confirmed recurrent tumor in 72 of 84 such lesions. Previously ablated foci had a CT appearance of a hypodense, nonenhancing lesion without evidence of adjacent enhancing foci. Laparoscopic ultrasound appearance was of a hypoechoic lesion with a coarse internal pattern with the tracks of the ablation catheter probes often still visible. Biopsy found necrotic tissue in 21 of 22 such lesions appearing radiologically to be without recurrence. Biopsy of an ablated focus adjacent to an area of suspected recurrence showed necrotic tissue in 17 of 22 lesions and viable cancer in 5. Conclusion CT and LUS appearance of previously ablated foci showed good correlation with core biopsies. CT scan is reliable in following RFA lesions, without the need for routine biopsy. LUS reliably distinguished recurrent from ablated lesions in patients undergoing repeat ablation. Presented at the AHPBA 2005 Congress on 4/14–17/2005 in Ft. Lauderdale, Florida as a poster     

CT导向肝脏肿瘤射频消融病灶定位的研究

目的 探讨CT导向肝脏肿瘤射频消融的技术和方法.方法 2011年1月~2013年5月,选择67例肝脏肿瘤患者共75个肿瘤,直径2.1~6 cm,其中〈3.5 cm 64个,〉3.5 cm 11个.把CT定位图像导入肿瘤精确放射治疗计划系统内,将直径〉3.5 cm的11个肿瘤共划分成52个直径〈3.5 cm的肿瘤,共按照116个直径〈3.5 cm的小肿瘤,在CT导向下,利用研制的肿瘤穿刺辅助器械进行定位和穿刺,利用肿瘤精确放射治疗计划系统对穿刺效果和消融灶进行验证评估,采用RITA多极射频肿瘤消融仪对每个小肿瘤进行射频消融.结果 116个小肿瘤在空间内的平均穿刺误差2.9 mm（1~5 mm）,肝内75个肿瘤全部被消融灶包含,消融过程中和消融后无严重并发症发生.术后4~6周复查增强CT,75个肿瘤及其消融灶边缘均无强化.术后3个月肝脏CT增强扫描,75个肿瘤所在区域为低密度,动脉期未见强化.均为完全消融.结论 借助CT导向和肿瘤穿刺辅助器械对肝脏肿瘤进行穿刺和射频消融,穿刺准确,消融彻底安全.