Radiofrequency thermal ablation of a splenic metastasis

Percutaneous radiofrequency ablation of ovarian cancer metastasis in the spleen: a therapeutic option to consider

Splenic metastasis are rare clinical entities developing in less than 1% of all metastatic cancers and usually in the setting of disseminated disease. To date, splenectomy is traditionally the first line therapy in patient with splenic metastasis, however non-surgical therapies have been reported. Here we described the case of a 57-year-old patient with splenic metastasis from ovarian cancer successfully treated by percutaneous radiofrequency ablation. Furthermore, we performed a literature systematic review of the cases of splenic metastases treated by thermal ablation.

Analysis of feasibility, safety and effectiveness of ultrasound-guided percutaneous microwave ablation of splenic neoplasm

The present study aimed to analyze the feasibility, safety and effectiveness of ultrasound-guided percutaneous microwave ablation of splenic neoplasm. A total of 62 patients with splenic neoplasm admitted to Second People's Hospital of Liaocheng between January 2009 and December 2012 were selected, and randomly divided into the observation group (n=31) and control group (n=31). The control group was treated with open ablation, while the observation group was treated with ultrasound-guided percutaneous microwave ablation. The splenic hemodynamics and ablation effects of patients after treatment were detected via color Doppler ultrasound. The changes in peripheral blood cell count before treatment, and at 3, 7 and 14 days after treatment were monitored. The side effects and complications were compared between the two groups. Patients were followed up for 5 years to observe the survival rates of the two groups. At 1 week after treatment, the peak velocity of splenic artery in observation group was significantly lower than that in control group, and the diameter, velocity and flow of splenic vein were significantly lower than those in control group (P<0.05). After treatment, the white blood cell and platelet counts in both groups were significantly increased compared with those before treatment, and the counts in observation group were obviously higher than those in control group (P<0.05). There were no significant changes in the red blood cell counts in both groups before and after treatment (P>0.05). The ablation volume, ablation ratio and 1-week shrink ratio in both groups had no significant differences (P>0.05). The incidence rates of side effects and complications in observation group were significantly lower than those in control group (P<0.05). The 5-year survival rates of both groups were >50%, and the survival time and survival rate were not significantly different (P<0.05). The curative effects of open ablation and ultrasound-guided percutaneous microwave ablation in the treatment of splenic neoplasm were significant, and the 5-year survival rate of patients was higher; compared with open ablation. The ultrasound-guided percutaneous microwave ablation is characterized by the small trauma, lower incidence rates of adverse reactions and complications and better safety, which can increase the peripheral blood cell count, and improve the splenic blood flow and coagulation function, playing a role in the regulation of the patient's body status.

Magnetic Resonance Mediated Radiofrequency Ablation

To introduce magnetic resonance mediated radiofrequency ablation (MR-RFA), in which the MRI scanner uniquely serves both diagnostic and therapeutic roles. In MR-RFA scanner-induced RF heating is channeled to the ablation site via a Larmor frequency RF pickup device and needle system, and controlled via the pulse sequence. MR-RFA was evaluated with simulation of electric and magnetic fields to predict the increase in local specific-absorption-rate (SAR). Temperature-time profiles were measured for different configurations of the device in agar phantoms and ex vivo bovine liver in a 1.5 T scanner. Temperature rise in MR-RFA was imaged using the proton resonance frequency method validated with fiber-optic thermometry. MR-RFA was performed on the livers of two healthy live pigs. Simulations indicated a near tenfold increase in SAR at the RFA needle tip. Temperature-time profiles depended significantly on the physical parameters of the device although both configurations tested yielded temperature increases sufficient for ablation. Resected livers from live ablations exhibited clear thermal lesions. MR-RFA holds potential for integrating RF ablation tumor therapy with MRI scanning. MR-RFA may add value to MRI with the addition of a potentially disposable ablation device, while retaining MRI's ability to provide real time procedure guidance and measurement of tissue temperature, perfusion, and coagulation.

Hepatectomy combined with microwave ablation of the spleen for treatment of hepatocellular carcinoma complicated with splenomegaly: A retrospective study

The present retrospective study aimed to investigate the mid-term safety and efficacy of hepatectomy combined with microwave ablation of the partial spleen for treatment of liver cancer complicated with hypersplenism. A retrospective analysis was performed on 23 patients who underwent hepatectomy combined with microwave ablation of the partial spleen for liver cancer, complicated with hypersplenism that was secondary to cirrhosis. The splenic and ablated volumes were calculated according to a contrast-enhanced computed tomography scan prior to and 2 weeks after the operation. Complete blood count and liver function tests were examined prior to and following the surgery, and complications and changes in the blood tests were monitored for 6 months. Over this period of investigation, the splenic volume was reduced by a mean value of 34.0%. The levels of serum alanine aminotransferase and aspartate aminotransferase were increased on the first day after the operation (P<0.05), although they recovered to the normal level within 1 week (P<0.05). The total level of bilirubin increased slightly, along with moderately decreased levels of albumin and cholinesterase on the first day, although these changes were not significant compared with the baseline (P>0.05). The white blood cell count was persistently significantly higher compared with the baseline over the course of the 6 months (P>0.05). The platelet count did not increase significantly for the first week after the operation (P>0.05); however, it was revealed to be significantly increased 1 month after the surgery (P<0.05). No significant complications were occurred during the follow-up period. In conclusion, hepatectomy combined with microwave ablation of the spleen was demonstrated to be a safe and effective procedure for patients with liver cancer and hypersplenism in the mid-term.

Image-guided percutaneous splenic interventions

In the spleen, image-guided interventional procedures such as biopsy and catheter drainage have not been widely performed because of the perceived increased risk of complications. The ability of image-guided biopsy to allow tissue diagnosis of a focal splenic mass without the need for splenectomy is the driving force behind use of this procedure in oncology patients. The literature on image-guided splenic biopsy suggests that the highest biopsy yield is achieved with core biopsy and the lowest complication rate is achieved with fine-needle aspiration. Image-guided catheter drainage is an effective alternative to splenectomy for management of infected splenic collections. In clinical practice, image-guided splenic biopsy, fluid aspiration, and catheter drainage have high success rates. Image-guided alcohol ablation is effective in treatment of splenic cysts. The literature on splenic radiofrequency ablation (RFA) is sparse; therefore, further studies are needed to determine the role of RFA in management of splenic neoplasms and hypersplenism. Image-guided percutaneous thrombin injection can be used to treat splenic artery pseudoaneurysms. Awareness of the correct interventional techniques and their limitations is important for safe performance of image-guided percutaneous splenic interventions.

Percutaneous ablation in the kidney

Percutaneous ablation in the kidney is now performed as a standard therapeutic nephron-sparing option in patients who are poor candidates for resection. Its increasing use has been largely prompted by the rising incidental detection of renal cell carcinomas with cross-sectional imaging and the need to preserve renal function in patients with comorbid conditions, multiple renal cell carcinomas, and/or heritable renal cancer syndromes. Clinical studies to date indicate that radiofrequency ablation and cryoablation are effective therapies with acceptable short- to intermediate-term outcomes and with a low risk in the appropriate setting, with attention to pre-, peri-, and postprocedural detail. The results following percutaneous radiofrequency ablation and cryoablation in the treatment of renal cell carcinoma are reviewed in this article, including those of several larger scale studies of ablation of T1a tumors. Clinical and technical considerations unique to ablation in the kidney are presented, and potential complications are discussed.

Ultrasound-guided percutaneous microwave ablation of splenic metastasis: report of four cases and literature review

PURPOSE

To investigate the feasibility, safety and efficacy of ultrasound guided percutaneous microwave (MW) ablation for small splenic metastasis.

MATERIALS AND METHODS

A total of four patients with five pathologically proven splenic metastases (from ovarian, pulmonary, gastric adenocarcinoma and hepatocellular carcinoma, respectively) 1.3 to 2.9 cm in diameter were treated with microwave ablation. A cooled-shaft needle antenna was percutaneously inserted into the tumour under ultrasound guidance. One thermocouple was placed about 0.5 cm away from the tumour to monitor temperature in real time during ablation. Microwaves were emitted at 60 W for 600 s routinely and prolonged as necessary to attain temperatures sufficient to ensure tumour killing. Treatment efficacy was assessed by contrast-enhanced imaging at 1, 3 and 6 months, and every 6 months thereafter.

RESULTS

All tumours were completely ablated at a single session and no complications occurred. No local tumour progression was observed at a mean follow up of 22 ± 17.1 months (range 4 to 43 months). The ablation zone was well defined on contrast-enhanced imaging and it gradually shrank with time. One new metastatic lesion was detected in the spleen at 11 months after the ablation and was successfully treated by another MW ablation. The post-ablation survival was mean 22 months. No other complications were observed except for fever and abdominal pain.

CONCLUSIONS

Ultrasound-guided percutaneous MW ablation appears to be a safe and effective minimally invasive technique for management of small splenic metastasis in selected patients.

Radiofrequency ablation for renal tumors: our experience

OBJECTIVES

To report our results of percutaneous radiofrequency ablation (RFA) for renal tumors and to assess predictors of therapeutic efficacy.

METHODS

Forty patients (median age 73 years) with renal tumors were treated with RFA under local or epidural anesthesia. All of them had high surgical risk or refused radical surgery. Tumors were punctured percutaneously using the Radionics Cool-tip RF System under computed tomography or ultrasonographic guidance. Median tumor diameter was 24 mm. After RFA, contrast-enhanced computed tomography or magnetic resonance imaging was performed within 1 month. Complete response (CR) was defined as no enhancement inside the tumor. Factors related to the outcome and to renal function were assessed.

RESULTS

Median follow up was 16 months. CR was observed in 34 cases (85.0%). A significant difference in CR rate was observed between tumors < or =30 mm and those >30 mm. Outcomes tended to be better for tumors in the mid to lower kidney, and those away from the renal hilum. Recurrence was observed in one case (2.9%), but a CR was obtained again by additional RFA. Out of a total of 77 RFA procedures, complications occurred in only three cases (3.9%), and conservative treatment was possible in all cases. Serum creatinine levels 3 months after RFA did not differ from those before RFA.

CONCLUSIONS

Percutaneous RFA is a safe and effective treatment for small renal tumors in patients with high surgical risk or who refuse radical surgery.

Thermal ablation of prostate diseases: advantages and limitations

Both benign and malignant conditions affecting prostate gland are very common in elderly men. However, the conventional treatment of these conditions can be associated with significant side effects and complications, and less invasive treatment alternative has been always searched for. Because of the anatomical location and easy accessibility of prostate, many newer treatment modalities using thermal ablation have been applied to the organ. These include not only heating of the pathological tissue but also freezing. Some of such treatment techniques have shown to be effective and safe and been clinically used widely. In this review article, various tissue ablation techniques using temperature change applied to prostate gland are covered. Each procedure's advantages and disadvantages are compared and discussed.

Radiofrequency ablation of the spleen in patients with thalassemia intermedia: a pilot study

OBJECTIVE

We investigated the efficacy and safety of radiofrequency ablation on the hematologic parameters in patients with thalassemia intermedia (TI).

MATERIALS AND METHODS

Radiofrequency ablation of the spleen was performed in 15 children with TI under general anesthesia using a cool-tip radiofrequency probe. These patients were regarded as the radiofrequency ablation group. Nine patients with TI who underwent partial splenectomy during the past 3 years and another 14 patients with TI who underwent total splenectomy were also enrolled in this study as the first and second control groups (CG1 and CG2).

RESULTS

In the radiofrequency ablation group, two (13%) patients showed a significant increase in the mean hemoglobin level compared with the year before (1.5 and 1.8 g/dL). In addition, three (20%) other patients became transfusion-free in the year after radiofrequency ablation. In CG1, one (11%) patient showed a significant increase in hemoglobin the year after partial splenectomy, and another two (22%) patients became transfusion-free. In CG2, six (43%) patients revealed a significant increase in hemoglobin in the year after total splenectomy, and another four (29%) revealed a significant decrease in the need for transfusions. The mean increase in hemoglobin and platelet count was more significant in CG2 than in the radiofrequency ablation group and CG1. The mean hospital stay was significantly shorter in the radiofrequency ablation group (1.7 days vs 7.5 and 8.2 days in CG1 and CG2, respectively).

CONCLUSION

We believe that radiofrequency ablation of the spleen can be a safe procedure in patients with TI and is at least as effective as partial splenectomy, having only minor self-limiting complications.

Surgical management of metastases to the adrenal gland: open, laparoscopic, and ablative approaches

The adrenal gland is a potential site of metastasis for various malignancies. Metastases to the adrenal gland are the second most common type of adrenal mass lesion after adenomas. Differentiation of a metastatic lesion from a primary adrenal lesion can be challenging and requires the selective use of radiologic imaging, serologic testing, and adrenal biopsy. In patients who present with an isolated adrenal metastasis, adrenalectomy is often considered to aid in cancer control. Numerous studies have reported improved survival with resection of solitary adrenal metastases for various types of primary tumors. Traditionally, open adrenalectomy was the preferred option for these patients. More recently, laparoscopic adrenalectomy has offered a minimally invasive approach, with its resultant advantages of improved perioperative parameters. Proper patient selection for the laparoscopic versus open approach remains paramount in deciding the best treatment for the individual patient.

Percutaneous radiofrequency ablation of renal tumours: Case series of 11 tumours and review of published work

Detection of renal cell carcinoma (RCC) is increasing with the greater use of cross-sectional imaging and up to two-thirds of RCCs are discovered incidentally in asymptomatic patients. The traditional option of nephrectomy or partial nephrectomy may not always be appropriate. A minimally invasive treatment alternative is radiofrequency ablation (RFA). We retrospectively reviewed the RFA cases for renal tumours at our institution between January 2004 and June 2006. Thirteen RFA treatment sessions were conducted for 11 neoplasms in 11 patients. Mean patient age was 74.4 years (61-88 years). Imaging was carried out after ablation with a mean follow up of 8.0 months (2-26 months). No residual tumour was observed after the first RFA treatment in 82% of patients (nine of 11). Two patients required a second RFA treatment for residual (one) or recurrent tumour (one). RFA is emerging as a useful technique for treatment of small renal tumour. A number of short-term studies reflect this, however, long-term findings are still lacking.

Current status of sonographically guided radiofrequency ablation techniques

OBJECTIVE

The purpose of this article was to review the current clinical applications of sonographically guided radiofrequency ablation (RFA) techniques.

METHODS

Publications regarding RFA extracted from a computerized database (MEDLINE) and from references cited in these articles were reviewed to evaluate the clinical effect and patient outcome.

RESULTS

Radiofrequency ablation has shown some promising effects in the treatment of tumors in various parts of the body. The recent advances in RFA technology enable larger volumes of treatment and make RFA clinically practical. It is most often used for hepatic and renal tumors, and applications for other organs and structures are increasing and rapidly developing. Sonography provides a convenient way to guide and monitor the procedure in most situations.

CONCLUSIONS

Effectiveness of RFA in the treatment of tumors in various body parts has been achieved. Radiofrequency ablation should be considered as an alternative or complementary method in the integration of oncologic management to obtain the greatest benefit to patients.

Renal tumors: technical success and early clinical experience with radiofrequency ablation of 18 tumors

PURPOSE

To evaluate the feasibility, safety, and technical efficacy of image-guided radiofrequency ablation (RFA) for the treatment of small peripheral renal tumors and to report our early results with this treatment modality.

METHODS

Twenty-two RFA sessions for 18 tumors were performed in 11 patients with renal tumors. Indications included coexistent morbidity, high surgical or anesthetic risk, solitary kidney, and hereditary predisposition to renal cell carcinoma. Ten patients had CT-guided percutaneous RFA performed on an outpatient basis. One patient had open intraoperative ultrasound-guided RFA. Technical success was defined as elimination of areas that enhanced at imaging within the entire tumor. With the exception of one patient with renal insufficiency who required gadolinium-enhanced MRI, the remaining patients underwent contrast-enhanced CT for post-treatment follow-up assessment. Follow-up was performed after 2-4 weeks and then at 3, 6, 12 months, and every 12 months thereafter.

RESULTS

Fourteen (78%) of 18 tumors were successfully ablated with one session. Three of the remaining four tumors required two sessions for successful ablation. One tumor will require a third session for areas of persistent enhancement. Mean patient age was 72.82 +/- 10.43 years. Mean tumor size was 1.95 +/- 0.79 cm. Mean follow-up time was 10.91 months. All procedures were performed without any major complications.

CONCLUSIONS

Our early experience with percutaneous image-guided radiofrequency ablation demonstrates it to be a feasible, safe, noninvasive, and effective treatment of small peripheral renal tumors.

Microwave Ablation: Results with a 2.45-GHz Applicator in ex Vivo Bovine and in Vivo Porcine Liver

PURPOSE

To characterize the relationship between applied power and treatment duration in their effect on extent of coagulation produced with a 2.45-GHz microwave applicator in both an ex vivo and a perfused in vivo liver model.

MATERIALS AND METHODS

All experimentation was approved by the Institute of Animal Care and Use Committee. Multiple tissue ablations were performed in ex vivo bovine liver (120 ablations) and in vivo porcine liver (45 ablations) with a 5.7-mm-diameter 2.45-GHz microwave applicator. The applied power was varied from 50 to 150 W (in 25-W increments ex vivo and 50-W increments in vivo), while treatment duration varied from 2 to 20 minutes (in eight time increments for ex vivo and five for in vivo liver). Three-dimensional contour maps of the resultant short- and long-axis coagulation diameters were constructed to identify the optimal parameters to achieve maximum coagulation in both ex vivo and in vivo models. Multivariate analysis was performed to characterize the relationship between applied power and treatment duration.

RESULTS

Power and treatment duration were both associated with coagulation diameter in a sigmoidal fashion (ex vivo, R(2) = 0.78; in vivo, R(2) = 0.74). For ex vivo liver, the maximum short-axis coagulation diameter (7.6 cm +/- 0.2 [standard deviation] by 12.3 cm +/- 0.8) was achieved at greatest power (150 W) and duration (20 minutes). In vivo studies revealed a sigmoidal relationship between duration and coagulation size, with a relative plateau in coagulation size achieved within 8 minutes duration at all power levels. After 8 minutes of treatment at 150 W, the mean short-axis coagulation diameter for in vivo liver was 5.7 cm +/- 0.2 by 6.5 cm +/- 1.7, which was significantly larger than the corresponding result for ex vivo liver (P < .05).

CONCLUSION

Large zones of ablation can be achieved with the 2.45-GHz microwave applicator used by the authors. For higher-power ablations, larger zones of coagulation were achieved for in vivo liver than for ex vivo liver with short energy applications, a finding previously not seen with other ablation devices, to the authors' knowledge.

Combined Radiofrequency Ablation and Adjuvant Liposomal Chemotherapy: Effect of Chemotherapeutic Agent, Nanoparticle Size, and Circulation Time

PURPOSE

To evaluate the effects of liposomal chemotherapeutic agent, nanoparticle size, and liposome circulation time on tissue coagulation and intratumoral drug uptake when radiofrequency (RF) ablation is combined with adjuvant intravenous liposomal chemotherapy in an animal breast tumor model.

MATERIALS AND METHODS

Ninety-one R3230 mammary adenocarcinoma nodules were implanted in 48 Fischer rats. First, standardized RF ablation was combined with intravenous liposomal doxorubicin, cisplatin, or 5-fluorouracil (35 tumors each). Second, three different-sized doxorubicin-containing nanoparticle preparations were combined with standardized RF ablation. Last, two doxorubicin-containing liposome preparations with different blood elimination half-lives were combined with RF ablation. Coagulation diameter and interstitial doxorubicin concentration were measured 48 hours after treatment and compared with use of statistical analysis.

RESULTS

All combinations of RF with liposomal chemotherapy caused significantly greater tumor necrosis than RF alone (P<.05). Significantly increased necrosis was observed with intravenous liposomal RF/doxorubicin and RF/cisplatin compared with intravenous liposomal RF/5-fluorouracil (P<.01). Greater coagulation was observed with RF combined with 100-nm nanoparticles compared with 20-nm or 250-nm nanoparticles (P=.01 and P=.04, respectively). Additionally, greater intratumoral doxorubicin uptake was observed in the group treated with 20-nm nanoparticles compared with those treated with other sizes of nanoparticles (P<.05). RF plus liposomal doxorubicin produced greater coagulation and intratumoral doxorubicin uptake than RF plus 1,2-dipalmitoyl-sn-glycero-3-phosphatidic acid (P<.05).

CONCLUSION

When combined with RF ablation, modification of adjuvant intravenous liposomal chemotherapy, including nanoparticle size, circulation time, and chemotherapeutic agent, can influence intratumoral drug accumulation and tissue coagulation.

Radiofrequency Thermal Ablation: Increase in Lesion Diameter with Continuous Acetic Acid Infusion

PURPOSE

To evaluate the influence of continuous infusion of acetic acid 50% during radiofrequency ablation (RFA) on the size of the thermal lesion produced.

METHODS

Radiofrequency (RF) was applied to excised bovine liver by using an expandable needle electrode with 10 retractable tines (LeVeen Needle Electrode, RadioTherapeutics, Sunnyvale, CA) connected to a commercially available RF generator (RF 2000, RadioTherapeutics, Sunnyvale, CA). Experiments were performed using three different treatment modalities: RF only (n = 15), RF with continuous saline 0.9% infusion (n = 15), and RF with continuous acetic acid 50% infusion (n = 15). RF duration, power output, tissue impedance, and time to a rapid rise in impedance were recorded. The ablated lesions were evaluated both macroscopically and histologically.

RESULTS

The ablated lesions appeared as spherical or ellipsoid, well-demarcated pale areas with a surrounding brown rim with both RF only and RF plus saline 0.9% infusion. In contrast, thermolesions generated with RF in combination with acetic acid 50% infusion were irregular in shape and the central portion was jelly-like. Mean diameter of the coagulation necrosis was 22.3 +/- 2.1 mm (RF only), 29.2 +/- 4.8 mm (RF + saline 0.9%) and 30.7 +/- 5.7 mm (RF + acetic acid 50%), with a significant increase in the RF plus saline 0.9% and RF plus acetic acid 50% groups compared with RF alone. Time to a rapid rise in impedance was significantly prolonged in the RF plus saline 0.9% and RF plus acetic acid 50% groups compared with RF alone.

CONCLUSIONS

A combination of RF plus acetic acid 50% infusion is able to generate larger thermolesions than RF only or RF combined with saline 0.9% infusion.

Concepts, Considerations, and Concerns on the Cutting Edge of Radiofrequency Ablation

Radiofrequency (RF) ablation is rapidly expanding from a tool to treat isolated hepatic malignancy to a therapy for patients with renal, adrenal, skeletal, breast, lung, and other soft-tissue neoplasms. The purpose of this article is to review the status of RF ablation outside the liver and lung and compare outcomes with current clinical standards when appropriate. The author also reviews how differences in local tissue environments play a role in creation of a thermal lesion and achievement of subsequent clinical success.

Radiofrequency ablation for hypersplenism in patients with liver cirrhosis: a pilot study

Radiofrequency ablation is a relatively new technique used for local ablation of unresectable tumors. We investigated the feasibility and efficacy of radiofrequency ablation for hypersplenism and its effect on liver function in patients with liver cirrhosis and portal hypertension. Nine consecutive patients with hypersplenism due to cirrhotic portal hypertension underwent radiofrequency ablation in enlarged spleens. The ablation was performed either intraoperatively or percutaneously. Patients are followed up for over 12 months. After treatment, between 20% and 43% of spleen volume was ablated, and spleen volume increased by 4%-10.2%. White blood cell count, platelet count, liver function, and hepatic artery blood flow showed significant improvement after 1-year follow-up. Splenic vein and portal vein blood flow were significantly reduced. Only minor complications including hydrothorax (three of nine patients) and mild abdominal pain (four of nine patients) were observed. No mortality or other morbidity occurred. Radiofrequency ablation is a safe, effective, and minimally invasive approach for the management of splenomegaly and hypersplenism in patients with liver cirrhosis and portal hypertension. Increased hepatic artery blood flow may be responsible for sustained improvement of liver condition. Radiofrequency ablation may be used as a bridging therapy for cirrhotic patients waiting for liver transplantation.

[Spontaneous splenic rupture due to splenic metastasis of lung cancer]

We report the case of a patient who underwent splenectomy for spontaneous rupture of the spleen due to splenic metastasis. Pathologic examination revealed diffuse infiltration by carcinoma. Chest X-ray revealed a right lung superior lobe tumor, related to poorly differentiated carcinoma. Total splenectomy is a good option for diagnosis and treatment of splenic metastases.

Interventional radiology in pediatric oncology

There are many radiological interventions necessary for pediatric oncology patients, some of which may be covered in other articles in this publication. I will discuss a number of interventions including percutaneous biopsy for solid tumor and hematological malignancy diagnosis or recurrence, for the diagnosis of graft versus host disease after stem cell or bone marrow transplantation, and for the diagnosis of complications of immunosuppression such as invasive pulmonary aspergillosis. In the past, tumor localization techniques have been necessary to biopsy or resect small lesions. However improved guidance techniques have allowed for more precise biopsy and the use of thermal ablation instead of excision for local tumor control. A percutaneously placed radio frequency, microwave, laser or cryogen probe can ablate the primary and metastatic tumors of the liver, lung, bone, kidney and other structures in children. This is an alternative treatment for the local control of tumors that may not be amenable to surgery, chemotherapy or radiotherapy. I will also describe how chemoembolization can be used to treat primary or metastatic tumors of the liver that have failed other therapies. This treatment delivers chemotherapy in the hepatic artery infused with emboli to increase the dwell time and concentration of the agents.

Review of radiofrequency ablation for renal cell carcinoma

This review will discuss how minimally invasive, image-guided radiofrequency (RF) tumor ablation [i.e., coagulating tumor using short-duration heating (<15 minutes) by directly applying temperatures >50 degrees C via needle electrodes] is being incorporated as a clinical tool for the treatment of renal cell carcinoma. RF ablation has been used to treat focal liver tumors. Potential benefits of this thermal therapy include reduced morbidity and mortality compared with standard surgical resection and the ability to treat nonsurgical patients. More recently, this technique has been introduced to treat focal renal tumors, particularly incidental lesions smaller than 3 cm in elderly patients and those with comorbid conditions. Other uses have included treatment in patients with von Hippel-Lindau syndrome and other diseases that predispose patients to multiple renal carcinomas, where renal parenchymal preservation is desired. Techniques, complications, and results will be discussed. Additionally, strategies that we are currently studying to improve RF outcomes and enable the potential treatment of larger tumors will be addressed. Most notably, recent data on increased coagulation achieved by combining RF ablation with antivascular/antiangiogenic therapies, such as arsenic trioxide, that reduce blood flow and promote heat retention are provided.

Radiofrequency ablation of 40 lung neoplasms: preliminary results

OBJECTIVE

Radiofrequency thermal ablation is a minimally invasive treatment widely used for treatment of liver neoplasms and has also been tested on other types of tumor. Few studies have been published regarding the use of radiofrequency thermal ablation in the treatment of lung neoplasms. This study was performed to evaluate the technical feasibility, the safety, and the efficacy of lung radiofrequency thermal ablation.

SUBJECTS AND METHODS

Between February 2002 and March 2003, 18 subjects with unresectable lung neoplasms, four of whom had primary neoplasms and 14 of whom had metastatic neoplasms, underwent lung radiofrequency ablation. The technique was performed percutaneously using a monopolar cooled-tip electrode needle under CT guidance with the patient under general anesthesia. Patients had no more than three nodules with a total diameter of 10 cm and no evidence of extrathoracic disease. A total of 40 nodules were treated in 24 therapeutic sessions. After treatment, patients underwent follow-up every 3 months by CT and nuclear MRI with gadolinium for a median time of 8 months (range, 2-14 months).

RESULTS

No evidence of local relapse was discovered in 94.4% of subjects. The treatment was safe and well tolerated. Complications encountered included massive pneumothorax, which occurred in one subject, requiring pleural drainage. Other complications were moderate pneumothorax (also requiring pleural drainage), cough, fever, slight dyspnea, and pain, but these complications were short in duration and successfully treated.

CONCLUSION

Radiofrequency thermal ablation is a promising technique in the treatment of patients with lung neoplasms and has been found to be both safe and technically feasible.

Percutaneous tumor ablation: reduced tumor growth with combined radio-frequency ablation and liposomal doxorubicin in a rat breast tumor model

PURPOSE

To determine whether combined intravenous liposomal doxorubicin and radio-frequency (RF) ablation decreases tumor growth and increases endpoint survival over those with RF or liposomal doxorubicin alone in an animal tumor model.

MATERIALS AND METHODS

Subcutaneous R3230 mammary adenocarcinoma (1.1-1.4 cm) was implanted in female Fischer rats. Initially, 35 tumors were randomized into four experimental groups: (a) conventional monopolar RF (70 degrees C for 5 minutes) alone, (b) liposomal doxorubicin (1 mg) alone, (c) RF ablation followed by liposomal doxorubicin, and (d) no treatment. Ten additional tumors were randomized into two groups that received a 90 degrees C RF dose either with or without liposomal doxorubicin. Tumor growth rates and the defined survival endpoint, the time at which the tumor reached 3.0 cm in diameter, were recorded. The effect of treatments on endpoint survival and tumor doubling time were analyzed by means of the Kaplan-Meier method and analysis of variance statistics.

RESULTS

Differences in endpoint survival and tumor doubling time in the six groups were highly significant (P <.001). Endpoint survivals were 9.1 days +/- 2.5 for the control group, 16 days +/- 3.7 for tumors treated with 70 degrees C RF alone, 16.5 days +/- 3.2 for tumors treated with liposomal doxorubicin alone, and 26.6 +/- 5.3 days with combined treatment. For 90 degrees C RF ablation, endpoint survivals were 16.6 days +/- 1.2 and 31.5 days +/- 3.0 without and with liposomal doxorubicin (P <.01). Mean endpoint survival and tumor doubling times for the three RF levels (0, 70 degrees C, and 90 degrees C) were all significantly different (P =.01). Additionally, animals that received combined liposomal doxorubicin and 90 degrees C RF ablation survived longer than did animals that received combined liposomal doxorubicin and 70 degrees C RF ablation (P <.01).

CONCLUSION

Combined RF ablation and liposomal doxorubicin retards tumor growth and may increase animal survival compared with that with either therapy alone or no therapy.

Experimental study on the feasibility and safety of radiofrequency ablation for secondary splenomagely and hypersplenism

AIM: To assess the feasibility and safety of radiofrequency ablation (RFA) in treatment of secondary splenomagely and hypersplenism.

METHODS: Sixteen healthy mongrel dogs were randomly divided into two groups, group I (n = 4) and group II (n = 12). Congestive splenomegaly was induced by ligation of splenic vein and its collateral branches in both groups. At the end of 3rd week postoperation, RFA in spleen was performed in group II via laparotomy, complications of RFA were observed, CT scan was performed and the spleens were obtained. The radiofrequency (RF) thermal lesions and histopathology of spleen were examined regularly.

RESULTS: No complication or death was observed in both groups; CT revealed that the splenomegaly lasted over 2 months after ligation of splenic vein; the segmental RF lesions included hyperintense zone of coagulative necrosis and more extensive peripheral hypointense infarcted zone, the latter was called “bystander effect”. The infarcted zone would be absorbed and subsequently disappeared in 4-6 weeks after RFA accompanied with shrinkage of the remnant spleen. The fundamental histopathological changes of splenic lesions caused by RF thermal energy included local coagulative necrosis, peripheral thrombotic infarction zone, subsequent tissue absorption and fibrosis in the zone of thrombotic infarction, the occlusion of vessels in remnant viable spleen, deposition of extensive fibrous protein, and disappearance of congestive splenic sinusoid - “splenic carnification”. Those pathologic changes were underline of shrinkage of spleen.

CONCLUSION: It is feasible and safe to perform RFA in spleen to treat experimental splenomegaly and hypersplenism. The RFA could be safely performed clinically via laparotomy or laparoscopic procedure while spleen was strictly separated from surrounding organs.

Renal cell carcinoma: clinical experience and technical success with radio-frequency ablation of 42 tumors

PURPOSE

To evaluate clinical experience with percutaneous image-guided radio-frequency (RF) ablation of renal cell carcinoma (RCC) and to assess factors that may influence technical success.

MATERIALS AND METHODS

Thirty-four patients who underwent RF ablation of 42 RCC tumors during a 3.5-year period were evaluated. Overlapping ablations were performed on the basis of tumor size and geometry. Technical success was defined as elimination of areas that enhanced at imaging within the entire tumor. With the exception of those patients with renal insufficiency, who were followed up with unenhanced and gadolinium-enhanced magnetic resonance imaging, patients were followed up with unenhanced and contrast material-enhanced computed tomography. Univariate analysis of the results was performed with the Fisher exact test to assess the effect of tumor size and location on technical success. P <or=.05 was considered to represent a significant difference. Complications and the management and outcomes of the complications were recorded.

RESULTS

All 29 exophytic tumors (mean size, 3.2 cm; size range, 1.1-5.0 cm) were completely ablated, as were two parenchymal tumors. The remaining 11 tumors had a component in the renal sinus. For large (>3.0 cm) tumors, presence of a tumor component in the renal sinus was a significant negative predictor of technical success (P =.004); only five of these 11 tumors were completely treated, compared with 11 of 11 tumors without a renal sinus component. A similar analysis was not possible for small tumors because no small tumors involved the renal sinus. Four complications occurred in a total of 54 ablation sessions: one minor hemorrhage, two major hemorrhages, and one ureteral stricture.

CONCLUSION

RF ablation of RCC can be successful in exophytic RCC tumors up to 5.0 cm in size. Tumors larger than 3.0 cm with a component in the renal sinus are more difficult to treat but can be ablated successfully.

Adrenal-preserving minimally invasive surgery: the role of laparoscopic partial adrenalectomy, cryosurgery, and radiofrequency ablation of the adrenal gland

Adrenalectomy has become the standard of care for the management of hormonally active adrenal masses. Various surgical therapies have been proposed to excise completely or destroy these adrenal lesions, which may be benign or malignant. New minimally invasive, adrenal-sparing procedures have recently been introduced, among them laparoscopic partial adrenalectomy, cryosurgery, and radiofrequency ablation. These procedures focus on reducing patient morbidity and hastening postoperative recovery while preserving normal adrenal tissue. However, questions remain about the risks and benefits associated with routine application of minimally invasive therapies for adrenal-sparing surgery in terms of complete tumor extirpation. Clearly, more experience and longer follow-up is necessary to validate these procedures. Herein we describe the surgical techniques and early results of treatment with adrenal-sparing surgery.

Radiofrequency ablation of head and neck tumors: dramatic results from application of a new technology

BACKGROUND

Radiofrequency ablation (RFA) is a new treatment modality used over the past decade predominantly in the treatment of unresectable liver tumors. We find no prior reported series on the use of RFA for malignant tumors of the head and neck.

METHODS

Four patients with recurrent tongue tumors not amenable to standard surgical or radiation therapy were treated with RFA administered transorally, endoscopically, or percutaneously.

RESULTS

There was no perioperative mortality. Significant palliation was achieved consisting of substantial reduction in tumor size and alleviation of tumor-induced pain. One patient has survived for 8 months with no progression of tumor. Three patients had complications, including line sepsis, pneumonia, and enlargement of an orocutaneous fistula.

CONCLUSIONS

RFA was relatively straightforward to apply, achieved substantial palliation, and was associated with minimal perioperative morbidity and no mortality. It might easily be combined with other therapies such as chemotherapy, immunotherapy, or radiation. Further investigation is necessary and ongoing.

Radio frequency ablation of renal cell carcinoma: preliminary clinical experience

PURPOSE

We assess the feasibility, safety and efficacy of radio frequency ablation of small peripheral renal cell carcinomas.

MATERIALS AND METHODS

Five patients with a histologically proven renal cell carcinoma 30 to 40 mm. in diameter were treated with radio frequency ablation. A triple needle electrode was percutaneously advanced into each tumor under sonographic (4 cases) or computerized tomography (CT) (1) guidance. The radio frequency generator was activated for 15 minutes in each location where the electrode had been placed. Patients were then followed with CT and blood tests every 2 months for 6 months and every 3 months thereafter.

RESULTS

Four tumors required 1 radio frequency delivery and 1 required 2 applications during the same session. No complications were encountered except for a subcapsular hematoma in 1 patient, which resolved spontaneously. Two patients experienced transient hematuria. Of the patients 4 were discharged from the hospital after 2 days and 1 after 1 day. After 6 to 18 months (median 9) all patients were tumor-free on CT without suppress additional treatment.

CONCLUSIONS

In this small preliminary study radio frequency ablation of small peripheral renal cell carcinomas appears to be a feasible, safe and promising technique.

Percutaneous tumor ablation with radiofrequency

BACKGROUND

Radiofrequency thermal ablation (RFA) is a new minimally invasive treatment for localized cancer. Minimally invasive surgical options require less resources, time, recovery, and cost, and often offer reduced morbidity and mortality, compared with more invasive methods. To be useful, image-guided, minimally invasive, local treatments will have to meet those expectations without sacrificing efficacy.

METHODS

Image-guided, local cancer treatment relies on the assumption that local disease control may improve survival. Recent developments in ablative techniques are being applied to patients with inoperable, small, or solitary liver tumors, recurrent metachronous hereditary renal cell carcinoma, and neoplasms in the bone, lung, breast, and adrenal gland.

RESULTS

Recent refinements in ablation technology enable large tumor volumes to be treated with image-guided needle placement, either percutaneously, laparoscopically, or with open surgery. Local disease control potentially could result in improved survival, or enhanced operability.

CONCLUSIONS

Consensus indications in oncology are ill-defined, despite widespread proliferation of the technology. A brief review is presented of the current status of image-guided tumor ablation therapy. More rigorous scientific review, long-term follow-up, and randomized prospective trials are needed to help define the role of RFA in oncology.