Tumor Ablation Therapy Research Articles

Irreversible Electroporation

Bioelectrics, an interesting new area of medicine, combines pulsed high-voltage engineering with cell biology and has many potential applications. Pulsed electric current can be used to produce irreversible electroporation (IRE) of cell membranes with resulting cell death. This process has been shown to ablate tumors in animal studies. A clinical trial of IRE as a tumor ablation therapy was performed at our institution. A pulsating direct current of 20 to 50 A and 500 to 3000 V was delivered into metastatic or primary tumors in the liver, kidney, or lung via needle electrodes inserted under computed tomography (CT) or ultrasound guidance. Patients required a relaxant general anesthetic. We describe some challenges presented to anesthesiologists. Guidelines for anesthesia were produced and modified as issues became apparent. The patients' charts were audited throughout. We noted a number of issues. The electrical discharge produced generalized upper body muscular contractions requiring neuromuscular blockade. Two patients developed positional neuropraxia because of the extended arm position requested for CT scanning. After experimentation, we have developed a modified arm position. Some patients developed self-limiting ventricular tachycardias that are now minimized by using an electrocardiogram synchronizer. Three patients developed pneumothoraces as a result of the needle electrode insertion. Relaxant general anesthesia is required for IRE of the liver, lung, and kidney. An electrocardiogram synchronizer should be used to minimize the risk of arrhythmias. Attention to the position of the arms is required to maximize CT scan quality but minimize brachial plexus strain. Simple postoperative analgesia is all that is required in most patients.

Micro-bubble enhanced HIFU

High intensity focused ultrasound (HIFU) treatment that employs microbubbles to provide enhanced heating has been investigated in order to develop a less invasive and more rapid tumor ablation therapy. It has been demonstrated that microbubbles have significant effects on heating enhancement in vitro and in vivo experiments, however ultrasound propagation could be disturbed when there are too many microbubbles between the transducer and the focus. In this study, we develop a method to make a clear pass way for obtaining enhanced heating by using microbubbles just at the focus, thus avoiding heating on the pass way from the transducer to the target region. In this method, microbubbles are destroyed in front of the HIFU focus (on the transducer side) by irradiating a intense burst wave of microsecond order, before irradiating the ultrasound waves for heating the target region. The experiment is conducted in a medium of a polyacrylamide gel containing microbubbles, and a temperature-sensing liquid crystal sheet is set in the focus to observe the temperature distribution. The ultrasound frequency was 2.2 MHz and the intensity was 5000 W/cm2, and 20 burst waves were irradiated at pulse repetition frequency of 1 kHz. The number of wave pulses was varied. The continuous-wave frequency, intensity and irradiation time are 2.2 MHz, 1000 W/cm2 and 60 sec, respectively. As the number of pulses increased, the heating region moves from the transducer side to the focus. This is because microbubbles in front of the focus are destroyed and the ultrasound propagates around the target position effectively. These results suggest that the microbubble distribution and the heating position in the developed HIFU system can be controlled.

0604: High-Intensity Focused Ultrasound Ablation for Patients with Hepatocellular Carcinoma

PurposeTo evaluate the use of HIFU for local therapy of unresectable hepatocellular carcinoma(HCC).Materials and MethodsWe evaluated 29 consecutive patients with nonresectable HCC who underwent HIFU under general anesthesia. The extracorporeal, ultrasound-guided Model-JC system(HAIFU, Chongqing, China) was used. 26 patients received transarterial chemoembolization before HIFU. For the technical effectiveness, we divided patients into 4 categories. I, Complete ablation without evidence of recurrence; II, Apparent complete ablation of target mass with new lesions on follow up; III, Local tumor progression after complete ablation; IV, Incomplete ablation. Complications were also recorded.ResultsWe treated total 44 tumors in 29 patients. The tumor size ranged from 2 to 11 cm. Average procedure time was 129 minutes with 37minutes treatment time. We made the artificial pleural effusion to get treatment field in 19. Mean follow-up period was 26 months(4-36 months). No tumor recurrence was observed in two patients of category I at average 28 months after HIFU. New nodules were developed at average 13 months in 17 of category II. Complete ablation without local tumor progression was observed in 19 of 29 patients(66%). Local tumor progression was observed at average 7 months in three of category III. Incomplete ablation was seen in seven. One patient showed delayed right hemidiaphragmatic rupture at 20 months after HIFU. Eight patients died due to hepatic failure at average 14 months after HIFU.ConclusionHIFU is a safe and effective treatment option for local image-guided tumor ablation therapy with satisfactory short term efficacy for patients with HCC. PurposeTo evaluate the use of HIFU for local therapy of unresectable hepatocellular carcinoma(HCC). To evaluate the use of HIFU for local therapy of unresectable hepatocellular carcinoma(HCC). Materials and MethodsWe evaluated 29 consecutive patients with nonresectable HCC who underwent HIFU under general anesthesia. The extracorporeal, ultrasound-guided Model-JC system(HAIFU, Chongqing, China) was used. 26 patients received transarterial chemoembolization before HIFU. For the technical effectiveness, we divided patients into 4 categories. I, Complete ablation without evidence of recurrence; II, Apparent complete ablation of target mass with new lesions on follow up; III, Local tumor progression after complete ablation; IV, Incomplete ablation. Complications were also recorded. We evaluated 29 consecutive patients with nonresectable HCC who underwent HIFU under general anesthesia. The extracorporeal, ultrasound-guided Model-JC system(HAIFU, Chongqing, China) was used. 26 patients received transarterial chemoembolization before HIFU. For the technical effectiveness, we divided patients into 4 categories. I, Complete ablation without evidence of recurrence; II, Apparent complete ablation of target mass with new lesions on follow up; III, Local tumor progression after complete ablation; IV, Incomplete ablation. Complications were also recorded. ResultsWe treated total 44 tumors in 29 patients. The tumor size ranged from 2 to 11 cm. Average procedure time was 129 minutes with 37minutes treatment time. We made the artificial pleural effusion to get treatment field in 19. Mean follow-up period was 26 months(4-36 months). No tumor recurrence was observed in two patients of category I at average 28 months after HIFU. New nodules were developed at average 13 months in 17 of category II. Complete ablation without local tumor progression was observed in 19 of 29 patients(66%). Local tumor progression was observed at average 7 months in three of category III. Incomplete ablation was seen in seven. One patient showed delayed right hemidiaphragmatic rupture at 20 months after HIFU. Eight patients died due to hepatic failure at average 14 months after HIFU. We treated total 44 tumors in 29 patients. The tumor size ranged from 2 to 11 cm. Average procedure time was 129 minutes with 37minutes treatment time. We made the artificial pleural effusion to get treatment field in 19. Mean follow-up period was 26 months(4-36 months). No tumor recurrence was observed in two patients of category I at average 28 months after HIFU. New nodules were developed at average 13 months in 17 of category II. Complete ablation without local tumor progression was observed in 19 of 29 patients(66%). Local tumor progression was observed at average 7 months in three of category III. Incomplete ablation was seen in seven. One patient showed delayed right hemidiaphragmatic rupture at 20 months after HIFU. Eight patients died due to hepatic failure at average 14 months after HIFU. ConclusionHIFU is a safe and effective treatment option for local image-guided tumor ablation therapy with satisfactory short term efficacy for patients with HCC. HIFU is a safe and effective treatment option for local image-guided tumor ablation therapy with satisfactory short term efficacy for patients with HCC.

An effective point-based registration tool for surgical navigation

Surgical navigation assists in endoscopic surgeries by enabling surgeons to see concealed lesions and surrounding organs. Successful surgical navigation depends on accurate registration between a medical image and a patient. For accurate point-based registration, it is important to determine the matching order and positions of the markers correctly. It is particularly difficult to determine the order and positions when part of the markers cannot be located on the patient's body or when they cannot be identified in the images. By using the automatic marker-matching option of the proposed tool, an optimum registration result can be obtained even with the partial loss of markers. In addition, this tool provides an intuitive marker selection interface that displays the registration error of each marker pair in different colors. The efficiency of the described tool in terms of the registration accuracy and time has been confirmed in more than 70 clinical applications. The fiducial registration errors were 1.28 + or - 1.09 mm in ear, nose, and throat surgery and 3.55 + or - 1.30 mm in liver tumor ablation therapy. The proposed automatic matching scheme with marker selection interface was particularly effective where the markers were partly lost or incorrectly identified.

Image-Guided Ablation Therapy of Bone Tumors

A wide range of thermal and cryoablation methods is currently available for the curative eradication or palliative treatment of a variety of bone and soft-tissue tumors. Radiofrequency ablation has been developed as a multipurpose tool for the skeletal system. Cryoablation has the added advantages of direct computed tomography or magnetic resonance visualization and monitoring of treatment outcome with less peri- and postoperative pain. Use of appropriate thermo-sensors and insulation techniques, like carbon dioxide insufflation, results in enhanced safety and efficacy. Ablation of weight-bearing bones has to be supplemented with cement consolidation. The authors present an overview of the current status of percutaneous image-guided ablation therapy of bone and soft-tissue tumors, analyze the merits and limitations of the various systems available, and discuss possible new applications for the future.

Tumor ablation therapy of liver cancers with an open magnetic resonance imaging-based navigation system

As minimally invasive treatments for liver cancers, percutaneous ablation therapies represent a valid alternative to liver resections, especially in patients with poor liver function. Recently, image-guided surgical and interventional procedures using open magnetic resonance imaging (MRI) have been introduced. We performed percutaneous ablation therapy for 51 nodules of liver cancer in 34 patients using a navigation system based on open MRI. During the ablation therapy, the ultrasonography (US) probe, needle, and tumor were displayed on the MR image. Immediately after the procedure, the therapeutic effect was evaluated by open MRI. In all cases, percutaneous puncture into the tumors was successful, even in the case of tumor undetectable by US. Mean fiducial registration error was approximately 3 mm. MR images captured after the procedure clearly demonstrated the ablated area. No mortality or major complications occurred, except for mild hemorrhage, pyrexia, and ascites. We developed a novel navigation system integrating US and MR images using open MRI for percutaneous ablation therapy of liver cancers. The presented system allows a safe and accurate approach to liver cancers, especially certain tumors that cannot be adequately visualized by US, and an evaluation of therapeutic results immediately after the procedures.

Percutaneous tumor ablation or surgical resection for small hepatocellular carcinoma?

Percutaneous tumor ablation or surgical resection for small hepatocellular carcinoma?

Prospective Evaluation of a New High Power Argon Plasma Coagulation System (VIO APC) in Gastrointestinal Endoscopy: Experience with 216 Patients

Prospective Evaluation of a New High Power Argon Plasma Coagulation System (VIO APC) in Gastrointestinal Endoscopy: Experience with 216 Patients Hendrik Manner, Andrea May, Thomas Rabenstein, Lars Nachbar, Oliver Pech, Markus D. Enderle, Christian Ell Background: We sought to evaluate the safety and efficacy using a new high power argon plasma coagulation system (hp-APC) in the gastrointestinal tract.Methods: From 02/2005 to 06/2005, 216 patients (167 males (77.3%); mean age 66 G 11 years) were treated using hp-APC in a total of 275 sessions. In various indications (additive ablation therapy in curative intention in early Barrett’s cancer (132 patients); palliative treatment of esophageal cancer (n Z 20); gastric polyps/cancer (n Z 17); angiodysplasia (n Z 16); Zenker’s diverticulum (n Z 8); duodenal adenomas (n Z 7); and other), the new VIO APC device (VIO 300 D with APC 2; ERBE Elektromedizin, Tubingen, Germany) was used (pulsed APC; 15-120 W). Pushand-Pull Enteroscopy using double-balloon technique (PPE; new 1.5 mm APC probes) was used in 11 patients (5.1%). Safety and efficacy of hp-APC were recorded after each individual treatment session. Results: The mean number of treatment sessions required using hp-APC in various indications was 1.7 (1-5). For palliative tumor ablation therapy in the esophagus, it was 2.3 (1-5). Minor complications (pain, dysphagia, irritation of the intestinal wall) were observed in 24/216 patients (11.1%), major complications (gas accumulation in the intestinal wall, perforation, stenosis) in 5 patients (2.3%). Conclusions: Hp-APC appears to be safe and effective. Due to a low number of treatment sessions required, the VIO APC device might be used as an alternative to Nd:YAG laser in tumor debulking. Using the new 1.5 mm probes for PPE, hp-APC was effective in the treatment of GI bleeding.

WE-E-J-6B-02: Image-Guided Minimally Invasive Robotic Surgery

Image‐guided surgery allows surgeons to specifically target diseased tissue while sparing healthy tissue, reducing morbidity and improving patient outcomes. Minimally invasive surgical techniques deliver specific intervention without the morbidity associated with large open incisions. Image‐guidance technology has the potential to provide significant benefits for minimally invasive surgery, where surgeons must usually cope with difficult access and reduced visualization. A new generation of minimally invasive surgery has emerged that uses a robot to hold surgical tools during laparoscopy or thoracoscopy, under direct control by the surgeon. Surgical robots offer an excellent platform upon which to fuse the benefits of image‐guided and minimally invasive surgery. The da Vinci surgical robot system has a high‐fidelity video display, a stereo endoscope, and sensors to track the position of each surgical instrument and the endoscope, offering a potentially ready‐made stream of data for registration and tracking. The proposed project involved an academic/industry collaboration to give da Vinci the fundamentally new capability of steering to a specific point in the patient's frame of reference. Using the traditional da Vinci control paradigm, the robot simply follows the surgeon's relative motions and has no concept of the patient's frame of reference. With the new ability to navigate through the patient's frame of reference as described by preoperative imagerydata sets registered to the patient during surgery, da Vinci will enable surgeons to more accurately perform targeted tasks such as biopsy, tumor ablation, resection planning, and gene therapy in a minimally invasive manner. The project used liver surgery as a motivating application. This work addressed three feasibility milestones: Establishing communication between the surgical robot and existing image‐guidance software, establishing robot tracking error under 2 mm, and establishing surface registration errors under 5 mm.

Current status of hepatic resection for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common tumors worldwide. For this disease, a variety of therapeutic measures have been applied, including hepatic resections, total hepatectomy followed by allografting, transarterial chemoembolization, and percutaneous tumor ablative therapy by ethanol, microwave coagulation, and radiofrequency ablation. This article focuses on the current status of hepatic resections for HCC.

From the Editors

SummaryDear colleagues,Interstitial therapies have been introduced in the spectrum of minimally invasive cancer treatments for a decade, meanwhile a standardization has been introduced in the field of image-guided tumor ablation. This is an important criterion for facilitating effective ideas and for performing appropriate comparisons between treatments with different technologies. Tumor ablation and interstitial therapies are defined as a direct application of chemical or thermal therapies to a specific focal tumor in an attempt to achieve eradication or substantial tumor destruction. Via the term “direct” these therapies are defined as a “direct” differentiation from those therapies which are applied orally or via an intravascular approach.In this issue on “Interstitial Therapies” different technologies are presented which are based on well-known groups of different authors who have presented their experience in image-guided interstitial therapies for the treatment of lung, liver, and head and neck neoplasms. Although at present there are many technologies under investigation, the present issue aims at showing that image-guided tumor ablation has become an integrated part in modern oncology, opening the field of interventional oncology for the future.We do wish to inspire the reader to get involved in this field of interstitial therapies, which is, in fact, one of the most fascinating, exciting and rapidly growing ones.Thomas J. VoglNahum Goldberg

Perkutane Radiofrequenzablation - klinische Indikationen und Ergebnisse

Percutaneous interstitial tumor ablation therapy is a relatively new and steadily growing field within interventional radiology. Radiofrequency ablation (RFA) became one of the most accepted techniques among hyperthermal ablation procedures, presumably due to its superior relation between probe diameter and efficacy. The first part of this review provided an overview of the underlying principles, technical background and application techniques. This second part describes the indications, techniques and results of clinical RFA applied to primary and secondary liver tumors as well as experiences with extrahepatic RFA applied to kidney, bone and lung, together with a discussion of the current literature.

1198 Tumor ablation plus interferon therapy for HCV-related early hepatocellular carcinoma: a meta-analysis of randomized controlled trials

1198 Tumor ablation plus interferon therapy for HCV-related early hepatocellular carcinoma: a meta-analysis of randomized controlled trials

Lithotripter shock waves with cavitation nucleation agents produce tumor growth reduction and gene transfer in vivo

Cavitation nucleation agents (CNA) can greatly enhance DNA transfer and cell killing for therapeutically useful applications of nonthermal bioeffects of ultrasound (US). Renal carcinoma (RENCA) tumor cells were implanted and grown to about 400 μL tumor volumes on the hind legs of syngeneic Balb/c mice. Before treatment, mice were anesthetized, the tumor region was shaved and depilated, and a DNA plasmid coding for marker proteins was injected into the tumor. Two sets of tests were completed: the first set involved measurement of tumor growth for 4 days and use of a β-galactosidase marker plasmid for localization of transfection, and the second set involved 2 days of growth and use of a luciferase marker plasmid for assessing overall protein expression. Either saline, Optison® US contrast agent, a vaporizing perfluoropentane droplet suspension (SDS) or air bubble was also injected intratumorally at 10% of tumor volume as a CNA. In some tests, droplets or contrast agent were injected IV. Shock waves (SW) were generated from a spark-gap lithotripter at 7.4 MPa peak negative pressure amplitude. For sham exposure, tumor volume increased by a factor of 3.6 in 4 days. With 500-SW treatment, all the CNA reduced 4-day tumor growth about the same amount (to factors of 1.2 to 1.9). Marker gene expression was generally localized to the region around the needle injection path. All the agents, except saline, produced statistically significant increases of 11.8- to 14.6-fold in luciferase expression after 2 days, relative to sham exposure. IV injection of Optison® or droplet nucleation agents before SW treatment reduced tumor growth to factors of 1.0 and 0.7, but did not increase transfection. These results demonstrate the efficacy of CNA in vivo and should lead to improved strategies for simultaneous SW tumor ablation and cancer gene therapy. (E-mail: douglm@umich.edu)

Percutaneous tumor ablation with radiofrequency.

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. 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. 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. 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.

The role of contrast-enhanced sonography for radiofrequency ablation of liver tumors.

To assess the feasibility and usefulness of contrast-enhanced sonography for tumor detection and guidance of liver VX2 tumor ablation and to evaluate post radiofrequency ablation effectiveness. VX2 tumors were implanted into the livers of 6 rabbits. Both conventional and harmonic gray scale and power Doppler imaging were performed with a commercially available scanner to evaluate the liver tumors before and after intravenous injection of a sonographic contrast agent before and after radiofrequency ablation. Contrast-enhanced imaging was used to detect the tumors before ablation, to guide needle insertion, and to measure the ablation sites after radiofrequency ablation. Pathologic examination was performed for comparison. Three tumors were seen without contrast enhancement, whereas 10 tumors (<1 cm) were detected with contrast enhancement. Intentionally, 2 tumors were completely ablated and 5 tumors were partially ablated. In 3 cases, incompletely ablated tumors could only be identified on contrast-enhanced Doppler imaging by enhancing the detection of residual tumor vascularity. There was excellent concordance between sonographic imaging and gross pathologic findings. Contrast-enhanced sonographic imaging appears useful for detection of liver tumors and for guiding and monitoring tumor ablation therapies.

MR-guided microwave ablation therapy for hepatic tumor through multiple access route

Microwave Ablation is one of the useful treatments of hepatic tumor. It has been used as an interventional device for thermoablation therapy under ultrasonographic or laparoscopic guidance. We have done clinical studies of MR-guided microwave ablation therapy of hepatic tumors since January 2000. From January through September 2000, 18 patients with liver tumors were hospitalized in the 1st Department of Surgery at Shiga University of Medical Science. There were 13 cases of metastatic hepatic tumor. All of which had previously had primary surgery. The other 5 cases were primary hepatic cancer. All patients were selected because percutaneous ethanol injection therapy (PEIT) or transcathetal arterial embolization (TAE) was ineffective, and surgical resection could not be done because of hepatic dysfunction.We had already performed MR-guided microwave ablation therapy to hepatic tumors located in every segment of the liver. However, percutaneous puncture of the tumors in the subphrenic area was not easy with the abdominal approach. In these cases, a combination of thoracoscopic and MR-guidance has been beneficial. MR compatible endoscope made us easily to puncture hepatic tumors located in every segment of the liver. MR-guided microwave ablation therapy is a feasible treatment for hepatic tumors.

肝細胞癌の経皮的局所療法―現状と今後の展望― 幹細胞癌の診断と治療―最近の進歩―

肝細胞癌の経皮的局所療法―現状と今後の展望― 幹細胞癌の診断と治療―最近の進歩―

IMPLANT RECONSTRUCTION FOLLOWING REMOVAL OF TUMORS OF THE HEAD AND NECK

Functional maxillofacial rehabilitation following tumor ablation depends on many variables. These include the magnitude of hard or soft tissue defects, the use of adjunctive chemotherapy or radiation therapy, and the presence of underlying systemic disease. The physiologic effects of tumor ablation and radiation therapy on local tissues and grafted bone are discussed in this article in relation to the ultimate use of implant supported prostheses. Cases are presented to illustrate a variety of clinical situations.

Analysis of tissue and arterial blood temperatures in the resting human forearm. 1948.

Analysis of tissue and arterial blood temperatures in the resting human forearm. 1948.