Volume Of Coagulation Necrosis Research Articles

High-Intensity Focused Ultrasound Ablation for Postoperative Recurrent Desmoid Tumors: Preliminary Results.

This study was aimed at evaluating the feasibility, safety and therapeutic effects of high-intensity focused ultrasound ablation (HIFUA) in the treatment of post-operative recurrent desmoid tumors. From September 2017 to May 2020, 42 consecutive patients with pathologically proven desmoid tumors treated with HIFUA for the first time were enrolled. These were divided into two groups: post-operative recurrent group (30 cases) and non-surgery group (12 cases). The basic characteristics, treatment parameters, ablation efficacy, tolerance and adverse events were recorded and compared between groups. The minimum distance between the tumor and skin surface in the post-operative recurrent group was significantly smaller than that in the non-surgery group (6.9 mm vs. 10.8 mm, p=0.011), but there was no significant difference in the other basic characteristics (p > 0.05). The average acoustic power and intensity of treatment in the post-operative recurrent group were significantly lower than those in the non-surgery group (p=0.006 and 0.036, respectively), but there was no significant difference in the remaining parameters or in ablation efficacy between groups (p > 0.05). HIFUA was successfully performed, and a large volume of coagulation necrosis was obtained from all patients without serious or life-threatening adverse events. Furthermore, there was no significant difference in the incidence of moderate adverse events and average length of stay between groups (p > 0.05). The average power and intensity of HIFUA treatment were adversely affected by surgical scar and tumor infiltration along the surgical path. However, HIFUA can still be used as an effective minimally invasive therapy for the local control of post-operative recurrent desmoid tumors.

Preparation of doxorubicin-loaded metallic organic nanoparticles and their effect for enhancing efficacy of high-intensity focused ultrasound therapy in tumor-bearing mice

To prepare metallic organic nanoparticles that produce synergistic effect in high-intensity focused ultrasound (HIFU) therapy of tumors. Glucose oxidase (GOD), MnO2, ferric iron (Fe3+) and doxorubicin (DOX) were self-assembled by physical adsorption with previously prepared manganese dioxide (MnO2) nanoparticles to obtain GOD-MnO2-Fe3+-DOX nanoparticles (GMFD NPs). HepG2 tumor-bearing nude mouse models were given intravenous injections of normal saline or GMFD NPs followed 4 h later by HIFU at the acoustic power of 90 W with a total treatment time of 3 s. The changes of tumor gray value before and after HIFU irradiation were observed and 24 h after HIFU irradiation, coagulation necrosis in the tumor tissues was examined; the histological changes of the tumor tissues were observed with HE staining. We successfully prepared GMFD NPs, which had an average particle size of 131.23±0.84 nm with a surface potential of 21.87±1.72 mV. GMFD NPs, with a drug loading rate of 40.18%, was capable of releasing more than 77.2% of the loaded DOX within 4 h in acidic environment. In the tumor-bearing mouse models, HIFU irradiation following GMFD NP injection, as compared with saline injection, resulted in significantly enhanced gray value of the tumor (25.5±4.5 vs 18.7±3.9, P=0.04) and greater volume of coagulation necrosis (105.80 ± 1.21 mm3 vs 38.02 ± 0.34 mm3). The energy efficiency factor (EEF) was significantly lower in GMFD NPs group than in saline group (1.79 vs 4.97, P < 0.001). GMFD NPs prepared in this study can enhance tumor ablation efficacy of HIFU and release DOX for further treatment of the residual tumor tissue in mice.

Escherichia coli expressing gas vesicles is safe for enhancing the ablation effect of highintensity focused ultrasound in tumor-bearing mice

To investigate the effect and safety of Escherichia coli (E.coli) expressing gas vesicle (GVs) for enhancing the efficacy of tumor ablation by high intensity focused ultrasound (HIFU) in tumor-bearing mice. Thirty-two female BALB/c mice were used to establish mouse models bearing 4T1 tumor, which were randomized into GVs group [E.coli BL21 (AI)-PET28a-Arg1] and control group (PBS), and the efficacy of HIFU ablation was evaluated by examining coagulative necrotic volume and pathology of the tumors. Another 104 BALB/c mice were also randomly divided into GVs group and control group, and body weight changes of the mice were recorded on days 1, 4 and 15 after intravenous injection of E.coli containing GVs or PBS. White blood cells, red blood cells, hemoglobin and platelet counts and liver and renal function parameters of the mice were detected, and serum levels of TNF-α and IL-1β were examined using ELISA. The pathological changes in the liver and spleen were evaluated using HE staining to assess the safety of the treatments. HIFU ablation resulted in a significantly greater volume of coagulative necrosis and severer tissue damage in GVs group than in the control group (P < 0.001). In the 104 BALB/c mice without tumor cell inoculation, intravenous injection of E.coli expressing GVs, as compared with PBS, did not significantly affect body weight or cause changes in white blood cell, red blood cell and platelet counts or hemoglobin level (P1=0.59, P2=0.27, P3=0.76, P4=0.81). The liver and kidney function parameters (P1=0.12, P2=0.46, P3=0.62, P4=0.86) and serum levels of TNF-α and IL-1β (P1=0.48, P2=0.56) were all comparable between GVs group and control group. No obvious pathological changes were detected in the liver and spleen tissues in either GVs group or the control group. E.coli expressing GVs is safe for enhancing the ablation effect of HIFU in tumor-bearing mice.

Evaluation of Ultrasound-Guided Radiofrequency Ablation as a Treatment Option for Papillary Thyroid Microcarcinoma in the Isthmus: A Retrospective Study.

BackgroundAbout 3–9.2% of papillary thyroid carcinomas (PTC) are found in the isthmus, which has unique anatomic properties, making treatment more challenging. The aim of this study was to evaluate the treatment and undesirable effects of ultrasound-guided radiofrequency ablation (RFA) for PTC in the isthmus.MethodsThis retrospective case series study assessed 112 patients with single papillary thyroid microcarcinoma in the isthmus, pathologically diagnosed before RFA at the General Hospital of Chinese PLA in 2014–2018. Follow-up was performed by contrast-enhanced ultrasound (CEUS) and ultrasound examinations at 1, 3, and 6 months and every 6 months thereafter. The complete ablation (CAR), disappearance (DR), and volume reduction (VRR) rates of nodules, the incidence of complications, and the rate of lymph-node metastasis were recorded.ResultsThe CAR of the tumors was 100%. During follow-up, the volume of coagulation necrosis gradually decreased. DRs at 1, 3, 6, 12, and 18 months after RFA were 0.8% (1/112), 10.7% (12/112), 51.7% (58/112), 91.0% (102/112), and 100% (112/112), respectively. The VRR evaluated by ultrasound and CEUS gradually increased. One recurrent case (0.8%) was found at 7 months after RFA. No complications, lymph node metastasis confirmed by ultrasound, and abnormal thyroid function were observed.ConclusionsThis retrospective study shows that RFA is beneficial for the treatment of PTMC in the isthmus.

Perfused hypertonic-saline-augmented needle enlarges ablation zones in ex vivo porcine livers.

There is a great clinical requirement to improve radiofrequency ablation (RFA) efficacy and create larger coagulation necrotic areas. The aim of the present study was to assess the ability of a hypertonic-saline (HS)-enhanced multipolar RFA technique using a perfused electrode to increase RF-created coagulation necrosis, and to compare that technique with natural saline-augmented needle and conventional multipolar RFA. A total of 18 ablations were performed in explanted porcine livers. A total of 6 thermal ablation zones were created in each of 3 groups treated with the conventional multipolar mode, the multipolar mode with 0.9% NaCl and the multipolar mode with 6% NaCl, respectively. During RFA, the dimensions and volumes of the ablation zones were compared, and gross and microscopic pathological evaluations were performed. Multipolar RFA with 6% NaCl created the largest short-axis diameters and volumes of coagulation necrosis (3.89±0.09 mm and 40.01±2.86 mm3, respectively) among the three groups (conventional group: 2.31±0.04 mm and 8.99±0.52 mm3, respectively; 0.9% NaCl solution group: 3.17±0.05 mm and 21.79±1.05 mm3, respectively). Overall, multipolar RFA with the instillation of 6% NaCl solution through an open perfusion system created a larger ablation zone compared with the conventional and 0.9% NaCl modes. Therefore, HS-enhanced multipolar RFA may be a promising approach for treating large liver tumors.

Abstract CT103: A phase II study to evaluate outpatient magnetic resonance image-guided laser focal therapy for prostate cancer: A 20-year survival study (seven-year interim results)

Abstract Purpose: In the United States alone, new prostate cancer cases for 2016 were estimated at 180,890 and deaths at 26,120. Focal therapies for low risk and intermediate risk localized prostate cancer are increasingly being explored. Additionally, new treatments for patients with biochemical recurrence of prostate cancer are also under investigation. Our objective is to investigate the safety and feasibility of using outpatient MR-guided laser focal therapy for MR visible prostate cancer utilizing a transrectal approach for laser applicator placement and therapy delivery in an outpatient setting. Method and Materials: All MRI-guided therapy was delivered using a 1.5 Tesla MRI system for both image acquisition and real-time thermometry. Commercially available hardware and software were used for image analysis and interventional planning. Laser therapy was delivered using a 15W, 980 nm diode laser applicator with fiber-cooling catheter introduced transrectally using a commercially available MRI-compatible introducer system. Results: 80 men were treated. 112 cancer foci were treated. Total procedure time was between 1.5 and four hours MRI volume of coagulation necrosis ranged from 0.57 to 22.93 cc. No serious adverse events or morbidity were reported. 17 treatment regions were positive at six months biopsy, consistent with residual or recurrent cancer 26% of subjects 18% of treated regions.We observed a 40% decrease in mean PSA at 1 year post therapy and no statistically significant change in IPSS and SHIM scores at 6 months post-treatment. Conclusion: Our data indicate that outpatient, transrectally delivered MRI-guided laser focal therapy for prostate cancer is both safe and feasible. Clinical Relevance/Application: In the current climate of cost-reduction and emphasis on minimally-invasive treatment of cancer, focal treatment of prostate cancer may be an attractive option. The precise energy delivery under MRI-guidance may have favorable results for cost control and quality of life without eliminating the possibility of whole-gland treatment in the patient’s future. Citation Format: Bernadette Marie Greenwood, John F. Feller, Stuart T. May, Wes Jones, Axel Winkel. A phase II study to evaluate outpatient magnetic resonance image-guided laser focal therapy for prostate cancer: A 20-year survival study (seven-year interim results) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT103. doi:10.1158/1538-7445.AM2017-CT103

Comparison of the synergistic effect of lipid nanobubbles and SonoVue microbubbles for high intensity focused ultrasound thermal ablation of tumors

Microbubbles (MBs) are considered as an important enhancer for high intensity focused ultrasound (HIFU) treatment of benign or malignant tumors. Recently, different sizes of gas-filled bubbles have been investigated to improve the therapeutic efficiency of HIFU thermal ablation and reduce side effects associated with ultrasound power and irradiation time. However, nanobubbles (NBs) as an ultrasound contrast agent for synergistic therapy of HIFU thermal ablation remain controversial due to their small nano-size in diameter. In this study, phospholipid-shell and gas-core NBs with a narrow size range of 500–600 nm were developed. The synergistic effect of NBs for HIFU thermal ablation was carefully studied both in excised bovine livers and in breast tumor models of rabbits, and made a critical comparison with that of commercial SonoVue microbubbles (SonoVue MBs). In addition, the pathological changes of the targeted area in tumor tissue after HIFU ablation were further investigated. Phosphate buffer saline (PBS) was used as the control. Under the same HIFU parameters, the quantitative echo intensity of B-mode ultrasound image and the volume of coagulative necrosis in lipid NBs groups were significantly higher and larger than that in PBS groups, but could not be demonstrated a difference to that in SonoVue MBs groups both ex vivo and in vivo. These results showed that the synergistic effect of lipid NBs for HIFU thermal ablation were similar with that of SonoVue MBs, and further indicate that lipid NBs could potentially become an enhancer for HIFU thermal ablation of tumors.

Evaluation of in vivo efficacy of radiofrequency ablation with D-sorbitol in animal liver.

Percutaneous radiofrequency ablation (RFA) enables cauterization of liver cancer in a limited number of sessions without major complications. In contrast to the efficacy of this technique, the size of coagulation necrosis is limited due to increased impedance. D-sorbitol has been used as an irrigating fluid during transurethral resection of the prostate, since it is considered to be a dielectric fluid. In order to determine whether D-sorbitol enhances the effect of RFA, RFA was performed by slowly injecting 3% D-sorbitol near the tip of the RFA needle. The maximum of the total injected volume of D-sorbitol was 20 ml and RFA was terminated if the threshold of impedance was exceeded. RFA and D-sorbitol RFA were performed in 5 different parts of pig livers and dog livers in vivo. The total volumes of coagulation necrosis in the D-sorbitol RFA group were significantly higher compared with those in the RFA group. The total delivered energy in the D-sorbitol RFA group was also higher compared with that in the RFA group, due to the suppression of impedance elevation. No significant complications, such as bleeding or damage, were observed during the D-sorbitol RFA procedure in the in vivo model. In conclusion, RFA combined with D-sorbitol increases the total volume of coagulation necrosis through controlling impedance in the ablated liver and, therefore, D-sorbitol may be useful for the treatment of liver cancers.

Preliminary study on the relationship between the blood supply of rabbit liver VX2 tumor models and the HIFU

Objectives To explore the effects of the blood supply extent on the temperature of target site of tumor and volume of coagulation necrosis (V), and to provide experimental evidence for further precise control of dosage of high intensity focused ultrasound (HIFU) and improve the efficiency of HIFU in the treatment. Methods Twenty-four rabbit liver VX2 tumor models were established and were divided into four groups: 10 d group, 15 d group, 20 d group, no blood supply group (rabbits were put to death in the 10 d after the models were established). The same irradiation parameters of HIFU were used to irradiate the hepatic tumor tissue of every group, the real-time temperature of target site of tumor were measured, the software from temperature controller was used to plot the time-temperature curve (TTC), V was measured after HIFU. Residual tumor tissue was resected for pathological observation and microvascular density (MVD) determination. Results ⑴ Histopathological analysis showed that the extent of a tumor's blood supply followed the order 10 d group > 15 d group > 20 d group (P 0.05), Tmax, T1, and k1 between three groups with no blood supply group had statistical difference (P 15 d group > 20 d group > no blood supply group; T2: 10 d group < 15 d group < 20 d group < no blood supply group; ⑷V: 10 d group < 15 d group < 20 d group < no blood supply group. Conclusions The extent of a tumor's blood supply had a significant effect on the temperature-decrease phase but not on the temperature-increase phase during HIFU treatment. The more abundant blood supply of the tumor was, the faster heat abstraction after HIFU was; and the easier the tissue return to normal temperature, the smaller the volume of coagulation necrosis tissue were. Key words: Liver neoplasms, experimental/BS/TH; Ultrasound, high-intensity focused, transrectal; Disease models, animal

Evaluation of superparamagnetic iron oxide-polymer composite microcapsules for magnetic resonance-guided high-intensity focused ultrasound cancer surgery

BackgroundSuperparamagnetic poly (lactic-co-glycolic acid) (PLGA)-coated Fe3O4 microcapsules are receiving increased attention as potential diagnostic and therapeutic modalities in the field of oncology. In this study, PLGA-coated Fe3O4 microcapsules were combined with a magnetic resonance imaging-guided high-intensity focused ultrasound (MR-guided HIFU) platform, with the objective of investigating the effects of these composite microcapsules regarding MR-guided HIFU liver cancer surgery in vivo.MethodsPLGA-coated Fe3O4 microcapsules consisting of a liquid core and a PLGA-Fe3O4 shell were fabricated using a modified double emulsion evaporation method. Their acute biosafety was confirmed in vitro using MDA cells and in vivo using rabbits. To perform MR-guided HIFU surgery, the microcapsules were intravenously injected into a rabbit liver tumor model before MR-guided HIFU. T2-weighted images and MR signal intensity in normal liver parenchyma and tumor tissue were acquired before and after injection, to assess the MR imaging ability of the microcapsules. After MR-guided HIFU ablation tissue temperature mapping, the coagulative volume and histopathology of the tumor tissue were analyzed to investigate the ablation effects of MR-guided HIFUs.ResultsScanning and transmission electron microscopy showed that the microcapsules displayed a spherical morphology and a shell-core structure (mean diameter, 587 nm). The hysteresis curve displayed the typical superparamagnetic properties of the microcapsules, which are critical to their application in MR-guided HIFU surgery. In MR-guided HIFU surgery, these microcapsules functioned as an MRI contrast agent, induced significant hyperthermal enhancement (P < 0.05) and significantly enhanced the volume of coagulative necrosis (P < 0.05).ConclusionsThe administration of PLGA-coated Fe3O4 microcapsules is a potentially synergistic technique regarding the enhancement of MR-guided HIFU cancer surgery.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2407-14-800) contains supplementary material, which is available to authorized users.

Short-term efficacy of ultrasound-guided percutaneous ethanol injection enhanced single needle radiofrequency ablation in the treatment of liver cancer

Objective To investigate the short-tern efficacy of ultrasound-guided percutaneous ethanol injection (PEI) enhanced single needle radiofrequency ablation ( RFA) in the treatment of liver cancer.Methods The clinical data of 71 patients who were admitted to the Xijing Hospital from June 2010 to June 2011 were retrospectively analyzed.All patients were divided into the RFA group (25 patients ) and RFA + PEI group (46 patients).In the RFA group,the needle of RFA was injected into the tumor for coagulation with the guidence of ultrasound.In the RFA + PEI group,95％ ethanol was injected into the tumor with the guidence of ultrasound,and then RFA was performed.The tumor necrosis volumes of the 2 groups were assessed by contrast-enhanced ultrasound at 2 weeks after RFA.The relationship between the average RFA energy and volume of ethanol applied and necrosis volume was analyzed.All data were analyzed by using the chi-square test,t test and Pearson correlation coefficient.Results The volume of coagulative necrosis of the RFA group was (22 ± 17) cm3,which was significantly smaller than (55 ± 44) cm3 of the RFA + PEI group (t =3.85,P ＜ 0.05 ).In the RFA + PEI group,the volume of ethanol injected was positively correlated with the volume of coagulative necrosis (r =0.615,t =5.86,P ＜ 0.05 ),but negatively correlated with the treatment efficacy ( r =- 0.709,t =- 7.52,P ＜ 0.05 ).The amount of required energy was positively correlated with the volume of coagulative necrosis (r =0.884,t =14.13,P ＜0.05 ),whereas no significant correlation was detected between the amount of required energy and the treatment efficacy ( r =- 0.225,t =- 1.72,P ＞ 0.05 ).The equation for calculating the volume of ethanol required was conducted:Y =2.526X - 2.693 [ Y:volume of ethanol required ( ml),X:diameter of the tumor (cm) ].Three patients in the RFA + PEI group were complicated by transient pain,flushing and cardiac acceleration after the operation,and the symptoms were alleviated by symptomatic treatment.The levels of transaninase were increased in the 3 groups,and then back to normal at 2 weeks after the treatment.No complications such as hepatic rupture,intestinal perforation,bile leakage or tumor implantation were detected in the 2 groups.The levels of alphafetoprotein (AFP) were significantly decreased.The AFP expressions of 20 patients (80％) in the RFA group and 39 patients (85％) in the RFA + PEI group changed to negative,with no significant difference between the 2 groups ( x2 =0.42,P ＞ 0.05 ).Conclusion PEI helps to increase the volume of coagulative necrosis and to reduce the energy requirement of routine RFA,and enhances the efficacy of single needle RFA. Key words: Liver neoplasms; Ultrasound guidence; Percutaneous ethanol injection; Radiofrequency ablation, single needle

Effect of microbubble contrast agent during high intensity focused ultrasound ablation on rabbit liver in vivo

To evaluate the effect of a microbubble contrast agent (SonoVue) during HIFU ablation of a rabbit liver. HIFU ablations (intensity of 400W/cm(2) for 4s, six times, with a 5s interval between exposures) were performed upon 16 in vivo rabbit livers before and after intravenous injection of a microbubble contrast agent (0.8ml). A Wilcoxon signed rank test was used to compare mean ablation volume and time required to tissue ablation on real-time US. Shape of ablation and pattern of coagulative necrosis were analyzed by Fisher's exact test. The volume of coagulative necrosis was significantly larger in the combination microbubble and HIFU group than in the HIFU alone group (P<0.05). Also, time to reach ablation was shorter in the combination microbubble and HIFU group than in the HIFU alone group (P<0.05). When analyzing the shape of tissue ablation, a pyramidal shape was more prevalently in the HIFU alone group compared to the combination microbubble and HIFU group (P<0.05). Following an analysis of the pattern of coagulative necrosis, non-cavitary necrosis was found in ten and cavitary necrosis in six of the samples in the combination microbubble and HIFU group. Conversely, non-cavitary necrosis occurred in all 16 samples in the HIFU alone group (P<0.05). HIFU of in vivo rabbit livers with a microbubble contrast agent produced larger zones of ablation and more cavitary tissue necrosis than without the use of a microbubble contrast agent. Microbubble contrast agents may be useful in tissue ablation by enhancing the treatment effect of HIFU.

Combined Treatment of Large Hepatocellular Carcinoma with Transcatheter Arterial Chemoembolization and Percutaneous Ethanol Injection with a Multipronged Needle: Experimental and Clinical Investigation

This study was designed to evaluate the usefulness of percutaneous ethanol injection (PEI) with a multipronged needle for the treatment of large hepatocellular carcinoma (HCC). An experimental animal study and a clinical investigation were performed. In the experimental study, 20 ml of 99.5% ethanol was injected into porcine liver in vivo with a multipronged needle (n = 5) or a straight needle (n = 5), and the volumes of coagulation necrosis were compared. In the clinical investigation, PEI was performed in 17 patients (10 men, 7 women; mean age 73.4 ± 6.7 years) with single, large HCC (mean tumor diameter, 47.2 ± 11.5 mm; range, 32-70 mm) by using a multipronged needle. Fifteen of 17 patients received transarterial chemoembolization (TACE) before PEI. The volume of coagulation in porcine liver in vivo was significantly increased with the multipronged needle compared with the straight needle (longest perpendicular diameters, 34.2 ± 3.6 mm × 30.2 ± 3.6 mm vs. 22.6 ± 2.5 mm × 19 ± 2.2 mm, respectively; P < 0.05). In the clinical trial, initial complete response (CR) of the tumor was achieved in 17 of 17 patients, 7 of whom required two PEI sessions. During the follow-up, local recurrence was detected in 4 of 17 patients at 3-19 months after the procedure, for a rate of sustained local CR of 76%. No major complication occurred. Use of a multipronged needle substantially increases the volume of coagulation in vivo with respect to the conventional PEI technique. Combined TACE and PEI with multipronged needles is a safe and effective option for percutaneous treatment of single, large HCC.

Radiofrequency ablation of liver tumors (II): clinical application and outcomes

Radiofrequency ablation is one of the alternatives in the management of liver tumors, especially in patients who are not candidates for surgery. The aim of this article is to review applicability of radiofrequency ablation achieving complete tumor destruction, utility of imaging techniques for patients' follow-up, indications for local ablative procedures, procedure-associated morbidity and mortality, and long-term results in patients with different tumors. The success of local thermal ablation consists in creating adequate volumes of tissue destruction with adequate "clear margin," depending on improved delivery of radiofrequency energy and modulated tissue biophysiology. Different volumes of coagulation necrosis are achieved applying different types of electrodes, pulsing energy sources, utilizing sophisticated ablation schemes. Some additional methods are used to increase the overall deposition of energy through alterations in tissue electrical conductivity, to improve heat retention within the tissue, and to modulate tolerance of tumor tissue to hyperthermia. Contrast-enhanced computed tomography, magnetic resonance imaging, ultrasound or positron emission tomography are applied to control the effectiveness of radiofrequency ablation. The long-term results of radiofrequency ablation are controversial.

Interstitial laser therapy in hemangiomatosis of the liver – A case report

Abstract Objective Diffuse neonatal hemangiomatosis (DNH) is a severe disease with multiple organ involvement. If left untreated, it results in high mortality rates. Death occurs due to intractable heart failure following arteriovenous shunting or due to massive cerebral or gastrointestinal bleeding. If there are large liver hemangiomas and medical treatment is not sufficient, it is necessary to use interventional or surgical procedures such as embolization or ligation of the hepatic artery. We present another local tumor destruction procedure to treat liver hemangiomas in DNH, the interstitial laser therapy (ILT). Method ILT was performed in a 3-month-old male infant suffering from DNH with intractable heart failure and multiple liver hemangiomas. Due to the severity of the infant's condition and the minimally invasive character of the treatment, the ILT was performed directly in the neonatal intensive care unit. The ILT was carried out percutaneously by guiding a bare fiber (0.6 mm core diameter) via a puncture needle into the pathologically altered liver region. A Nd:YAG laser (1064 nm) was used as a light source for ILT because its light penetrates deeply into biological tissue. Tissue destruction was achieved with moderate laser power of 4–6 W and a long application time of 90–300 s. Using these applied physical laser parameters, almost spherical volumes of coagulation necrosis could be obtained with diameters of up to 1–2 cm. Puncture and the laser application were monitored by color-coded duplex sonography (CCDS). A decrease in color signal intensity at the tip of the bare fiber indicated the increasing tissue coagulation during application time. Results After 2 sessions of ILT of liver manifestation in 10 days the cardiac output was reduced by 50%. Postoperative Doppler imaging showed fibrosis in the treated areas of the liver. The child was transferred back to his country of origin but he died 3 months later of intracranial bleeding. Conclusion In our opinion interstitial laser therapy can be an effective minimally invasive method to treat life-threatening liver hemangiomas in diffuse neonatal hemangiomatosis.

4.09] Interstitial laser therapy of hemangiomatosis of the liver

Objective Diffuse neonatal hemangiomatosis (DNH) is a severe disease with multiple organ involvement. Untreated, there is a high mortality of approximately 60%. Death occurs due to intractable heart failure following arterio-venous shunting or due to massive cerebral or gastrointestinal bleeding. If there are large liver hemangiomas and medical treatment is not sufficient, interventional or surgical procedures like embolization or ligation of the hepatic artery has been used. We present another local tumor destruction procedure to treat liver hemangiomas in DNH, the interstitial laser therapy (ILT). Patient and methods We performed ILT in an infant with intractable heart failure in large liver hemangiomas in DNH. Due to the severe condition of the infant and the minimally invasive character of the treatment we performed the ILT directly in the neonatal intensive care unit. The ILT was carried out by guiding the laser applicator via a puncture needle into the pathologically altered liver region. Due to photon absorption and heat conduction coagulative and hyperthermic effects were obtained leading to an immediate or delayed tissue destruction. As light source for ILT a Nd:YAG laser (1064 nm) was used because its light penetrates deeply into biological tissue. Tissue destruction was achieved with moderate laser power of 5 W and a long application time of 90–300 s. With these applied physical laser parameters nearly spherical volumes of coagulation necrosis could be obtained showing diameters of up to 1–2 cm. The puncture and the laser application were monitored by color-coded duplex sonography (CCDS). The decrease in intensity of color signal at the tip of the bare fiber indicates the increasing tissue coagulation during application time. Results After 2 sessions of ILT of liver manifestation in ten days the cardiac output was reduced by 50%. Postoperative Doppler imaging showed fibrosis in the treated areas of the liver. The child was transferred back to his country. The boy died 2 month later because of progressive cranial and pulmonary manifestation. Conclusion In our opinion interstitial laser therapy can be an effective minimally invasive method to treat life threatening liver hemangiomas in diffuse neonatal hemangiomatosis.

Comparison of a Single Perfusion Device and an Internally Cooled Cluster Device: Laboratory Experience in ex Vivo Liver Tissue with Longer Duration of Energy Application

To determine with comparison of two different monopolar radiofrequency (RF) devices whether a longer duration of energy application has an effect on coagulation necrosis in ex vivo bovine liver tissue. The volume and short- and long-axis diameters of the coagulation were assessed in ex vivo bovine livers after RF application for 5-60 minutes. A power of 60 W was used for the single perfusion applicator (n = 48), and a power of 200 W was used for the internally cooled cluster applicator (n = 48). Reproducibility and coagulation shape were assessed and compared. For statistical evaluation, the mean values of the dimensions were compared by using analysis of variance with the following factors: applicator, RF duration, and their interaction. RF application up to 60 minutes produced a mean maximum volume of coagulation of 116.8 cm(3)(95% confidence interval [CI]: 98.4 cm(3), 138.8 cm(3)) for the single perfusion device and 89.5 cm(3)(95% CI: 75.4 cm(3), 106.3 cm(3)) for the internally cooled cluster applicator. For both devices, duration of energy application up to 60 minutes showed a significant interaction for the volume and the short- and long-axis diameters of coagulation (P < .0001). The volumes of coagulation necrosis induced with the internally cooled cluster applicator were more reproducible than those induced with the single perfusion applicator (P < .0001). The shape of the lesion was closer to a sphere (mean shape ratio, 0.98) for the internally cooled cluster than for the single perfusion applicator (mean shape ratio, 1.21) (P < .0001). There is a significant interaction between RF duration and both RF devices influencing the dimensions of coagulation. Longer durations of energy application expand the volume of coagulation with a better reproducibility and more spherical shape of coagulation for the internally cooled cluster device.

A combination therapy of ethanol injection and radiofrequency ablation under general anesthesia for the treatment of hepatocellular carcinoma

To summarize the effects of laparoscopic ethanol injection and radiofrequency ablation (L-EI-RFA), thoracoscopic (T-EI-RFA) and open-surgery assisted EI-RFA (O-EI-RFA) under general anesthesia for the treatment of hepatocellular carcinoma (HCC). Time-lag performance of RFA after ethanol injection (Time-lag PEI-RFA) was performed in all cases. The volume of coagulated necrosis and the applied energy for total and per unit volume coagulated necrosis were examined in the groups treated under general (group G) or local anesthesia (group L). The results showed that the total applied energy and the applied energy per unit volume of whole and marginal, coagulated necrosis were significantly larger in group G than those in the group L, resulting in a larger volume of coagulated necrosis in the group G. The rate of local tumor recurrence within one year was extremely low in group G. These results suggest that EI-RFA, under general anesthesia, may be effective for the treatment of HCC because a larger quantity of ethanol and energy could be applied during treatment under painfree condition for the patients.

Comparative study of the effects of percutaneous ethanol injection and radiofrequency ablation in cases treated with a straight or expandable electrode

Radiofrequency ablation (RFA) has become mainstream among non-surgical treatment modalities in clinical settings for the treatment of hepatocellular carcinoma. We have previously described the novel combination therapy of percutaneous ethanol injection and RFA (PEI-RFA) and reported that this combination therapy was more effective than RFA alone in terms of the induced volume of coagulated necrosis and the energy requirement for the treatment. RFA instruments are mainly divided into two types according to the electrode used, either the straight or expandable type electrode. Although PEI-RFA can be performed by either of the electrodes, there may be some important differences in PEI-RFA according to the type of electrode used. In the present study, the effect of using the straight or expandable electrode in PEI-RFA was evaluated by analyzing the ablation time, volume of coagulated necrosis, the energy requirement for ablation and the amount of injected ethanol into HCC. The comparative study showed that ablation time, total energy requirement and per unit volume of energy requirement for whole and marginal coagulated necrosis were significantly smaller in the group treated with the expandable electrode (E group) than those in the group treated with the straight electrode (S group). The volume of coagulated necrosis was similar between these groups. In group E, the amount of injected ethanol showed a positive correlation with the volume of coagulated necrosis and the size of the tumors. These results suggest that prior injection of ethanol works mainly by shortening the time and energy requirement for ablation in the time-lag PEI-RFA using the expandable electrode. Thus, prior injection of ethanol before RFA may make RFA treatment less invasive in the time-lag PEI-RFA using the expandable electrode as previously shown HCC cases treated with straight electrode.

Radiofrequency ablation of lung tumours - new perspective in treatment of lung neoplasms

Background. Percutaneous radiofrequency ablation (RFA) is a minimally invasive technique used to treat solid tumours. Because of its ability to produce large volume of coagulation necrosis in controlled fashion this technique has been progressively tested as a possible treatment of lung malignancies. Recent clinical studies have shown that RFA enables successful treatment of relatively small lung malignancies with high rate of complete response and acceptable morbidity and have suggested that the technique could represent a viable alternate or complementary method for patients with non-small cell lung cancer or lung metastases of favourable histotypes who are not candidates for surgical resection. Conclusions. Initial intenational studies as well as the clinical experience of Institute of Radiology in Clinical Center Ljubljana, although limited, indicated that RFA is mostly well tolerated by patients and also, that it can result in complete necrosis of targeted lesion. Pneumothorax is most common procedure related complication, occurring in up to 40% of cases, with approx. half of them requiring drainage.