Guangbin He

Extracorporeal Ablation of Uterine Fibroids With High-Intensity Focused Ultrasound Imaging and Histopathologic Evaluation

The purpose of this study was to evaluate the therapeutic efficacy of high‐intensity focused ultrasound (HIFU) in the treatment of uterine fibroids by using imaging and histopathologic examination.

Enhancement of ultrasound contrast agent in high-intensity focused ultrasound ablation.

High-intensity focused ultrasound (HIFU) is becoming an increasingly attractive modality for ablation. Enhancement of HIFU is an important issue that has been discussed and investigated worldwide. Ultrasound contrast agents are considered to constitute an efficient medium for changing acoustic characteristics and improving energy deposition in the focal region. The role of microbubbles in inducing enhanced heating, cavitation, and other related events in HIFU ablation has been investigated, with the goal of improving coagulation necrosis volume or decreasing acoustic power and exposure duration. Consequently, with the use of ultrasound contrast agents, applications of HIFU are expected to become more efficient, safe, and accurate and to produce fewer adverse effects. This paper reviews studies that have been conducted to investigate the enhancement of ultrasound contrast agents in HIFU ablation through experiments that were carried out in vitro and in vivo; an analysis of results of this enhancement mechanism is provided.

Enhancing Effects of SonoVue, a Microbubble Sonographic Contrast Agent, on High-Intensity Focused Ultrasound Ablation in Rabbit Livers In Vivo

The purpose of this study was to explore the enhancing biological effects of SonoVue (Bracco SpA, Milan, Italy), a sulfur hexafluoride sonographic contrast agent, on high‐intensity focused ultrasound (HIFU) ablation in vivo.

Sonographically guided extracorporeal ablation of uterine fibroids with high-intensity focused ultrasound: midterm results.

To the Editor: In our previous study, we reported the imaging and pathologic results of high-intensity focused ultrasound (HIFU) treatment of uterine fibroids in 119 patients.1 However, we did not mention the follow-up results of these patients. In the following period, we treated another 26 patients. We are very concerned about the follow-up results of these patients, including quality-of-life improvement and symptom recovery. In this study, we mainly focused on the clinical midterm results and complications analysis of these 145 patients. Noninvasive treatment of tumors is highly desirable and provides an alternative to surgery. One such treatment undergoing active research is HIFU.2,3 Although studies have been performed in many different areas, including breast, brain, and liver tumors,4–7 the largest body of work to date has taken place in women with symptomatic uterine fibroids. Most studies in European countries are focused on magnetic resonance imaging–guided HIFU.8–11 In China, however, sonographically guided HIFU is much more popular. In our previous study, we reported our experience using extracorporeal sonographically guided HIFU for the treatment of patients with uterine fibroids and described the imaging and histopathologic evaluation results of the efficacy of HIFU treatment. In this study, we have included more patients and will mainly report the clinical midterm results and complication analysis. Patients with symptomatic fibroids were enrolled in this study at Xijing Hospital of the Fourth Military Medical University, Xi’an, China. Finally, 145 consecutive patients with 220 uterine fibroids underwent HIFU ablation between May 2004 and October 2005. This study was approved by the Institutional Review Board, and written informed consent was obtained from all patients. Table 1 describes the patient data and baseline characteristics of uterine fibroids. An HIFUNIT 9000 tumor therapy system (Shanghai Aishen Technology, Shanghai, China) was used. A schematic diagram of the therapeutic arrangement used in this work is shown in Figure 1. The specific treatment method and treatment parameters are as in the previous study.1 Before treatment, all patients from the study were asked to fill out a questionnaire about fibroid-related symptoms. They were supposed to report the occurrence (yes or no) and intensity (on a scale from 1 to 10, where 1 meant no such symptom and 10 meant maximal severity of the symptom) of the following conditions: (1) menometrorrhagia or hypermenorrhea, (2) dysmenorrheal, (3) dyspareunia, (4) pelvic pain, (5) dysuria, and (6) bulk-related symptoms. Each woman was interviewed 1 week after treatment, and the interest was focused on early complications and the duration until full recovery. Office visits were also planned at 1, 3, 6, and 12 months after HIFU treatment. A telephone interview or office visit also was completed every year thereafter. The women were asked to evalu-

Clinical Application of Contrast-Enhanced Ultrasonography in Diagnosis of Superficial Lymphadenopathy

Objective. The purpose of this study was to evaluate the value of contrast‐enhanced ultrasonography (CEUS) in differential diagnosis of superficial lymphadenopathy. Methods. Ninety‐four superficial enlarged lymph nodes in 94 patients were studied by conventional ultrasonography (gray scale and color Doppler) and CEUS. Contrast‐enhanced sonograms were analyzed using contrast‐specific quantification software. All of the results were compared with pathologic diagnoses. Results. Of the 94 lymph nodes examined, 44 were benign and 50 were malignant (33 metastases and 17 lymphomas). The sensitivity, specificity, and accuracy of conventional ultrasonography in differential diagnosis between benign and malignant nodes were 51%, 47%, and 55%, respectively. Contrast‐enhanced ultrasonography showed intense homogeneous enhancement in 39 of 44 benign lymph nodes, inhomogeneous enhancement in 32 of 33 metastases, and intense homogeneous enhancement and absence of perfusion in 9 of 17 and 6 of 17 lymphomas, respectively. The sensitivity specificity, and accuracy of CEUS were 84%, 79%, and 80%. After time‐intensity curve gamma variates were calculated, the area under the curve of the benign lymph nodes was greater than those of the metastatic lymph nodes and lymphomas (P < .01). Conclusions. These results indicate that the use of CEUS and contrast‐specific software has a higher degree of diagnostic accuracy than conventional ultrasonography for evaluations of superficial lymphadenopathy. The contrast enhancement patterns and time‐intensity curves provide valuable diagnostic information for differential diagnosis of benign and malignant lymph nodes.

Role of Sonography for Implantation and Sequential Evaluation of a VX2 Rabbit Liver Tumor Model

Objective. We investigated the role of sonography in the implantation process of a VX2 rabbit liver tumor model and sequential evaluation. Methods. Fifty rabbits were divided into 2 groups. Animals in group I underwent surgical implantation, whereas those in group II received percutaneous sonographically guided implantation. At 7, 14, 21, and 28 days after implantation, respectively, 5 rabbits in each group were examined with conventional, color Doppler (CD), contrast‐enhanced (CE) pulse inversion harmonic (PIH), and CE CD sonography. Pathologic examination was performed with hematoxylin‐eosin, nicotinamide adenine dinucleotide phosphate‐diaphorase, and succinic dehydrogenase stains. Results. Twenty‐one rabbits with tumors survived in group I, and 22 with tumors survived in group II. The mean duration of implantation ± SD in group II was 16.9 ± 3.4 minutes, whereas that in group I was 21.5 ± 4.1 minutes (P < .05). The tumor volume measured by conventional sonography increased from 0.28 ± 0.14 cm3 at 7 days to 16.49 ± 5.50 cm3 at 28 days in group I and from 0.31 ± 0.19 to 19.79 ± 4.70 cm3 in group II, whereas no significant difference existed between the groups. On CD, CE PIH, and CE CD sonography, most tumors were hypervascular before 14 days and after 14 days had peripheral vessels and central hypovascular areas, which were shown as necrotic areas by pathologic examination. Conclusions. Sonographically guided implantation achieved a good success rate with convenient inoculation performance. Conventional gray scale, CD, CE PIH, and CE CD sonography were useful in sequential evaluation of tumor growth and characteristic vascularity.

Transmission electron microscopy of VX2 liver tumors after high-intensity focused ultrasound ablation enhanced with SonoVue®

IntroductionThe purpose of this study was to observe sequential changes in rabbit VX2 liver tumors using transmission electron microscopy after high-intensity focused ultrasound (HIFU) ablation enhanced with the contrast agent SonoVuer® (Bracco, Milan, Italy).MethodsThirty New Zealand rabbits with VX2 liver tumors were randomly divided into two groups. The liver tumors of rabbits in Group A underwent single HIFU ablation; those in Group B were given the ultrasound contrast agent SonoVue 0.2 mL/kg before HIFU exposure. Five rabbits from each of the two groups were killed at 0 hours, 6 days, and 14 days after HIFU ablation. Tissue samples that included targeted and untargeted tissue were observed using transmission electron microscopy.ResultsUsing transmission electron microscopy, it was evident that most of the cellular organs in the targeted areas of tumors in Groups A and B had disappeared early after HIFU, but the basic cell structure was seen in Group A. On the sixth day after HIFU ablation, all cells in the targeted areas were disrupted, and fibrous bands were detected in the rims of targeted areas in both groups. In the surrounding areas, cell swelling in Group B was more severe than in Group A, and a greater number of apoptotic bodies were found in Group B.ConclusionThe use of an ultrasound contrast agent can enhance the effects of HIFU ablation on the destruction of cell ultrastructure and can enlarge the region of HIFU ablation; this provides experimental evidence for the use of contrast agents in controlling the effects of HIFU.

Ultrasound-guided percutaneous laser and ethanol ablation of rabbit VX2 liver tumors

Background Only a small percentage of patients with hepatocellular carcinoma (HCC) may benefit out of surgical resection. Thus, lots of these patients are in need of local control, such as percutaneous ethanol injection (PEI), percutaneous laser ablation (PLA), or radiofrequency thermal ablation (RF). Purpose To investigate the effects of ultrasound-guided PLA combined with PEI on rabbit VX2 liver tumors, using conventional gray-scale ultrasonography (US), color/power Doppler (CD/PD)US, contrast-enhanced (CE) US, and histologic examination. Material and Methods VX2 tumors were implanted in the livers of 80 rabbits. Fourteen days after implantation, animals were randomly separated into four groups of 20 rabbits. Treatment of the four groups was with: (i) PLA; (ii) PEI; (iii) combined therapy of PLA immediately followed by PEI; and (iv) combined therapy of PEI immediately followed by PLA. Conventional gray-scale US, CD US, PD US, and CE US were performed before and after ablation. The effects on ablated areas were assessed by histologic examination. Results Conventional gray-scale US showed a clear boundary around the ablated area in groups 1, 3, and 4. An isoechoic treated region with an irregular boundary was seen in group 2. On CE US, coagulated areas demonstrated a perfusion defect. Both conventional gray-scale US and CE US showed that the ablated volume in group 4 was larger than that in groups 1, 2, and 3. CD US and PD US demonstrated residual tumor in the periphery of ablated areas in groups 1 and 2, but not in groups 3 and 4. CE US demonstrated no residual tumor in group 4, unlike in groups 1, 2, and 3. Examination of treated tumors demonstrated necrosis in the ablated zones and increasing surrounding fibrous bands in the four treatment groups. Residual viable tissue in group 4 was less than that in groups 1, 2, and 3. Conclusion Combined therapy of PEI immediately followed by PLA can coagulate significantly larger volumes of tumor and reduce residual tumor.

Effects of radiofrequency ablation versus other ablating techniques on hepatocellular carcinomas: a systematic review and meta-analysis

BackgroundPercutaneous ablation has quickly arisen as one of the important alternative treatments for hepatocellular carcinoma (HCC). We aimed to compare the therapeutic effects of radiofrequency ablation (RFA) and other ablative techniques on HCCs.MethodsDatabases were searched to identify literature on complete tumor ablation (CTA), overall survival (OS), local tumor recurrence (LTR), and complications of RFA in the treatment of HCC, compared with those of microwave ablation (MWA), percutaneous ethanol injection (PEI), PEI plus RFA, cryoablation (CRA), laser ablation (LSA), and high-intensity focused ultrasound. Randomized controlled trials and high-quality cohort studies were included in the assessment.ResultsThe effects of MWA and CRA appeared to be similar to those of RFA, but lower rates of LTR and higher rates of CTA in large tumors compared with RFA were reported (P < 0.05). CTA rates were lower in patients treated with PEI (odds ratio [OR] 0.16, 95% confidence interval [CI] 0.06–0.42), and higher in those treated with PEI plus RFA (OR 2.28, 95% CI 1.19–3.60), with an increased incidence of fever (P < 0.05). LSA resulted in lower CTA rates (OR 0.32, 95% CI 0.13–0.81) and OS (hazard ratio 1.47, 95% CI 1.01–2.15), with a lower incidence of complications.ConclusionsCompared with RFA, identical effects were found in MWA and CRA groups. Fewer complications were observed in PEI and LSA group. PEI plus RFA appeared more effective, with a higher rate of complications. Well-designed randomized controlled trials are further needed to confirm above results.

Efficacy of radio frequency thermocoagulation in surgery for giant supratentorial meningiomas: A historical control study

BACKGROUND Surgery for giant meningiomas carries a high risk of bleeding and is time-consuming. This historical control study tests the hypothesis that the use of radio frequency thermocoagulation (RFT) during surgery improves outcome. METHODS From November 2010 to October 2011, 20 giant vascularized meningiomas were surgically resected with intraoperative use of ultrasound-guided RFT prior to resection. The historical control group consisted of 25 patients in whom tumors were removed without RFT by the same surgical team. Blood loss during resection, changes in tumor consistency, time taken for the operation, and the extent of resection were compared between the two groups. RESULTS There was less blood lost during resection and the duration of the operation was shorter in RFT-assisted surgery than in the historical control group (P<0.05). Apart from the effect of devascularization, the tumor consistency became soft after RFT, which could also be beneficial. CONCLUSIONS Satisfactory devascularization and tumor softening were achieved after RFT without incremental complications. RFT-assisted surgery for giant vascularized supratentorial meningiomas is easier and safer than non-RFT surgery.