Ultrasound-guided High-intensity Focused Ultrasound Ablation Research Articles

Long-term re-intervention after USgHIFU and prediction of NPVR in different ages of patients with uterine fibroids

Objective Long-term re-intervention after ultrasound-guided high intensity focused ultrasound (USgHIFU) ablation was reported, and the prediction of non-perfusion volume ratio (NPVR) in differently aged patients with uterine fibroids (UFs) was explored. Materials and Methods Patients with UFs who underwent USgHIFU ablation from January 2012 to December 2019 were enrolled and divided into < 40-year-old and ≥ 40-year-old groups. Cox regression was used to analyze the influencing factors of re-intervention rate, and receiver operating characteristic (ROC) curve was used to analyze the correlation between NPVR and re-intervention rate. Results A total of 2141 patients were enrolled, and 1558 patients were successfully followed up. The 10-year cumulative re-intervention rate was 21.9%, and the < 40-year-old group had a significantly higher rate than the ≥ 40-year-old group (30.8% vs. 19.1%, p < 0.001). NPVR was an independent risk factor in both two groups. When the NPVR reached 80.5% in the < 40-year-old group and 75.5% in the ≥ 40-year-old group, the risk of long-term re-intervention was satisfactory. Conclusion The long-term outcome of USgHIFU is promising. The re-intervention rate is related to NPVR in differently aged patients. Young patients need a high NPVR to reduce re-intervention risk.

Long-term outcomes of ultrasound guided high intensity focused ultrasound ablation for patients with uterine fibroids classified by T2WI: a multicenter retrospective study

Objective To evaluate the long-term outcomes of ultrasound-guided high-intensity focused ultrasound (USgHIFU) ablation of uterine fibroids classified by T2-weighted magnetic resonance imaging (T2WI-MRI). Materials and methods The data of 1427 premenopausal women with symptomatic uterine fibroids who underwent USgHIFU at four teaching hospitals in China were analyzed retrospectively. The uterine fibroids were classified based on their T2WI-MRI signal intensities relative to that of skeletal muscle, myometrium and endometrium as: hypointense, isointense, heterogeneous hyperintense fibroids (HHF), slightly HHF (sHHF) and markedly HHF (mHHF), respectively. The rates of symptom relief and reintervention post-USgHIFU ablation were compared between the classified groups. Results A total of 1303 patients were followed up for 44 (40, 49) months. The symptom relief rate of the hypointense and isointense fibroids was 83.3% and 79.5%, respectively, which were significantly higher (p < .05) compared to that of HHF, sHHF and mHHF (58.3%, 44.2% and 60.4%), respectively. sHHF had the lowest symptom relief rate (p < .05). The cumulative reintervention rate for hypointense, isointense, HHF, sHHF and mHHF types were 8.8%, 10.8%, 21.4%, 39.9% and 19.8%, respectively. The reintervention rate of hypointense/isointense fibroids was significantly lower than that of HHF/mHHF/sHHF (p < .01), while sHHF had the highest re-intervention rate (p < .01). Thus, reintervention rate is inversely correlated to the rate of symptom relief. Conclusions USgHIFU ablation is effective for hypointense, isointense, HHF and mHHF with acceptable long-term follow-up outcomes. However, sHHF is associated with a higher reintervention rate.

High-intensity focused ultrasound as a pretreatment combined with hysteroscopic resection for gestational trophoblastic neoplasia with chemotherapy intolerance: a case report

Background Due to resistance and intolerance to chemotherapy, localized lesion resection may be required in some patients with Gestational trophoblastic neoplasia (GTN), which may lead to massive bleeding. In this case report, we describe the successful use of high-intensity focused ultrasound (HIFU) as an effective pretreatment method for surgical procedure in a patient with GTN to reduce the perioperative risk and the impact on fertility. Case presentation A 26-year-old woman was diagnosed with high-risk GTN (FIGO Stage III: 12 prognostic scores) after a hydatidiform mole. The fifth chemotherapy cycle was interrupted due to severe chemotherapy toxicity. However, the uterine lesion was still present and the beta-human chorionic gonadotropin (β-hCG) level was not restored to normal. Therefore, ultrasound-guided HIFU was performed as a pretreatment method to shrink the lesion and prevent massive bleeding during localized lesion resection. The effectiveness of ablation was evaluated immediately using contrast-enhanced ultrasound and Color Flow Doppler ultrasonography. One month after HIFU treatment, the uterine lesion was completely resected under hysteroscopic surgery. During the surgery, HIFU was found to have shrunk the lesion and there was minimal bleeding (5 mL). The uterine cavity morphology and menstruation returned to normal after surgery. The patient has showed no signs of recurrence as of one-year follow-up. Conclusion Ultrasound-guided HIFU ablation may be a new choice for high-risk GTN patients with chemoresistance or chemo-intolerance. As a noninvasive pretreatment method, HIFU can shrink the uterine lesion, and reduce the risk of bleeding with no obvious effect on fertility.

Factors influencing magnetic resonance imaging finding of endopelvic fascial edema after ultrasound-guided high-intensity focused ultrasound ablation of uterine fibroids

Objective Investigate the relationships between endopelvic fascial edema and its influencing factors after ultrasound-guided high-intensity focused ultrasound (USgHIFU) ablation of uterine fibroids. Methods This retrospective study included 688 women with uterine fibroids treated by USgHIFU; based on post-treatment MRI, the patients were divided into two groups: endopelvic fascial edema group and nonedema group. The specific location of fascial edema of each patient was also recorded. Fascial edema and fibroid features and treatment parameters were set as the dependent and independent variables, respectively, and the correlations were studied using univariate and multivariate analyses. The relationship between the pain-related adverse events and location of fascial edema was analyzed by χ2 and fisher's exact tests. Results Edema and nonedema groups had 556 and 112 patients, respectively. Among the edema patients, posterior fascial edema incidence was the highest. Multifactorial analysis showed that the energy efficiency factor (EEF), fibroid location, and enhancement type were positively associated with endopelvic fascial edema (p < 0.05), while the distance from dorsal surface of the fibroid to sacrum was negatively correlated (p < 0.001). Patients with anterior, posterior and perirectal, and right lateral fascial edemas were associated with lower abdominal pain, sacrococcygeal pain, and leg numbness/pain, respectively. Conclusion Post-USgHIFU ablation, patients were prone to developing endopelvic fascial edema, and some of them experienced pain-related adverse events. The fibroid location, its types of contrast enhancement, the distance from the dorsal surface of the fibroid to the sacrum, and EEF were the influencing factors resulting in the endopelvic fascial edema after USgHIFU ablation.

Effectiveness and safety of ultrasound-guided high-intensity focused ultrasound ablation for the treatment of colorectal cancer liver metastases

Objective To investigate the effectiveness and safety of high-intensity focused ultrasound (HIFU) ablation for patients with colorectal liver metastases (CRLMs) who were unsuitable for hepatectomy. Methods This is a multicenter retrospective study. 238 CRLM patients underwent ultrasound-guided HIFU (USgHIFU) ablation in three medical centers from October 2014 to December 2020. Patients who had complete colorectal cancer resection, but exhibited extra-hepatic metastasis were excluded from this study. HIFU ablation procedure was performed, and contrast-enhanced MR imaging and/or contrast-enhanced CT examinations were conducted and mRECIST was used for the assessment of tumor ablation effectiveness before and after treatment, and every 3 months thereafter. Adverse events and complications were recorded. Results 43 CRML patients (27 male, 16 female, aged 29–82 years) were enrolled and underwent a USgHIFU ablation procedure. CR (complete response) was achieved in 21 patients, while PR (partial response) was observed in 21 patients and SD (stable disease) was achieved in one patient, respectively. The objective response rate was 97.7%. Median OS (overall survival) was estimated to be 31 months, and1-year and 18-month overall survival was 90.7% (39/43) and 72.1% (31/43), respectively. For CR and PR patients, the median OS was 35 months and 23 months, respectively (p = 0.00). The majority of adverse events were pain in 22 cases (51.2%) and local skin edema in 33 cases (76.7%). No severe adverse events or complications were reported and recorded. Conclusions USgHIFU ablation is a safe and effective treatment option for CRLM patients, especially for patients who are unsuitable for hepatectomy.

Preliminary study on ultrasound-guided high-intensity focused ultrasound ablation for treatment of broad ligament uterine fibroids

Objective To investigate the feasibility, efficacy and safety of ultrasound-guided high-intensity focused ultrasound (HIFU) ablation for treating the broad ligament uterine fibroid (BLUF). Methods A total of 236 patients with symptomatic uterine fibroids were enrolled and treated with JC-200 extracorporeal ultrasound-guided HIFU under conscious sedation between January 2017 and December 2018. Of them, data of 12 patients with 13 broad ligament fibroids were retrospectively analyzed. The patients’ mean age was 38.6 ± 6.3 years. The focused ultrasound target was deployed and moved from the deeper layer to the superficial layer of BLUFs. All patients underwent contrast-enhanced MRI (CE-MRI) before, immediate post-operation, and six months after the HIFU ablation procedure. The fibroid size, non-perfusion volume (NPV) ratio, the reduction of fibroid volumes, adverse events, symptom changes, and abnormal MRI findings associated with the HIFU treatment were analyzed. Results Ultrasound-guided HIFU ablation in the twelve patients was technically successful with one session treatment. The mean longest diameter of BLUFs was 6.2 ± 2.3 cm. The mean NPV ratio of fibroids was 84.08%± 9.4%. After HIFU ablation, lower abdominal pain occurred in 7 cases, sacrococcygeal pain in 3 cases, and mild skin pain in 6 cases. There were no severe adverse events and complications associated with the treatment. At 6 months post-treatment follow-up, the mean fibroid volume decreased by 56.2%± 9.0% (p < 0.05), and the symptoms related to broad ligament fibroids were improved or disappeared Conclusions Ultrasound-guided high-intensity focused ultrasound ablation is feasible, effective, and safe for treating broad ligament fibroids.

The safety and ablation efficacy of ultrasound-guided high-intensity focused ultrasound ablation for desmoid tumors

Objective To evaluate the safety and efficacy of ultrasound-guided high-intensity focused ultrasound (USgHIFU) ablation for desmoid tumors (DTs). Method A total of 111 patients with histologically proven DTs were included and treated by USgHIFU ablation. Adverse events were continuously evaluated according to the Common Terminology Criteria for Adverse Events (CTCAE) v5.0 until 3 months after treatment. The incidence of non-perfused areas within the treated tumors, non-perfused volume rate (NPVR) and tumor volume reduction were evaluated using contrast-enhanced MRI before and one week and 3 months after the procedure. Results The enrolled patients (32 male, 79 female, mean age 29.5 ± 1.0 years) with 145 DTs (118 extra-abdominal, 16 abdominal wall, 11 intra-abdominal; median maximum diameter: 9.6 cm, range: 3–34.5 cm) underwent 188 sessions of HIFU ablation, and the mean number of ablations was 1.7 (range, 1–7) per patient. In majority of cases (143/145 cases, 98.6%), no serious adverse events were observed. There was no significant difference in the incidence of adverse events between patients who received a single treatment and those who received multiple treatments. Non-perfused area was observed within every treated tumor, and the median NPVR was 84.9% (range, 1.9–100%). The tumor volume reduction rate was 36.1 ± 4.2% at 3 months after treatment. Conclusion USgHIFU ablation, as a noninvasive and easily repeatable local treatment, is a promising treatment for DTs.

A comparison of the pregnancy outcomes between ultrasound-guided high-intensity focused ultrasound ablation and laparoscopic myomectomy for uterine fibroids: a comparative study

Objective To compare the pregnancy outcomes between ultrasound-guided high-intensity focused ultrasound (USgHIFU) ablation and laparoscopic myomectomy (LM). Materials and methods This study included 676 women with symptomatic uterine fibroids who wished to become pregnant underwent USgHIFU or LM at three hospitals in China from 1 May 2009 to 31 May 2018. The related information of pregnancy and delivery were followed up and analyzed using the chi-square test and two-sided Student t-test. Results The median follow-up duration was 5 (1–8) years; 20 patients (2.9%) were lost to follow-up. 320 patients were treated with UsgHIFU, and 336 were treated with LM. Two hundred nineteen (68.4%) women became pregnant after USgHIFU ablation, and 224 (66.7%) became pregnant after LM. Four hundred forty-three patients had 501 pregnancies (natural pregnancies, 405; in vitro fertilisation-embryo transfer pregnancies, 38). Average times to pregnancy were 13.6 ± 9.5 months after USgHIFU and 18.9 ± 7.3 months after LM (p < 0.05). The rate of cesarean delivery was lower in the USgHIFU group (41.6%) than in the LM group (54.9%) (p < 0.05). Incidences of placenta increta, placenta previa, and postpartum hemorrhage were low after USgHIFU compared with after LM. Incidences of preterm birth, fetal distress, fetal growth restriction, and puerperal infection were higher after USgHIFU than after LM. There was a risk of uterine rupture after both procedures. Conclusions Compared with LM, USgHIFU ablation can significantly shorten the time to pregnancy, although pregnancy rates of the two procedures are similar. Some risks in pregnancy and delivery after HIFU should be evaluated and monitored.

Ultrasound-Guided High Intensity Focused Ultrasound Ablation forSymptomatic Uterine Fibroids: Preliminary Clinical Experience.

To evaluate the middle-term efficacy and complications of ultrasound-guided high intensity focused ultrasound (USgHIFU) for the treatment of symptomatic uterine fibroids in an NHS population. A prospective observational single-center study at a single university hospital in Oxford, UK. Patients with symptomatic uterine fibroids who declined standard surgical/radiological intervention and were referred to the HIFU unit were considered for USgHIFU treatment. Clinical evaluation, adverse event monitoring, uterine fibroid symptoms and health-related quality of life questionnaire (UFS-QOL) and contrast-enhanced pelvic magnetic resonance imaging (MRI) were performed before and at regular intervals after treatment to assess patient outcome. 12 of 22 referred patients underwent one session of USgHIFU ablation of 14 fibroids overall and received a two-year follow-up. No serious adverse events were reported, but a second-degree skin burn was observed in one patient who had a surgical scar from a previous caesarean section. Mean symptom severity scores (SSS-QOL) improved significantly from 56.5 ± 29.1 (SD) at baseline to 33.4 ± 23.3 (p < 0.01) at three months, 45.0 ± 35.4 (p < 0.05) at one year and 40.6 ± 32.7 (p < 0.01) at two years post-treatment. The mean non-perfused volume ratio was 67.7 ± 39.0 % (SD) in the treated fibroids (n = 14) within three months of treatment. The mean volume reduction rates of the treated fibroids were 23.3 ± 25.5 % (SD) at 3 months post-treatment (p < 0.01, n = 14), 49.3 ± 23.7 % at 12 months (p < 0.05, n = 8), and 51.9 ± 11.1 % at 24months (p < 0.005, n = 8). This study demonstrates the clinical efficacy of USgHIFU ablation of uterine fibroids and the low risk of complications. We believe that this noninvasive approach may offer an alternative therapy for women with symptomatic uterine fibroids. While HIFU is fast becoming the standard of care for fibroid ablation in other countries, to our knowledge, this study is the first to present clinical experience of US-guided HIFU ablation of symptomatic uterine fibroids in an NHS population. High intensity focused ultrasound (HIFU) can be used for the noninvasive ablation of symptomatic uterine fibroids, and MR-guided treatment has already gained FDA approval. Ultrasound-guided HIFU has the advantage of offering practicalities in anesthesia and considerable cost-savings over MR-guided treatments. In this prospective study we have demonstrated the middle-term efficacy and favorable safety profile of ultrasound-guided HIFU for the treatment of symptomatic uterine fibroids for the first time in an NHS population.

Unintended pregnancies with term delivery following ultrasound-guided high-intensity focused ultrasound (USgHIFU) ablation of uterine fibroid and adenomyosis

Purpose of Investigation: This study aimed to assess the pregnancy outcome of patients with uterine fibroid or adenomyosis treated by ultrasound-guided high-intensity focused ultrasound (USgHIFU) ablation. Materials and Methods: Treatment was administrated using a focused ultrasound tumor therapeutic system. In this study, there were 23 unintended pregnancies after USgHIFU ablation. Results: Twelve patients developed no complication during pregnancy and continued until full term delivery. Vaginal and cesarean section deliveries were also uneventful. The following are the pregnancy outcome of the patients: three patients experienced spontaneous abortions, one patient experienced preterm delivery, and five patients remained pregnant at this point. Conclusions: USgHIFU seems to have the effectiveness to precisely treat adenomyosis and uterine fibroid, allowing for normal reproduction. Well-designed prospective trials are needed to ascertain the safety of this treatment with pregnancy due to the lack of large-scaled study.

Factors influencing MR changes associated with sacral injury after high-intensity focused ultrasound ablation of uterine fibroids

Purpose: We investigated the risk factors influencing MR changes associated with sacral injury from ultrasound-guided high-intensity focused ultrasound (USgHIFU) ablation for uterine fibroids.Methods: We retrospectively analyzed a total of 346 patients with symptomatic uterine fibroids who received USgHIFU ablation. All of the patients underwent contrast-enhanced magnetic resonance imaging (CE-MRI) before and after treatment. Injury to the sacrum was set as the dependent variable, while fibroid features and the treatment parameters were set as independent variables. These variables were used to assess respectively their correlation with sacral injury by using univariate and multivariate analyses.Results: The results of univariate analysis revealed that the volume, distance from the fibroid to the skin, maximal diameter, distance from the fibroid to the sacrum, fibroid types, degree of enhancement, therapeutic dosimetry (TD), energy efficiency factor (EEF) and non-perfused volume (NPV) ratio manifested significant correlations with the sacral injury (p < .05). Multivariate analysis showed that the degree of enhancement, TD and EEF were independent risk factors for sacral injury (p < .05), while the distance from fibroid to sacrum and intramural or subserosal types were protective factors (p < .05). The incidence of sacral tail pain and leg pain showed a significant positive correlation with sacral injury (p < .05).Conclusion: As important affecting factors, the degree of enhancement, distance from fibroid to sacrum and fibroid types all possess significant correlations with MR changes associated with sacral injury.

Vaginal delivery outcomes of pregnancies following ultrasound-guided high-intensity focused ultrasound ablation treatment for uterine fibroids

Objective: To evaluate the feasibility and safety of vaginal delivery after ultrasound-guided high-intensity focused ultrasound (HIFU) ablation treatment for women with uterine fibroids of child-bearing ages.Methods: A prospective study was conducted on women who underwent ultrasound-guided HIFU therapy for uterine fibroids at the Chinese PLA General Hospital from January 2008 to December 2014. Patients were interviewed yearly to assess their fertility outcomes, including conception method, delivery mode, neonatal outcomes and complications during pregnancy, labor, and delivery.Results: A total of 174 patients with plans for future pregnancy were included, and 88 pregnancies in 81 women occurred. The pregnancy rate was 46.6% (81/174), and the median follow-up time was 76 months. The rate of pregnancies that ended in miscarriages was 10% (9/88), the rate of elective pregnancy termination was 6% (5/88), and 84% (74/88) of the pregnancies resulted in deliveries, with 3 of the 71 women having two deliveries. A cesarean section was requested by 50% (37/74) of the women, and 50% (37/74) opted for a vaginal delivery. Eleven of the 37 pregnancies were scheduled for elective cesarean sections, owing to pregnancy complications; the remaining 26 pregnancies were scheduled for vaginal delivery, and 21 (80.8%) were successful. None of the patients with a vaginal delivery experienced any complications during pregnancy and labor.Conclusions: Ultrasound-guided HIFU ablation could be considered a promising clinical treatment for women with uterine fibroids and plans for future pregnancy, and vaginal delivery after ultrasound-guided HIFU ablation treatment appear to be feasible and safe.

A clinical investigation treating different types of fibroids identified by MRI-T2WI imaging with ultrasound guided high intensity focused ultrasound

Clinical data from 172 cases of uterine fibroids with different appearances on MRI-T2WI and accepted ultrasound guided high intensity focused ultrasound (USgHIFU) treatment were retrospectively analyzed. This study aimed to evaluate the clinical safety and efficacy of ablating different types of fibroids, classified by T2-weighted magnetic resonance imaging (MRI-T2WI). Based on MRI-T2WI signal intensities, uterine fibroids were classified as three types: hypointensive (52 cases), isointensive (64 cases) and hyperintensive (56 cases). Evaluation parameters including treatment time, ablation efficiency, percentage non-perfused volume, fibroid reduction rate, adverse reactions, symptom severity scores (SSS) and re-intervention rate were assessed from 3 months to 1 year. The percentage non-perfused volume and ablation efficiency of hyperintensive uterine fibroids were lower than those of isointensive and hypointensive uterine fibroids. All fibroids shrunk and the SSS continued to reduce at 3 and 6 months after treatment respectively. At 12-month postoperative assessments, hypointensive fibroids continued to shrink, while the isointensive fibroids enlarged but remained smaller than pre-treatment. The incident rate of postoperative Society of Interventional Radiology B-class (SIRB-class) adverse events showed no significant differences. The re-interventional rate of hyperintensive fibroids was higher than in isointensive and hypointensive groups. USgHIFU ablation of all types of fibroids were safe and effective.

Clinical Predictors of Long-term Success in Ultrasound-guided High-intensity Focused Ultrasound Ablation Treatment for Adenomyosis: A Retrospective Study.

The long-term outcomes of ultrasound-guided high-intensity focused ultrasound (USgHIFU) ablation treatment for adenomyosis and the relevant factors affecting the durability of symptom relief were assessed in this study.A total of 230 women with adenomyosis who were treated with USgHIFU ablation between January 2007 and December 2013 were retrospectively analyzed. The contrast-enhanced ultrasonography (CEUS) was performed immediately after the treatment to evaluate the ablation effect, and the nonperfused volume (NPV) ratio was then calculated. Regular follow-up was conducted and the visual analog scale (VAS) score was used to assess the changes in dysmenorrhea. The effect of treatment was evaluated after an average follow-up length of 3 months and the factors affecting clinical success and symptom relapse were identified.Of the 230 treated patients, 208 (90.4%) were followed up regularly, with a median follow-up length of 40 months (range, 18–94 months). Mean value of the NPV ratio calculated immediately after the treatment was 57.4 ± 24.4%. Varying degrees of symptomatic relief of dysmenorrhea based on the VAS scores were observed in 173 (83.2%) patients and 71.0% of the patients were asymptomatic during follow-up. Women with higher NPV ratio (OR = 0.964, 95% CI = 0.947–0.982, P = 0.000) and older age (OR = 0.342, 95% CI = 0.143–0.819, P = 0.016) were more likely to achieve clinical success. Dysmenorrhea recurred in 45 (26%) out of 173 cases; the median recurrence time was 12 months after treatment. The lower BMI (OR = 1.221, 95% CI = 1.079–1.381, P = 0.001) and the higher acoustic power (OR = 0.992, 95% CI = 0.986–0.998, P = 0.007) were associated with less risk of relapse. Twelve of the 14 patients who were retreated by USgHIFU ablation after experiencing dysmenorrhea recurrence achieved clinical success.USgHIFU ablation is an effective uterus-conserving treatment for symptomatic adenomyosis with an acceptable long-term success rate. Higher chance of clinical success can be achieved in patients with larger NPV ratio and older age, whereas higher BMI and lower acoustic power may result in a higher chance of recurrence. These factors are helpful in selecting suitable patients for USgHIFU and in predicting the durability of symptom relief.

Cesarean scar pregnancy: noninvasive and effective treatment with high-intensity focused ultrasound

The aim of this preliminary study was to investigate whether ultrasound-guided high-intensity focused ultrasound (HIFU) can play a role in treating cesarean scar pregnancy (CSP). Between November 2011 and December 2012, 16 patients with CSP were treated with ultrasound-guided HIFU ablation. Successful treatment was defined as disappearance of CSP mass, undetectable serum beta human chorionic gonadotropin, and no serious complications such as severe bleeding, uterine rupture, or hysterectomy. All patients were successfully treated in the outpatient department and none required readmission. After 2-5 treatment sessions, the mean time for achieving undetectable serum beta human chorionic gonadotropin was 4.94 ± 2.32 weeks, and the mean time for CSP mass disappearance was 6.69 ± 3.36 weeks. Three patients experienced moderate abdominal pain that subsided in 1-2 days, and nine patients experienced mild vaginal bleeding (<30 mL) that resolved within 2-3 days. All 16 patients had recovered their normal menstruation function at follow-up. These preliminary results suggest that ultrasound-guided HIFU ablation is a noninvasive, feasible, and effective method for the treatment of CSP.

An ex Vivo Human Lung Model for Ultrasound-Guided High-Intensity Focused Ultrasound Therapy Using Lung Flooding

The usability of an ex vivo human lung model for ablation of lung cancer tissue with high-intensity focused ultrasound (HIFU) is described. Lung lobes were flooded with saline, with no gas remaining after complete atelectasis. The tumor was delineated sono-morphologically. Speed of sound, tissue density and ultrasound attenuation were measured for flooded lung and different pulmonary cancer tissues. The acoustic impedance of lung cancer tissue (1.6–1.9 mega-Rayleighs) was higher than that of water, as was its attenuation coefficient (0.31–0.44 dB/cm/MHz) compared with that of the flooded lung (0.12 dB/cm/MHz). After application of HIFU, the temperature in centrally located lung cancer surrounded by the flooded lung increased as high as 80°C, which is sufficient for treatment. On the basis of these preliminary results, ultrasound-guided HIFU ablation of lung cancer, by lung flooding with saline, appears feasible and should be explored in future clinical studies.

Outcome of unintended pregnancy after ultrasound-guided high-intensity focused ultrasound ablation of uterine fibroids

ObjectiveTo evaluate the safety of ultrasound-guided high-intensity focused ultrasound (USgHIFU) ablation of uterine fibroids among women with unintentional pregnancy within 1year of therapy. MethodsA retrospective analysis was conducted of 435 women who underwent USgHIFU therapy at Chongqing Medical University, China, between October 1, 2006, and October 1, 2009. ResultsUnplanned pregnancy was reported by 24 women within 1year of USgHIFU ablation; 8 of these women had desired pregnancy before undergoing treatment. A total of 27 fibroids were detected, 24 of which were treated (mean volume 65.9±58.8cm3). Pregnancy was continued by 7 women without any complications. One pregnant woman who had desired pregnancy before therapy underwent an induced abortion owing to concerns about the effects of USgHIFU on the fetus. Fourteen women without pregnancy intention before USgHIFU therapy chose to undergo induced abortion; 2 women experienced spontaneous abortion. No adhesion occurred after USgHIFU therapy. Furthermore, USgHIFU, labor, and abortion had no effect on subsequent menstruation or sexual activities. ConclusionPregnancy within 1year after USgHIFU ablation of uterine fibroids appears safe; however, large scale studies are required to confirm these data.

Ultrasound-guided high-intensity focused ultrasound ablation for adenomyosis: the clinical experience of a single center

To assess the midterm outcomes after ultrasound-guided high-intensity focused ultrasound (HIFU) ablation in treatment of patients with symptomatic adenomyosis. A prospective clinical trial. University teaching hospital. Seventy-eight patients with symptomatic adenomyosis. A single treatment session of ultrasound-guided HIFU ablation for adenomyosis. Dysmenorrhea and menorrhagia scores and the incidence of complications. In all 78 patients, 84.6% tolerated the treatment procedure well with pain scores between 0 and 4. Treatment was terminated in only one patient because of increased blood pressure persistently. Sixty-nine patients have finished at least an 18-month follow-up; the mean follow-up time was 24.2 months. Nonperfused regions in lesions were observed in 60 (87.0%) patients on the enhanced magnetic resonance imaging scans. Scores for menorrhea and dysmenorrhea decreased. Clinical effectiveness of the treatment was observed in 62 women (89.9%) with varying degrees of symptomatic relief of dysmenorrhea. Eight patients had relapses. Twenty-two patients (28.6%) had 27 complications. Of these, four had two or more complications. Twenty-three events (85.1%) did not need medical intervention (Society of Interventional Radiology class A). No serious complications including death or major permanent injuries were observed. Ultrasound-guided HIFU ablation may be a safe and effective noninvasive alternative in the treatment of symptomatic adenomyosis.

High-intensity focused ultrasound ablation of uterine localized adenomyosis

To introduce recent developments in a noninvasive treatment of using high-intensity focused ultrasound (HIFU) for ablating uterine localized adenomyosis, and to discuss their potential in this application. This literature roughly reviewed conservative therapy for uterine localized adenomyosis and emphasized using HIFU for ablating it. The main histological change of HIFU treatment was the coagulative necrosis of adenomyosis cells, with damage on small blood vessels of adenomyoma. MR-guided focused ultrasound surgery (MRgFUS) and ultrasound-guided HIFU ablation of focal adenomyosis were with satisfactory results. MRgFUS was less invasive and safely ablated adenomyosis tissue close to the endometrium or to serosal surface. HIFU might be safe and effective for treating patients with adenomyosis, and the acoustic intensity was a key factor for therapeutic efficacy as the severity of symptoms might correlate with lesion extent in some patients. At a given therapeutic dose, the influence of acoustic intensity on focal temperature rise was greater than that of exposure time. Some other experiments showed that the size of adenomyoma was increased 3-4 months after HIFU treatment. The reasons were related to the size of tumor, treatment parameters, operation procedure, and the blood supply of the targeted tissue. Although recent results have been very encouraging, further trials are essential to evaluate the long-term efficacy, and cost-effectiveness of HIFU ablation in localized adenomyosis. Compared with current conservative treatments, HIFU may be a noninvasive approach and may offer complete ablation of adenomyoma, with less trauma, less complication, and low cost and short hospital stay for treating patients with uterine localized adenomyosis.

Evaluation of the therapeutic efficacy of high-intensity focused ultrasound ablation of hepatocellular carcinoma by three-dimensional sonography with a perflubutane-based contrast agent

Objective We performed contrast-enhanced three-dimensional sonography (CE 3D US) with a perflubutane-based contrast agent to immediately evaluate the completeness of ablation of small hepatocellular carcinoma (HCC) lesions by extracorporeal high-intensity focused ultrasound (HIFU). Subjects and methods Twenty-one HCC lesions were treated by a single ultrasound-guided HIFU ablation session, and CE 3D US was performed before, immediately after, and 1 week, and 1 month after HIFU, and contrast-enhanced CT (CE CT) or contrast-enhanced MRI (CE MRI) was performed before HIFU, 1 week and 1 month after HIFU, and during the follow-up period. Results Immediately and 1 month after HIFU, 17 lesions were evaluated as adequately ablated by CE 3D US, and the other 4 lesions as residual tumors. One month after HIFU, 18 were evaluated as adequately ablated by CE CT or CE MRI, and the other 3 as residual tumors. The evaluation by CE 3D US immediately after HIFU and by CE CT or CE MRI 1 month after HIFU was concordant with 20 lesions. The kappa value for agreement between the findings of CE 3D US and other modalities by two blinded observers was 0.83. When the 1-month CE CT or CE MRI findings were used as the reference standard, the sensitivity, specificity, and accuracy of CE 3D US immediately after HIFU for the diagnosis of the adequate ablation were 100%, 75%, and 95%, respectively. Conclusion CE 3D US appears to be a useful method for immediate evaluation of therapeutic efficacy of HIFU ablation of HCC lesions.