In the realm of high-intensity focused ultrasound (HIFU) therapy, the precise prediction of lesion size during treatment planning remains a challenge, primarily due to the difficulty in quantitatively assessing energy deposition at the target site and the acoustic properties of the tissue through which the ultrasound wave propagates. This study investigates the hypothesis that the echo amplitude originating from the focus is indicative of acoustic attenuation and is directly related to the resultant lesion size. Echoes from multi-layered tissues, specifically porcine tenderloin and bovine livers, with varying fat thickness from 0 mm to 35 mm were collected using a focused ultrasound (FUS) transducer operated at a low power output and short duration. Subsequent to HIFU treatment under clinical conditions, the resulting lesion areas in the ex vivo tissues were meticulously quantified. A novel treatment strategy that prioritizes treatment spots based on descending echo amplitudes was proposed and compared with the conventional raster scan approach. Our findings reveal a consistent trend of decreasing echo amplitudes and HIFU-induced lesion areas with the increasing fat thickness. For porcine tenderloin, the values decreased from 2541.7 ± 641.9 mV and 94.4 ± 17.9 mm2 to 385(342.5) mV and 24.9 ± 18.7 mm2, and for bovine liver, from 1406(1202.5) mV and 94.4 ± 17.9 mm2 to 502.1 ± 225.7 mV and 9.4 ± 6.3 mm2, respectively, as the fat thickness increases from 0 mm to 35 mm. Significant correlations were identified between preoperative echo amplitudes and the HIFU-induced lesion areas (R = 0.833 and 0.784 for the porcine tenderloin and bovine liver, respectively). These correlations underscore the potential for an accurate and dependable prediction of treatment outcomes. Employing the proposed treatment strategy, the ex vivo experiment yielded larger lesion areas in bovine liver at a penetration depth of 8 cm compared to the conventional approach (58.84 ± 17.16 mm2 vs. 44.28 ± 15.37 mm2, p < 0.05). The preoperative echo amplitude from the FUS transducer is shown to be a reflective measure of acoustic attenuation within the wave propagation window and is closely correlated with the induced lesion areas. The proposed treatment strategy demonstrated enhanced efficiency in ex vivo settings, affirming the feasibility and accuracy of predicting HIFU-induced lesion size based on echo amplitude.

OBJECTIVE: To report the long-term re-intervention of patients with uterine fibroids after ultrasound-guided high-intensity focused ultrasound (USgHIFU) ablation and to analyse the influencing factors of re-intervention in patients in the NPVR ≥ 80% group.
METHODS: Patients with a single uterine fibroid who underwent USgHIFU at our hospital from January 2012 to December 2019 were enrolled. The patients were divided into four groups according to different nonperfusion volume ratio (NPVR). Kaplan-Meier survival curve was used to analyse long-term re-intervention in different NPVR groups, and Cox regression was used to analyse the influencing factors of re-intervention in the NPVR ≥ 80% group.
RESULTS: A total of 1,257 patients were enrolled, of whom 920 were successfully followed up. The median follow-up time was 88 months, and the median NPVR was 85.0%. The cumulative re-intervention rates at 1, 3, 5, 8 and 10 years after USgHIFU were 3.4%, 11.8%, 16.8%, 22.6% and 24.1%, respectively. The 10-year cumulative re-intervention rate was 37.3% in the NPVR < 70% group, 31.0% in the NPVR 70-79% group, 18.2% in the NPVR 80-89% group and 17.8% in the NPVR ≥ 90% group (P < 0.05). However, no difference was found between the group of NPVR 80-89% and the group of NPVR ≥ 90% (P = 0.499). Age of patients and signal intensity on T2-weighted imaging (T2WI) of tumours were found to be independent risk factors for long-term re-intervention in the NPVR ≥ 80% group. A younger age and greater signal intensity on T2W images corresponded to a greater risk of re-intervention.
CONCLUSIONS: USgHIFU, an alternative treatment for uterine fibroids, has reliable long-term efficacy. NPVR ≥ 80% can be used as a sign of technical success, which can reduce re-intervention rates. However, an important step is to communicate with patients in combination with the age of patients and the signal intensity on T2WI of fibroids.
BACKGROUND: This retrospective study was approved by the ethics committee at our institution (Registration No. HF2023001; Date: 06/04/2023). The Chinese Clinical Trial Registry provided full approval for the study protocol (Registration No. CHiCTR2300074797; Date: 16/08/2023).

Complex twin reduction surgery is a common but challenging procedure that aims to reduce the risks and complications of multiple pregnancies. The search for safer and more effective methods has led to the development of high-intensity focused ultrasound (HIFU) technology in the field of fetal reduction. This technology utilizes high-energy sound waves to focus precisely on specific areas, achieving non-invasive therapeutic effects. This paper discusses the principles and features of HIFU technology, as well as its application in complex twin reduction surgery. The paper aims to elucidate the important role of this technology in improving surgical outcomes and reducing risks, explore the current limitations of the modality, and propose directions for future development. Through these investigations, it is hoped to improve overall understanding of HIFU, and thereby promote the application of this technology in the field of fetal reduction.

UNASSIGNED: The application of high-intensity focused ultrasound (HIFU) in the treatment of uterine fibroids is becoming increasingly widespread, and postoperative collateral thermal damage to adjacent tissue has become a prominent subject of discussion. However, there is limited research related to bone injury. Therefore, the aim of this study was to investigate the potential factors influencing unintentional pelvic bone injury after HIFU ablation of uterine fibroids with magnetic resonance imaging (MRI).
UNASSIGNED: A total of 635 patients with fibroids treated with HIFU in the First Affiliated Hospital of Chongqing Medical University were enrolled. All patients underwent contrast-enhanced MRI (CE-MRI) pre- and post-HIFU. Based on the post-treatment MRI, the patients were divided into two groups: pelvic bone injury group and non-injury group, while the specific site of pelvic bone injury of each patient was recorded. The univariate and multivariate analyses were used to assess the correlations between the factors of fibroid features and treatment parameters and pelvic bone injury, and to further analyze the factors influencing the site of injury.
UNASSIGNED: Signal changes in the pelvis were observed on CE-MRI in 51% (324/635) of patients after HIFU. Among them, 269 (42.4%) patients developed sacral injuries and 135 (21.3%) had pubic bone injuries. Multivariate analyses showed that patients with higher age [P=0.003; odds ratio (OR), 1.692; 95% confidence interval (CI): 1.191-2.404], large anterior side-to-skin distance of fibroid (P<0.001; OR, 2.297; 95% CI: 1.567-3.365), posterior wall fibroid (P=0.006; OR, 1.897; 95% CI: 1.204-2.989), hyperintensity on T2-weighted imaging (T2WI, P=0.003; OR, 2.125; 95% CI: 1.283-3.518), and large therapeutic dose (TD, P<0.001; OR, 3.007; 95% CI: 2.093-4.319) were at higher risk of postoperative pelvic bone injury. Further analysis of the factors influencing the site of the pelvic bone injury showed that some of the fibroid features and treatment parameters were associated with it. Moreover, some postoperative pain-related adverse events were associated with the pelvic bone injury.
UNASSIGNED: Post-HIFU treatment, patients may experience pelvic injuries to the sacrum, pubis, or a combination of both, and some of them experienced adverse events. Some fibroid features and treatment parameters are associated with the injury. Taking its influencing factors into full consideration preoperatively, slowing down treatment, and prolonging intraoperative cooling phase can help optimize treatment decisions for HIFU.

To evaluate the therapeutic effect of high-intensity focused ultrasound (HIFU) treatment for adenomyotic patients with primary infertility and to explore the factors that affect the pregnancy outcomes.
Twenty-seven adenomyotic patients with primary infertility who underwent HIFU at HUNAN Provincial Maternal and Child Health Care Hospital, China, between July 2018 and December 2022 were retrospectively reviewed. We evaluated the pregnancy outcomes and analyzed the factors that may affect pregnancy outcomes including time to conception, pregnancy approach, gestational age, delivery mode, neonatal outcomes, and complications during pregnancy and delivery.
Among the 27 adenomyotic patients with primary infertility, 10 patients had a total of 11 pregnancies after HIFU treatment. Of these, eight (72%) cases were natural pregnancies and three (23%) were in vitro fertilization (IVF) pregnancies. The median time to conception was 10 (range 4-25) months. There were eight (72%) successful deliveries. The rate of full-term deliveries was 90%. Of the eight live births, four (50%) were born vaginally and four (50%) by cesarean section. No severe complications occurred. The mean birth weight of newborns was 3.1 (range: 2.3-3.9) kg; all newborns developed well without complications during postpartum and breastfeeding.
HIFU treatment for adenomyosis could improve fertility of patients with primary infertility. HIFU is a promising therapeutic approach for patients with adenomyosis and infertility who wish to achieve pregnancy and have live birth deliveries.

UNASSIGNED: Desmoid-type fibromatosis (DF) is a locally aggressive tumor characterized by peripheral infiltration of neoplastic cells and remote metastasis disability. This systematic review examined the efficacy and safety of thermal ablative therapy for DF tumors.
UNASSIGNED: A literature search was conducted using PubMed, Web of Science, Cochrane Library, and Embase from January 1, 2000, to November 12, 2022. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement was used to guide literature selection. The inclusion criteria were the following: (I) the patients were diagnosed with aggressive fibromatosis pathologically, (II) the patients were treated by thermal ablations, and (III) a focus on treatment efficacy and safety. Meanwhile, the exclusion criteria were the following: (I) cohorts of patients with hypertrophic scar, Gardner fibroma, or nodular fasciitis; (II) conference abstracts, reviews, case reports, letters to editors, comments, or editorials; (III) number of patients <5; (IV) in vitro or animal experiments; and (V) non-English language articles. The inverse variance method with a random effects model was used to obtain the pooled data. Subgroup analyses were performed to identify treatment factors. Egger test was conducted to assess the risk of publication bias.
UNASSIGNED: After literature selection, 694 DF tumors were identified in 23 studies. In terms of modality, 13 studies used cryoablation, 9 studies used high-intensity focused ultrasound (HIFU), and 1 study used microwave ablation (MWA). The pooled symptom relief rate was 90% [95% confidence interval (CI): 80-97%], with that for HIFU being 100% (95% CI: 85-100%), that for cryoablation being 87% (95% CI: 74-97%), and that MWA being 89% (95% CI). The pooled major complication rate was 3% (95% CI: 1-7%), and that for each modality was as follows: HIFU =2% (95% CI: 0-6%), cryoablation =4% (95% CI: 1-8%), MWA =11%, ultrasound =6% (95% CI: 1-13%), computed tomography (CT) =2% (95% CI: 0-7%), and magnetic resonance imaging (MRI) =3% (95% CI: 0-14%). The pooled nonperfused volume rate (NPVR) was 76% (95% CI: 71-81%), and that for each modality was as follows: HIFU =77% (95% CI: 71-85%), cryoablation =74% (95% CI: 69-79%), ultrasound =75% (95% CI: 67-83%), CT =76% (95% CI: 67-87%), and MRI =78% (95% CI: 70-87%). The pooled local control rate was 88% (95% CI: 79-94%) and that for each modality was as follows: HIFU =99% (95% CI: 96-100%), cryoablation =80% (95% CI: 68-90%), and MWA =78%. The differences in major complication rate (P=0.77) and NPVR between imaging-guided modalities (P=0.40) were not significant, nor were the differences in symptom relief rate (P=0.32) and major complication rate (P=0.61) between ablative techniques; however, the differences in local control rate (P=0.01) were significant between ablative techniques.
UNASSIGNED: Imaging-guided thermal ablative therapies contribute to symptom relief with a duration of more than 6 months and a low major complication rate of DF tumors.

This nonrandomized prospective clinical trial aimed to assess the efficacy, safety and follow-up outcomes of ultrasound-guided high-intensity focused ultrasound (USgHIFU) surgery in patients with breast fibroadenoma.
With the approval of the institutional ethics committee and written informed consent, a total of 113 patients diagnosed with breast fibroadenoma by core-needle biopsy in our hospital were recruited. USgHIFU surgery was performed under local anesthesia. Contrast-enhanced ultrasound (CEUS) or contrast-enhanced MRI (CEMRI) was performed to evaluate the nonperfused volume (NPV). The patients were followed up with physical examination and ultrasound imaging.
The clinical outcome of 85 patients with 147 fibroadenomas with a follow-up time of more than 3 months was analyzed in this study. Fifty-two patients had one lesion, twenty-one patients had two lesions and twelve patients had more than two lesions. During USgHIFU, the median localization time for all fibroadenomas was 3 (interquartile range: 1, 5) min, and the median treatment time was 9 (interquartile range: 5, 15) min. Under local anesthesia, all the patients tolerated the treatment well. No serious epidermal burns were observed in any of the patients. Based on CEUS or CEMRI imaging evaluation, the median NPV ratio was 100% (interquartile range: 79.2%, 116.8%). The VRR were 26.77 ± 50.05%, 50.22 ± 42.01% and 72.74 ± 35.39% at 3-6 months, 6-12 months and >12 months, respectively, which showed significant statistical difference (p < .001).
Ultrasound-guided HIFU surgery is an effective and safe noninvasive alternative technique for the treatment of breast fibroadenoma.

This study used contrast-enhanced MRI (CE-MRI) examination to assess the efficacy of high-intensity focused ultrasound (HIFU) for submucosal fibroids.
A total of 81 submucosal fibroids, including 33 cases of type 1, 29 cases of type 2, and 19 cases of type 2-5, treated by HIFU were retrospectively reviewed. CE-MRI was performed in all cases immediately after HIFU, the non-perfused volume ratio (NPVR) and the degree of endometrial impairment were recorded. Thereafter, CE-MRI was repeated in all cases after three months, and the change of fibroid volume shrinkage rate (FVSR), NPVR and the degree of endometrial impairment were recorded.
The immediate NPVR was 86.4 ± 19.3% in type 1, 90.0 ± 13.3% in type 2 and 90.3 ± 7.2% in type 2-5. Among 81 fibroids, grades 0, 1, 2 and 3 endometrial impairments were observed in 38.3%, 16.1%, 14.8% and 30.9%, respectively. Three months later, NPVR was 68.0 ± 36.4% in type 1, 74.3 ± 27.7% in type 2 and 85.0 ± 16.1% in type 2-5. Grades 0, 1, 2 and 3 endometrial impairments were observed in 64.2%, 23.5%, 9.9% and 2.4%.FVSR was 49.0 ± 1.3% in type 1, 39.6 ± 1.7% in type 2 and 37.2 ± 2.1% in type 2-5. The FVSR in submucosal fibroid type 1 was superior to type 2 and type 2-5 (p < 0.05). The NPVR of submucosal fibroids in type 2-5 were higher than type 1 (p < 0.05) .There was no difference among different types of submucosal fibroids in endometrial impairment (p > 0.05) three months after HIFU.
At three months after HIFU, FVSR was better for submucosal fibroid type 1 than for type 2 and type 2-5. And there was no difference in endometrial impairment among the different types of submucosal fibroid groups.

High-intensity focused ultrasound (HIFU) is a non-invasive treatment of adenomyosis. Uterine rupture during pregnancy is a rare adverse event after HIFU treatment, because HIFU treatment results in tissue coagulative necrosis.
We reported a case of uterine rupture in a 34-year-old woman. The woman had HIFU treatment for adenomyosis eight months before unplanned pregnancy. She was closely monitored during the pregnancy and the antenatal course was uneventful. At the gestational age of 38 weeks and 2 days, an emergency lower segment cesarean section was performed because of inexplainable abdominal pain. After delivery of the fetus, a 2 × 2 cm serous membrane rupture was observed in the HIFU treatment area.
Uterine rupture during pregnancy after HIFU is a rare adverse event, however, attention is required during the whole pregnancy in case of unexpected uterine rupture.

To investigate the influencing factors of ultrasound-guided HIFU (USgHIFU) ablation for adenomyosis with a non-perfused volume ratio (NPVR)≥50%.
A total of 299 patients with adenomyosis who underwent USgHIFU ablation were enrolled. Quantitative signal intensity (SI) analysis was performed on T2WI and dynamic enhancement type. The energy efficiency factor (EEF) was defined as the ultrasound energy delivered for ablating 1 mm3 of tissue. NPVR ≥ 50% was used as the criterion for technical success. Adverse effects and complications were recorded. Logistic regression analyses of variables were conducted to identify the factors affecting NPVR ≥ 50%.
The median NPVR was 53.5% (34.7%). There were 159 cases in the NPVR ≥ 50% group and 140 cases in the NPVR < 50% group. The EEF in NPVR < 50.0% group was significantly higher than that in NPVR ≥ 50% group (p < 0.05). The incidence of intraoperative adverse effects and postoperative adverse events in the NPVR < 50% group were higher than those in the NPVR ≥ 50% group (p < 0.05 for both). Logistic regression analysis showed that abdominal wall thickness, SI difference on T2WI between adenomyosis and rectus abdominis, and enhancement type on T1WI were protective factors for NPVR ≥ 50% (p < 0.05), while the history of childbirth was an independent risk factor (p < 0.001).
Compared with NPVR < 50%, NPVR ≥ 50% did not increase the intraprocedural and postprocedural adverse reactions. The possibility of NPVR ≥ 50% was higher in patients with thinner abdominal walls, showed slight enhancement of adenomyosis on T1WI, with a history of childbirth, or in whom the SI difference on T2WI between adenomyosis and rectus abdominis was more minor.