500 Cases of High-intensity Focused Ultrasound (HIFU) Ablated Uterine Fibroids and Adenomyosis

ObjectiveClinical outcomes of 500 high-intensity focused ultrasound (HIFU)-treated uterine fibroids and adenomyosis are analyzed and presented.Materials and methodsThis is a retrospective cross-sectional analysis from a single tertiary medical center. From April 2015 to October 2018, 546 cases were enrolled for the study. After excluding 46 patients with less than 3 months of follow-up period, there were 404 fibroids, 149 adenomyosis and 53 mixed conditions entered for analysis. The patients’ uterine fibroids and adenomyosis were treated by HIFU according to Chongqing Haifu protocol, with 12 cm diameter transducer of focal length 10–16  cm at 0.8 or 1.6 MHz T2-weight MRI imaging was rendered prior to and 3 month post treatment to assess lesion volume change using non-perfusion volume, which was the primary outcome. Secondary outcomes including quality of life, subjective satisfaction, adverse events and pregnancy rate were determined using self-reported questionnaires. The mean follow up period ranged from 3 to 38 months with an average of 21 months.ResultsThree months after HIFU-treated uterine fibroids and adenomyosis, the lesion size reduced 40.2% and 46.3%, respectively. Symptoms all improved with better quality of life for the fibroid group, while those with adenomyosis or combined diseases benefit the most from pain control. Serum CA125 decreased significantly for all studied groups, and LDH only showed improvement for fibroids group. Number of adverse events is comparable to Chongqing data (approximately 10.2%), with mostly mild and self-resolving conditions. No permanent sequelae or death was documented. Twelve pregnancies are reported in this cohort.ConclusionHIFU is safe and effective in treating uterine fibroids and adenomyosis. The results are reproducible if standardized treatment schedules are followed. It is a promising treatment alternative with the advantages of precision, non-invasiveness, rapid recovery and readiness for pregnancy.     

高强度聚焦超声及其医学应用

HIFU技术的研究在国内外已掀起了热潮．到目前为止．HIFU技术已得到广泛的实验和临床支持。本文将对HIFU治疗设备的总体结构做一阐述．并讨论其在医学领域中的应用及发展方向。     

利用磁共振成像实现肿瘤热疗中实时无创测温的方法

肿瘤热疗特别是高强度聚焦超声（HIFU）技术，已成为一种重要且非常具有前景的肿瘤治疗方法，温度是直接决定热疗效果的重要参数，实时准确的进行深部无创测温是目前制约肿瘤热疗进一步发展的一项关键技术。近来利用磁共振成像（MRI）进行无创测温，正受到越来越多的研究者的重视。本文简述了MRI无创测温的三种方法，比较了不同测温原理的特点和适用条件，报道了已有研究发展状况，并介绍了尚待解决的问题。     

高强度聚焦超声在医学领域中应用的新进展

本文综述了国内外在高强度聚焦超声（high intensity focused ultrasound，HIFU）技术方面研究与应用的新进展。介绍了HIFU的治疗功能原理，特别给出了焦斑半径的具体计算公式和对相关组织的热效应、空化效应、机械效应，辐照效应等损伤机理，重点研究了热效应随声波频率及声强变化的规律。给出了HIFU的一般试验模型即分层组织模型以及HIFU应用与临床的情况。重点研究了HIFU源，主要讨论了换能器的聚焦方式（1）球面自聚焦换能器，（2）声透镜聚焦换能器，（3）大功率多元超声换能器，（4）电子扫描或相控阵列聚焦换能器，以及频率选择与目标深度和辐照强度的关系，并指出与其匹配的几类聚焦换能器的优缺点，列举了HIFU技术在泌尿科、肿瘤学、神经外科、眼科、妇科、止血以及其他医学领域中的最新应用。最后评价了目前HIFU在治疗方面的优势与某些不足以及可能改进的有效措施．展望了HIFU技术广阔的应用前景．     

高强度聚焦超声终止小鼠妊娠的实验研究

目的:探讨高强度聚焦超声(H IFU)终止妊娠的可能性。方法:利用H IFU治疗机(780 kHZ)6种声强各60s体内直接照射妊娠第7天小鼠胚胎,妊娠15 d时观察各组胚胎死亡率和胎盘、子宫的形态学变化。结果:对照组胚胎总死亡率为12.65%(32/253);照射组中声强3 W/cm2、6 W/cm2及≥9 W/cm2组的胚胎死亡率分别为25.00%(12/48)、72.88%(43/59)和100%(64/64、43/43、40/40、35/35)。超声照射后8 d的改变:光镜下主要为胎盘出血、变性、坏死;电镜下胎盘组织细胞坏死呈致密团块状,子宫改变轻微。变化随剂量的增加而明显。结论:胎盘较子宫对H IFU更敏感,更易受损,H IFU抗早孕具有潜在的可行性,值得进一步研究。     

高强度聚焦超声治疗及控制兔肝VX2肿瘤发展的实验研究

目的 探讨高强度聚焦超声(HIFU)治疗及控制肝肿瘤发展转移的效果.方法 采用兔肝VX2肿瘤模型进行HIFU辐照.辐照后不同时期处死动物以观察其病理变化.另以辐照组及对照组动物各8只,于2周后处死,比较肿瘤生长及肺转移的情况.结果 HIFU辐照后肿瘤细胞立即发生凝固性坏死,电镜下亦见到不可逆的破坏.2周后有6只动物的肿瘤原发灶已被完全破坏;另2只靶区外有少量肿瘤残存,其体积为59.8 mm3和10.4mm3,而对照组的肿瘤平均体积为(1571.1±349.7)mm3.辐照组有2只(25%)发生肺转移,转移结节数为10和3;对照组全部发生肺转移,转移结节数为54±30.两组差异有显著性.结论 HIFU对兔肝VX2肿瘤有很强的杀伤作用,对控制肿瘤的发展及转移有一定的疗效.     

Higher Dosage of HIFU Treatment May Lead to Higher and Longer Efficacy for Moderate to Severe Perennial Allergic Rhinitis

Objectives: This study was to compare the efficacies and side effects of high intensity focused ultrasound (HIFU) treatment for perennial allergic rhinitis (PAR) with regular and increased dosage.Study design: A prospectively assembled cohort was retrospectively analyzed through visual analogue scale (VAS).Methods: Regular dosage of HIFU treatment was applied to 56 PAR patients in group A. An increased dosage as twice as the regular one was applied to 48 patients in group B. Nasal obstruction, sneezing, rhinorrhea and rhinocnesmus, which were recognized as the four main symptoms of allergic rhinitis (AR), were evaluated before treatment, 3 months after treatment, and 1 year after treatment. The satisfaction of patients was also evaluated at 1 year postoperatively. Biopsy of the inferior turbinate and morphometric analysis were applied to 11 patients in group A and 10 in group B before HIFU treatment and 3 months after treatment.Results: Comparing the AR symptoms before treatment, There is no statistical difference observed between group A and B (p>0.05). The four main symptoms at 3 months and 1 year after treatment were all significantly improved (p<0.01) in both group A and B. The VAS scores of AR symptoms in Group B were lower than those in Group A at the same stage after treatment, especially at 1 year after treatment (p<0.05). Comparing the results at 3 months and 1 year after treatment, a tendency of recurrence of these symptoms was observed statistically in group A (p<0.05), but not in group B (p>0.05). More cases of nasal dryness and perirhinal swelling were found in group B than those in group A (p<0.05), while all side effects were mild and temporary. Patients in group B were more satisfied than those in group A (p=0.0866 >0.05), though not statistically significant. More reduction of the eosinophils, other inflammatory cells, and the submucosal glands was observed after HIFU treatment in group B than that in group A (p<0.05).Conclusions: A proper increment of HIFU dosage may be recommended to meet the needs of more improvement of AR symptoms and less recurrence.     

Image-Guided High-Intensity Focused Ultrasound for Conduction Block of Peripheral Nerves

The objective of our work has been to investigate the use of ultrasound image-guided high-intensity focused ultrasound (HIFU) to non-invasively produce conduction block in rabbit sciatic nerves in vivo, a technique that could become a treatment of spasticity and pain. The work reported here involved the investigation of the duration of such conduction blocks after HIFU treatment and whether they resulted in axon degeneration. The right sciatic nerves of 12 rabbits were treated, under guidance of ultrasound imaging, with repeated 5-s applications of 3.2 MHz HIFU with in situ intensity of 1930 W/cm² (spatial-average, temporal-average) until conduction block was achieved. Survival endpoints were 0, 7, or 14 days after HIFU treatment, at which point the nerve conduction was assessed. Qualitative and quantitative histological analysis of nerve sections proximal and distal to the HIFU site was performed. Conduction block of all 12 nerves was achieved with average HIFU treatment time of 10.5±4.9 s (mean±SD). The volume of necrosis of adjacent muscle was measured to be 1.59±1.1 cm³ (mean±SD). For all nerves, conduction block remained at the survival endpoint and the block resulted in degeneration of axons distal to the HIFU site, as confirmed by electrophysiological and histological methods. Potential clinical applications include treatment of spasticity in patients with spinal cord injury or pain in cancer patients.