Investigation Of Eligibilityand Accessibility For Ultrasound Guided High Intensity Focused Ultrasound Ablation Of Uterine Fibroids And Clinical Utility Of A Microbulebble-enhancing Contrast ("Sonovue") In Treatment Of Uterine Fibroids With HIFU

Background:Uterine fibroid tumors (or leiomyomas) are the most common benigntumors found in gynecologic practice. The prevalence of uterine fibroids isdifferent across races, and generally reported as20%to40%amongreproductive age women. In an effort to decrease the cost, morbidity, andlifestyle impact of surgery, several less invasive treatment optionsincluding hormonal therapy, uterine artery embolization, and high intensityfocused ultrasound (HIFU) have been used for the treatment of uterinefibroids. Among these techniques, HIFU is second only to hormones innon-invasive status. Because of HIFU is a new technology. The recognitionof doctors and patients is not enough. So, We hope to analyze the conditionof counseling patients and the patients accepted HIFU treatment toinvestigate the reason that patients didn’t take HIFU ablation. Then we canimprove this technology and improve the accessibility of this techniqueionUltrasound is used to guide HIFU treatment, and changes in grey scale during treatment correlate well with the volume of induced necrosis;however, such changes are not observed in some cases and may betransient. Can microbubble contrast-enhanced ultrasound (US) be used toevaluate the treatment response of uterine fibroids during HIFU?Objective：1. To investigate eligibility and accessibility of high intensity focusedultrasound (HIFU) treatment for patients with symptomatic uterine fibroids.2. To evaluate the clinical value of the contrast agent SonoVue in thetreatment of uterine fibroids with ultrasound-guided high intensity focusedultrasound (HIFU) therapeutic ablation.Methods：1. Retrospective analysis of729patients referred for HIFU treatment ofuterine fibroids from two new HIFU centers. The patients were firstevaluated following the eligibility criteria from the State Food and DrugAdministration of China. Then, the eligible patients underwent simulation,pelvic MRI and clinical examination to determine suitability for theprocedure.2. Analyze31patients with solitary uterine fibroids from the FirstHospital of Chongqing Medical University. All patients underwentpre-treatment and post-treatment MR imaging with a standardized protocol.All patients underwent contrast-enhanced ultrasound (CEUS) examinationsduring pre-evaluation, treatment, and immediately post-treatment. Then, we compared the results of CEUS and MRI.3. A total of291patients with solitary uterine fibroids from threecenters were treated with ultrasound-guided HIFU. Among them,129patients from Suining Central Hospital of Sichuan were treated withoutusing SonoVue.162patients from the First Hospital of Chongqing MedicalUniversity and Chongqing Haifu Hospital were treated with using SonoVuebefore, during and after HIFU procedure to assess the extent of HIFU.Results1.33.5%of patients (244/729) accepted HIFU treatment. The mainreasons that patients didn’t take HIFU treatment are: patients did not desireHIFU treatment (36.2%;264/729); not suitable for HIFU (12.5%;91/729);choose gynecologic surgery (12.3%;90/729); ultrasound ablation equipmentlimitations (1.6%;12/729); financial difficulties (3.3%;24/729).2. Results from CEUS correlated well with results from MRI. Therewas no significant difference in fibroid volume, fibroid size, non-perfusedvolume and fractional ablation between CEUS and MRI. Patientsunderwent CEUS examination, the average fibroid volume was98.2±74.7cm3, the average non-perfused volume was83.8±72.4cm3, the averagefractional ablation was84.4±16.7%. Patients underwent MRI examination,the average fibroid volume was103.5±79.2cm3. On the basis ofcontrast-enhanced T1-weighted images immediately after HIFU treatment,the average non-perfused volume was86.7±79.1cm3, the average fractional ablation was83.3±18.6%.3. The non-perfused volume (indicative of successful ablation) wasobserved in all treated uterine fibroids immediately after HIFU ablation;median fractional ablation, defined as non-perfused volume divided by thefibroid volume immediately after HIFU treatment, was86.0%(range,28.8%-100.0%) in the group with using SonoVue, and83.0%(8.7%-100.0%) in the group without using SonoVue. The rate of massivegrey scale changes was higher in the group with using SonoVue than thatwithout using SonoVue. The sonication time to achieve massive grey scalechanges was shorter with SonoVue than without using it. The sonicationtime for ablating1cm3of fibroid volume was significantly shorter withusing SonoVue than without using it. No major complication was observedin any patients.Conclusions：1. The proportion of patients who accepted HIFU ablation is still low.We need to do more work in improving the accessibility of this technique.2. Post-treatment images of CEUS clearly showed the non-enhancingareas of treatment within the fibroid. Results from CEUS correlated wellwith results from MRI.3. SonoVue can be used safely to assess extent of treatment for uterinefibroids during HIFU. Based on our results, it seems that SonoVue mayalso enhance the outcomes of HIFU ablation.