Clinical Investigation Of High Intensity Focused Ultrasound Ablation For Adenomyosis

Adenomyosis is a common benign gynecological diseasecharacterized by the invasion of endometrial glands and stroma intomyometrium. Based on the MRI appearance, adenomyosis was classifiedas focal adenomyosis in which there are discrete and well-definedadenomyotic lesions or nodules within the uterine muscle or diffuseadenomyosis in which the invading endometrium causes a generalizedexpansion of the uterine walls. Patients with adenomyosis often reportmenorrhagia and dysmenorrhea, and sometimes complain pelvic pressureand frequent urination. Currently, hysterectomy is the only definitivetreatment for adenomyosis. However, hysterectomy is only suitable tothose patients who are ending their fertility and those who are not opposedto surgery. As a non-surgical technique, HIFU is capable of producingcoagulative necrosis at a precise focal point within the body, withoutharming overlying and adjacent structures even within the path of thebeam. More recently, a small, nonrandomized trial with2years offollow-up demonstrated that HIFU ablation is safe and effective in treating symptomatic adenomyosis. However, to the best of our knowledge, no onehas yet compared HIFU treatment for focal adenomyosis with HIFUtreatment for diffuse adenomyosis. Meanwhile, the treatment time seemstoo long to some patients to tolerate. Therefore, we try to find a way tosafely improve the therapeutic efficacy.In this study, we retrospectively reviewed the efficacy and safety ofhigh intensity focused ultrasound (HIFU) ablation for focal adenomyosisand diffuse adenomyosis. We also explored the effects of oxytocin on highintensity focused ultrasound (HIFU) ablation of adenomysis by comparingthe therapeutic efficacy between with and without oxytocin duingtreatment.Objectives1. To retrospectively investigate the efficacy of high intensity focusedultrasound (HIFU) ablation for adenomyosis and compare the clinicaloutcomes of high intensity focused ultrasound (HIFU) ablation for focaladenomyosis and diffuse adenomyosis by following up the improvement ofsymptoms after treatment.2. To explore the effects of oxytocin on high intensity focusedultrasound (HIFU) ablation of adenomysis by comparing EEF(energy-efficiency factor) and the required time to sonicate a single unit of volumeof adenomyotic lesions with and without oxytocion in the teatment. Methods1.Two hundred and two patients with symptomatic adenomyosis whowere treated with HIFU in Suining Central Hospital of Sichuan wereretrospectively reviewed. Among them,120patients were classified asfocal adenomyosis;82were classified as diffuse adenomyosis. All patientsunderwent the pre-and post-treatment MRI with standardized protocol toevaluate treatment effects. All side effects were recorded.2.86patients with adenomyosis from three hospitals were treated withultrasound-guided HIFU. The patients were randomly assigned in oxytocingroup or control group. To compare energy, sonication time required toablate1cm3of adenomyosis, side-effects between with and withoutoxytocin.Results1.The non-perfused volume (indicative of successful ablation) wasobserved in all treated adenomyotic lesions. The mean fractional ablation,defined as non-perfused volume divided by the adenomyotic lesion volumeimmediately after HIFU treatment, was71.6±19.1%. The averagemenorrhagia severity score and the average dysmenorrhea severity painscore decreased significantly after HIFU in these patients compared tobaseline. No significant difference was observed between the patients withfocal adenomyosis and with diffuse adenomyosis except in complete reliefrate of dysmenorrhea. No major complications occurred in any patients.2.With using oxytocin, the non-perfused volume (NPV) ratio was（80.7±11.6）%; the EEF was8.1±9.9） J/mm3, sonication timerequired to ablate1cm3was（30.0±36.0）s/cm3. Without using oxytocin,the non-p erfused volume ratio was （70.8±16.7）%, EEFwas （15.8±19.6） J/mm3, sonication time required to ablate1cm3was （58.2±72.7） s/cm3. Significantly difference in NPV ratio, EEF,sonication time required to ablate1cm3between the two groups wasobserved.Conclusion1.Based on our results, HIFU appears to be a safe and effectivetechnique to ablate both focal and diffuse adenomyotic lesions to alleviatethe symptoms of menorrhagia or dysmenorrhea.2.Oxytocin could significantly decrease the energy for ablatingadenomysis with HIFU, enhance the treatment efficiency. It has a potentialvalue for clinical application.