Elsevier

European Journal of Radiology

Volume 83, Issue 9, September 2014, Pages 1607-1611
European Journal of Radiology

Effects of oxytocin on high intensity focused ultrasound (HIFU) ablation of adenomysis: A prospective study

https://doi.org/10.1016/j.ejrad.2014.05.008Get rights and content

Abstract

Objective

To investigate the effects of oxytocin on high-intensity focused ultrasound (HIFU) ablation for the treatment of adenomyosis.

Materials and methods

Eighty-six patients with adenomyosis from three hospitals were randomly assigned to the oxytocin group or control group for HIFU treatment. During HIFU treatment, 80 units of oxytocin was added in 500 ml of 0.9% normal saline running at the rate of 2 ml/min (0.32 U/min) in the oxytocin group, while 0.9% normal saline was used in the control group. Both patients and HIFU operators were blinded to oxytocin or saline application. Treatment results, adverse effects were compared.

Results

When using oxytocin, the non-perfused volume (NPV) ratio was 80.7 ± 11.6%, the energy-efficiency factor (EEF) was 8.1 ± 9.9 J/mm3, and the sonication time required to ablate 1 cm3 was 30.0 ± 36.0 s/cm3. When not using oxytocin, the non-perfused volume ratio was 70.8 ± 16.7%, the EEF was 15.8 ± 19.6 J/mm3, and the sonication time required to ablate 1 cm3 was 58.2 ± 72.7 S/cm3. Significant difference in the NPV ratio, EEF, and the sonication time required to ablate 1 cm3 between the two groups was observed. No oxytocin related adverse effects occurred.

Conclusion

Oxytocin could significantly decrease the energy for ablating adenomyosis with HIFU, safely enhance the treatment efficiency.

Introduction

Adenomyosis is a common gynecologic disorder, defined as benign invasion of the endometrium in the myometrium, affecting premenopausal women [1]. The prevalence of adenomyosis varies from 8.8 to 31%, and nearly two-thirds of the diseased women are symptomatic with menorrhagia and dysmenorrheal [2], [3]. Traditionally, the usual treatment for symptomatic adenomyosis is hysterectomy, which could be performed in women who are not intent on preserving their uteruses [4]. However, this surgical operation is unsuitable for patients wishing to remain fertility or keep the uterus. Conservatively, the levonorgestrel-releasing intrauterine device (IUD) appears to be an effective method in alleviating dysmenorrhea associated with adenomyosis, and gonadotropin-releasing hormone analogs (GnRHa), nonsteroidal anti-inflammatory drugs (NSAIDs), as well as oral contraceptives are also available for symptom relief. However, effects of these treatments are limited due to the side-effects, resulting in recurrence of symptoms after the therapy cessation [5].

High-intensity focused ultrasound (HIFU) ablation is a novel technology. Over the last ten years, this non-invasive therapeutic ablative technique has been used to treat patients with a variety of malignancies and benign diseases [6], [7], [8], [9], [10], [11]. Many studies have shown that HIFU ablation results in a decrease of fibroid size and reduction of symptoms in women with symptomatic uterine leiomyomas with an excellent safety profile [7], [8]. Recently, a few studies have examined the application of HIFU for treating patients with symptomatic adenomyosis [12], [13], [14], [15]. Fukunishi et al. reported their early results of adenomyosis in 20 patients treated with magnetic resonance imaging-guided focused ultrasound surgery (MRgFUS), indicating the feasibility of MRgFUS application on adenomyosis [13]. Zhou et al. and Fan et al. demonstrated that ultrasound-guided or MRI-guided HIFU treatment was safe and effective in ablating adenomyotic lesions and in alleviating its symptoms [14], [15]. However, in clinical practice, we found that the treatment time was long and the high non-perfused volume (NPV) ratio wasn’t achieved in some cases, since the NPV ratio is related to re-interventional rate and long-term symptom relief. Therefore, it is necessary to explore the possibilities of enhancing the ablation effects of HIFU and thus reducing treatment time.

Oxytocin, a naturally occurring octapeptide hormone, is important in the genesis and maintenance of uterine contractions and is widely used to prevent postpartum hemorrhage during labor [16]. By binding to its receptors on the surface of the uterine myocyte, oxytocin causes uterine smooth muscle contraction, resulting in the decrease of blood perfusion in the vessels among the uterine smooth muscles. Recently, Wang and his colleagues demonstrated that the use of oxytocin during laparoscopic myomectomy could decrease operative blood loss [17]. Therefore, we hypothesized that high dose of oxytocin would safely cause uterine contraction and thus reduce blood perfusion of adenomyotic lesion. This study is designed to explore the effect of oxytocin on the HIFU ablation of adenomyosis.

Section snippets

Materials and methods

This prospective study was approved by the ethics committees at our institutions. Written informed consent was obtained from each patient before every treatment procedure.

Patients’ demographic characteristics

Between November 2010 and June 2012, a total of 86 patients with symptomatic focal adenomyosis from three clinical centers were randomized to the oxytocin group or the control group, comprising 43 patients in each arm. Of 86 patients, 58 were from Suining Central Hospital, 18 were from Three Gorges Central Hospital of Chongqing, and ten were from Fuling Central Hospital of Chongqing. The mean age of the patients was 41.2 ± 3.9 years in the oxytocin group and 41.0 ± 5.4 years in the control group.

Discussion

Oxytocin is one of the most commonly used uterotonic agents in obstetric practice during women parturition. Prophylactic use of oxytocin could decrease the risk of postpartum hemorrhage [18]. Oxytocin promotes uterine smooth muscle contraction, thus reduces blood loss from the site of placental attachment following delivery [19]. Recently, Richter et al. [20] have shown that oxytocin receptors not only enriched in the pregnant uteri, but also expressed on the surface of non-pregnant uterine

Conclusion

Based on our results, we concluded that oxytocin could significantly decrease the energy of HIFU for ablating adenomyosis; it could safely enhance the treatment efficiency without increasing the oxytocin-related adverse effects. Further studies, such as large sample size clinical trials, are essential to ascertain the optimal oxytocin dose regimen to enhance the treatment effects of HIFU for adenomyosis.

Conflict of interest

Lian Zhang is a consultant to Chongqing Haifu, Chongqing, China. The other authors have no conflict of interests claimed.

Acknowledgements

This study was supported by the State Key Program of National Natural Science of China (Grant No. 30830040), National Key Technology R&D Program in the 11th Five year Plan of China (Grant No. 2006BAI03A02) and Chongqing Science and Technology Key Project (Grant No. [2007]11CSTC, 2007AA502).

References (24)

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1

Xin Zhang, Min Zou, and Cai Zhang are joint first authors who all contributed equally to this study.

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