Treatment Of Benign Thyroid Mass With Ultrasound-Guided Radiofrequency Ablation: Preliminary Clinical Study

Objective:To explore the feasibility, safety, efficacy, clinical out-comes and operation experiences of benign thyriod mass treated by ultra-sound-guided Radiofrequncey Ablation(RFA),with an attempt to offer an alternative approach to minimally invasive surgery of benign thyroid mass.Methods:The medical records of 16 patients with benign thyriod mass who were not eligible for or refused surgery or radioiodine therapy underwent RFA in Dalian Municipal Central Hospital and The First Affiliated Hospital of Dalian Medical University from June 2009 to September 2009 were analyzed retrospectively. Meanwhile, relevant literatures both abroad and domestic were reviewed. Among them, three males and thirteen females,mean age 35.1 years with standard deviation 9.2 years, range from 19 to 51 years and median age 34.5 years. No one had a history of surgery or irradiation to the head and neck. None had a cardiac pacemaker implantation,hoarseness,bucking while drinking water,or dys-phagia and so on.Prior to RFA, each patient was performed an thorough physical examination, Colour Ultrasonography for bilateral throids,thyroid function test,hepatic and renal function determination,blood coagulation test,and Fine Needle Aspiration Biopsy(FNAB). On Colour Ultrasonography, all masses were solitary, with well-defined margin, regular shape and homogeneous echogenicity,10 masses on the left lobe of the thyroid and 6 on the right lobe,with the largest diameter of ranged from 1.3cm to 3.0cm and the mean volume of 2.4±1.8 (ranged from 0.9 to 7.5) ml.. Sandy calcific-ation,involvement with adjacent structures, enlargement of the cervical lymph nodes and vascularity within and surrounding the masses was absent and all patients were euthyroid. Hepatic and renal function and blood coagulation were all within the normal reference limits. FNAB shows nodular thyroid goiter.On the basis of subjective descriptions of echography from US physician, masses were divided into the following three subgroups:(1) predo-minantly solid,with solid components more than and equal to 80%. (2)predominantly cystic,with cystic components more than and equal to 80%.(3)mixed type,other than predominantly solid or cystic.According to this criteria,ther were 8 predominantly solid masses,5 predominantly cystic masses and 3 mixed type masses.If necessary,10mg diazepam was injected intramuscularly to a neverous patient before being sent to the operating room.All patients fast for 8 hours and had a skin preparation before RFA. Prior to the procedures,all patients signed the written informed consent document which contained the following items:the expected number of RFA sessions and likelihood of recurrence,possible complications such as the injury to superior and recurrent laryngeal nerve,pain,hemorrhage,tracheal and esophageal trauma, abscess and hematoma formation, infection, hypothyroidism, hypoparathyroidism et al.All patients took a supine position, with cervical hyperextension, local anesthesia with 1% lidocaine at the puncture site,lmm skin incision was made.Under realtime US-guidance, the RFA needle active tip inserted into the center of the mass, then began the ablation,4-6 watt of the power,lasting for 5-10 minutes,depending on the size and component of the mass. The tip of the electrode was repeatedly moved from an ablated site to an unablated site. Ablation was considered completed when the total mass and its periphery was filled entirely with high-echogenic microbubbles.As to a cystic mass containing much fluid,aspiration was perormed with a syringe of 5 ml followed by the ablation. Finally, pressure dressing for a while,given hemostatic medications and antibiotics.During the ablation, the power was turned off or down if pain can not be tolerated. Besides,we intermittently ask the degree of pain that they felt in order to check voice changing in time.Results:RFA were successfully done with all patients,with none suspended for intolerable pain. All were ambulant immediately after the procedures,no serious complications was encountered, such as hematoma, vocal changing, trauma to the esophagus and trachea, hypothyroidism, hypoparathyroidism during and after the procedures,with one had an regional infection at the incision after procedures, manifested by redness and swelling and heat and pain, no suppuration, resolved after 7 days of active anti-infection treatment.Three had a fever,37.4-38.2℃, normalized afer 3 days of anti-inflammatory treatment and discharged from the hospital.All the others only had a mild malaise,with a normal body temperature, preventively given a 24 hours of antibiotcs, then 2 days of observation in hospital before discharging.On the follow-up Ultrasonography of six mounth after RFA, the masses disappeard on 6 patients,the VRR of more than 50% on 9 and 49.33% on 1 patient,respectively.Conclusions:This study suggests that RFA under ultrasound-guidance is a feasible and safe and efficacious alternative for patients with benign thyriod mass,who were not eligible for or refused to conventional surgery, especially for young women and patients with contraindications for surgery, with obvious microtrauma, good cosmetic result, high patients'satisfaction, reduced hospitalization stay, less postoperative pain,It is worth to be generalized in clinical practice.