title: Ultrasound-guided percutaneous microwave ablation of sporadic renal angiomyolipoma: preliminary results.
abstract: BACKGROUND
  Microwave ablation (MWA) has been developed as one of the most commonly used local oncologic treatments. However, there is still a dearth of studies concerning MWA in the treatment of renal angiomyolipomas (AML).
  
  
  OBJECTIVE
  To evaluate the efficacy and safety of ultrasound (US)-guided percutaneous MWA when treating AML.
  
  
  METHODS
  Nineteen lesions with pathologically confirmed AML in 14 patients (5 men, 9 women; mean age, 49.2 ± 14 years) were treated with US-guided percutaneous MWA with one or two cooled-shaft needle antennae. A power output of 45 W or 50 W for 300-1140 s was emitted to achieve complete tumor necrosis. Contrast-enhanced ultrasound (CEUS) was performed to observe the treatment efficacy 3 days later. Patients were followed up with CEUS, computed tomography (CT), and/or magnetic resonance imaging (MRI) after 1, 3, and 6 months, and long-term ablation efficacy was evaluated every 6 months thereafter.
  
  
  RESULTS
  Among the 19 renal lesions, 17 achieved complete ablation as monitored by US after one session of MWA, and two patients required a second session of MWA. Postoperative evaluation with CEUS showed that complete ablation was obtained in 15 lesions; however, in four lesions, complete ablation could not be attained. During the follow-up period of 6-36 months (median, 10 months), a fistula to the descending colon was found in one patient and local infection around the ablation zone was found in another. Neither injury to the renal pelvis nor damage to renal function was observed. None of the patients exhibited hematuria or abnormalities in routine urine tests during the hospitalization period or during follow-up. Minor complications, such as subcapsular bleeding, mild to moderate pain, and fever were eliminated after appropriate treatment.
  
  
  CONCLUSIONS
  MWA is an effective and minimally invasive technique for the management of AML that can preserve renal function with acceptable complication rates.
authors: Department of Interventional Ultrasonics, General Hospital of Chinese PLA, Beijing, PR China.
authors: Zhi-yu
authors: ZY
authors: Han
authors: Department of Interventional Ultrasonics, General Hospital of Chinese PLA, Beijing, PR China liangping301@yahoo.com.cn.
authors: Ping
authors: P
authors: Liang
authors: Department of Interventional Ultrasonics, General Hospital of Chinese PLA, Beijing, PR China.
authors: Xiao-ling
authors: XL
authors: Yu
authors: Department of Interventional Ultrasonics, General Hospital of Chinese PLA, Beijing, PR China.
authors: Zhi-gang
authors: ZG
authors: Cheng
authors: Department of Interventional Ultrasonics, General Hospital of Chinese PLA, Beijing, PR China.
authors: Fang-yi
authors: FY
authors: Liu
authors: Department of Interventional Ultrasonics, General Hospital of Chinese PLA, Beijing, PR China.
authors: Jie
authors: J
authors: Yu
mesh_terms: D018207:Angiomyolipoma / Q000000981:diagnostic imaging* / Q000628:therapy*; D017115:Catheter Ablation / Q000379:methods*; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging* / Q000628:therapy*; D008297:Male; D008872:Microwaves / Q000627:therapeutic use; D008875:Middle Aged; D010865:Pilot Projects; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D025321:Surgery, Computer-Assisted / Q000379:methods*; D016896:Treatment Outcome; D014463:Ultrasonography / Q000379:methods*
keywords: Microwave ablation; benign tumor; renal angiomyolipoma; ultrasound