title: Ultrasound guided percutaneous microwave ablation for small renal cancer: initial experience.
abstract: OBJECTIVE
  We evaluated the feasibility, safety and efficacy of ultrasound guided percutaneous microwave ablation for small renal cell cancers.
  
  
  METHODS
  A total of 12 patients with a pathologically proven renal cell cancer 1.3 to 3.8 cm in diameter were treated with microwave ablation. A cooled shaft needle antenna was percutaneously inserted into the tumor under ultrasound guidance. One antenna was used for tumors 2 cm or smaller and antennae were used for tumors larger than 2 cm. One thermocouple was placed about 0.5 cm away from the tumor to monitor temperature in real time during ablation. Microwaves were emitted at 50 W for 500 seconds and prolonged as necessary to attain temperatures sufficient to ensure tumor kill. Immediate treatment efficacy was assessed by contrast enhanced ultrasound 1 day after ablation. Short-term efficacy was assessed by contrast enhanced computerized tomography and/or contrast enhanced ultrasound at 1, 3 and 6 months, and every 6 months thereafter.
  
  
  RESULTS
  All tumors were completely ablated at a single session and no complications occurred. No residual tumor or recurrence was observed at a median followup of 11 months (range 4 to 20). The ablation zone was well defined on contrast enhanced imaging and it gradually shrank with time.
  
  
  CONCLUSIONS
  Ultrasound guided percutaneous microwave ablation appears to be a safe and effective technique for small renal cell cancer in select patients.
authors.affiliation: Department of Ultrasound, Chinese People's Liberation Army General Hospital, Beijing, People's Republic of China. liangping301@hotmail.com
authors.forename: Ping
authors.initials: P
authors.lastname: Liang
authors.forename: Yang
authors.initials: Y
authors.lastname: Wang
authors.forename: Dakun
authors.initials: D
authors.lastname: Zhang
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Yu
authors.forename: Yongyan
authors.initials: Y
authors.lastname: Gao
authors.forename: Xiaoxia
authors.initials: X
authors.lastname: Ni
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002292:Carcinoma, Renal Cell / Q000601:surgery*; D017115:Catheter Ablation / Q000295:instrumentation / Q000379:methods*; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000601:surgery*; D008297:Male; D008872:Microwaves / Q000627:therapeutic use*; D008875:Middle Aged; D010865:Pilot Projects; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional