title: MRI-guided percutaneous laser ablation of small renal cell carcinoma: Initial clinical experience.
abstract: BACKGROUND
  The number of detected small renal cell carcinomas (RCCs) has been rising, largely due to advances in imaging. Open surgical resection is the standard management of small RCCs; however, imaging-guided percutaneous ablative therapies have emerged as a minimally invasive treatment alternative, especially for patients who are poor candidates for surgery.
  
  
  OBJECTIVE
  To evaluate the initial clinical experience of magnetic resonance imaging (MRI)-guided percutaneous laser ablation of small RCCs.
  
  
  METHODS
  Eight patients with 10 tumors were treated with percutaneous MRI-guided laser ablation. All tumors (diameter range 1.5-3.8 cm, mean 2.7 cm) were biopsy-proven RCCs. By using a 0.23 T open MRI system and general anesthesia in patients, one to four (mean 2.6) laser fibers were placed and the tumors were ablated under near real-time MRI control by observing the signal void caused by the temperature change in the heated tissue. The treatment was considered successful if the tumor showed no contrast enhancement at follow-up imaging.
  
  
  RESULTS
  All except one tumor were successfully ablated in one session. The first patient treated showed enhancing residual tumor in post-procedural MRI; she has thus far declined retreatment. One complication, a myocardial infarction, occurred; all other patients tolerated the procedure well. No local recurrence was discovered during the follow-up (range 12-30 months, mean 20 months).
  
  
  CONCLUSIONS
  In this small group of patients with relatively short follow-up period, MRI-guided percutaneous laser ablation proved to be a promising treatment option for small RCCs.
authors.affiliation: Department of Radiology, Department of Surgery, Oulu University Hospital, Oulu, Finland. juho.kariniemi@oulu.fi
authors.forename: Juho
authors.initials: J
authors.lastname: Kariniemi
authors.forename: Risto
authors.initials: R
authors.lastname: Ojala
authors.forename: Pekka
authors.initials: P
authors.lastname: Hellström
authors.forename: Roberto Blanco
authors.initials: RB
authors.lastname: Sequeiros
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002292:Carcinoma, Renal Cell / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods*; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000601:surgery*; D053685:Laser Therapy / Q000379:methods*; D053783:Magnetic Resonance Imaging, Interventional / Q000379:methods*; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome