Safety and feasibility of radiofrequency ablation for treatment of Bosniak IV renal cysts.
To describe our initial experience with radiofrequency ablation (RFA) of Bosniak IV renal cysts.



From 2010 to 2014, 154 renal tumor cases were treated with percutaneous thermal ablation, of which 10 cases (6.4%) from nine patients were complex renal cysts and were treated with radiofrequency ablation.



All complex cysts were classified as Bosniak IV (four women and five men; mean age: 63.6 yrs, range: 33-83 years). One patient had a single kidney. Lesion size ranged from 1.5 to 4.1cm (mean: 2.5cm) and biopsy was performed on four cysts immediately before the procedure, all of which were malignant (two clear cell and two papillary carcinoma). Mean volume reduction of complex cysts was 25% (range: 10-40%). No patients required retreatment with RFA and no immediate or late complications were observed. The follow-up of Bosniak IV cysts had a median of 27 months (interquartile range [IQR], 23 to 38) and no recurrence or significant loss of renal function were observed.



Mid-term follow-up of the cases in our database suggests that image-guided percutaneous RFA can treat Bosniak IV cysts with very low complication rates and satisfactorily maintain renal function.
Serviço de Intervenção Guiada de Radiologia e Imagem, Instituto do Câncer do Estado de São Paulo, Universidade de São Paulo, SP, Brasil.|Serviço de Intervenção Guiada de Radiologia e Imagem, Hospital Sírio Libanês, São Paulo, SP, Brasil.
Marcos Roberto de
MR
Menezes
Serviço de Intervenção Guiada de Radiologia e Imagem, Instituto do Câncer do Estado de São Paulo, Universidade de São Paulo, SP, Brasil.|Serviço de Intervenção Guiada de Radiologia e Imagem, Hospital Sírio Libanês, São Paulo, SP, Brasil.
Publio Cesar Cavalcante
PC
Viana
Serviço de Intervenção Guiada de Radiologia e Imagem, Hospital Sírio Libanês, São Paulo, SP, Brasil.
Tassia Regina
TR
Yamanari
Serviço de Intervenção Guiada de Radiologia e Imagem, Hospital Sírio Libanês, São Paulo, SP, Brasil.|Departamento de Urologia, Hospital das Clínicas da Faculdade de Medicina Universidade de São Paulo, SP, Brasil.
Marco Antonio
MA
Arap
Departamento de Urologia, Pontifícia Universidade Católica de Campinas, PUC - Campinas, Campinas, SP, Brasil.
Leonardo Oliveira
LO
Reis
Departamento de Urologia, Hospital das Clínicas da Faculdade de Medicina Universidade de São Paulo, SP, Brasil.
William
W
Nahas
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D017115:Catheter Ablation / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D052177:Kidney Diseases, Cystic / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery*; D007680:Kidney Neoplasms / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012307:Risk Factors; D025321:Surgery, Computer-Assisted / Q000379:methods; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome