Vol. 42 (3): 456-463, May – June, 2016

doi: 10.1590/S1677-5538.IBJU.2015.0444


Safety and feasibility of radiofrequency ablation for treatment of Bosniak IV renal cysts

Marcos Roberto de Menezes 1,2, Publio Cesar Cavalcante Viana 1,2, Tássia Regina Yamanari 2, Marco A. Arap 2,3, Leonardo Oliveira Reis 3, William Nahas 4
1 Serviço de Intervenção Guiada de Radiologia e Imagem, Instituto do Câncer do Estado de São Paulo, Universidade de São Paulo, SP, Brasil; 2 Serviço de Intervenção Guiada de Radiologia e Imagem, Hospital Sírio Libanês, São Paulo, SP, Brasil; 3 Departamento de Urologia, Pontifícia Universidade Católica de Campinas, PUC – Campinas, Campinas, SP, Brasil; 4 Departamento de Urologia, Hospital das Clínicas da Faculdade de Medicina Universidade de São Paulo, SP, Brasil


Purpose: To describe our initial experience with radiofrequency ablation (RFA) of Bos¬niak IV renal cysts.
Materials and Methods: From 2010 to 2014, 154 renal tumor cases were treated with percutaneous thermal ablation, of which 10 cases (6.4%) from nine patients were com¬plex renal cysts and were treated with radiofrequency ablation.
Results: 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 compli¬cations 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.
Conclusions: 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.

Keywords: Safety; Feasibility Studies; Catheter Ablation; Renal cysts and diabetes syndrome [Supplementary Concept]

[Full Text]