Radio-frequency ablation helps preserve nephrons in salvage of failed microwave ablation for a renal cancer in a solitary kidney

ABSTRACT

Recurrent tumors after renal ablative therapy present a challenge for clinicians. New ablative modalities, including microwave ablation [MWA], have very limited experience in methods of retreating ablation failures. Additionally, in MWA, no long-term outcomes have been reported. In patients having local tumor recurrence, options for surveillance or surgical salvage must be assessed. We present a case to help assess radio-frequency ablation [RFA] for salvage of failed MWA. We report a 63-year-old male with a 4.33-cm renal mass in a solitary kidney undergoing laparoscopic MWA with simultaneous peripheral fiber-optic thermometry [Lumasense, Santa Clara, CA, USA] as primary treatment. Follow-up contrast-enhanced computed tomography [CT] scan was performed at 1 and 4.3 months post-op with failure occurring at 4.3 months as evidenced by persistent enhancement. Subsequently, a laparoscopic RFA [LRFA] with simultaneous peripheral fiber-optic thermometry was performed as salvage therapy. Clinical and radiological follow-up with a contrast-enhanced CT scan at 1 and 11 months post-RFA showed no evidence of disease or enhancement. Creatinine values pre-MWA, post-MWA, and post-RFA were 1.01, 1.14, and 1.17 mg/ml, respectively. This represents a 15 decrease in estimated glomerular filtration rate [eGFR] [79 to 67 ml/min] post-MWA and no change in eGFR post-RFA. Local kidney tumor recurrence often requires additional therapy and a careful decision making process. It is desirable not only to preserve kidney function in patients with a solitary kidney or chronic renal insufficiency, but also to achieve cancer control. We show the feasibility of RFA for salvage treatment of local recurrence of a Tib tumor in a solitary kidney post-MWA