Bipolar-Multipolar Radiofrequency Ablation of Small Renal Masses (<=4cm)

There is solid evidence that partial nephrectomy (excision) is as effective as
radical (total) nephrectomy in the treatment of (srm*s=) small renal
masses/tumors (<=4 cm). Until recently, an open operation was the gold standard
approach. Laparoscopic partial nephrectomy is an emerging option. However,
laparoscopic excision is technically very demanding and has to be performed
under general anesthesia. Therefore an energy-based ablative technique that can
eventually be applied percutaneously (image-guided) and under local anesthesia
would be an important advancement. Two techniques i.e. cryoablation and
radiofrequency ablation are currently being developed. To be fully acceptable
for clinical application, the technique should ideally result in complete
destruction of the tumor. Currently used cryoablation and monopolar RFA
techniques have been shown to be feasible in the treatment of srm*s but
complete destruction of the tumor cannot yet be achieved consistently.

To find an energy dose for the complete destruction of a renal tumour with
bipolar-multipolar RFA.

Dose finding study using a treat-and -resect protocol.

Radiofrequency ablation (RFA) of the renal tumour in an open surgical setting
followed by partial or total nephrectomy (treat-and-resect protocol)

The total time of the operation is prolonged by the time needed for the biopsy
and the RFA. Complications of laparoscopic or percutaneous monopolar RFA are
damage to the ureter and urinoma formation; these have been reported in 3-15%
of the cases; bleeding was rarely seen [Klingler 2007]. Bipolar-multipolar RFA
in an open setting, a well-known technique for the treatment of liver masses,
is a new approach for the kidney, is likely to result in less complications.