Correspondence (letter to the editor): Part of the Treatment Strategy in Other Countries

It is encouraging that finally an article about thermal ablation of renal tumors has been published in Deutsches Ärzteblatt as in Germany, unlike in other countries, this treatment option has scarcely been adopted in clinical practice due to the resistance of the primary surgical treatment providers. However, it is by no means a “novel“ technique since percutaneous ablation has been an integral part of the management concept in other countries for more than 10 years (1). My experience has taught me that in Germany the indication for percutaneous ablation is restricted to patients who either insist to have this treatment done or are high-risk patients for surgery (for example, due to imminent renal failure along with a tumor in a solitary kidney after partial resection). Let us hope that in the delayed S3-guideline of the German Cancer Society (Deutsche Krebsgesellschaft, DKG) thermal ablation will be recommended as the first-line treatment for small renal cell carcinoma (RCC) with good percutaneous access and not only as an intervention for difficult-to-treat patients.

In Figure 1, the authors show a heat shield protecting the colon from thermal necrosis created by interstitial instillation of 5% dextrose solution. For reasons related to the physical properties of the material (the thermal conductivity of gas [ambient air, CO₂] is approximately 20 to 30 times lower), instillation of 5% dextrose solution should only be considered as the method of second choice. In contrast to gas-filled spaces, the thermal insulation effect of interstitial dextrose or saline solution cannot be reliably evaluated using imaging technologies, and continuous thermal monitoring of all parts of adjacent critical structures is not practical (2). Instillation of gas for organ protection during thermal ablation procedures performed to treat renal cell carcinoma has already been proposed in 2004; this technique has been successfully used by several working groups and myself at numerous occasions (3).