German S3 guideline for renal cell carcinoma. Presentation and discussion of essential aspects for the radiation oncologist

We aim to introduce and discuss the statements and recommendations of the German S3 guideline on renal cell cancer for daily practice of radiation oncologists. This report comprises indication, treatment decision, dose prescription and current literature including treatment of oligometastatic disease. According to different stages of the disease and the structure of the guideline we focus on five treatment situations and recommendations for decision making: (1) Neo-/adjuvant treatment before or after nephrectomy: No indication for radiotherapy. (2) Small renal mass: Stereotactic ablative radiotherapy is currently seen as experimental option due to small patient numbers reported in the literature. However, local tumor control achieved by SBRT appears favourable with >90% at 2 years. (3) Oligometastasis: Radiation treatment with higher local doses or stereotactic treatment is possible after interdisciplinary discussion. Indications for palliative (4) and symptomatic treatment (5) are not different compared to other tumor entities. Currently, there is no evidence-based indication for radiation treatment in the primary setting (adjuvant/neoadjuvant or definitive) of renal cell cancer. In the future stereotactic radiotherapy should have a stronger role in the treatment of medically inoperable patients with primary renal cell cancer and especially in the setting of oligometastasis. (orig.)